P1
HIV-1 Nef expression in microglia causes mania-like behaviors with altered dopaminergic
function
Shaona Acharjee1, William Branton1, Pornpun Vivithanaporn1, Ferdinand Maingat1, Amber
Paul1, Peter Dickie2, Glen Baker3, Christopher Power1
(presenting author: chris.power@ualberta.ca)
1Department of Medicine, University of Alberta;
2Department of Medical Microbiology and Immunology, University of Alberta
3Department of Psychiatry, University of Alberta
Background: Neuropsychiatric disorders in HIV/AIDS are common although the contribution
of HIV-1 infection of the brain, and in particular individual HIV-1 genes, to the
occurrence of these brain disorders is unknown. Herein, an in vivo transgenic model
was generated in which the HIV-1 Nef gene was expressed in myeloid cells and the ensuing
neurobehavioral phenotype and associated molecular changes were investigated.
Methods: Transgenic (Tg) mice were generated that expressed full length HIV-1 nef
under the control of the c-fms promoter. Neurobehavioral performance was assessed
by locomotory, forced swim (FST), elevated plus maze (EPM) and T-maze tests. Host
gene and transgene expression was assessed in brain and myeloid cells by sqRT-PCR,
immunoblotting, enzymatic activity and immunohistochemistry. Biogenic amines were
measured by HPLC.
Results: Tg animals exhibited Nef expression in brain microglia and cultured macrophages.
Tg animals displayed hyperactive behaviors including augmented locomotor activity,
decreased immobility in forced swim test and increased open-arm EPM exploration compared
to wildtype (Wt) littermates (p<0.05). Total dopamine levels, MAO activity and dopamine
transporter (DAT) expression were reduced in the striatum of Tg animals (p<0.05).
Tg animals displayed increased CCL2 expression with concurrent IFN-alpha suppression
in striatum compared with wildtype littermates (p<0.05).
Conclusions: Nef expression in microglia disrupted striatal dopaminergic pathways
in conjunction with increased CCL2 expression, resulting in a mania-like behavioral
phenotype.
P2
Atypical neurologic complications of varicella zoster virus
Shruti Agnihotri1, Nagagopal Venna2
(presenting author: sagnihot@bidmc.harvard.edu)
1Massachusetts General Hospital, Harvard Medical School, Boston, MA. Current affiliation:
Beth Israel Deaconess Medical Center, Boston
2Massachusetts General Hospital, Harvard Medical School, Boston, MA
Background: Varicella Zoster Virus (VZV) reactivation is well known to cause herpes
zoster. However, it is also associated with various other neurologic complications
that can occur with or without a rash. Here, we describe such cases seen at our institution,
which can present a diagnostic challenge.
Case 1: A 59 year old healthy male presented with hemi-neglect due to a parietal hemorrhage.
Over next several months, he developed multi-territory ischemic infarcts and then
seizures. Vascular imaging and Cerebrospinal fluid (CSF) examination were normal.
Eight months since initial presentation, he developed meningoencephalitis, herpes
zoster and CSF was positive for VZV PCR.
Case 2: A 56 year old male with AIDS, recent chemotherapy for Burkitt’s lymphoma presented
with progressive monoparesis followed by paraparesis and urinary retention. MRI showed
patchy T2 hyperintense and gadolinium enhancing lesions in the lower spinal cord and
conus. A zoster rash emerged about 10 days into his illness and CSF PCR for VZV was
positive.
Case 3: A 32 year old HIV positive male, not on treatment developed fever, dysphagia
and somnolence. MRI demonstrated hydrocephalus, confluent T2 hyperintensities along
the basal cisterns, slyvian fissures along with diffuse leptomeningeal enhancement.
Initial LP showed 9 WBCs which increased to 75, three days later. He later developed
a zoster rash, seizures and CSF VZV PCR was positive.
Case 4: A 30 year old female with AIDS developed hemiparesis and difficulty with speech.
MRI of the brain identified multiple acute infarcts and CTA showed irregularities
is multiple large and medium sized vessels. CSF showed 0 WBCs, normal protein and
was positive for VZV PCR.
Conclusion: VZV reactivation can be complicated by vasculopathy, meningoencephalitis,
cranial nerve palsies, myelopathy or myeloradiculitis. These can also occur in seemingly
immunocompetent patients, preceded by or even in absence of rash. CSF may or may not
show pleocytosis.
P3
Characterizing HIV-Infected Monocytes that Transmigrate Across an In-Vitro Blood-Brain-Barrier
as a Tool to Study HAND Pathogenesis
Melissa Agsalda-Garcia1, Dionna W. Williams2, Joan W. Berman2, Cecilia Shikuma1, Lishomwa
C. Ndhlovu1, Bruce Shiramizu1
(presenting author: bshirami@hawaii.edu)
1Hawaii Center for AIDS, John A. Burns School of Medicine, University of Hawaii, Honolulu,
HI;
2Albert Einstein College of Medicine, New York, NY
Background: CD14+ monocytes (MO) are an increasingly recognized reservoir for HIV
that are implicated in the pathogenesis of HIV-associated neurocognitive disorders
(HAND) despite effective combination antiretroviral therapy (cART). The transmigrating
characteristics of monocytes that traffic to the central nervous system by MO subset
and HIV DNA content may be important in understanding mechanisms leading to HAND.
We sought to adapt an established in-vitro blood-brain-barrier (BBB) model for use
in a translational approach. Using blood from patients drawn in real time, we set
up PBMC co-cultures to establish MO subset transmigration through this BBB model and
quantitated HIV DNA from subsets.
Materials: Fresh peripheral blood mononuclear cells (PBMC) were obtained from 2 cART-suppressed
HIV-seropositive patients. Four distinct MO subsets based on variations in CD14 and
CD16 expression were isolated from PMBC by cell sorting and integrated HIV DNA quantified
from each MO subset by PCR (pre-BBB). Another aliquot of PBMC was placed in a transwell
culture in an in-vitro BBB model established from human vascular endothelial cells
and astrocytes and targeted for migration using the MCP-1 chemokine. After 24 hours,
the transmigrated cells were re-phenotyped to assess MO subsets representation and
cell sorted to re-analyze for HIV DNA copy number (post-BBB).
Results: The MO subsets from PBMC that transmigrated across the BBB were characterized
by flow cytometry. There was an approximately 1 log higher copy number of HIV DNA
in the post-BBB transmigrated MO cells.
Conclusion: Translational use of this in-vitro BBB model may be helpful in clinical
research examining the role of MO in HAND. Incorporating a combination of in-vitro
BBB transmigration studies and quantifying HIV DNA to characterize MO subsets in intervention
studies may contribute to our understanding of the pathogenesis of HAND. [AI081450,
NS053345, MD007584 (MA, CS, LN, BS); MH075679 (JWB, DWW), Merck Graduate Science Dissertation
Fellowship (DWW)]
P4
Differential HIV-1 X4 and R5 genetic signatures within the LTR, Tat and Vpr
Benjamas Aiamkitsumrit1, Michael Nonnemacher1, Wen Zhong1, Tatyana Russo1, Vanessa
Pirrone1, Brian Frantz1, Matthew Rimbey1, Shendra Passic1, Brandon Blakey1, Nirzari
Parikh1, Julio Martin-Garcia1, Jeffrey Jacobson2, Brian Moldover3, William Dampier1,
Brian Wigdahl1
(presenting author: ba52@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine; 3B-Tech Consulting, Ltd
Human immunodeficiency virus type 1 (HIV-1) infection results in the production of
an extensive number of genetic variants based on the infidelity of viral reverse transcriptase
and selective pressures encountered during the course of disease. Viral adaptation
involves genetic alterations across the genome with genetic signatures preferentially
associated with viral phenotypes which can be categorized based on the co-receptor
usage that are CCR5-utilizing (R5), CXCR4-utilizing (X4) and the dual tropic (X4R5)
viruses. The envelope-V3 (Env-V3) sequence is currently a major co-receptor usage
determinant, which can be predicted by different in silico methodologies. Utilizing
the position-specific scoring matrix (PSSM) algorithm, Env-V3 sequences derived from
the Los Alamos National Laboratory (LANL) database and DrexelMed HIV/AIDS Genetic
Analysis cohort, can be classified into X4 and R5 genotypes, with associated specific
co-linear long terminal repeat (LTR), Tat, and Vpr, genotypic patterns. Differential
amino acid (DAA) signatures in both Tat and Vpr, as well as differential nucleotide
(DN) signatures in the LTR were identified between the R5 and X4 virus. Utilizing
maximum likelihood tree building strategy, genetic relatedness of Env-V3 between X4
and R5 was readily characterized, whereas, those of Tat, Vpr and LTR were not. On
the other hand, genetic diversities of all genes/region of interest determined by
the mean genetic distance (MGD) were evaluated between the group of X4 and R5, indicating
the differential evolution of viral genetics. It has been theorized that these differential
signatures can also be used to define different genotypes and phenotypes of X4 and
R5 viruses more accurately in order to develop the next generation of diagnostic and
prognostic tools to examine HIV-1 disease and to develop new therapeutics and vaccines
to prevent and treat HIV/AIDS and associated neurological complications. This work
is supported by NIH/NINDS R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177, and NIMH
T32 MH079785.
P5
The NCOR2-Nurr1-CoREST Transrepression Axis Impairs HIV Reactivation in Latently Infected
Microglial Cells
David Alvarez, Biswajit Das, Jonathan Karn
(presenting author: dxa150@case.edu)
Case Western Reserve University
Whereas the incidence of HIV-associated dementia (HAD) has declined due to successful
anti-retrovirals treatment, prevalence of milder forms of HAD, which include asymptomatic
neurocognitive impairment (ANI) and minor neurocognitive disorder (MND) has increased.
Both ANI and MND are part of what is known as HIV-associated neurocognitive disorders
(HAND). However, the molecular mechanisms explaining regulation of HIV activation
in the brain remain ill-defined. The Nurr1/CoREST transrepression pathway has been
recently described as a regulator of glial cells response to brain inflammation by
limiting over-reactivation of NF-kappaB-dependent pro-inflammatory genes. We report
here that, unlike in latently-infected T-cells, in latently-infected microglial cells
(CHME-5/HIV), HIV is induced by pharmacological inhibitors of the CoREST complex chromatin-modifying
enzymes LSD1 and G9a/GLP; these inhibitors also sensitized CHME-5/HIV cells for LPS-mediated
HIV reactivation. shRNA-mediated knockdown of Nurr1, LSD1, or CoREST yielded similar
results. Chromatin immunoprecipitation analysis followed by high throughput next generation
sequencing revealed that upon microglia treatment with TNFalpha, the nuclear receptor
co-repressor 2 (NCOR2/SMRT), which strongly interacts with Nurr1 to facilitate transrepression,
is present at the HIV promoter before activation, then recruited at the earliest time
points, and then its presence fluctuates over time. Likewise, Nurr1, CoREST, LSD1,
and G9a are recruited to the HIV promoter, changing the epigenetic signature (lower
H3K4Me/higher H3K9Me2). The repressor role of these proteins in regulating HIV emergence
from latency has been confirmed by unbiased shRNA screens for factors involved in
maintaining HIV silenced in latently-infected microglial cells. Our data indicate
that the NCOR2-Nurr1-CoREST axis plays a role in preventing HIV over-reactivation
in microglial cells, and studying this mechanism in detail may provide therapeutic
targets for the treatment of HAND.
P6
Distinct Patterns of TLR-Mediated HIV Reactivation in Latently-Infected Microglial
Cells and Monocytes
David Alvarez, Yoelvis Garcia-Mesa, Biswajit Das, Stephanie Milne, Rojas Roxana, Jonathan
Karn
(presenting author: dxa150@case.edu)
Case Western Reserve University
Toll-like receptors (TLRs) recognize molecules derived from microbes and play a key
role in mediating innate immune responses. Multiple TLRs are typically expressed in
cells of the monocytic lineage, including microglia. Microglial cells constitute the
major reservoir for HIV infections in the brain, where inflammatory conditions in
the central nervous system (CNS) are believed to induce HIV-associated neurocognitive
disorders (HAND). Using HIV-latently infected microglial cell lines, we investigated
whether TLR stimulation can induce HIV transcription. Treatment with a panel of TLR
ligands, including Mycobacterium tuberculosis (Mtb)-derived molecules, we found that,
unlike in monocytic cells, reactivation of HIV by TLR ligands was significantly restricted
in microglia. Flagellin (TLR5 agonist) and, to a lesser extent, lipopolysaccharide
(LPS; TLR4 agonist) were able to reactivate HIV in hTERT-immortalized glial (hT_Hmicroglia/HIV)
and in SV40-immortalized (CHME-5/HIV) human fetal microglial cells. By contrast, agonists
for TLR1, 2, 4, 5, 6, or 8 (but not for TLR3, 7, or 9), potently reactivated HIV in
THP-1/HIV cells and, to a lesser extent, in U937/HIV and SC/HIV monocytic cells in
an NF-kappaB-dependent manner. Mtb-derived molecules PIM6 and LprG, which are potent
TLR2 agonists, reactivated HIV in THP-1/HIV, but not in U937/HIV or SC/HIV cells which,
unlike THP-1/HIV, showed no significant expression of TLR2. We conclude that TLR signaling
probably plays only a minor role in activating HIV replication in the CNS, but can
potentially drive replication in peripheral monocytic cells.
P7
HIV+ Brains With Neurocognitive Disorders (HAND) Without Encephalitis Have Higher
RNA Expression of Heme Oxygenase-1 (HO-1) than HIV- Brains
Surendra Ambegaokar1, Alexander Gill1, Colleen Kovacsics1, Stephanie Cross1, Patricia
Vance1, Lorraine Kolson1, Benjamin Gelman2, Dennis Kolson1
(presenting author: asuren@mail.med.upenn.edu)
1Department of Neurology, Perelman School of Medicine, University of Pennsylvania;
2Department of Pathology, University of Texas Medical Branch
In primary human monocyte-derived macrophages (MDM) infected with HIV, expression
of the inducible antioxidant response protein heme oxygenase-1 (HO-1) is specifically
and strongly reduced late in infection at a time that correlates with increased neurotoxin
release from infected MDM. We examined RNA derived from frontal cortex of 157 autopsied
individuals from the Texas NeuroAIDS Research Center brain bank. Of this cohort, 67
were HIV- and 90 were HIV+; of the 90 HIV+ cases, 37 were confirmed to have HAND with
no encephalitis, and 14 were confirmed with encephalitis (HIVE). RNA levels were measured
by qPCR with ABI Taqman primers. Target genes were normalized to GAPDH; values are
reported as deltaCt. In contrast to HO-1 protein reduction, there was a significant
and specific increase in HO-1 mRNA in HIV+ patients. When grouped separately, this
difference was significant in HIVE patients but not in non-encephalitic brains. Additionally,
HAND patients without encephalitis also showed increased HO-1 mRNA levels. We observed
an positive correlation of HO-1 mRNA to interferon induced changes in the proteasome
apparatus, which may lead to increased HO-1 degradation despite the increased RNA.
There is a small but significant decrease of HO-1 RNA inn HIV infected MDM, but there
are similar decreases in Nqo1 and Nrf2 RNA, and thus cannot account for the strong
and specific reduction of HO-1 protein. We infer that the source of the increased
HO-1 RNA in HIV+ brains is not from infected MDM, and posit that astrocytes, in which
HO-1 is highly inducible, are the major source of HO-1 RNA. We conclude that HO-1
RNA expression is induced as a potential anti-inflammatory response in the brain,
but that HIV infection leads to specific HO-1 protein loss, possibly through enhanced
proteasomal degradation. Restoring this HO-1 loss could be a feasible therapeutic
target for neuroprotection against HAND.
P8
Mechanism of dengue infection and CNS dysfunction in the human central nervous system
Carlo Amorin Daep, Eliseo Eugenin
(presenting author: carlo.daep@rutgers.edu)
Rutgers University - Public Health Research Institute
Dengue virus (DENV) annually affects 100 million individuals worldwide, with approximately
20% of cases developing into dengue hemorrhagic fever. With no known treatments or
available vaccines currently on the market and increasing global dispersal of DENV
and its mosquito vectors, this emerging pathogen demands further attention. Patients
suffering from severe DENV infection often exhibit encephalopathy and encephalitis.
This suggests that the virus successfully infiltrates the blood-brain barrier (BBB)
and infects local cell populations, thus negatively impacting normal central nervous
system (CNS) function. However, the exact mechanism of DENV neuropathogenesis is unknown.
Currently, our data shows that DENV infection of human primary PBMC’s leads to 2-
and 3-fold increases (T = 24 and 48 hrs P.I.) in absolute monocyte populations as
compared with the uninfected control. We also detected significant elevation of several
adhesion molecules (i.e. CD99, JAM-A and PECAM-1) on the surface of monocytes that
are required for monocyte transmigration across the BBB as determined by qRT-PCR,
western blot, and confocal microscopy. Furthermore, our results showed that despite
infecting only ~4% of human primary astrocytes, a ~1.4- to 1.7-fold increase in CCL2
was observed in culture supernatants collected from DENV-infected human primary astrocytes.
Similarly, our laboratory previously showed, that CCL2 elevation during HIV infection
is essential for enhance monocyte transmigration into the CNS. Together, these data
suggest that DENV infection increases monocyte populations and, akin to HIV, increase
adhesion molecule expression and chemokine production among BBB cells such as astrocytes.
We propose that elevation of CCL2 in astrocytes and the increased expression of surface
adhesion molecules are key components of DENV neuropathogenesis.
P9
Accumulation of neurofilament heavy chain in neurons and CSF of HIV patients on antiretroviral
drugs with normal neurocognitive function
Caroline Anderson1, Gloria von Geldern1, Tory Johnson1, Ned Sacktor2, Justin McArthur2,
Avindra Nath1
(presenting author: caroline.anderson2@nih.gov)
1Section of Infections of the Nervous System, National Institute of Neurological Disorders
and Stroke, National Institute of Health;
2Johns Hopkins University, Department of Neurology
Background: While it is clear that neurocognitive dysfunction may occur despite adequate
antiretroviral therapy, it is unknown if there may be ongoing neuronal injury in neurocognitively
normal individuals.
Methods: We immunostained autopsy brain tissue from seven HIV-infected virologically
well-controlled individuals and five HIV-negative age and gender matched controls
with antibody to neurofilament heavy chain (NfH). We developed an ELISA for measurement
of NfH (sensitivity of 19.2 pg/ml). CSF from a cohort of HIV infected patients was
analyzed and compared to patients with remitting relapsing multiple sclerosis (MS)
(n=29) and other non-inflammatory neurological diseases (OND) (n=15). All values are
presented as mean+SEM.
Results: Immunostaining of the parietal lobes showed that NfH was found in the cytoplasm
of neurons of HIV-infected individuals more frequently than the HIV negative controls
(P=0.02). CSF analysis at baseline showed that HIV patients had significantly (P<0.0001)
elevated NfH (range: 42-207 pg/ml) vs MS (11-88 pg/ml) and OND (10-45 pg/ml). Individuals
with Normal neurocognitive function (n=9) had (109+13.5 pg/ml) which was not significantly
different from asymptomatic (n=18; 107+6.2 pg/ml), mild neurocognitive dysfunction
(n=10; 87.5+9.2 pg/ml) or dementia (n=24; 95.2+6.2). All patients had undetectable
CSF and plasma viral load. In this group, patients >50 yrs of age had higher NfH levels
(120.7+5.0 versus 107+3.3; P<0.02). No correlation with nadir CD4 cell counts or CNS
penetration efficacy score of ART was noted. At 12 month follow up older patients
had greater increase NfH levels.
Conclusions: There is clear evidence of ongoing neuronal injury in neurocognitively
normal individuals with HIV infection. The degree of injury is comparable to neurocognitively
impaired individuals but is influenced by age.
P10
HTLV-1 epigenetic modification of the FoxP3 TSDR in HAM/TSP decreases the functional
proliferative suppression of Tregs
Monique Anderson1, Yoshimi Enose-Akahata2, Raya Massoud2, Nyater Ngouth2, Yuetsu Tanaka3,
Unsong Oh4, Steven Jacobson2
(presenting author: andersonmr2@mail.nih.gov)
1Neuroimmunology Branch, NINDS, NIH, UVA; 2Neuroimmunology Branch, NINDS, NIH;
3Department of Immunology, Graduate School of Medicine, University of the Ryukus;
4Department of Neurology, Virginia Commonwealth University
HTLV-1 is a human retrovirus that is associated with adult T-cell leukemia/ lymphoma
(ATLL) as well as the neuroinflammatory disorder HTLV-1 associated myelopathy/ tropical
spastic paraparesis (HAM/TSP). In these patients, HTLV-1 is primarily found in the
CD4+CD25+ T cell subset (Regulatory T cells or Tregs), the cells that are responsible
for peripheral immune tolerance and which are known to be dysfunctional in HAM/TSP.
However, due to the inherent inflammatory component of HAM/TSP, markers normally used
to characterize T regs, such as CD25, FoxP3, and CTLA4 are problematic in differentiating
Tregs. Recent evidence has shown that FoxP3 expression and function is determined
epigenetically, specifically through DNA methylation in the Treg-specific methylation
region (TSDR). To more precisely characterize Treg cells, we analyzed the methylation
status of specific CpGs in the TSDR in PBMCs, CD4+ T cells, and CD4+CD25+ T cells
from normal healthy donors (NDs) and HAM/TSP patients. We demonstrated that there
is decreased demethylation in PBMCs and CD4+CD25+ T cells from HAM/TSP patients as
compared to NDs, despite the increased CD4+CD25+ frequency in HAM/TSP. Further, decreased
TSDR demethylation correlates with decreased functional suppression in Treg cells
of HAM/TSP patients. Additionally, increased HTLV-1 tax expression in PBMC culture
correlates with this decrease in FoxP3 TSDR demethylation. Overall, we suggest that
HTLV-1 infection decreases Treg functional suppressive capacity in HAM/TSP through
epigenetic modification within the FoxP3 locus and that this dysregulation of Treg
function may contribute to HAM/TSP disease pathogenesis.
P11
Multiple HIV-1 LTR single nucleotide polymorphisms (SNPs) that occur in peripheral
blood and correlate with disease severity are also present in infected brain samples
Gregory Antell1, Michael Nonnemacher2, Vanessa Pirrone2, William Dampier2, Benjamas
Aiamkitsumrit2, Jean Williams2, Sonia Shah2, Shendra Passic2, Brandon Blakey2, Wen
Zhong2, Brian Moldover3, Rui Feng4, Jeffrey Jacobson5, Brian Wigdahl1
(presenting author: gregory.christopher.antell@drexel.edu)
1School of Biomedical Engineering, Science and Health Systems, Drexel University,
Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel Unive;
2Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine,
3B-Tech Consulting, Ltd;
4Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistics, University of Pennsylvania School of Medicine;
5Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine
The identification of HIV-1 long terminal repeat (LTR) single nucleotide polymorphisms
(SNPs) from peripheral blood (PB)-derived integrated proviral DNA that correlate with
clinical parameters of disease severity can be used to inform the role of viral genetics
in HIV-1 pathogenesis. HIV-1 LTR sequences from subtype B patients enrolled in the
DrexelMed HIV/AIDS Genetic Analysis Cohort in Philadelphia were analyzed with respect
to CD4+ T-cell count and viral load over multiple visits. The HIV-1 LTR serves as
the viral promoter and is responsible for regulating the transcriptional activity
of the integrated provirus. Current studies focus on the identification of LTR signatures
derived from PB virus that can be used as molecular markers of increased risk for
developing more severe HIV disease or neurological complications. To date, eight SNPs
have been identified that associate with CD4+ T-cell count or viral load. To complement
and compare data collected from the integrated provirus of cells in the PB compartment,
brain samples obtained from the National NeuroAIDS Tissue Consortium (NNTC) were also
analyzed. The LTR sequences derived from provirus extracted from multiple brain regions
demonstrated the presence of all eight SNPs, which independently associated with neurocognitive
status at the time of death. These results suggest that evolution of the HIV-1 genomic
swarm throughout disease may result in viral phenotypes that are indicative or predictive
of severe HIV disease. Given that these SNPs were also present in the CNS at end stage
disease, these polymorphisms may also be associated with HIV-associated neurocognitive
disorders (HAND). This work is supported by NIH/NINDS R01 NS32092, NIDA R01 DA19807,
NIMH P30 MH092177, and NIMH T32 MH079785.
P12
Characterization of Monocytes and Microglia of SIV Infected Pigtailed Macaques
Claudia Avalos, Suzanne Queen, Brandon Bullock, Ming Li, Erin Shirk, Lucio Gama, Janice
Clements
(presenting author: cavalos2@jhmi.edu)
Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine
The main barrier to HIV eradication continues to be the presence of viral reservoirs
in infected patients despite treatment with antiretroviral drugs. Furthermore, as
patients are living longer under treatment, the prevalence of HIV-associated neurocognitive
disorders (HAND) has increased. Postmortem analyses of CNS tissues suggest that HAND
is dependent on the migration of monocytes to the brain. Monocytes have been shown
to traffic through the blood brain barrier and populate the perivascular sites where
they differentiate into macrophages and contribute to viral persistence and latency.
In addition, infected monocytes have been found in the blood of HIV infected patients
treated with HAART. Our laboratory has developed and characterized an accelerated,
consistent SIV infected pigtailed macaque model for HIV AIDS and neurologic disease.
Using SIV infected pigtailed macaques we have characterized by flow cytometry the
activation state of monocytes and microglia during infection. In addition, we have
recently developed an assay to quantitate the number of infected blood monocytes and
tissue macrophages similar to the quantitative outgrowth assay used on HIV and SIV
CD4+ T cells. Our assay has allowed us to further investigate the number of SIV infected
cells in peripheral blood and tissues of SIV infected pigtailed macaques that could
potentially contribute to SIV persistence in the brain.
P13
Morphine reduces gp120-mediated cell death in vitro by altering the processing of
proBDNF
Alessia Bachis, Lee Campbell, Allyssia Boelk, Italo Mocchetti
(presenting author: bachisa@georgetown.edu)
Department of Neuroscience, Georgetown University Medical School
Opioids have been shown to potentiate glia responses to HIV viral protein Tat and
gp120 and to exacerbate gp120 and Tat toxicity. However, morphine protects cortical
cultures against the toxic effect of M-tropic gp120 BaL. Using rat primary neurons
we have observed that repeated exposure to morphine for 5 days attenuates gp120 IIIB-mediated
neurotoxicity. Thus, further research is required to determine whether opioids exhibit
neuroprotective or neurotoxic activity in the presence of HIV and HIV viral proteins.
HIV and the envelope protein gp120 have been shown to reduce the levels of the trophic
factor BDNF by altering the enzymatic processing of its precursor proBDNF. Interestingly,
chronic morphine has been shown to increase the levels of tissue plasminogen activator
(tPA), the activator of plasmin, that converts proBDNF into BDNF. Thus, opioids may
reduce the neurotoxic effect of HIV/gp120 by augmenting the downstream enzymatic processing
of proBDNF. Using rat cortical neurons, we observed that morphine increases the levels
and release of BDNF while at the same time decreases proBDNF. Interestingly, a similar
imbalance in the ratio proBDNF/mature BDNF was confirmed in rats chronically (5 days)
injected with morphine. The effect of morphine on proBDNF is due to an increase in
the levels and activity of tPA. These data suggest that morphine’s ability to alter
proBDNF processing might be crucial to its neuroprotective effect against gp120. Our
studies identify a new mechanism of interaction between morphine and HIV proteins.
P14
Manganese Enhanced MRI as a Diagnostic Tool for HIV-1 Associated Neurocognitive Disorders
in Murine NeuroAIDS
Aditya Bade1, Santhi Gorantla1, Prasanta Dash1, Edward Makarov1, Jaclyn Knibbe1, Larisa
Poluektova1, Howard Gendelman1, Michael Boska2, Yutong Liu2
(presenting author: yutongliu@unmc.edu)
1Department of Pharmacology and Experimental Neuroscience, University of Nebraska
Medical Center;
2Department of Pharmacology and Experimental Neuroscience, Department of Radiology,
University of Nebraska Medical Center
Despite the wide-spread use of antiretroviral therapy (ART), up to 52% of infected
patients suffer some form of cognitive impairment termed HIV-1 associated neurocognitive
disorders (HAND). HAND, however, remains a diagnosis of exclusion of a range of opportunistic
infections and cancers. Thus, tests that can distinguish HAND from such disorders
are sorely needed in monitoring disease progressions and for therapeutic intervention.
To this end, we developed manganese enhanced magnetic resonance imaging (MEMRI) to
differentiate the specific consequence of HIV-1 infection to the brain in a mouse
model of human neuroAIDS. MEMRI signal intensity, in the hippocampus and amygdala,
of virus-infected animals showed profound changes in Mn2+ accumulation. Such region-specific
affects highlight neuronal aberrations linked to cognitive function in infected animals.
We posit that MEMRI could be used as imaging biosignature to investigate neuropathologic
aberrations associated with advanced viral infection.
P15
Activation of TRPML1 clears intraneuronal Abeta in pre-clinical models of HIV infection
Mihyun Bae1, Veera Venkata Ratnam Bandaru1, Myounghwa Lee2, Avindra Nath2, Xuesong
Chen3, Jonathan D. Geiger3, Myriam M. Gorospe4, Mark P. Mattson5, Norman Haughey1
(presenting author: mbae002@gmail.com)
1The Johns Hopkins University School of Medicine, Department of Neurology, Division
of Neuroimmunology and Neurological Infections, Baltimore, MD.;
2Section of Infections of the Nervous Systems, NINDS, NIH, Bethesda, MD.;
3Department of Pharmacology, Physiology and Therapeutics, University of North Dakota
School of Medicine and Health Sciences, Grand Forks, ND;
4Laboratory of Genetics, NIA, NIH, Baltimore, MD.;
5Laboratory of Neurosciences, NIA, NIH, Baltimore, MD.
The widespread use of cART in developed countries has dramatically increased the expected
lifespan of HIV-infected patients. This extended lifespan is frequently accompanied
by premature brain aging, and accelerated deposition of amyloid beta (Abeta) peptides
primarily located to lysosomal and autophagic compartments. The molecular mechanism
that regulates the intraneuronal deposition pattern of Abeta is not understood. In
this study we identified a series of cellular events evoked by neurotoxic HIV-gp120
that promotes the formation and intraneuronal deposition of Abeta. In triple transgenic
gp120/APP/PS1 mice, Abeta1-42 containing plaques were deposited at a younger age with
an intraneuronal deposition pattern. This Abeta deposition was accompanied by increased
levels of sphingomyelin and ceramide. Ultrastructural analysis of brain tissues showed
enlarged lysosomes with numerous electron dense and lipid inclusions in gp120/APP/PS1
mice. In neuronal cultures, gp120 accelerated the formation and perturbed the clearance
of Abeta through mechanisms that involved an atypical activation of the chemokine
receptor CXCR4, with signaling through protein kinase A, and cJun N-terminal kinase
(JNK). This mitogen activated protein kinase pathway diverged at the level of JNK
to increase transcriptional expression of beta-secretase (BACE1) through inhibition
of peroxisome proliferator-activated receptor gamma, and increased amyloid precursor
protein (APP) expression through a post-transcriptional mechanism involving enhanced
binding of the heterogeneous nuclear ribonucleoprotein C (hnRNPC) to APP mRNA. APP
and BACE1 were co-sequestered into membrane microdomains where BACE1 activity was
enhanced, and Abeta production increased. This increased Abeta was not effectively
cleared, and accumulated in lysosomes in conjunction with sphingomyelin and calcium.
Stimulating calcium efflux from lysosomes with an agonist of TRPML1 channels facilitated
the clearance of sphingomyelin and Abeta. These data suggest that strategies to preserve
or restore lysosomal function in neurodegenerative settings may provide neuronal protection
by increasing the cellular clearance of sphingolipids and Abeta peptides.
P16
Establishment of non-lytic VZV infection in human neurons
Nicholas Baird1, Jacqueline Bowlin1, Charles Grose2, Randall Cohrs1, Don Gilden3
(presenting author: nicholas.baird@ucdenver.edu)
1Department of Neurology, University of Colorado School of Medicine;
2Department of Pediatrics, Children’s Hospital, University of Iowa, Iowa City, Iowa;
3Departments of Neurology and Microbiology, University of Colorado School of Medicine
Varicella zoster virus (VZV), an exclusively human neurotropic alphaherpesvirus, causes
varicella (chickenpox). After primary infection, VZV becomes latent in ganglionic
neurons along the entire neuraxis. VZV reactivation usually results in zoster (shingles),
often complicated by postherpetic neuralgia, and less frequently by VZV meningitis,
vasculopathy, myelopathy and ocular disease. Attempts to study VZV infection of neurons
in vitro has been difficult, primarily because "contaminating" non-neuronal cells
become lytically infected leading to destruction of the culture. During lytic VZV
infection, VZV DNA replicates, viral genes are transcribed and translated, and high
titers of infectious particles are produced leading to cell death in a week or less.
Herein, we show that VZV-infected differentiated neurons (>95% beta III-tubulin positive)
do not develop a cytopathic effect and lack markers of an activated apoptotic pathways
(cleaved caspase-3 and -9). In neuronal cultures, a steady state level of VZV DNA
is maintained; virus gene transcription is delayed ~7 days and reduced 3- to 6-fold
compared to lytically infected fibroblasts. VZV glycoprotein C, an important structural
protein involved in virion assembly, is reduced. Electron microscopic analysis revealed
high numbers of aberrant viral particles, frequently lacking DNA cores, suggesting
that non-lytic infection of neurons in vitro results from defective virus assembly,
in part due to reduced glycoprotein C production. Our successful development of a
model of non-lytic VZV infection of neurons will allow studies that elucidate molecular
mechanisms involved in virus reactivation.
P17
Perturbation of eicosanoids are associated with neuroinflammation in HAND
Veera Venkata Ratnam Bandaru1, Michelle M. Mielke2, Justin C. McArthur3, Igor Grant4,
Scott Letendre4, Norman J. Haughey1
(presenting author: vbandar2@jhmi.edu)
1Department of Neurology, Johns Hopkins University School of Medicine, 600 North Wolfe
Street, Baltimore MD 21287;
2Departments of Epidemiology and Neurology, Mayo Clinic, Rochester, MN;
3Departments of Neurology, Pathology, Medicine and Epidemiology, Johns Hopkins University
School of Medicine, 600 North Wolfe Street, Baltimore MD 21287;
4HIV Neurobehavioral Research Program and Department of Psychiatry, School of Medicine,
University of California, San Diego, La Jolla, CA
Despite effective viral control through combinational antiretroviral therapies, approximately
half of HIV-infected patients will develop some form of cognitive impairment. While
we do not fully understand why some individuals infected with HIV will develop cognitive
impairments while others do not, persistent low-level inflammation is thought to contribute
to cognitive decline. Eicosanoids are a family of signaling molecules produced through
the oxidation of 20-carbon fatty acids that regulate inflammation and immunity. Although
the eicosanoids are comprised of a large number of products, those derived from the
omega-3 fatty acids docosahexaenoic acid (DHA), or eicosapentaenoic acid (EPA) tend
to be protective, while those obtained through omega-6 fatty acids arachidonic acid
(AA), or linoleic acid (LA) are more often pro-inflammatory. In the present study,
we measured eicosanoids in plasma from 98 HIV+ patients, and 25 healthy control subjects.
We found 8 eicosanoid metabolites that were undetectable in control subjects and elevated
in HIV+ patients. These included a mixture of EPA derived metabolites (15-HEPE, 18-HEPE,
8(9)-EpETE), DHA derived metabolite (13-HDoHE), and AA metabolites (LXA4, 8(9)-DiHETrE,
HxB3, 5(12)-DiHETE). At baseline, cognitively impaired HIV+ patients who had better
cognitive performance at the following visit had higher levels of 26 eicosanoid metabolites
compared to HIV+ patients who were either cognitively normal, or cognitively impaired
at both visits, or to cognitively normal control subjects. These included 3 EPA metabolites,
DHA and 9 DHA metabolites, LA and 4 LA metabolites, AA and 8 AA metabolites. A number
of these metabolites have been associated with vascular and cardiac dysfunction, and
altered platelet aggregation. As these HIV+ patients cognitive status improved, levels
of these metabolites decreased. These preliminary results suggest that alterations
in eicosanoid production in HIV-infected patients may contribute to cognitive impairment
through mechanisms that involve alterations in vascular and platelet function. Supported
by P30-Pilot Award, JHUNIMH Center to Bandaru
P18
Expression of FLT3 and its ligand (FL) is increased in the CNS in SIV/HIV infection
and encephalitis: A possible role in cell survival in HIV-associated neurocognitive
disorders
Srimoye Banerjee, Lindsey Gerngross, Tracy Fischer-Smith
(presenting author: srimoye.banerjee@temple.edu)
Temple University School of Medicine
HIV encephalitis (HIVE) is the neuropathological correlate of the most severe form
of HIV-associated neurocognitive disorders (HAND), which affect most HIV infected
individuals. Previously, we reported expansion of a monocyte subset (CD14+/CD163+/CD16+)
in HIV infected individuals with detectable plasma viremia that is phenotypically
similar to macrophages that accumulate in the central nervous system (CNS) in HIVE.
We hypothesize that macrophage colony stimulating factor (M-CSF), which is elevated
in cerebral spinal fluid in HIVE, drives expansion of this monocyte subset. In peripheral
blood mononuclear cells (PBMC), M-CSF increases the frequency of FLT3+ monocytes.
Hence, we examined CNS tissue from SIV infected rhesus macaques and patients with
HIV for possible alterations in FLT3 expression. Independent of the presence or absence
of infection, neuronal expression of FLT3 is observed in all CNS tissues examined
but is increased in SIV/HIV, with even greater expression in SIVE/HIVE. A relationship
between FLT3 expression and neuronal injury is implied by the corresponding decrease
in MAP2 positivity with increased FLT3. FLT3 ligand (FL) reveals a similar pattern
of increased neuronal expression in SIVE. In contrast to neuronal FLT3 and FL, macrophage/microglial
expression is only observed in SIV/HIV infection, with greater expression seen in
encephalitis. In vitro studies demonstrate altered FLT3 expression in differentiated
SK-N-SH cells in response to various concentrations of FL, interleukin-34 (IL-34)
and M-CSF and over different time intervals, suggesting multiple factors may contribute
to altered FLT3 expression in the CNS. The functional role of FLT3/FL expression in
SIV/HIV is unclear; however, interaction of FLT3 with its ligand is associated with
neuronal survival in the developing CNS. As such, FLT3 and FL expression in CNS disease
may be neuroprotective through promotion of neuronal survival. FLT3 expression by
macrophage/microglia, however, may contribute to CNS pathogenesis in HIV/SIV by promoting
survival of activated infected and non-infected macrophages/microglia.
P19
Characterization and Inhibition of Neurological Sequelae Induced by Alphavirus Infection
Victoria Baxter1, Michelle Potter2, Robert Mathey2, Barbara Slusher2, Diane Griffin1
(presenting author: vbaxter1@jhmi.edu)
1Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School
of Public Health, Baltimore, MD;
2Brain Science Institute, Department of Neurology, Johns Hopkins University School
of Medicine, Baltimore, MD
Recent outbreaks of encephalomyelitis caused by arthropod-borne alphaviruses reveal
their importance as an emerging cause of human disease and disability. Patients that
recover from the acute disease, especially infants and children, are often left with
life-long debilitating neurological defects, such as cognitive deficits, impaired
motor control, and emotional and behavioral disturbances. Sindbis virus (SINV), the
prototypic alphavirus, produces rash and arthritis in humans but is neurotropic in
mice, providing an excellent model for studying alphavirus-induced encephalomyelitis.
Previous studies have shown that infectious virus is cleared within 7-8 days, but
viral RNA is cleared more slowly and persists at low levels for the life of the animal.
Neuronal damage seen with alphavirus infection is thought to be due to both the immune
response and glutamate excitotoxicity. Five-week-old C57BL/6 mice were intranasally
inoculated with SINV or PBS. A battery of behavioral tests was used to assess motor
and neurocognitive function at different phases of infection. Following behavioral
tests, brains and spinal cords were collected, and infectious virus titers, SINV RNA
levels, and viral antigen presence were assessed. At the height of active virus infection,
characterized by peak infectious virus titers and detectable viral antigen in the
brain, SINV-infected mice demonstrated increased activity in open field-testing and
markedly impaired hippocampal-dependent memory in contextual and cued fear conditioning.
Following recovery from clinical disease, SINV-infected mice continued to show memory
deficits in contextual fear conditioning when only viral RNA was present in the brain.
Treatment with a glutamine inhibitor that affects both inflammation and glutamate
excitotoxicity, 6-diazo-5-oxo-L-norleucine, partially inhibited clinical disease and
neurological deficits as measured by contextual fear conditioning. These findings
show that SINV induces long-term neurological sequelae in mice that persist beyond
active virus infection, and inhibition of both inflammation and glutamate excitotoxicity
can partially mitigate development of these deficits.
P20
QTL Analysis of Myelin Oligodendrocyte Glycoprotein-Induced Experimental Allergic
Encephalomyelitis Using B6/PWD Consomic Strains Of Mus Musculus: A Useful Pathway
Comparison to Human MS-GWAS-Predicted Genetic Control of Multiple Sclerosis
Frank Bearoff1, Laure Case2, Emma Wall2, Naresha Saligrama2, Jiri Forejt3, Elizabeth
Blankenhorn1, Cory Teuscher2
(presenting author: fb99@drexel.edu)
1Drexel University College of Medicine;
2University of Vermont;
3Insitute of Molecular Genetics, Academy of Sciences of the Czech Republic
Multiple sclerosis (MS) is a debilitating chronic inflammatory disease of the nervous
system which affects approximately one million individuals worldwide with higher occurrences
in females. Consomic mouse lines, also known as chromosome (Chr) substitution strains,
are unique in that they allow for accelerated detection (compared to traditional backcross
or F2 intercross mapping) of binary/quantitative trait loci by direct genome-wide
physical mapping from genetically distinct parental strains. We have employed myelin
oligodendrocyte glycoprotein-induced experimental allergic encephalomyelitis (MOG-EAE),
a mouse model of MS, to evaluate the sex differences in consomic B6-Chr#PWD/PhJ mice
(Mus musculus domesticus). We utilized a panel of 26 B6-Chr#PWD/PhJ consomic and sub-consomic
strains of mice covering 17 autosomes from the wild derived PWD strain (Mus musculus
musculus) to position genes controlling MOG-EAE in this strain combination, fifteen
of which exhibited evidence of such loci. Of the twenty linkages found, seven were
male-specific, four female-specific, and nine were non-sex specific, suggesting a
greater genetic load in males than in females. We then identified common evolutionarily
conserved pathways underlying the sexual dimorphisms in EAE and multiple sclerosis
(MS) susceptibility. We find that there is a greater overlap of pathways common to
MS and male EAE compared to female EAE (33 vs. 7) that are the basis for these sexual
dimorphisms. Importantly, our results provide a scheme by which consomic mouse strains
can provide a better understanding of polygenic human diseases.
P21
Consequences of immune selection in a pigtailed macaque model of SIV CNS disease
Sarah Beck, Suzanne Queen, Joseph Mankowski
(presenting author: sbeck8@jhmi.edu)
Johns Hopkins University School of Medicine
Immune pressure exerted by MHC class I-mediated cytotoxic T-lymphocytes (CTLs) drives
HIV escape mutations; nonetheless, the relationship between viral escape and HIV CNS
disease remains poorly understood. MHC-I allele Mane-A1*084:01:01 confers resistance
to SIV-induced CNS disease in pigtailed macaques, and prototypic escape (K165R) develops
in the immunodominant SIV Gag KP9 epitope. We hypothesize that 1) escaped virus has
reduced fitness in vivo and in vitro, and 2) CTL-mediated immune pressure switches
from the immunodominant Gag epitope to a subdominant epitope in animals inoculated
with SIV K165R. We used site-directed mutagenesis to insert the K165R Gag escape mutation
into the backbone of the neurovirulent molecular clone SIV/17E-Fr, producing the clone
SIV/17E-Fr K165R. Replication of SIV/17E-Fr K165R versus SIV/17E-Fr was compared in
CEMx174 cells and primary macaque microglia, macrophages, and lymphocytes. Although
K165R was replication competent in all cell types, viral replication was reduced compared
to SIV/17E-Fr. To extend in vitro findings, Mane-A1*084:01:01 expressing macaques
were inoculated: three with SIV/17E-Fr K165R, and three with wildtype, parental SIV/17E-Fr.
There were no differences in plasma viral loads and slightly lower CSF viral loads
in animals inoculated with K165R versus those inoculated with wildtype. In the absence
of the immunodominant epitope Gag KP9, CTL-mediated immune pressure redirected to
the sub-dominant Mane-A*084:01:01-restricted SIV Tat epitope KVA10 with no viral escape
evident. Most surprisingly, in animals inoculated with K165R, the escape mutation
K165R was genotypically stable in the plasma, but rapidly reverted to WT Gag KP9 in
both CSF and in microglia. These data clearly demonstrate that viral fitness in the
CNS is different from the periphery. As therapeutic vaccination strategies to enhance
CTL responses against HIV gag could promote HIV escape, it is vital that we understand
the consequences of viral escape on CNS disease.
P22
Allele Frequencies of the Apolipoprotein E Gene in the Multicenter AIDS Cohort Study
as a Function of Recruitment Cohort, Race, Survivorship and Neuropsychological Outcomes
James T. Becker1, Jeremy J. Martinson2, Sudhir Penugonda3, Lawrence Kingsley2, Samantha
Molsberry2, Steven Wolinsky3, Sandra Reynolds4, Aaron Aronow5, Andrew Levine6, Eileen
Martin7, Eric Miller8, Cynthia Munro9, Ann Ragin10, Ned Sacktor11
(presenting author: BeckerJT@upmc.edu)
1Departments of Psychiatry, Neurology, and Psychology, University of Pittsburgh;
2Department of Infectious Diseases and Microbiology, University of Pittsburgh;
3Division of Infectious Diseases, Department of Medicine, Northwestern University;
4Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health;
5Department of Neurology, Cedars-Sinai Medical Center; 6Department of Neurology, University
of California Los Angeles;
7Department of Psychiatry, Rush University School of Medicine;
8Department of Psychiatry, University of California Los Angeles;
9Department of Psychiatry, The Johns Hopkins University School of Medicine;
10Department of Radiology, Northwestern University;
11Department of Neurology, The Johns Hopkins University School of Medicine;
The gene ApoE is mapped to chromosome 19, and the E*4 allele is found in approximately
14% of the population. Several recent studies have examined ApoE among individuals
with HIV disease, and to date, the data suggest that any links are weak, at best.
We describe here the relationships among ApoE genotypes, subject characteristics,
incident neuropsychological impairment, and time to death among men enrolled in the
Multicenter AIDS Cohort Study (MACS). Genomic DNA was isolated from lysates of either
buffy-coat or B-cell immortalized cell lines from 2846 men (median age: 34, range:
17-69) in the MACS. Genomic DNA concentration and quality was assessed using UV and/or
by fluorometric quantitation. End-point genotyping of ApoE variants rs429358 [C/T]
and rs7412 [C/T] was performed using TaqMan and OpenArray technologies. 1689 of the
men were HIV-infected and 1157 were uninfected. 23.2% of the men who identified themselves
as white had at least one copy of the E*4 allele, whereas 31.2% of other races had
at least one E*4 allele (Odd’s Ratio = 0.65 (0.54 - 0.79)). In separate models by
race (White/Minority), we found no significant associations between the presence of
an E*4 allele and age, HIV status, death, or neuropsychological outcome. We used Cox
Proportional Hazard Models to investigate time to death and found a significant association
between HIV infection and time to death (all cause), as well as older age, race, and
education. ApoE status was not significantly associated with time to death. There
were significant associations between time to neuropsychological impairment, age,
education, and HIV serostatus, but no association with ApoE*4. There were no interactions
between ApoE*4, HIV infection, age and the outcomes of interest. These results confirm
and extend previous findings that that the ApoE*4 allele is not associated with death
or neuropsychological impairment among men in this age group.
P23
Recruitment Differences and Survival Biases Among Men with Neuropsychological Evaluations
in the Multicenter AIDS Cohort Study (1987-2012)
James T. Becker1, Lawrence Kingsley2, Samantha Molsberry2, Sandra Reynolds3, Aaron
Aronow4, Andrew Levine5, Eileen Martin6, Eric Miller7, Cynthia Munro8, Ann Ragin9,
Ned Sacktor10, Ola Selnes10
(presenting author: sam220@pitt.edu)
1Departments of Psychiatry, Neurology, and Psychology, University of Pittsburgh;
2Department of Epidemiology, University of Pittsburgh;
3Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health;
4Department of Neurology, Cedars-Sinai Medical Center; 5Department of Neurology, University
of California Los Angeles;
6Department of Psychiatry, Rush University;
7Department of Psychiatry, University of California Los Angeles;
8Department of Psychiatry, The Johns Hopkins University School of Medicine;
9Department of Radiology, Northwestern University;
10Department of Neurology, The Johns Hopkins University School of Medicine
The Multicenter AIDS Cohort Study follows the natural and treated history of HIV,
and a key component is the biannual assessment of cognitive functions. We describe
here an analysis of cohort and survivorship factors. 5470 men (78.5%) in the MACS
cohort completed at least one neuropsychological test battery; 3687 enrolled in Cohort
1 (1984/1985), 474 in Cohort 2 (1987/90) and 1309 in Cohort 3 (2001/03. C1 was predominantly
white, whereas C2 and C3 were predominantly African-American. Also, C1 had more education
than C2, which had more education than C3. The men in C3 were older than those in
C1 or C2. The men in C3 endorsed more depressive symptoms than did C1 or C2. Estimated
IQ differed as a function of cohort (i.e., C1>C2>C3) and on measures of psychomotor
speed, verbal and non-verbal memory and fine motor coordination. As of December 2012,
the men were classified as active, inactive, or dead; 32% of C1 and C2 were still
active, compared with 66% of the men in C3. Among the uninfected men, there was no
difference in the rate of cognitive abnormality between C1/C2 (combined) and C3, whereas,
for the infected men, the rate of abnormality was significantly lower in C3 than in
C1/C2. The seronegative men who remained alive and active in the study showed a small,
but consistent increase in the rate of abnormal cognition between the first and last
visits (6.8 vs. 9.2%). Severe cognitive abnormality rose to 12.5% among the inactive
men and 16.4% among the individuals who died during follow-up. Differences in volunteer
recruitment are reflected in the cohort characteristics at the baseline visit, and
they tended to persist among the active participants in 2012. Loss of data due to
death or drop-out may affect the estimates of prevalence of neuropsychological abnormalities
among the study participants.
P24
Human Polyomavirus JC monitoring and noncoding control region analysis in dynamic
cohorts of individuals affected by multiple sclerosis under treatment with natalizumab:
an observational study
Anna Bellizzi1, Elena Anzivino1, Donatella Maria Rodio1, Sara Cioccolo1, Manuela Morreale2,
Simona Pontecorvo3, Silvia Carluccio4, Lucia Nencioni5, Ada Francia3, Anna Teresa
Palamara5,6, Valeria Pietropaolo1,7
(presenting author: bellizzi.anna@yahoo.com)
1Department of Public Health and Infectious Diseases, Sapienza University of Rome;
2Department of Medico-Surgical Sciences and Biotechnologies, Section of Neurology,
Sapienza University of Rome;
3Department of Neurology and Psychiatry, Sapienza University of Rome;
4Department of Biomedical, Surgery and Dental Sciences, University of Milan;
5Department of Public Health and Infectious Diseases, Institute Pasteur, Cenci-Bolognetti
Foundation, Sapienza University of Rome;
6San Raffaele Pisana Scientific Institute for Research, Hospitalization and Health
Care, Rome;
7Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology,
College of Science and Technology, Temple University, Philadelphia, Pennsylvania,
USA
Progressive multifocal leukoencephalopathy (PML) onset, caused by Polyomavirus JC
(JCPyV) in patients affected by multiple sclerosis (MS) during natalizumab treatment,
raised concerns about the safety profile of this agent. Therefore, the aims of this
study were the JCPyV reactivation monitoring and the noncoding control region (NCCR)
and viral protein 1 (VP1) analysis in patients affected by MS and treated with natalizumab.
We performed JCPyV-specific quantitative PCR of biological samples collected at moment
of recruitment (t0) and every 4 months (t1, t2, t3) for 1 year. Subsequently, analysis
of NCCR and VP1 rearrangements was carried out. Moreover a 2-step virus-like particle-based
enzyme-linked immunosorbed assay was performed at t0 and t3, to detect specific anti-JC
virus antibodies in serum of the enrolled subjects. Data were analyzed using chi-square
test. Results showed a significant association between JC viruria and JCPyV antibodies
after 1 year of natalizumab (p=0.04). Moreover, sequences isolated from peripheral
blood mononuclear cells (PBMCs) of 2 patients with JCPyV antibody at t0 and t3, showed
a NCCR Type IIR with a duplication of a 98bp unit and a 66bp insert, resulting in
a boxB deletion and 37 T to G transversion into the Spi-B binding site. In all patients,
a prevalence of genotypes 1A and 1B, the predominant JCPyV genotypes in Europe, was
observed. In conclusion, it could be important to understand whether the specific
inflammatory scenario of multiple sclerosis could affect JCPyV reactivation from latency,
in particular from kidneys. Moreover, for a more accurate PML risk stratification,
testing JC viruria seems to be useful to identify patients who harbor JCPyV but with
an undetectable JCPyV-specific humoral immune response. In these patients, it may
also be important to study the JCPyV NCCR rearrangement: in particular, Spi-B expression
in PBMCs could play a crucial role in JCPyV replication and NCCR rearrangement.
P25
HIV-1 Transgenic Rat: Altered Internal Motivational State for Natural Rewards
Sarah J. Bertrand, Charles F. Mactutus, Steven B. Harrod, Amanda J. Morgan, Rosemarie
M. Booze
(presenting author: bertrans@email.sc.edu)
Psychology Department University of South Carolina
HAND patients exhibit changes in the key brain regions responsible for motivational
drive (mesocorticolimbic system). The HIV-1 transgenic rat is chronically exposed
to low levels of HIV-1 proteins in the brain, which may occur in humans with cART.
The present study used adult female, ovariectomized, HIV-1 transgenic rats (N=29).
Initially, a five bottle preference test, using 0%, 1%, 3%, 10%, and 30% (w/v) sucrose
solutions, following 22 h of water restriction, was used to evaluate response to novelty
as well as potential sensory differences between HIV-1 and control rats. Although
there was no difference in overall volume consumed on the initial test day, HIV-1
rats consumed significantly more of the 10% sucrose solution, suggesting a heightened
novelty response. Across the following 5 days of testing, HIV-1 and control rats did
not significantly differ in their pattern of consumption of sucrose, suggesting that
overall taste preference for sucrose was not altered. Subsequently, rats learned to
respond for 5% sucrose (w/v) reinforcement in operant conditioning chambers. Animals
were briefly water restricted during autoshaping; all animals eventually progressed
onto non-restricted training, according to an increasing fixed-ratio requirement (FR1,
FR2, FR3). There was a significant retardation in the rate at which the HIV-1 rats
progressed to higher FR schedules compared to controls, suggesting a change in the
basal internal motivational state. Most critically, the present results suggest alterations
in the internal motivational state of HIV-1 animals, as displayed by their inability
to meet criterion and progress through the fixed ratio schedules, which were not readily
attributable to any alterations in novelty or taste preference. These results suggest
that the HIV-1 transgenic rat may have underlying internal motivational deficits for
obtaining natural rewards such as sucrose, not unlike their alterations in responding
for drugs of abuse.
Grant numbers: DA013137, HD043680, GM081740
P26
Malaria Co-infection among HIV Infected Individuals in Nigeria: Impact on Cognition
and Role of Biomarkers
Ajay Bharti1, Scott Letendre1, Davey Smith1, Mariana Cherner1, Anya Umlauf1, Tricia
Burdo2, Kenneth Williams2, William Blattner3, Walter Royal4
(presenting author: abharti@ucsd.edu)
1HIV Neurobehavioral Research Program, University of California San Diego;
2Department of Biology, Boston College;
3Department of Medicine, University of Maryland;
4Department of Neurology, University of Maryland
Objective: In endemic areas, malaria and HIV frequently infect the same host but their
combined effects on the brain are poorly understood. We hypothesized that the combination
of malaria and HIV would amplify monocyte/macrophage activation and contribute to
worsening of neurologic HIV disease.
Methods: 269 subjects, 174 HIV+ and 95 HIV-, were evaluated using a comprehensive
neuropsychological test battery. Global and domain-specific deficit scores (GDS and
DDS) were generated and used for determining impairment. All subjects lacked symptoms
of acute malaria and AM was diagnosed based on peripheral smear findings. Hemoglobin,
hematocrit, CD4+ T-cell counts, HIV RNA levels, soluble CD163, and soluble CD14 were
measured.
Results: AM was not statistically significantly more common in HIV+ than in HIV- subjects
(36% vs. 29%, odds ratio (OR) 1.36, p > 0.10). Overall, AM was not associated with
NCI (p > 0.10). Among AM subjects, HIV+ were more likely to have motor impairment
than HIV- (35% vs. 42%, p=0.03). AM trended toward an association with executive functioning
impairment after accounting for HIV status (p<0.10). An interaction between CD4+ counts
and AM was present: AM was associated with NCI among people with CD4+ counts below
200 (35% vs. 22%, OR 1.90) but the opposite was true for subjects who had higher CD4+
counts (21% vs. 30%, OR 0.61). sCD14 levels were significantly higher in the M+/H+
group compared to the M-/H+ group (p=0.015). Higher sCD14 levels were associated with
higher odds of impairment (OR=9.4, 95% CI=1.1,88; p=0.046) but the interaction with
malaria was not significant.
Conclusion: AM is common among HIV+ individuals in Nigeria. Malaria may lead to worse
NC functioning, specifically in motor and executive functioning. Individuals with
greater immunosuppression are more likely to experience impairment when co-infected
with malaria. Malaria also results in higher levels of biomarkers of monocyte/macrophage
activation.
P27
Human beta-defensin 2 and 3 inhibit HIV in primary macrophages: implications for HIV
infection of the CNS
Jennifer P. Bharucha1, Mark Lafferty1, Olga Latinovic2, Wuyuan Lu3, Suzanne Gartner4,
Alfredo Garzino-Demo2
(presenting author: jbharucha@ihv.umaryland.edu)
1Institute of Human Virology, University of Maryland School of Medicine;
2Institute of Human Virology, University of Maryland School of Medicine;
2Institute of Human Virology, Department of Microbiology and Immunology, University
of Maryland School of Medicine;
3Institute of Human Virology, Department of Biochemistry, University of Maryland School
of Medicine;
4Institute of Human Virology, Department of Medicine, University of Maryland School
of Medicine
Human beta-defensins (hBDs) are broad-spectrum antimicrobial peptides, secreted by
epithelial cells and astrocytes, which we and others have shown to inhibit HIV-1 in
primary CD4+ T cells. In T cells, the intracellular inhibitory activity is mediated
by CCR6, a receptor that binds both the chemokine MIP-3alpha and hBDs. Although loss
of T cells contributes to mucosal immune dysfunction, macrophages, by virtue of their
roles in both innate and adaptive immunity, are a major source of persistence, spread
of HIV, and development of complications, especially in the brain. Interestingly,
hBDs are expressed in the CNS but very little is known about their role in the brain.
We hypothesized that, besides T cells, hBDs protect microglial cells and perivascular
macrophages from productive HIV infection. Our data on primary monocyte-derived macrophages
(MDM), which we use as an in vitro model for microglial cells, show that hBD2 and
-3 inhibit HIV replication in a dose-dependent manner. We investigated the mechanism(s)
involved. We determined that hBD2 neither alters surface expression of HIV receptors
nor induces expression of anti-HIV cytokines or beta-chemokines in MDM. Studies using
a G-protein signaling antagonist in a single-cycle reporter virus system showed that
hBD2 suppresses HIV at an early post-entry stage via GPCR-mediated signaling. Our
data also illustrate that hBD2 blocks HIV by enhancing expression of APOBEC3A and
3G. MDM express the shared chemokine-hBD receptors CCR2 and CCR6, albeit at variable
levels among donors. However, neither of these receptors is necessary for hBD2-mediated
HIV inhibition, suggesting that hBD2 can signal via additional receptor(s). Preliminary
data also show that hBD2 is internalized in early endosomes in MDM. These findings
suggest that hBD2 inhibits HIV in MDM via more than one mechanism, and may aid the
development of new approaches to treat HIV infection systemically and in the CNS.
P28
Human Herpes Virus 6 in Human Epilepsy: Data from Surgical Resections
Bridgette Jeanne Billioux1, Emily Leibovitch1, Giovanna Brunetto1, Irene M. Dustin2,
Sarah Inati3, John Schreiber2, Chigo Eze2, Kareem Zaghloul4, Steve Jacobson1, William
H. Theodore2
(presenting author: bridgette.billioux@nih.gov)
1Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke,
National Institutes of Health;
2Clinical Epilepsy Section,National Institute of Neurological Disorders and Stroke,
National Institutes of Health;
3EEG Laboratory,National Institute of Neurological Disorders and Stroke, National
Institutes of Health;
4Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke,
National Institutes of Health;
Background: Previous studies suggested a possible role for HHV-6B in mesial temporal
lobe epilepsy (MTLE). HHV-6B is the etiologic agent of roseola, while HHV-6A is associated
with central nervous system (CNS) disorders and may be more neurotropic than HHV-6B.
Methods: Using digital droplet PCR (ddPCR) to examine HHV-6A and HHV-6B viral DNA,
we studied a new cohort of 10 MTLE patients and six with focal cortical dysplasia
(FCD). DdPCR is a highly sensitive and precise novel PCR technology that enables absolute
quantification of target DNA molecules.
Results: Viral DNA was detected in 60% of MTLE patients. This positivity frequency
is consistent with our previous findings. In addition, we detected HHV-6A as well
as HHV-6B. Moreover, HHV-6A and HHV-6B DNA also were detected in a subset of FCD patients.
The detected viral copy numbers varied across a wide range between patients and even
within a given patient, depending on regional sampling.
Conclusions: Our new data suggest viral presence in patients with FCD and extend our
findings in patients with MTLE, with detection of HHV-6A not previously reported.
P29
Innate immune signalling initiates B cell response in viral induced demyelination
Kaushiki Biswas 1, Sankar Addya2, Alexander Choe3, Paolo Fortina2, Lawrence C. Kenyon4,
Kenneth S. Shindler Shindler5, Randall Cohrs3, Jayasri Das Sarma6
(presenting author: dassarmaj@iiserkol.ac.in)
1Department of Biological Science, Indian Institute of Science Education and Research-Kolkata
(IISER-K);
2Kimmel Cancer Centre, Thomas Jefferson University, Philadelphia, Pennsylvania;
3Department of Neurology, University of Colorado, Denver School of Medicine, Aurora,
Colorado;
4Department of Anatomy, Pathology and Cell Biology, Thomas Jefferson University, Philadelphia,
Pennsylvania;
5Scheie Eye Institute and FM Kirby Centre for Molecular Ophthalmology, University
of Pennsylvania, Philadelphia, Pennsylvania;
6Department of Biological Science, Indian Institute of Science Education and Research-Kolkata
(IISER-K) and Department of Ophthalmology, University of Pennsylvania, Philadelphia,
Pennsylvania
Multiple sclerosis (MS) is a demyelinating disorder of the central nervous system
(CNS), believed to be autoimmune in nature. Characteristic presence of oligoclonal
bands (OCBS) in CSF of almost 95% of MS patients supports the long standing hypothesis
of viral etiology. OCBs are found in infectious CNS disorders where their antigenic
target represents the causative agent, but a definite target of OCBs in MS patients
remains obscure. Mouse hepatitis virus (MHV) induced neuroinflammation in mice is
an experimental model used to study mechanisms of demyelination. Neurotropic MHV strains
induce meningitis, encephalitis, and myelitis during their acute phase and progressive
demyelination in the chronic phase of infection when viral particle is cleared and
acute inflammation is resolved. Affymetrix microarray analysis of the mRNA expression
from demyelinating MHV strain infected spinal cord tissue revealed that during acute
infection there is a robust upregulation of various innate immune genes which are
mainly involved in antiviral immune responses, phagolysosome maturation and MHC Class-II
expression. During chronic infection, there is a 10-fold upregulation of several Ig
mRNAs (Ighg3, IGJ, Igk-V28 andIgkv4-68), with a shift of Th1 and Th2 immune responses
in acute and chronic inflammation stages. It has been known for a long time that viral
infection can induce Ig molecules, but the mechanism of induction was not clear. Demyelinating
MHV infection induced innate immune signalling and the innate immune effector molecules
induce B cell activation and expression of several oligoclonal genes which could play
a major role in antibody mediated progressive demyelination. This cause effect relationship
of viral infection and induction of oligoclonal Ig mRNAs paves a way to understanding
B cell activation in demyelination. Findings may help advance our understanding of
viral induced and antibody mediated demyelination in MS.
P30
The role of resident and infiltrating macrophages in dorsal root ganglia pathology
and intraepidermal nerve fiber loss using a rhesus macaque model of AIDS-associated
peripheral neuropathy
Ayman Bodair1, Deepika Dinesh1, Ryan O’Donnell2, Luke Ollila1, Neal Shah1, Andrew
Miller3, Tricia Burdo1
(presenting author: burdot@bc.edu)
1Department of Biology, Boston College, Chestnut Hill, MA 02467;
2Cutaneous Nerve Laboratory, Department of Neurology, Johns Hopkins School of Medicine,
Baltimore, MD 21231;
3Department of Comparative Pathology, New England Primate Research Center, Harvard
Medical School, Southborough, MA 01772
Symptomatic abnormalities of the peripheral nervous system (PNS) are among the most
common complications of HIV-1 infection. Although anti-retrovirals have been successful
in ameliorating the constitutional manifestations of AIDS and reducing the severity
of many neurological complications caused by HIV infection, there has been no significant
impact on the incidence or severity of HIV sensory neuropathy (HIV-SN). Here, we used
12 SIV-infected CD8 depleted rhesus macaques as a model of HIV-SN and 5 uninfected
controls. 10 of the 12 SIV-infected animals (83%) developed moderate-to-severe dorsal
root ganglia (DRG) pathology. DRG tissues had extensive activation of satellite cells,
as measured by CD68 and CD163 immunoreactivity, some of which were productively SIV-infected
via immunohistochemistry (0.1-8.2%). BrdU pulse studies showed an increase in monocyte
traffic from bone marrow to the DRGs, which correlated with the severity of pathology;
uninfected 0.8%, mild 1.7%, moderate 2.6% and severe 6.7%. Intraepidermal nerve fiber
(IENF) densities were determined from biopsies of the central food pad. There was
a significant decline in IENF densities in 7 of the 8 animals by 21 days post infection
with an average of a 48.7% loss in fibers at necropsy. A positive correlation between
the percentage of CD163+ macrophages surrounding the sacral DRG neurons and the percent
loss of IENF densities was seen at necropsy (r= 0.94, P= 0.006). We conclude that
both resident macrophage activation and monocyte infiltration play significant primary
roles in DRG damage during HIV-SN. Our data also suggest a link between macrophage
activation in the DRGs, DRG pathology, and IENF loss in the periphery in a rhesus
macaque model of AIDS-induced peripheral neuropathy. Thus, future adjunctive therapies
that diminish macrophage activation and monocyte infiltration may serve to ameliorate
the HIV-SN severity previously observed.
P31
Proteomics evaluation of CSF patients with HIV-associated neurocognitive impairment
using iTRAQ labeling
Adriana Bora1, Ceereena Ubaida Mohien2, Raghothama Chaerkady3, Linda Chang4, Richard
Moxley,IV1, Ned Sacktor1, Justin C. McArthur1, Norm Haughey1, Avindra Nath5, David
R. Graham2
(presenting author: abora1@jhmi.edu)
1Neurology Department, Johns Hopkins School of Medicine;
2Dept. of Molecular & Comparative Pathobiology, Johns Hopkins School of Medicine;
3Proteomics Core Facility; Johns Hopkins School of Medicine;
4Dept. of Medicine, John A. Burns School of Medicine, University of Hawaii;
5National Institute of Neurological Disorders and Stroke, National Institutes of Health
HIV invasion of the CNS is coincident with acute HIV infection, and persists due to
the chronic infection of long-lived microglial cells, astrocytes and perivascular
macrophages. Cerebrospinal fluid (CSF) is becoming one of the most frequently used
biofluids for physiological studies of neurological disorders since it is an ultra-filtrate
of plasma and is the collection point for drainage of the brain parenchyma. In this
proteomics study we used a relative quantitation method to study pooled CSF samples
from 10 HIV-infected patients with cognitive impairment, 10 HIV-infected patients
with normal cognition, and 10 healthy individuals, with the goal to identify potential
biomarkers for cognitive impairment. We used advanced two dimensional separation strategies
and bioinformatics to identify a total of identification of overall 673 proteins.
Using statistical interpretation of the isobaric tags for relative and absolute quantitation
(iTRAQ) reporter intensities, 193 proteins with 95% confidence interval and p-value
≤ 0.05 were selected based on permutation test that were interpretable for quantitation.
Using a cut off of 1.5 fold for upregulation and 0.6 fold for downregulation, 16 proteins
were differentially expressed in HIV-infected individuals with cognitive impairment
(reporter p-value ≤ 0.05). Seven of these proteins have been previously described
as HIV-interacting proteins including: endoplasmin, mitochondrial damage mediator-BH3-interacting
domanin death agonist (BID), orosomucoid, apolipoprotein E, metalloproteinase inhibitor
2, peroxiredoxin-2 and the nuclear protein, ruvB-like 2. Several proteins with possible
neurological implications were also identified including: forming-binding protein
1, C-reactive protein, leukocyte-associated immunoglobulin receptor 1, renin receptor,
mediator of RNA polymerase II transcription subunit 14, multimerin-2, alpha-N-acetylglucosaminidase,
caldesmon, cadherin EGF LAG G-type receptor. This suggests that not only a few but
possibly a combination of biomarkers that are highly correlated can predict neurocognitive
status in HIV-infected patients and might be involved in monocyte or macrophage activation.
P32
Recombinant Adenovirus Vaccine Vector and DNA Construct Boost Cellular Immune Response
to JC virus in Mice
Thomas Broge1, Chelsea Bleckwehl2, Peter Abbink2, Dan Barouch2, Igor Koralnik1, Chen
Sabrina Tan3
(presenting author: ctan@bidmc.harvard.edu)
1Center for Virology and Vaccine Research, Department of Medicine, Division of NeuroVirology,
Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School;
2Center for Virology and Vaccine Research, Department of Medicine,Beth Israel Deaconess
Medical Center, Harvard Medical School;
3Center for Virology and Vaccine Research, Division of Infectious Diseases, Department
of Medicine, Division of NeuroVirology, Department of Neurology, Beth Israel Deaconess
Medical Center, Harvard Medical School
Background: JCV causes progressive multifocal leukoencephalopathy (PML) in immunocompromised
patients. While there is no effective anti-viral therapy against JCV, the cellular
immune response is crucial in containment of viral replication and is associated with
PML survival. Therefore, a preventative and therapeutic vaccine against JCV, which
can elicit this cellular immune response is urgently needed.
Methods: Replication incompetent adenovirus vaccine vector serotype 5 (rAd5) was generated
by insertion of the JCV VP1 gene. Naive C57BL/6 wildtype mice were immunized with
a single injection of either the rAd5-JCV or DNA rAd5-JCV. Days 14 to 21 after immunization,
mice were sacrificed and splenocytes were isolated, stimulated with overlapping JCV
VP1 peptide pools and assayed by intracellular cytokines staining (ICS) for IFN-gamma.
Control mice were injected with PBS and JC Mad-4 virions.
Results: Mice remained asymptomatic up to 21 days after injections of JC virions,
rAd5-JCV, DNA rAd5-JCV or PBS. While JC virions elicited minimal cellular immune responses,
rAd5-JCV and DNA rAd5-JCV significantly increased the percentages of JCV-specific
CD4+ T-cells compared with those elicited by JC virions (p<0.05). In addition, rAd5-JCV
significantly increased JCV-specific CD8+ T-cells compared to DNA rAd5-JCV (p=0.05),
and to JC virions (p<0.05). Furthermore, DNA rAd5-JCV significantly increased JCV-specific
CD8+ T-cells compared to JC virions (p<0.05).
Conclusions: Both recombinant Adenovector and DNA plasmids expressing JCV VP1 proteins
elicit strong JCV-specific cellular immune responses in mice. Further development
of these vaccines may lead to clinical applications for prevention and treatment of
JCV-associated brain diseases.
P33
Comprehensive survey of GABAergic neural transmission in HIV infection reveals correlation
with anomalies in the neurovascular unit and dopamine receptor expression in frontal
neocortex
Tetyana Buzhdygan1, Joshua Lisinicchia1, Vipulkumar Patel1, Tyler Clement1, Kenneth
Johnson1, Kristofer Jennings2, Dennis Kolson3, Benjamin Gelman4
(presenting author: tpbuzhdy@utmb.edu)
1Department of Pathology, University of Texas Medical Branch, Galveston, TX;
2Department of Preventive Medicine and Community Health, University of Texas Medical
Branch, Galveston, TX;
3Department of Neurology, University of Pennsylvania, Philadelphia, PA;
4Departments of Pathology and Neuroscience and Cell Biology, University of Texas Medical
Branch, Galveston, TX
HIV-associated neurocognitive disorders (HAND) are prevalent in patients given highly
active anti-retroviral therapy (HAART). Neurotransmitter systems including inhibitory
GABAergic elements often are neurochemically abnormal in HAND patients given HAART.
We surveyed GABAergic inhibitory neurotransmission in 449 brain specimens from subjects
with HIV infection, and 66 seronegative controls. mRNAs from two rate-limiting enzymes
of GABA synthesis (glutamic acid decarboxylase 1 and 2; GAD1 and GAD2) and a gap junction-associated
transcript expressed selectively in GABAergic neurons (GJD2) were assayed using qPCR.
All three GABA-associated mRNAs were significantly decreased in the dorsolateral prefrontal
cortex (DLPFC) of HIV-positive subjects. Abnormal expression was distributed widely
in the CNS including neocortex, neostriatum and cerebellum. Patients with and without
HIV encephalitis had significantly lower GABAergic mRNAs. Patients who died prior
to and after the era of HAART both had significantly lower GABAergic mRNAs. Low GABAergic
mRNAs were correlated significantly with higher expression of mRNA markers produced
by endothelial cells including PECAM1 and VWF, and with high expression of dopamine
receptor type 2 mRNA (DRD2L). Low GABAergic mRNA expression was specifically correlated
with worse performance on testing for verbal fluency. Immunoblotting and immunohistochemistry
showed protein-level changes in the HIV-infected brain specimens including loss of
GAD67 and parvalbumin staining intensity, higher DRD2 expression in some GABAergic
interneurons, and swelling of endothelial cells. We conclude that abnormal GABAergic
tone is prevalent in HIV infected patients, and it has a broad anatomical distribution
in the CNS. Novel associations with changes in dopamine transmission and endothelial
cell markers suggest roles in synaptic plasticity and connection to the neurovascular
unit.
P34
Macrophage/microglia lineage-related R5-tropic simian-human immunodeficiency viruses
as tools to induce and study HAND
Siddappa Byrareddy1,2, Swati Thorat2, Prachi Sharma3, Girish Hemashettar Hemashettar2,
Kenta Matsuda4, Vanessa Hirsch4, Umberto Girolami5, Francis Novembre3, Francois Villinger1,3,
Ruth Ruprecht2
(presenting author: siddappa.n.byrareddy@emory.edu)
1Department of Pathology and Laboratory Medicine, Emory University;
2Dana Farber Cancer Institute; Harvard Medical School;
3Yerkes National Primate Research Center, Emory University;
4Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious
Diseases, National Institutes of Health;
5Department of Pathology, Brigham and Women’s Hospital
Thanks to an increasing panel of antiretroviral drugs, HIV replication can be effectively
controlled in infected patients. However, there are limitations to ART, as immune
activation is not fully contained and penetration of most drugs into the central nervous
system (CNS) is inefficient. Thus, while NeuroAIDS cases have diminished, HIV-associated
neurocognitive disorders (HAND) have become a far more prominent problem. HIV neurovirulence
has been associated with viral tropism for macrophage/microglia (MG)/monocyte lineages,
but there is as yet a paucity of reliable animal models of neurotropic HIV. To address
this gap, we generated an MG-tropic SHIV, named SHIV-Bo159N4p2. The resulting virus
is highly fusogenic and replicates to high levels in monocyte-derived macrophages
(MDM) and MG. We tested its replicative capacity under the cover of depletion of CD8
cells or CD8 and CD20 B cells in rhesus or pigtailed macaques (PMs). These viruses
replicated very well in vitro and in vivo (upon intravenous or intrarectal inoculation)
and reached peak viral loads in plasma and CSF (10^6 to 10^9 copies/ml in plasma vs
10^5 to 10^8 copies/ml in CSF). Early-stage viruses were sensitive to broadly neutralizing
antibodies, soluble CD4 (sCD4) and induced cross-clade neutralizing antibody responses.
The late-stage viruses differed in their sensitivity to sCD4 and broadly neutralizing
antibodies but remained R5 tropic. Notably, under double depletion (CD8+CD20), 8 out
of 11 PMs rapidly progressed to disease within 2-4 months, while 2 out of 2 PMs progressed
to disease in < 2 years without depletion. Pathological changes in the brain in most
PMs included astrogliosis, chronic meningitis, perivascular cuffing or inflammation,
gliosis and few infected MG, suggesting that these viruses cause milder forms of neurological
diseases. In summary, macrophage/MG-tropic SHIVs will be valuable tools to study milder
forms of neurological disorders in a biologically relevant primate model.
P35
Dopamine Increases CD14+CD16+ Monocyte Transmigration Across the BBB: Implications
for Drug Abuse and HAND
Tina M. Calderon1, Dionna W. Williams1, Jacqueline S. Coley1, Lillie Lopez1, Peter
J. Gaskill1, Eliseo A. Eugenin2, Joan W. Berman3
(presenting author: tina.calderon@einstein.yu.edu)
1Department of Pathology, Albert Einstein College of Medicine;
2Public Health Research Institute, New Jersey Medical School - Rutgers, The State
University of New Jersey;
3Departments of Pathology and Microbiology and Immunology, Albert Einstein College
of Medicine
Studies suggest that uninfected and HIV infected CD14+CD16+ monocytes transmigrate
across the blood brain barrier (BBB), mediating viral entry into the CNS and contributing
to chronic neuroinflammation that results in HIV associated neurocognitive disorders
(HAND) in greater than 50% of HIV infected people. In some HIV infected drug abusers,
HAND is reported to be more severe. Increased extracellular CNS dopamine is a common
mechanism that occurs acutely in response to intermittent drug use. We report that
the number of peripheral CD14+CD16+ monocytes is increased in HIV infected drug abusers.
To study the effects of dopamine on chemokine mediated CD14+CD16+ monocyte influx
into the CNS, uninfected peripheral blood monocytes were cultured non-adherently with
M-CSF to expand the number of CD14+CD16+ cells. Cultured monocytes expressed CXCR4
and the transmigration of these cells in response to CXCL12 and/or dopamine was characterized
using our human BBB model. Unexpectedly, dopamine alone increased CD14+CD16+ monocyte
transmigration. In contrast, dopamine had no effect on T cells. Dopamine receptors
D1R and D5R are higher, while D4R is lower, in mature monocytes when compared to T
cells. The D1R/D5R agonist SKF 38393 increased CD14+CD16+ monocyte transmigration,
indicating the involvement of these receptors in dopamine induced transmigration.
Although dopamine does not cross the BBB, CD14+CD16+ monocyte transmigration may be
increased by dopamine mediated effects on BBB cells and/or on the transmigration process
once monocytes have penetrated the BBB in response to chemokines. Mature monocytes
were treated with dopamine to determine the direct effects of dopamine on cellular
processes involved in transmigration. Dopamine increased migration and pseudopodia
formation, a component of cellular polarization involved in movement. Thus, the combination
of higher numbers of circulating CD14+CD16+ monocytes and elevated dopamine in HIV
infected drug abusers may result in increased transmigration of these cells into the
CNS, contributing to the severity of HAND.
P36
Tysabri Treatment Suppresses Virus Traffic to the Brain and Gut Early, and Stabilizes
CNS Injury Late in Infection
Jennifer H. Campbell1, Eva-Maria Ratai2, Patrick Autissier1, Andrew G. MacLean3, Nicole
A. Renner3, David J. Nolan4, Andrew D. Miller5, Susan V. Westmoreland5, R. Gilberto
González2, Tricia H. Burdo1, Kenneth C. Williams1
(presenting author: jennifer.campbell.2@bc.edu)
1Boston College;
2Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging at Massachusetts
General Hospital;
3Tulane National Primate Research Center;
4Emerging Pathogens Institute, University of Florida;
5New England Regional Primate Research Center
Background: Whether active monocyte/macrophage traffic with HIV infection is required
for pathogenesis has not been directly demonstrated.
Methods: Here we used a VLA-4 blocking antibody, Tysabri (30 mg/kg once a week for
three weeks), and treated SIVmac251 infected, CD8+ lymphocyte depleted monkeys with
high viral load and CNS injury on 28 days post infection (dpi) to stop monocyte/macrophage
traffic (n=4). Additionally, we treated another cohort of animals at the time of infection
(day 0, n=6) to stop productive infection of the brain and gut, but not lymph nodes.
In animals treated at 28 dpi, metabolite concentrations of n-acetylaspartate over
creatine (NAA/Cr) were assessed biweekly by 1H MR spectroscopy (MRS).
Results: With Tysabri treatment at 28 dpi we found a stabilization of neuronal injury
(NAA/Cr) in frontal and parietal cortex. Tissue analysis revealed significantly lower
numbers of activated resident macrophages (CD68+), recently recruited monocytes/macrophages
(MAC387+, BrdU+), and productively infected cells (SIV p28+, RNA+) in the brain and
small intestine of Tysabri treated macaques when compared to controls. SIV DNA was
undetectable in all but one of 24 brain tissue samples analyzed from 0 dpi Tysabri
treated animals, whereas similar concentrations of proviral DNA were isolated from
gut tissue of Tysabri treated and untreated control macaques. Animals treated with
Tysabri had low to no LPS and soluble CD163 in plasma. Ex vivo PBMCs from treated
macaques exhibited impaired adhesive and transmigratory capabilities in response to
proinflammatory stimulation.
Conclusions: Our studies using Tysabri at 28 days post-infection in SIV-infected macaques
demonstrate that stopping monocyte traffic stabilizes CNS disease. Treating animals
at the time of infection blocked traffic of virus to brain, and reduced the number
of productively infected cells in the small intestine, raising the possibility that
Tysabri may be an effective agent for preventing the formation of reservoirs during
early HIV infection.
P37
Effect of Natalizumab treatment on peripheral blood mononuclear cells subsets in MS
patients
Silvia Carluccio1, Simone Dallari1, Serena Delbue1, Matteo Gastaldi2, Diego Franciotta2,
Roberto Bergamaschi2, Elena Colombo2, Lucia Signorini1, Francesca Elia3, Pasquale
Ferrante1,4
(presenting author: silvia.carluccio@unimi.it)
1Department of Biomedical, Surgical and Dental Sciences, University of Milan, Italy;
2Mondino Neurological Institute, Pavia, Italy;
3Fondazione Ettore Sansavini, Lugo, Italy;
4Cittá Studi Clinical Institute, Milan, Italy
Natalizumab is a humanized monoclonal antibody against the alpha4 subunit of VLA-4,
a major integrin involved in the transendothelial migration. Despite several trial
studies showed its efficacy in the treatment of Multiple Sclerosis (MS), Natalizumab
is not used as first-line drug since it was reported to increase the risk of developing
Progressive Multifocal Leukoencephalopathy (PML). Aim of this study was to determine
the immunological changes in Natalizumab-treated MS patients over the time, in order
to better understand the effects of the treatment on peripheral blood mononuclear
cells (PBMCs) subsets. For this purpose, the relative frequency of different leukocyte
subsets and their expression of the alpha4 and beta2 integrins were investigated.The
analysis were performed by flow cytometry on PBMCs recovered from blood samples of
11 MS patients treated with Natalizumab, followed up to two years. Eleven MS patients
treated with conventional therapy and 11 healthy subjects were also enrolled as control
groups.The analysis of the relative frequencies showed a decrease of the monocyte
population and an increase of the lymphocyte populations, in particular CD19+ and
CD34+ cells. Within the monocyte population, we could detect a significant decrease
of not classic CD14+CD16+, and an increase of classic CD14+CD16-, associated with
the course of the treatment. The integrins expression was assessed by evaluating the
Relative Fluorescence Intensity, which allowed to detect significant variations within
all the CD14+ subpopulations and the CD34+ population. Additionally, a patients’ stratification
based on the urinary JCV and BKV DNA excretion was done to define whether the viral
status could affect the natalizumab treatment and viceversa: CD3+ cells relative frequency
increased in patients excreting the viruses, while CD19+ relative frequency decreased.
P38
Digital Droplet PCR for Precise Quantification of Human T-Lymphotropic Virus 1
Breanna Caruso1, Giovanna Brunetto1, Raya Massoud1, Bill Switzer2, Steven Jacobson1
(presenting author: breanna.caruso@nih.gov)
1NIB/NINDS/NIH;
2NCHHSTP/OID/CDC
Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that is the etiologic
agent in a clinical neuromyelopathy known as HTLV-1 associated myelopathy/tropical
spastic paraparesis (HAM/TSP). Quantification of the amount of virus in a patient
samples is critical for monitoring infection, evaluating the efficacy of therapeutic
agents, and assisting with clinical diagnosis. Real-time PCR (qPCR) is the standard
method for determining HTLV-1 proviral load (PVL). However, qPCR is dependent upon
well-defined standards and calibration to a standard curve, precluding precise and
accurate quantification particularly at low cell concentrations. In this study, we
use a third generation PCR technique, digital droplet PCR (ddPCR), which allows for
direct quantification of PVL. DNA samples are partitioned into thousands of nanoliter-sized
droplets, amplified on a thermocycler, analyzed for fluorescent signal, and normalized
to a housekeeping gene. Poisson distribution statistics are used to determine absolute
copy numbers independently of a standard curve. We found that the intra-assay and
inter-assay reliability of ddPCR are robust and more consistent than those of qPCR.
Moreover, ddPCR yields similar patient PVL by quantifying different viral genes. Our
preliminary data suggests ddPCR can also be used to examine viral gene expression,
a key player in the pathogenesis of HAM/TSP and an important parameter to monitor
during therapeutic interventions in this condition. The reliability and precision
of ddPCR for HTLV-1 quantification should be widely acknowledged as it might be an
important tool to further understand the clinical correlates of the viral load in
the context of HAM/TSP and other HTLV-1 related conditions; however, further investigation
is required to determine the efficacy of ddPCR for mRNA analysis.
P39
Involvement of heat shock proteins in resistance to cell death in HIV+ microglia
Paul Castellano, Eliseo Eugenin
(presenting author: castelp1@gsbs.rutgers.edu)
Department of Microbiology and Molecular Genetics, Public Health Research Institute,
Graduate School of Biomedical Sciences, Rutgers University
HIV associated neurocognitive disorder (HAND) is a devastating consequence of HIV
infection in the current antiretroviral therapy (ART) era. The pathogenesis of HAND
is a multifactorial sequence of events including the transmigration of HIV infected
monocytes that cross the blood brain barrier (BBB) resulting in infection of the central
nervous system (CNS) resident cells such as macrophages, microglia, and a small population
of astrocytes. Infection activates inflammation and subsequent cellular dysfunction
and apoptosis. In addition, viral reservoirs are generated within the CNS, and upon
activation, propagate viral infection and inflammation years after primary infection.
Thus, elimination of these cell reservoirs is essential for the eradication of HIV
from the brain and its subsequent affects in pathogenesis of HAND. Our preliminary
data indicates that HIV infected microglia and astrocytes are protected from cell
death despite intracellular pro-apoptotic signaling from mitochondrial dysregulation.
Mitochondrial release of cytochrome c into the cytoplasm is normally induced by pro-apoptotic
stimuli and is followed by cell death. However, infected microglia and astrocytes
resist cell death even when cytochrome c is released from the mitochondria into the
cytoplasm. The mechanism by which HIV protects infected cells from cytoplasmic cytochrome
c is currently unknown, and understanding these mechanisms may yield novel pharmaceutical
targets for the treatment of HAND. Key negative regulators of apoptosis are heat shock
proteins (HSP), which inhibit the pathway by which cytochrome c induces cell death.
Our hypothesis is that HIV infected cells “hijack” heat shock proteins to avoid apoptosis
induced by cytoplasmic cytochrome c. Targeting a pathway utilized specifically by
HIV infected cells will generate a potential drug target for treatment of HAND.
P40
JC virus latency and reactivation in natalizumab-treated MS patients
Spyridon Chalkias1, Xin Dang 1, Evelyn Bord1, Stephanie Batson1, Marion Stein2, Philip
Kinkel2, Jacob Sloane2, Carolina Ionete2, Igor J. Koralnik1
(presenting author: schalkia@bidmc.harvard.edu)
1Center for Virology and Vaccine Research, Division of Infectious Diseases, Beth Israel
Deaconess Medical Center, Harvard Medical School, Boston, MA;
2Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School,
Boston, MA
Background: The risk of JC virus (JCV) reactivation and progressive multifocal encephalopathy
(PML), while on natalizumab, may increase with duration of exposure to the drug. We
sought to determine the prevalence of JCV reactivation and potential changes in JCV-specific
cellular immunity during prolonged treatment.
Methods: We enrolled 39 JCV-seropositive multiple sclerosis (MS) patients, including
32 on natalizumab monotherapy for 18-20 months (n=14), 22-25 months (n=7) and > 36
months (n=11), 2 on interferon-beta monotherapy >36 months and 5 untreated MS patients
as controls. We performed QPCR in CSF, blood and urine for JCV DNA and we determined
JCV specific T-cell responses using enzyme-linked immunospot (ELISpot) and intracellular
cytokine staining (ICS) essays, ex vivo and after in vitro stimulation with JCV peptides.
Results: JCV DNA was detected in the CSF of 3/35 (8.6%) subjects tested (1 in 18-20
and 2 in >36 months on natalizumab), who had no symptoms or MRI lesions consistent
with PML. None of the subjects had JCV DNA in plasma but viruria was detected in 8/39
(20.5%) patients. JCV-specific T cells were detected more frequently by ICS than ELISpot
ex vivo [26/39(66.7%) vs 6/39(15.3%);p<0.001] and after in vitro stimulation [39/39
(100%) vs 33/38 tested (86.8%);p=0.03]. Both assays were significantly more frequently
positive after in vitro stimulation than ex vivo (p<0.001). JCV-specific CD4+ T-cells
were more frequently detected than CD8+ T-cells after in vitro stimulation [39/39(100%)
vs 34/39(87.2%);p=0.05]. No differences in TΓÇôcell responses were observed between
patients with and without viruria. Testing of JCV DNA in peripheral blood mononuclear
cells is in progress.
Conclusions: Asymptomatic JCV reactivation may occur in CSF of natalizumab-treated
MS patients. In vitro stimulation with JCV peptides allows enhanced detection of JCV-specific
cellular immunity which is highly prevalent in MS patients regardless of treatment,
and is mediated by CD4+ and CD8+ T-cells.
P41
MicroRNA Profile Changes in Primary Human Microglia Post Human Immunodeficiency Virus-1
(HIV-1) Infection and HIV-1 Envelope Protein Exposure
Natalie Chen, Gokul Swaminathan, Julio Martin-Garcia
(presenting author: chennata@gmail.com)
Department of Microbiology and Immunology, Center for Molecular Virology & Translational
Neuroscience, Drexel University College of Medicine
Microglial cells, the resident macrophages of the central nervous system (CNS), play
important roles in maintaining homeostasis in the CNS and in the pathogenesis of HIV-associated
neurological disorders (HAND). Brain imaging reveals increased microglial activation
in patients with chronic HIV-1 infection, and in vitro studies suggest that altered
microglial function may affect neuronal health. The role of miRNAs in regulating microglia
activities in the context of HAND remains to be defined, although altered miRNA profiles
in blood mononuclear cells of patients with chronic HIV-1 infection have been reported.
Furthermore, differential expression of selected miRNAs in the cerebrospinal fluid
of HIV+ patients with and without encephalitis has been demonstrated. To date, no
study has profiled miRNA changes in primary human microglia upon HIV-1 infection and
exposure to HIV-1 envelope proteins. To address this, we infected primary human fetal
microglia (PHFM) with macrophage-tropic HIV-1 pseudotype (BAL), vesicular stomatitis
virus-G pseudotype (VSV-G) or incubated PHFM with HIV-1 envelope glycoprotein gp120.
RNAs was extracted from virus/envelope treated cells and mock treated cells at various
time points. ABI Openarray assay was performed on the extracted RNAs to profile miRNA
changes, and these were also examined using TaqMan quantitative Real-Time PCR (qRT-PCR).
BAL infection resulted in 4-fold increase in miR-146a levels at 48hr post infection
and gp120 exposure did not have significant effect on miR-146a levels. In future studies,
we will elucidate whether observed changes in miRNA levels contribute to altered microglial
function during the course of HIV infection in the CNS.
P42
Changes to the Genome of Theiler’s Virus Can Alter the Pathogenesis Leading to Immunosuppression
Matthew Cusick, Jane Libbey, Robert Fujinami
(presenting author: matthew.cusick@path.utah.edu)
University of Utah
Viruses, such as human immunodeficiency virus, hepatitis A, poliovirus, coxsackievirus
B3, and foot-and-mouth disease virus, use a variety of mechanisms to suppress the
human immune system in order to evade clearance by the host. Therefore, investigating
how a few changes in the viral genome of a non-lethal virus can lead to an alteration
in disease, from survivable to immunosuppression and death, would provide valuable
information into viral pathogenesis. In this study we provide a model of a murine
virus [DA stain of Theiler’s murine encephalomyelitis virus (TMEV)] which in its natural
host (the mouse) causes, when administered via a peripheral route (intraperitoneal
- i.p.), an asymptomatic infection followed by viral clearance with lasting immunity.
C57BL/6 mice infected with the DA strain of virus via the intracerebral (i.c.) route
develop acute encephalitis; mice survive the acute disease and clear the virus. A
mutant of the DA strain of TMEV was inadvertently created as a result of transcription
error(s) by the T7 polymerase while using a modified full-length infectious cDNA clone
of the DA virus as template. The H101 mutant virus encodes a point mutation (T101I)
in VP1 (called H101). In addition, in sequencing the H101 viral genome, there were
also several nucleotide substitutions in the 5’ untranslated region as well as additional
amino acid substitutions in the capsid protein coding region, suggesting that there
are a number of perturbations in the viral genome. C57BL/6 mice infected with the
H101 mutant virus via a peripheral route become immunosuppressed by killing T cells.
This study provides experimental evidence that a virus that is cleared by its natural
host can become lethal due to just a few changes in the viral genome.
P43
CCAAT Enhancer Binding Protein and Nuclear Factor of Activated T Cells Regulate HIV-1
LTR via a Novel Conserved Downstream Site in Cells of the Monocyte-Macrophage Lineage
Satinder Dahiya, Michael Nonnemacher, Brian Wigdahl
(presenting author: sd469@drexel.edu)
Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine
Transcriptional control of the human immunodeficiency virus type 1 (HIV-1) promoter
or long terminal repeat (LTR), is achieved by interactions with cis-acting elements
present both upstream and downstream of the transcriptional start site. In silico
transcription factor binding analysis of the HIV-1 subtype B LAI LTR revealed a potential
downstream CCAAT enhancer binding protein (C/EBP) binding site. This element is present
immediately downstream of nucleosome 1 in the viral promoter, which suggested that
it may have a functional role in transcriptional regulation because remodeling of
this nucleosome is a crucial event in transcription in productively infected cells.
Analysis across HIV-1 subtypes has indicated that the LTR downstream C/EBP binding
site displayed a high degree of conservation in terms of both nucleotide sequence
and physical location in the LTR. Interestingly, this element overlaps with a previously
identified AP3-like element, which has been shown to bind members of the nuclear factor
of activated T cells (NFAT) family of proteins. NFAT c2 exhibited a higher relative
affinity for this element as compared with members of the C/EBP family (C/EBP alpha
and beta). The downstream C/EBP element was able to compete efficiently with the low-affinity
upstream C/EBP binding site I with respect to C/EBP binding, suggesting utilization
of both NFAT and C/EBP. Moreover, cyclosporine A treatment, which has been shown to
prevent dephosphorylation and nuclear translocation of NFAT isoforms, resulted in
enhanced C/EBP beta binding. A downstream C/EBP binding site knockout mutant also
demonstrated reduced LTR-driven transcription under both basal and interleukin-6-stimulated
conditions, indicating that interactions at this site positively regulate HIV-1 transcription
in cells of the monocyte-macrophage lineage. This work is supported by NIH/NINDS R01
NS32092, NIDA R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P44
Longitudinal analysis of the impact of substance abuse on HIV-1-associated neurological
decline in the DrexelMed HIV/AIDS Genetic Analysis Cohort
William Dampier1, Nirzari Parikh1, Michael Nonnemacher1, Vanessa Pirrone1, Jean Williams1,
Benjamas Aiamkitsumrit1, Shendra Passic1, Wen Zhong1, Brian Moldover2, Rui Feng3,
Jeffrey Jacobson4, Brian Wigdahl1
(presenting author: wnd22@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2B-Tech Consulting, Ltd;
3Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistics, University of Pennsylvania School of Medicine;
4Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine
The DrexelMed HIV/AIDS Genetic Analysis Cohort in Philadelphia, PA currently follows
over 500 HIV-1-infected individuals longitudinally to examine viral genetic variation
in conjunction with clinical and neurological disease severity and the impact of comorbidities
like drugs of abuse on these parameters. This substantial cohort allows for a unique
analysis of neurological decline in the context of substance abuse. Along with standard
clinical parameters such as CD4+/CD8+ T-cell count, viral load measurements, and drug
testing, a modified version of the Hopkin’s Dementia Bedside Test (TMHDS) was performed.
Due to the longitudinal nature of the DrexelMed cohort, it has been possible to investigate
the complex effects of drug abuse on HIV-1-infected individuals. The complex nature
of drug abuse in an urban cohort complicates the traditional method of grouping patients
into mono-use categories. Instead we abandoned these traditional methods in favor
of Markov Chains. These chains model patients as “stateful machines” in which the
change in HIVD score at the next visit is a function of parameters measured at the
current visit. The current viral load, CD4+/CD8+ T-cell counts, adherence to HAART
therapy, and drug testing results were included in the model. Cocaine use was found
to have a detrimental effect on the TMHDS score while cannabinoids exhibited a small
but seemingly measurable protective effect. As this study progresses, we will work
to develop neurological testing protocols with increased sensitivity that will allow
us to better understand the effects of poly-abuse on neurocognitive decline. This
work is supported by NIH/NINDS R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177, and
NIMH T32 MH079785.
P45
Natalizumab-associated JC virus granule cell neuronopathy complicated by immune reconstitution
inflammatory syndrome in a patient with multiple sclerosis
Xin Dang1, Shruti Agnihotri1, Evelyn Bord1, Jonathan Carter2, Igor Koralnik1
(presenting author: xdang@bidmc.harvard.edu)
1Division of NeuroVirology, Department of Neurology, Center for Virus and Vaccine
Research, Department of Medicine, Beth Isreal Deaconess Medical Center;
2Department of Neurology, Mayo Clinic Arizona
Background: Natalizumab blocks trafficking of leukocytes to the brain, and has been
associated with reactivation of JC virus(JCV) leading to progressive multifocal leukoencephalopathy
(PML) in multiple sclerosis (MS) patients. JCV can also infect cerebellar granule
cell neurons resulting in JCVgranule cell neuronopathy (JCV GCN).
Case report: A 32 year-old JCV-seropositive gentleman with MS who received 63 infusions
of natalizumab monotherapy presented with changes in his handwriting, speech and gait.
Initial MRI did not identify any new lesions. CSF JCV PCR was positive 3 months after
symptoms onset and subsequent MRIs showed progressive cerebellar atrophy. Natalizumab
was discontinued and he received plasma exchange and IV steroids, followed by mirtazapine.
He developed progressive hyperintensities in the pons and cerebellar peduncles on
T2-weighted images on MRI, and contrast-enhancement, suggestive of immune reconstitution
inflammatory syndrome (IRIS). CSF JC viral load was 16,489 copies/ml. Intracellular
cytokine staining showed a robust cellular immune response mediated by JCV-specific
CD4+ and CD8+ T-cells.
Molecular analysis of CSF JCV strains revealed three different mutations in the C-terminus
of the VP1 gene, consistent with previously reported GCN type JCV strains. He was
treated with IV steroids, followed by a decrease in contrast enhancement in his cerebellum
on MRI. His neurological function stabilized concomitant with negative JCV CSF PCR.
Repeat MRI/MR spectroscopy showed stable low grade cerebellar enhancement and a Lip1/Cr
ratio <1.0 in cerebellum consistent with subsiding IRIS. However, there were more
extensive T2 signal changes in the pons and cerebellar peduncles.
Conclusion: This is the second patient with natalizumab-associated JCV GCN IRIS. Contrary
to the initial case-report 1, 2, this patient developed contrast enhancement in the
cerebellar cortex on MRI and extension of the lesions in the cerebellar white matter
and pons. JCV GCN is a novel complication of natalizumab therapy and should be suspected
in any MS patient developing cerebellar dysfunction.
P46
Innate immunity regulates blood brain barrier function during West Nile virus encephalitis
via type-I interferon.
Brian Daniels1, Lillian Cruz-Orengo2, David Holman2, Robyn Klein1-3
(presenting author: brian.daniels@wustl.edu)
1Department of Anatomy and Neurobiology, Washington University School of Medicine;
2Department of Internal Medicine, Washington University School of Medicine;
3Department Pathology and Immunology, Washington University School of Medicine
West Nile virus (WNV) is a mosquito-borne pathogen capable of infecting the central
nervous system (CNS) and causing lethal encephalitis in human hosts. However, the
mechanisms by which WNV accesses and infects the CNS are mysterious, as pathogens
are normally excluded from the CNS by the blood brain barrier (BBB). The BBB is a
complex assortment of vascular endothelial cells joined by tight junctions that prevent
circulating pathogens from escaping the vasculature in the CNS and accessing parenchymal
nervous tissue. Detection of WNV in the circulation by host tissues elicits innate
immune responses, including the production of type-I interferon (IFN), which has been
shown to promote and preserve BBB integrity in the context of CNS autoimmunity. Here,
we utilize an in vitro model of the BBB to demonstrate that pathogen detection of
WNV in the vascular endothelia of the BBB promotes barrier integrity via type-I IFN,
rescuing barrier dysregulation by inflammatory cytokines and limiting transendothelial
trafficking of WNV via modulation of endothelial Rho-GTPase signaling. Similarly,
mice with diminished type-I IFN signaling (IFNAR-/-, IRF7-/-) exhibit enhanced BBB
permeability after peripheral WNV infection and earlier entry of virus into the CNS.
Together, these data are the first to show a functional role for type-I IFN at the
BBB in the context of a neurotropic viral infection, suggesting new roles for type-I
IFN in the treatment of neuroinflammatory and infectious diseases.
P47
Molecular Regulation of JCV Gene Expression by Immune mediators in Glial Cells
Francesca De Simone, Onder Otlu, Ilker Sariyer
(presenting author: isariyer@temple.edu)
Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine, Philadelphia, PA
Immunosuppression caused by pathologic agents such as HIV-AIDS or by regiments used
for the treatment of different types of diseases such as multiple sclerosis puts patients
in high risk group of developing progressive multifocal leukoencephalopathy (PML),
a fatal demyelinating disease of the white matter caused by human neurotropic polyomavirus,
JCV. The virus establishes a latent infection and reactivates under immunosuppressive
conditions with an unknown mechanism. Immune-dependent reactivation of JCV and the
development of the disease suggest that JCV gene expression and replication are tightly
controlled by the immune system in latently infected cells potentially mediated by
immune mediators at the tissue level. We have developed an in vitro model to study
the role of immune-mediators secreted by active immune cells in the viral gene expression
and replication. PMBSc from peripheral blood were cultured and activated in tissue
culture and conditioned media (CM) was collected to treat glial cells infected with
JCV. A series of experiments suggested that CM from induced but not from un-induced
PBMCs inhibited the propagation of the virus suggesting immune-mediated control of
viral life cycle. Further studies revealed that soluble immune mediators from PBMCs
possessed a dual control on T-antigen expression at transcriptional and posttranscriptional
level. We recently identified the alternative splicing factor, SF2/ASF, as a potential
regulator of JCV as its overexpression in glial cells strongly suppresses viral gene
expression and replication. Results from our preliminary studies suggest that immune
mediators secreted from PBMCs induce the expression of SF2/ASF, and inhibit the replication
of JCV. These observations suggest operation of a novel immune signaling pathway between
peripheral immune cells and glial cells that controls the immediate early stage of
JCV gene expression during the course of viral reactivation.
This work was made possible by grants awarded by NIH to IKS.
P48
Lack of correlation between JC Virus urinary shedding and seropositivity in Multiple
Sclerosis patients treated with natalizumab
Serena Delbue1, Francesca Elia2, Camilla Carloni1, Valentina Pecchenini1, Silvia Carluccio1,
Diego Franciotta3, Matteo Gastaldi3, Pasquale Ferrante1
(presenting author: pasquale.ferrante@unimi.it)
1Department of Biomedical, Surgical and Dental Sciences, University of Milano, Milano;
2Fondazione Ettore Sansavini, Health Science Foundation, Lugo;
3Department of General Neurology, National Neurological Institute C. Mondino, Pavia
Background: The efficacy of natalizumab in the treatment of multiple sclerosis (MS)
is high, but 372 cases of progressive multifocal leukoencephalopathy (PML) have been
reported among treated patients. The risk of PML is calculated by assessing JC virus
(JCV) seropositivity in natalizumab-treated MS patients.
Methods: In total, 42 natalizumab-treated MS patients and 45 MS patients treated with
conventional therapies (controls) were enrolled in a case-control study. Urine and
blood samples were collected monthly for up to 60 months from the natalizumab-treated
patients and once from the controls; these samples were used to monitor JCV and BK
virus (BKV) replication. Viral loads were assessed using quantitative real-time PCR
(qPCR) assays, and serum anti-JCV antibodies were measured with the Stratify and/or
Stratify DxSelect tests.
Results: JCV DNA was found in 229 of 741 (30%) urine samples overall and at least
once in 21 of 42 (50%) urine samples from natalizumab-treated patients. However, JCV
DNA was also detected in 11 of 45 (24.4%) control samples (p<0.05). In the natalizumab-treated
patients, JCV DNA shedding in the urine significantly increased up to month 24 of
treatment (45.2%, R2=0.86). BKV was found in the urine of 59.5% (25/42) natalizumab-treated
patients and in a total of 126 of 741 (17.1%) urine samples overall. In contrast,
viral genomes were not detected in the blood. Additionally, JCV viruria and seropositivity
did not correlate with each other, and three viruric patients were seronegative according
to the Stratify and Stratify DxSelect tests.
Conclusions: Our findings demonstrate that natalizumab therapy may increase the rate
of JCV urinary shedding and that the correct identification of JCV carriers cannot
solely rely on serological tests. To correctly stratify patients by the risk of PML,
monitoring the presence of JCV DNA in the urine is needed.
P49
Role of exosomes from HIV-1 infected cells in neurodegeneration
Satish Deshmane, Paul Pozniak, Kamel Khalili, Prasun Datta
(presenting author: sld907@temple.edu)
Department of Neuroscience, Comprehensive NeuroAIDS Center, Temple University
Neuronal dysfunction and degeneration are the causative mechanisms for the HIV-Associated
Neurocognitive Disorders (HAND) in the era of highly active antiretroviral therapy
(HAART). In this study we assessed the effects of exosomes derived from PMA activated
promonocytic cells U1 that are latently infected with HIV-1 on human fetal neurons.
Exosomes secreted by U1 cells were found to be enriched in as many as 20 micro-RNAS,
potentially affecting expression of several essential genes in neurons. Neuronal cultures
treated with U1 exosomes were found to be severely compromised in their ability to
maintain existing neuronal network as well as their ability to form neurites in a
scratch-wound assay. Neuronal cultures treated with U1 derived exosomes showed low
levels of superoxide dismutase activity indicating heightened oxidative stress. Analysis
of the cytokine/chemokine profile in U1 exosomes revealed attenuated levels of MCP-1,
MIP-1alpha, MIF, RANTES and IL-4 in comparison to U937 derived exosomes. Similar analysis
of medium obtained from exosome-treated neuronal cells revealed increased expression
of MCP-2, MCP-3, MIP-3alpha, NAP-2 and uPAR in cultures treated with U937 exosomes.
Furthermore, we also analyzed the phosphorylation status of mitogen-activated protein
kinases (MAPKs) and other intracellular proteins and kinases, such as Akt, GSK-3,
p70S6 Kinase, mTOR, p53, and CREB that are important regulators of signal transduction
and cell proliferation, in neurons treated with U1 exosomes using antibody arrays.
These studies demonstrated that many signaling pathways that are known to be crucial
for cell survival such as Akt, mTOR, PI3K were found to be negatively affected in
U1 exosome treated neurons. Collectively, these observations demonstrate that exosomes
derived from HIV-1 infected cell can cause neuronal dysfunction and degeneration by
targeting multiple pathways. Supported by Comprehensive NeuroAIDS center (CNAC) developmental
core grant to PKD. The study also utilized services offered by core facilities of
CNAC (NIMH Grant#P30MH092177) to KK.
P50
Role of post translational modification of RelA in miR-146a gene regulation in astrocyte
by HIV-1 induced cytokine IL-1 beta
Satish Deshmane, Sagarika Banerjee, Prasun Datta
(presenting author: sld907@temple.edu)
Department of Neuroscience, Comphrehensive NeuroAIDS center, Temple University
Neuroinflammation mediated by pro-inflammatory cytokines such as interleukin (IL)-1
beta induced by HIV-1 infection of macrophages, microglia, and astrocytes in the CNS
play critical role in the pathogenesis of NeuroAIDS. Dysregulation of inflammation-associated
microRNAs such as miR-146a within the brain can accelerate the development of HIV
Associated Neurocognitive Disorders (HAND). Thus, we investigated the role of post-translational
modification of RelA in miR-146a gene regulation by IL-1 beta in human fetal brain
astrocytes and in astroglial cell lines. Our studies demonstrate that IL-1beta-induced
phosphorylation of IKKbeta, IkBalpha and p65 at serine 536 regulate NF-kappaB activation
in human fetal astrocytes and in astroglial cell lines. Additionally, our results
using phosphorylation defective mutants of p65 indicate that phosphorylation status
of serine residues 276 and 536 differentially regulate IL-1beta induced transcriptional
expression of miR-146a. To demonstrate the role of mitogen- and stress-activated protein
kinase1 (MSK1) that phosphorylates S276 in the regulation of mir-146a by IL-1 beta
we employed a pharmacological inhibitor of MSK1, H-89. Our studies demonstrate that
H-89 (5 and 10 microM) dose dependently inhibited miR-146a expression. Collectively,
our observations demonstrate that IL-1beta activates both canonical and noncanonical
NF-kappa B pathways to regulate mir-146a expression in astrocytes. Therefore, pharmacological
inhibitors that target NF-kappa B pathways may have therapeutic potential for the
treatment of neuroinflammation. This work is supported by NIH/NIDA grant to PKD. The
study also utilized services offered by core facilities of the Comprehensive NeuroAIDS
center (CNAC) NIMH Grant # P30MH092177.
P51
A metabolomics approach to the differentiation of cognitive states in HIV-infected
patients
Alex M. Dickens1, Daniel C. Anthony1, Michelle M. Mielke2, Timothy D. W. Claridge3,
Reena Deutsch4, Igor Grant4, Scott Letendre4, Thomas Marcotte4, Norman J. Haughey5
(presenting author: alex.dickens@pharm.ox.ac.uk)
1Department of Pharmacology, University of Oxford;
2Division of Epidemiology, Department of Health Sciences Research, College of Medicine,
Mayo Clinic;
3Department of Chemistry, University of Oxford;
4HIV Neurobehavioral Research Program and Department of Psychiatry, School of Medicine,
University of California;
5Department of Neurology, Johns Hopkins University
Currently, there are no defined surrogate measures to determine which HIV+ patients
are likely to develop cognitive impairment or to track the effectiveness of potential
neurotherapeutics. Here, we analysed CSF samples taken from HIV+ patients with differing
neurocognitive states using 1H-NMR spectroscopy and multivariate analysis to identify
novel metabolomic biomarkers for cognitive impairment. CSF samples from 100 HIV-infected
patients were collected at 2 time points with four distinct neurocognitive states
that were defined by temporal changes in cognitive status. These neurocognitive states
were stably-normal, stably-abnormal, improving, and worsening. 1D-NOESY 1H-NMR spectroscopy
was performed on these samples using a 16.4T NMR system. Multivariate Partial least
squares (PLS) regression models showed significant separations between neurocognitive
states with q2 values = 0.61 (stably-normal), 0.84 (stably-abnormal), 0.47 (worsened)
and 0.52 (improved). The metabolites that underpinned these changes were distinct
in each group, but were generally connected to amino acid, and energy metabolism.
Using a classification and regression tree analysis we identified changes in 5 energy
metabolites (pyroglutamate, citrate, creatine, alanine, and acetate) that were prognostic
indicators for declines in cognitive status (sensitivity 100%, specificity 88%), and
5 metabolites that were prognostic indicators for improved cognitive status (glutamate,
pyroglutamate, creatine, myoinositol, beta-glucose (sensitivity 91%, specificity 92%).
Linear regressions showed that increased levels of specific energy metabolites were
associated with poor performance on tasks that measure executive, learning, recall
and motor functions, but were not related to working memory performance. These findings
suggest that declines in cognitive function are accompanied by a compensatory increase
in specific energy metabolites. CSF levels of these energy metabolites may be useful
surrogate measures for temporal shifts in cognitive status, and reveal new insights
into the neuropathogenesis of HAND.
P52
TLR 2 is required for immune control of acute herpes simplex virus infection
Kevin Egan, Christina Kollias, Brian Wigdahl, Stephen Jennings
(presenting author: kpe23@drexel.edu)
Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine
Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen which causes recurrent
mild orofacial lesions in infected individuals. Acute infection initiates in mucosal
surfaces where the virus replicates within epithelial cells. Following propagation
of virus at the site of infection, innervating sensory neurons are infected and a
latent infection is established which persists for the lifetime of the host. The immune
system is critical for controlling initial virus replication in the periphery and
limiting infiltration into the nervous system. We investigated the mechanism that
immune cells use to detect productive viral replication in the periphery. TLR-2 knockout
(TLR2-/-) mice were more vulnerable to HSV-1-induced mortality than wild-type (WT)
controls. Although natural killer cells were normal, dendritic cell and CD8+ T-cell
activation was impaired in TLR2-/- mice. We observed a minor decrease in CD8+ T-cells
responding to virus infection in the knockout animals, but the responding cells exhibited
impaired production of interferon gamma. Both WT and knockout animals supported comparable
HSV-1 replication in the periphery, but the knockout mice had greater infiltration
into the nervous system and suffered greater mortality. These results demonstrate
the important role of TLR-2 in priming immune cells and control of acute HSV-1 infection.
In the future, we will investigate the role of TLR-2 in maintaining immune control
of HSV-1 latency by CD8+ T-cells. We will confirm that CD8+ T-cells in the trigeminal
ganglia belong to the recently described Tissue Resident Memory (TRM) class of memory
T cells. We will explore the homing mechanisms and proliferative capacity of TRM cells
for the purpose of enhancing CD8+ T-cell levels in the trigeminal ganglia. Increased
presence of CD8+ T-cells is a possible therapeutic treatment option for reducing reactivation
events.
P53
High frequency of HIV-related neurologic complications in a Romanian cohort of children
and young adults infected with subtype F
Luminita Ene1, Dan Duiculescu1, Roxana Radoi1, Gratiela Tardei1, Maria Nica1, Simona
Ruta2, Ronald Ellis3, Igor Grant4, Cristian Achim5
(presenting author: cachim@ucsd.edu)
1"Dr. Victor Babes" Hospital for Infectious and Tropical Diseases;
2“Stefan S. Nicolau” Institute of Virology and “Carol Davila” University of Medicine,
Bucharest;
3Department of Neurosciences, UC San Diego;
4HIV Neurobehavioral Research Program, Department of Psychiatry, UC San Diego;
5Department of Psychiatry, HNRP, UC San Diego
Objective: We studied the frequency and clinical features of HIV-related neurologic
complications in a Romanian cohort of HIV clade F infected subjects.
Design: This is a retrospective longitudinal study of children and adolescents with
HIV associated neurological complications followed between January 1996 and June 2010.
Methods: All patients with HIV encephalopathy (HIVE) or HIV related opportunistic
infections were included. We evaluated demographics, viral load markers and brain
imaging and hystology, to describe the clinical dynamics in this unique cohort.
Results: During the 14.5 year surveillance period a total number of 275 children and
young adolescents were diagnosed with neuroAIDS defining diseases representing 49.2%
out of 559 subjects. Although the number of HIV associated CNS complications decreased
after introduction of cART, the frequency among AIDS defining diseases increased from
44.5% before cART, to 54.1% thereafter. Unique features were observed in PML patients,
including cerebellar and brainstem location of lesions and improved survival in cART
regimens with good cerebrospinal fluid HIV viral control. Furthermore, we describe
a case series of 34 patients diagnosed with a fatal clinical entity: subacute myoclonic
measles encephalitis (SMME) that occurred during two consecutive outbreaks in Romania.
Conclusions: We found a high frequency of HIV-related neurological complications in
a cohort of parenterally infected children that, interestingly, increased in the cART
era. We also describe a new AIDS defining neurologic complication of measles in severe
immunosuppressed children: SMME. The frequency of almost 50% of neurological AIDS
complications suggests a neurotropic potential for HIV clade F.
P54
Correlation of increased CXCL13/IL-21 with intrathecal humoral immune responses to
HTLV-1 in CSF of patients with HAM/TSP
Yoshimi Enose-Akahata, Raya Massoud, Jussi Virtanen, Steven Jacobson
(presenting author: akahatay@ninds.nih.gov)
Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological
Disorders and Stroke, National Institutes of Health
Intrathecal antibody synthesis is a well-documented phenomenon in infectious neurological
diseases as well as in demyelinating diseases. Intrathecal antibody synthesis against
HTLV-1 has been reported in HAM/TSP, but little is known about the role of B cells
and humoral immune responses in the central nervous systems (CNS) of HAM/TSP patients.
Here we demonstrate profiles of HTLV-1-specific antibodies in cerebrospinal fluid
(CSF) of HAM/TSP patients. Of 36 HAM/TSP patients, antibody responses against Gag
and Tax were detected in CSF of all the patients. CSF/Serum anti-Gag antibody ratio
was elevated more than anti-Tax (anti-Gag: mean 1.20, anti-Tax: mean 0.85), and was
significantly correlated with proviral loads in PBMC. More importantly HAM/TSP patients
with lesions or atrophy in spinal cord showed higher CSF/Serum anti-Gag antibody ratio.
Antibody response against Env was detected in CSF of 94.4% of patients, but CSF/serum
anti-Env ratio was significantly lower than those of anti-Gag and anti-Tax (mean 0.18).
Interestingly, CXCL13 (B cell attracting chemokine-1) and IL-21 were increased in
CSF of HAM/TSP patients compared to HTLV-1 positive asymptomatic carriers, which was
associated with higher HTLV-1-specific antibody responses in CSF. In ex vivo experiments,
CD4+ T cells of HAM/TSP patients showed significantly higher IL-21 expression than
those of healthy normal donors. In addition, IL-21 stimulated B cells differentiate
into plasma cells and produce HTLV-1-specific antibodies in the cultured B cell of
HAM/TSP patients. These results highlight the importance of the B cell compartment
in HAM/TSP where production of HTLV-1-specific antibody may be required to control
viral persistence and/or may be associated with HAM/TSP disease progression.
P55
Raltegravir Decreases Interleukin-8 Production in HIV - Infected Microglia
Tatro Erick1, Benchawanna Soontornniyomkij1, Scott Letendre2, Cristian Achim1
(presenting author: etatro@ucsd.edu)
1Department of Psychiatry, University of California San Diego;
2Department of Medicine, Division of Infectious Diseases, University of California
San Diego
Background: Despite successful suppression of HIV-1 replication with combination antiretroviral
therapy, chronic immune activation persists in some patients, a process that may be
mediated through latently infected cells in various compartments, including the central
nervous system. Raltegravir, a potent HIV integrase inhibitor was previously shown
to inhibit immune activation in peripheral blood. The goal of the present study was
to determine how raltegravir influences pro-inflammatory cytokine production in HIV-infected
monocytes, microglia, and assess toxicity in neuron-glia cultures.
Methods: Primary human monocyte derived macrophages and microglia from fetal brain
tissue were grown in culture and infected with m-tropic HIV (BaL). Infected cultures
were treated with 20 nM raltegravir or vehicle (saline). Supernatant was removed periodically
for 9 days and pro-inflammatory cytokines were quantified using Mesoscale Discovery
7-plex platform. Primary neuron-glia cultures were exposed to 0, 20, 100 nM raltegravir
for 7 days, then stained for beta-III tubulin and glial fibrillary acidic protein,
and immunofluorescence quantified.
Results: In both microglia and monocyte derived macrophages, the rate of interleukin-8
secretion was significantly lower for HIV-infected cells treated with raltegravir
(132 pg/d) compared to Control (245 pg/d), HIV-infected (232 pg/d), and raltegravir
alone (268 pg/d), as determined by analysis of covariance and Tukey's Honestly Significant
Difference test; p < 0.001. TNF-alpha, interferon-gamma, IL10, IL12,IL1, and IL6 were
not significantly different. In the neuron-glia cultures, at 20 nM, there was significantly
more beta-III tubulin area. There was a stepwise decrease in GFAP area at 20 and 100
nM raltegravir.
Conclusion: Raltegravir, in the context of HIV infection, leads to diminished production
of the potent pro-inflammatory chemoactractant, IL-8 in both monocytes and microglia.
The data suggest that raltegravir inhibits astrogliosis and may be neuroprotective.
Further study on mechanisms, including NF-kappa B nuclear translocation are underway.
P56
Tunneling nanotubes (TNT) a pathway for HIV trafficking and communication: role in
HIV spread and reactivation
Eliseo Eugenin
(presenting author: eugeniea@umdnj.edu)
Public Health Research Institute anf Rutgers University
Cell to cell communication is essential for development of multicellular systems,
and is coordinated by soluble factors, membrane associated proteins, gap junction
channels and the recently described tunneling nanotubes (TNT). We and others reported
that TNT can be used for pathogens, such as HIV between communicated cells. However,
the characterization of these processes, especially in primary cells, and their role
in HIV infection has not been fully characterized. Our current data indicates that
TNT are composed of several smaller TNT. TNT in macrophages are not continuous tubes,
rather TNT establish contact with others macrophages by a synaptic type of contact.
We identify several blockers of TNT that reduces spread of HIV between HIV infected
and uninfected cells by transfer viral genetic material between communicated cells.
Blocking formation of TNT using mild actin blockers or siRNA reduced the spread of
HIV among connected cells. Thus, we characterize that TNT play a key role in the spread
of HIV among connected cells.
P57
Protective and cytotoxic roles for proinflammatory cytokines in neonatal CNS infections
Kristen N. Fantetti, Priya Ganesan, Apurva Kulkarni, Erica L. Gray, Lauren A. O'Donnell
(presenting author: odonnel6@duq.edu)
Department of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University
Viral infection and inflammation in the central nervous system (CNS) can induce significant
illness and neuropathology, particularly in the very young. Though neonates are capable
of mounting both innate and adaptive immune responses, they are often unable to control
viral infections in the brain and suffer extensive neuronal loss and tissue damage.
In order to study how the neonatal immune response interacts with infected CNS neurons,
our laboratory uses a transgenic mouse model (NSE-CD46) of neuron-restricted measles
virus (MV) infection. NSE-CD46 mice express the human isoform of CD46, a MV receptor,
under the control of the neuron specific enolase (NSE), allowing for infection only
in CNS neurons. Here, we show that the adaptive immune response is detrimental in
neonates during a viral infection in CNS neurons, as neonates lacking T- and B-cells
(CD46+/RAG2-KO mice) survive longer than immunocompetent pups. CD46+/RAG2-KO neonates
also control viral load more effectively than immunocompetent NSE-CD46 neonates. These
results are in contrast to adult NSE-CD46 mice, which survive the infection and clear
the virus from the brain in a T-cell dependent manner, whereas CD46+/RAG2-KO adult
mice succumb to the infection. In addition, neonatal mice that lack interferon-gamma
(IFNg), which is required for viral clearance from the adult brain, lose nestin-positive
precursor cells in contrast to NSE-CD46+ neonates despite higher levels of T-cell
infiltration in CD46+/ IFNg-KO neonates. These findings suggest that certain pro-inflammatory
cytokines can protect neural cells during a neonatal CNS infection, but that the full
adaptive response is associated with greater neuropathology. Current work addresses
defects in the neonatal T-cell response and the potential role of IFNg-producing natural
killer cells in limiting viral spread. Through these studies, we aim to better define
the protective and cytotoxic roles of innate and adaptive immune cells during a neonatal
CNS infection.
P58
Cocaine induces HIV gene expression by activating NF-kB and selective epigenetic modifications
Kalamo Farley1, Nazira El-Hage2, Ryan Fassnacht1, Fatah Kashanchi1, Kurt Hauser2,
Jonathan Karn3, Mudit Tyagi1
(presenting author: tmudit@email.gwu.edu)
1George Washington University;
2Virginia Commonwealth University;
3Case Western reserve University
Injection and non-injection illicit drug use and abuse remain significant cofactors
for HIV infection and transmission. Cocaine is one of the most widely abused drugs
in the United States, which both impair the normal functioning of brain cells and
also activate human immunodeficiency virus (HIV) expression in central nervous system
(CNS). As a result, HIV-infected individuals who abuse cocaine experience more severe
and rapid onset of NeuroAIDS than non-abusing individuals. It has been known that
cocaine affects the expression of numerous cellular genes by modulating various signaling
and epigenetic pathways. Some of those pathways also influence the expression of integrated
HIV proviruses and eventually end up enhancing HIV replication and transmission. It
is known that cocaine activates NF-kappaB, and given the importance of NF-kappaB during
HIV transcription, it is imperative to understand the underlying molecular mechanisms
that ultimately result in the enhanced HIV gene expression. Our results establish
that cocaine activate specific protein kinases, which in turn induce selective posttranslational
modifications in NF-kappaB. To further extend our understanding about the regulation
of HIV gene expression via cocaine induced NF-kappaB systems, we have employed a multi-level
approach to characterize the effect of cocaine on the chromatin state of provirus
by running several ChIP (Chromatin Immunoprecipitation) assays. Overall, our results
demonstrate the exchange of various key epigenetic modifications and associated factors
at HIV LTR following cocaine treatment. In summary, our data provide direct evidence
that cocaine enhances HIV gene expression not only by activating transcription factors
such as NF-kappaB, but also by inducing various selective epigenetic modifications.
These events eventually support the establishment of transcriptionally active chromatin
structure at HIV LTR and facilitate HIV transcription.
P59
Cell culture and bioinformatic identification of putative progressive multifocal leukoencephalopathy
risk factors
Michael Ferenczy1, Kory Johnson2, Eugene Major1
(presenting author: michael.ferenczy@nih.gov)
1Laboratory of Molecular Medicine and Neuroscience, National Institute of Neurological
Disorders and Stroke, National Institutes of Health;
2Bioinformatics Section, National Institute of Neurological Disorders and Stroke,
National Institutes of Health
JC virus (JCV) is the etiological agent of the human CNS demyelinating disease progressive
multifocal leukoencephalopathy (PML). Attempts to identify risk factors for PML are
hampered by the lack of an animal model and the limited cell types in culture that
are susceptible to JCV infection. To understand JCV pathogenesis, it was necessary
to develop a new system to identify transcription regulators important in the JCV
lifecycle and development of PML. Traditional techniques of protein over-expression
and knockdown are hampered by off-target effects when transcription regulators important
in viral gene expression are targeted, limiting the ability to discern direct from
indirect effects (over- or under-expression of genes regulated by the transcription
regulator of interest). Using multiple cell culture models with differing permissiveness
to JCV, cellular gene expression in both uninfected and infected cells was characterized.
Multiple known and novel transcription regulators with potential JCV-regulatory roles
were identified by transcriptome profiling of SV40 T antigen immortalized human fetal
brain cells displaying characteristics of either CNS stem cells or radial glia. Several
of these factors overlapped with factors identified during differentiation of less
permissive human fetal neural progenitor (progenitors) cells to highly permissive
progenitor-derived astrocytes (PDAs). Lymphoid Enhancer Factor 1 (LEF1) was identified
as a potential novel negative regulator of JCV transcription, and potential binding
sites for LEF1 in the JCV regulatory region were identified using computational promoter
analysis. Progenitor-derived neurons (PDNs) and PDAs were used to confirm LEF1 as
important for JCV transcription. Chromatin immunoprecipitation revealed that LEF1
bound the JCV promoter to a greater extent in JCV-repressive neurons than in JCV-permissive
astrocytes. These results demonstrate that human fetal brain derived CNS stem cell
models combined with bioinformatic approaches can facilitate the identification of
factors responsible for JCV multiplication and potential development of PML.
P60
Proinflammatory cytokines and gp120 may contribute to synaptic injury through upregulation
of neuronal ferritin heavy chain in HIV patients
Lindsay Festa1, Chris Gutoskey2, Brenna Duffy2, Barry Waterhouse2, Olimpia Meucci3
(presenting author: lkf43@drexel.edu)
1Department of Pharmacology & Physiology, Drexel University College of Medicine;
2Department of Neurobiology & Anatomy, Drexel University College of Medicine;
3Departments of Pharmacology & Physiology and Microbiology & Immunology, Drexel University
College of Medicine
The molecular mechanisms involved in HIV-induced synaptodendritic injury, the structural
basis for HIV-associated neurocognitive disorders, have yet to be fully elucidated.
In this study, we propose that HIV proteins and inflammatory cytokines induce dendritic
injury by altering the neuronal expression of the protein ferritin heavy chain (FHC),
a known negative regulator of the CXCL12/CXCR4 signaling pair. Previous work from
our lab suggests the importance of CXCL12 in increasing dendritic spine density, as
well as modulating the expression of specific glutamate receptor subunits (NR2B).
Additionally, we have found that opiates, including morphine, can negatively regulate
CXCR4 signaling through FHC. In vivo data from brain tissue of HIV+/drug abusers (and
SIV-infected/morphine-treated macaques) show an increase in neuronal FHC and a subsequent
decrease in CXCR4 activation (Ser339 phosphorylation). Thus, we sought to investigate
whether components of HIV infection could modulate FHC. Our results suggest that TNF-alpha
and IL-1 beta, as well as the HIV envelope glycoprotein gp120, upregulate FHC in neurons.
Both of the cytokines altered neuronal FHC in the presence or absence of glia; however,
gp120 (X4-or R5-using) only caused significant increases in neuronal/glial bilaminar
co-cultures, suggesting that glia are required for the changes in FHC protein levels
by gp120. In support of this, the presence of an IL-1 beta neutralizing antibody (or
receptor antagonist) in gp120-treated bilaminar cultures abrogated this effect. In
two in vivo models of HIV infection (gp120-ICV injected and HIV-Tg rats), we saw a
significant reduction in cortical neuron dendritic spine density compared to age-matched
controls. Overall, these studies suggest that the effects of gp120, proinflammatory
cytokines, and opiates may converge on dendritic spines, through FHC, and augment
synaptic injury in HIV/drug abuse patients.
P61
Screening for neutral sphingomyelinase inhibitors as a novel target in human immunodeficiency
virus-1 associated neurocognitive disorders
Mariana Figuera Losada1, Norman Haughey2, Camilo Rojas1, Barbara S. Slusher1
(presenting author: mfiguer8@jhmi.edu)
1Brain Science Institute. NeuroTranslational Drug Discovery Program. Department of
Neurology. Johns Hopkins University. School of Medicine;
2Richard T. Johnson Division of Neuroimmunology and Neurological Infections Department
of Neurology. Johns Hopkins University. School of Medicine
Perturbations in brain lipid metabolism with accumulation of the bioactive lipid ceramide
occur early in the course of human immunodeficiency virus 1 (HIV-1)-associated neurocognitive
disorders (HAND). Elevations of ceramide are thought to contribute to neuronal dysfunction
through biophysical effects that alter membrane excitability and molecular response
to stress. Ceramide can be rapidly generated in response to inflammatory stimuli and
by the HIV-1 coat protein gp120 through actions mediated by the sphingomyelin phosphodiesterase
neutral sphingomyelinase 2 (nSMase2). Expression and activity of nSMase2 is elevated
in brain tissues from HIV-1 infected patients in conjunction with cognitive impairment,
suggesting that inhibition of nSMase2 may preserve neuronal function by preventing
increases in ceramide. Indeed, both chemical and genetic modulation of nSMase2 expression
or activity are neuroprotective, making this enzyme an attractive therapeutic target.
There are a few known inhibitors of nSMase2 that include natural products and small
molecules, but these compounds lack specificity, are insoluble and/or exhibit low
potency. To identify novel inhibitors specific against human nSMase2, we screened
pharmacological active compounds, approved drugs, and inhibitors of acid sphingomyelinase
in 384-well format. Enzyme activity was monitored as increases in the fluorescence
emission of a product generated after three consecutive coupled reactions that involved
alkaline phosphatase, choline oxidase, and horseradish peroxidase. Hits were confirmed
using a direct assay with 14C-labeled sphingomyelin (SM) as substrate. Several inhibitors
with low micromolar potency were identified from distinct chemical series. The identified
compounds are being optimized in structure-activity relationship studies. Small molecule
inhibitors of nSMase2 may be useful therapeutic agents that could dampen the neuromolecular
response to HIV-1-infection and associated inflammation.
P62
Development of microglial activation phenotypic assays as a tool to screen therapeutic
agents for neuroAIDS and other neuroinflammatory disorders
Mariana Figuera Losada, Camilo Rojas, Barbara S. Slusher
(presenting author: mfiguer8@jhmi.edu)
Johns Hopkins University
The brains of human immunodeficiency virus-1 (HIV-1) patients show signs of chronic
inflammation including microglia activation which, in part, leads to neurodegeneration
and the manifestation of HIV-1-associated neurocognitive disorders (HAND). Activated
microglia and macrophages release excess glutamate which causes excitotoxicity that
ultimately results in neuronal dysfunction and death. Two proteins, the cystine/glutamate
antiporter (xCT), and the phosphate-activated glutaminase, are thought to be partially
responsible for the excess glutamate released from activated microglia. xCT is a sodium
independent amino acid transporter that imports extracellular cystine and exports
intracellular glutamate. Glutaminase is a mitochondrial enzyme that catalyzes the
production of glutamate from glutamine. Both have shown increased activity and/or
expression levels following infection of microglia or macrophages with HIV-1, or activation
with the viral protein Tat. We developed a cell-based phenotypic assay in 96-well
format to screen novel xCT and glutaminase compounds for their ability to inhibit
glutamate release from lipopolysaccharides (LPS)-activated microglia. Primary microglia
obtained from newborn rats cultured for 10-21 days were treated with 1-1000 ng/mL
LPS, which induced the production/release of glutamate in a dose-dependent manner
(2-20 fold increase in extracellular glutamate). Response was time- (16-24 h) and
cell number-dependent (10,000-50,000 cells/well). The prototype xCT inhibitor erastin
and the glutaminase inhibitor DON showed dose dependent inhibition of glutamate release/production
with EC50 values of 14 ± 3 nM and 1.5 ± 0.4 microM, respectively. Commensurate with
its weaker xCT inhibitory capacity, sulfasalazine was significantly less potent than
erastin (362 ± 60 nM). Phenotypic assays following excess glutamate release induced
by microglia activation represent a novel way to screen for agents to treat neuroAIDS
and other neuroinflammatory disorders.
P63
EFFECTS OF HIV-1 TAT AND MORPHINE ON THE BIOPHYSICAL PROPERTIES OF SODIUM CHANNELS
Sylvia Fitting1, Joy Ngwainmbi1, Pamela Knapp2, Kurt Hauser1, Hamid Akbarali1
(presenting author: sfitting@vcu.edu)
1Dept. Pharmacol. & Toxicol., Coll. of Medicine, Virginia Commonwealth Univ.;
2Dept. Anat. & Neurobiol., Coll. of Medicine, Virginia Commonwealth Univ.
Human immunodeficiency virus (HIV)-infection continues to be a major clinical manifestation
in the combination antiretroviral therapy era (cART), that is enhanced in opioid-drug
abusers. The gastrointestinal (GI) mucosa plays a major role in HIV-infection as HIV
is mostly transmitted across mucosal surfaces. The enteric nervous system (ENS) controls
several GI processes including motility and secretion which are specifically affected
in HIV-infected patients. Morphine and other opioids directly affect the ENS, causing
severe constipation. Because the virus does not infect neurons, it is suggested that
viral toxins, such as Tat, modulate neuronal function in HIV-1-infected patients.
Tat has been shown to increase neuronal excitability but not much is known about effects
of Tat on enteric neurons in combination with drug abuse. Recent experimental studies
in our lab have shown that Tat increases enteric neuronal excitability by shifting
the voltage-dependence of activation of sodium channels to more negative potentials.
In contrast, morphine alone decreases the availability of sodium channels in enteric
neurons reducing excitability. Voltage gated sodium channels (VGSCs) are responsible
for the generation and propagation of action potentials in neurons. In order to determine
the effects of Tat (100 nM) in combination with morphine (0.3 uM, 3 uM) on the voltage
dependence of steady-state activation/inactivation of sodium channels, we used a double-pulse
protocol in which a variable conditioning pulse was applied from -100 mV to +50 mV
in 10 mV steps for 50 ms followed by a test pulse. In Tat-treated neurons, the sensitivity
to morphine was significantly enhanced. The V0.5 for steady-state inactivation was
shifted in Tat-treated neurons at 0.3 uM morphine with 50% decrease in maximal availability
at -100 mV. Morphine did not alter the steady-state activation. Taken together, data
suggest that Tat increases the sensitivity to morphine in enteric neurons that may
exacerbate the deleterious effects of morphine on GI motility.
P64
Interferon-alpha is Toxic to Neurons
Cari Fritz-French1, William Tyor2
(presenting author: cfritzf@emory.edu)
1Neurology Department, Emory University;
2Department of Neurology, Emory University School of Medicine
Elevated levels of interferon-alpha (IFNalpha) in the central nervous system (CNS)
are linked to cognitive dysfunction in patients with inflammatory CNS diseases such
as HIV-associated dementia. Previous studies showed that IFNalpha treatment of neuronal
cultures caused a dose dependent decrease in dendritic branching and length, that
was prevented after pre-treatment with IFNalpha neutralizing antibodies. Antagonists
to NDMA receptor were also found to be partially protective against IFNalpha induced
neurotoxicity. To begin to determine the mechanism of IFNalpha induced neurotoxicity,
the cell signaling pathway involving IFNalpha receptor (IFNAR) was evaluated. We demonstrate
increased interferon stimulating gene 15 (ISG15) expression, an indicator for JAK-STAT
cascade activation, after IFNalpha stimulation. Inhibiting IFNAR was found to partially
protect neurons from IFNalpha neurotoxicity, but not as efficiently as neutralizing
antibodies to IFNalpha. Our preliminary studies suggest that IFNalpha is in part acting
through its receptor as well as NMDAR to reduce dendritic arborization in neurons.
Further studies are needed to determine what other signaling pathways may be involved
in IFNalpha induced neurotoxicity. Determining the mechanism of IFNalpha neurotoxicity
could lead to therapies for cognitive dysfunction during neuroinflammation.
P65
DOPAMINE RECEPTOR ACTIVATION INCREASES SUSCEPTIBILITY OF MACROPHAGES TO HIV ENTRY,
INCREASING HIV REPLICATION AND CONTRIBUTING TO HIV NEUROPATHOGENESIS
Peter J Gaskill1, Joan W Berman2
(presenting author: peter.gaskill@einstein.yu.edu)
1Department of Pathology, Albert Einstein College of Medicine;
2Departments of Pathology and Microbiology & Immunology, Albert Einstein College of
Medicine
Macrophages are one of the principle cell types infected with HIV, and the primary
source of virus in many tissues, including the CNS. Within the brain, macrophages
are exposed to the neurotransmitter dopamine. Dopamine is elevated by the use of drugs
of abuse such as cocaine and methamphetamine. We showed previously that macrophages
express dopamine receptors and other dopaminergic proteins, and that exposure to dopamine
increases HIV replication in macrophages and alters their cytokine production and
MAPK signaling. Our current data demonstrate that the dopamine mediated increase in
HIV replication is due to an increase in the ability of HIV to enter macrophages.
This effect is dose dependent, occurring at greater than 10 nM dopamine, and is not
affected by dopamine metabolites. A pan-dopamine receptor antagonist abrogated the
effect, indicating that dopamine receptor activation is necessary for increased entry.
Infection in the presence of D1-like or D2-like dopamine receptor agonists shows that
the increase can be induced by activation of both dopamine receptor subtypes. Antagonizing
CCR5 with TAK779 completely blocks entry, indicating that dopamine mediates is effects
through the CCR5 entry process. However, the increased susceptibility to entry is
not due to an increase in surface CCR5. These data demonstrate that the macrophage
dopaminergic system plays an important role in HIV infection of these cells. The development
of neuroinflammation and HAND may be accelerated by the effects of dopamine on macrophages,
and that these effects maybe exacerbated by drug abuse. In addition, although different
drugs of abuse act through distinct pharmacologic mechanisms, dopamine mediates the
addictive and reinforcing effects of many drugs of abuse and may be a common mechanism
by which drugs of abuse contribute to HIV associated neuropathogenesis.
P66
High expression of interleukin 10 and interferon regulatory factor 4 are correlated
with integrated HIV DNA in brain neocortex
Benjamin Gelman1, Joshua Lisinicchia1, Tetyana Buzhdygan1, Vipulkumar Patel1 Tyler
Clement1, Dennis Kolson2, Kristofer Jennings3
(presenting author: bgelman@utmb.edu)
1Departments of Pathology and Neuroscience and Cell Biology, University of Texas Medical
Branch, Galveston, TX;
2Department of Neurology, University of Pennsylvania, Philadelphia, PA;
3Department of Preventive Medicine and Community Health
HIV DNA that is integrated into human genomic DNA (HIVint) may become transcriptionally
repressed and immunologically inert in infected people in whom virus replication is
suppressed with highly active antiretroviral therapy (HAART). The “latent” pool of
HIVint represents a key obstacle to curing HIV infection because it re-seeds the body
with replicating HIV when HAART is stopped. Little is known about the neuroimmunological
factors involved in supporting the latent pool of HIVint in the brain. We measured
HIVint in genomic DNA extracted from the frontal neocortex of 40 HIV infected patients
using the O’Doherty Alu-Gag two-step assay. Cases were divided into two equal groups
having either a high proportion of HIVint (> 3% of the replication rate in brain)
versus low (< 3%). The groups had equivalent rates of HIV transcription (HIV RNA load)
in the brain specimens. A panel of neuroimmune marker mRNAs was quantified using qPCR
in the groups. The group with high HIVint had significantly greater expression of
interleukin 10 (IL10) and interferon regulatory factor 4 (IRF4) mRNAs. Several other
neuroimmunological marker mRNAs were not significantly different. These two proteins
are associated with in vitro polarization of macrophages towards M2 phenotypes. When
typical M2 marker mRNAs including CD163 were assayed, they were not expressed at significantly
higher rates in the specimens with high HIVint. Conclusion: High HIVint in the brain
is associated with IL10 and IRF4 expression, which play key roles in M2 macrophage
polarization. We suggest that HIVint accumulates preferentially in a numerically minute
subtype of M2 polarized macrophage in the brain. To identify the cellular sources
of latent HIV in the brain, we are screening specimens for M2 surface markers that
specifically segregate with high HIVint load.
P67
Higher Levels of Plasma Soluble Insulin-Like Growth Factor-1 Receptor are Associated
with Severity of HAND in HIV-seropositive Women
Yamil Gerena1, Raissa Menendez-Delmestre2, Richard Skolasky3, Rosa Hechavarria4, Sebastian
Perez5, Claudia Hilera6, Claribel Gonzalez2, Avindra Nath7, Valerie Wojna8
(presenting author: yamil.gerena@upr.edu)
1Departments of Pharmaceutical Sciences and Pharmacology, NeuroAIDS Research Program,
University of Puerto Rico-Medical Sciences Campus;
2NeuroAIDS Research Program, University of Puerto Rico-Medical Sciences Campus;
3Department of Orthopaedic Surgery, John Hopkins University;
4Department of Physical Medicine and Rehabilitation, NeuroAIDS Research Program, University
of Puerto Rico-Medical Sciences Campus;
5School of Medicine, University of Puerto Rico-Medical Sciences Campus;
6Department of Biology, University of Puerto Rico-Rio Piedras Campus;
7NIH, National Institute of Neurological Disorders and Stroke;
8Department of Internal Medicine, Neurology Division, NeuroAIDS Research Program,
University of Puerto Rico-Medical Sciences Campus
Background: Insulin resistance is present in HIV-seropositive people using combined
antiretroviral treatment (cART) and associated with HAND. However, the mechanisms
involved are not well understood. Recently, we reported that higher plasma soluble
Insulin Receptor (sIR) levels are associated with the presence and severity of HAND
in our cohort of HIV-seropositive women on cART. In this study, we investigated if
soluble insulin-like growth factor-1 receptor (sIGF1-R) in the plasma of HIV-infected
woman is associated with HAND and correlates with plasma sIR levels. Methods: Plasma
sIGF1-R levels were assayed in 34 HIV-seropositive women stratified by HAND into normal
cognitive (NC; n=11), asymptomatic impairment (AI; n=8), or symptomatic impairment
(SI; n=15) and five (5) controls without history of diabetes. Soluble sIGF1-R levels
(full-length or intact) were quantified by ELISA. Patients were also characterized
for plasma sIR and TNF-alpha levels as determined by ELISA. Nonparametric statistics
were used. Results: Higher levels of plasma sIGF1-R were associated with worse cognitive
performance (p=0.006) among HIV-seropositive women stratified by HAND. No significant
differences were observed in sIGF1-R levels between controls and HIV-seropositive
women with NC. However, significant differences were seen between the NC and AI (p=0.001)
and between the NC and SI groups (p=0.027). A positive correlation was observed between
plasma sIGF1-R and sIR levels (p=0.011). No correlations were observed with age, viral-immune
profile, antiretroviral therapy, or TNF-alpha levels. Conclusions: This study provides
evidence that sIGF1-R secretion is increased in HIV-infected women and may have a
role in the progression of HAND. Our findings also suggest that similar or coordinated
cellular mechanisms may be responsible for the secretion of both, sIGF1-R and sIR,
to the plasma of these patients and they could represent biomarkers for the presence
and severity of HAND. This work was supported by: R21MH095524, S11NS046278, U54NS043011,
U54RR026139, U54MD007587, G12RR003051, G12MD007600, and R25MH080661.
P68
Targeting the CD163+CD16+ monocyte subset for the prevention and treatment of HIV-associated
neurocognitive disorders (HAND)
Lindsey Gerngross1, Joseph Hardardt2, Ellen M. Tedaldi3, Tracy Fischer-Smith1
(presenting author: lindseyg@temple.edu)
1Department of Neuroscience, Temple University School of Medicine;
2Department of Biology, Temple University;
3Department of Medicine, Temple University School of Medicine
Chronic neuroinflammation in HIV-1 infection is believed to contribute to the development
of HIV-associated neurocognitive disorders (HAND). Previous work from our laboratory
and others suggest that the accumulation of activated central nervous system (CNS)-associated
macrophages and resident microglia results from the invasion and differentiation of
peripheral blood monocytes. This process is significant to the pathogenesis of HAND
because these cells constitute the principal cellular reservoirs of HIV-1 in the CNS.
Importantly, HIV infection results in altered monocyte/macrophage homeostasis, evidenced
by a skewed monocyte phenotype and activation status that may support the development
and maintenance of a neuroinvasive monocyte subset. We have previously reported expansion
of CD163+CD16+ monocytes in the peripheral blood of HIV+ patients that is phenotypically
similar to macrophages/microglia that accumulate in the CNS in HIV infection; however,
whether these cells are a source of new infection remains unclear. Here, we test the
hypothesis that specific monocyte populations with predilection for invasion are preferentially
infected with HIV-1. We compared the cellular location of HIV-1 in the monocyte subsets
isolated from the peripheral blood of a cohort of chronically HIV-1 infected donors
with a documented history of combination anti-retroviral therapy (cART) adherence,
with and without detectable plasma viremia, based on CD163 and CD16 expression. Further,
we explored a therapeutic strategy targeting the CD163+CD16+ monocyte subset using
experimental and FDA-approved tyrosine kinase inhibitors (TKIs) with selectivity for
cfms, a type III receptor tyrosine kinase that has been shown to promote this monocyte
phenotype in vitro. We anticipate that our studies will provide novel insights into
the role of altered monocyte/macrophage homeostasis in HIV disease and identify a
novel strategy for targeting long-lived cellular reservoirs of HIV through restored
immune homeostasis.
P69
Varicella Zoster Virus is a Major Cause of Giant Cell Arteritis
Don Gilden1, Nelly Khmeleva2, Alexander Choe2, Philip Boyer3, Denis Chatelain4, Charles
Eberhart5, Robert Poppiti6, Pratima Agarwal2, Anna Heintzman2, Victoria Pelak2, Vikram
D Durairaj7, Maria Nagel2
(presenting author: Don.gilden@ucdenver.edu)
1Department of Neurology and Microbiology, University of Colorado School of Medicine;
2Department of Neurology, University of Colorado School of Medicine;
3Department of Pathology, University of Colorado School of Medicine;
4Department of Pathology, Centre Hospitalier Universitaire du Nord, France;
5Department of Neuropathology, Johns Hopkins University School of Medicine;
6Department of Pathology, Mount Sinai Medical Center, Miami FL;
7Department of Ophthalmology, University of Colorado School of Medicine
Giant cell arteritis (GCA) and multifocal varicella zoster virus (VZV) vasculopathy
with temporal artery (TA) infection have overlapping clinical features and laboratory
abnormalities. Our analysis of TAs that were pathologically negative for GCA (GCA-)
revealed VZV antigen in 39/103 (38%) TAs. Viral antigen was found mostly, but not
exclusively in the adventitia. During our continuing search for VZV antigen in GCA-
TAs, abundant VZV antigen was found in multiple regions (skip areas) of an artery.
This led to additional pathological analysis of sections adjacent to those containing
VZV antigen. Re-examination revealed pathological changes with inflammation involving
the arterial media and abundant multinucleated giant cells characteristic of GCA.
When we analyzed TAs that had been pathologically confirmed to be GCA (GCA+), VZV
antigen was found in 17/26 (65%) TAs. Also, despite formalin-fixation, the presence
of VZV in TAs was further confirmed by the detection of VZV DNA in 24/31 (77%) of
TAs that contained VZV antigen. None of 27 normal TAs from subjects over age 50 contained
VZV antigen or VZV DNA. The detection of VZV antigen was noted in 65% of GCA+ TAs
in which inflammation with (1) multinucleated giant cells and/or epithelioid macrophages
and (2) damage to the media and/or internal elastic lamina is present. In contrast,
little or no inflammation in the adventitia of 38% of GCA- TAs indicates a continuum
of disease. Overall, after reactivation from latency in ganglia, VZV travels transaxonally
and initially infects the arterial adventitia resulting in clinical features that
lead to TA biopsy even though the classic pathological features of GCA described above
have not yet developed. By the time GCA pathology develops, ~65% of TAs contained
VZV. VZV is a major cause of GCA.
P70
Brain heme oxygenase-1 deficiency in HIV-infection: Role in macrophage-mediated neurodegeneration
Alexander Gill1, Stephanie Cross1, Colleen Kovacsics1, Benjamin Gelman2, Dennis Kolson1
(presenting author: agill@mail.med.upenn.edu)
1Department of Neurology, Perelman School of Medicine at the University of Pennsylvania;
2Department of Pathology, University of Texas Medical Branch
Although antiretroviral therapy (ART) has significantly improved clinical outcomes
in HIV+ patients, the prevalence and associated morbidity of HIV-associated neurocognitive
disorders (HAND) remain high (~50%). Thus, adjunctive neuroprotective therapeutic
targets that address the pathological processes persisting in ART-treated individuals
are needed. Our lab has identified heme oxygenase-1 (HO-1), a sentinel cytoprotective
protein, as a host factor protective against HIV-mediated neurodegeneration that is
deficient in the CNS of HIV+ individuals. In our current study, we quantified the
protein expression of HO-1 in the prefrontal cortex of HIV-, HIV+, and HIV encephalitic
brains (n=156). HO-1 protein levels were deficient in the prefrontal cortex of HIV+
patients compared to HIV- controls (p<0.01), with more severe HO-1 deficiency observed
in HIV encephalitis patients (p<0.001). Furthermore, this HO-1 deficiency correlated
significantly with CNS viral load as well as with brain parenchymal markers of macrophage
and innate immune activation. These results suggest CNS HIV infection reduces HO-1
protein expression in the prefrontal cortex. Notably, HO-1 deficiency was significantly
worse in patients with HAND compared to HIV+ individuals with normal cognition and
correlated with neurocognitive impairment in executive and speed of processing domains,
suggesting this HO-1 deficiency may play a role in neurocognitive impairment in HAND
patients. Using our in vitro model of HIV-mediated neurodegeneration in which HIV-infected
monocyte-derived macrophages (HIV-MDM) release neurotoxic levels of glutamate, we
have shown that HIV infection of MDM drastically decreased the protein expression
of HO-1. Moreover, pharmacologic induction of HO-1 decreased HIV-MDM neurotoxin production
and glutamate release; in contrast, inhibition of HO-1 increased neurotoxin production.
In summary, these findings report HO-1 deficiency in the brains of HIV+ individuals
and identify HO-1 as a potential modulator of macrophage-mediated neurodegeneration
in HAND. Therefore, pharmacologic inducers of HO-1 should be studied for the potential
to reduce the persistent prevalence of HAND in ART-treated individuals.
P71
P3D Normal Human Neural Progenitor Tissue-Like Assemblies: A Model of Persistent VZV
Infection
Thomas Goodwin1, Maureen McCarthy1, Nikolaus Osterrieder2, Benedikt Kaufer2, Don Gilden3,
Randall Cohrs3
(presenting author: randall.cohrs@ucdenver.edu)
1Disease Modeling/Tissue Analogues Laboratory, NASA Johnson Space Center; Houston,
TX USA;
2Institut fur Virologie, Freie Universitat Berlin, Berlin, Germany;
3Departments of Neurology and Microbiology, University of Colorado School of Medicine,CO
USA
Varicella zoster virus (VZV) is a ubiquitous neurotropic alphaherpesvirus. Primary
infection typically causes childhood varicella after which virus becomes latent in
ganglionic neurons along the entire neuraxis. As cell-mediated immunity to VZV declines
with age or immunosuppression, VZV can reactivate to cause zoster and other serious
neurologic and ocular diseases. Unfortunately, few models are available to study VZV
latency since the virus infects only humans and latency is established only in neurons.
We have successfully maintained normal human neural progenitor cells (NHNP) in tissue-like
assemblies (TLAs) in 3-dimenstional (3D) cultures for up to 6 months. NHNP TLAs are
a mixture of cells expressing markers for neuronal progenitor cells (CXCR4, CD90 and
nestin), terminally differentiated neurons (beta-III-tubulin) as well as non-neuronal
cells (GFAP). VZV infected NHNP-TLAs remained viable for 3 months during which time
VZV DNA replicates, VZV genes (ORFs 9, 40 and 63) are transcribed and infectious VZV
is sporadically released. The ability to maintain VZV infected NHNP cells in culture
for an extended time provides a unique opportunity to study molecular interactions
between VZV and neurons to an extent previously unattainable.
P72
Bone marrow derived neural crest lineage cells express JCV T-antigen: Possible role
of neural crest stem cells in pathogenesis
Jennifer Gordon1, Brian Augelli2, Ilker Sariyer1, Jessica Otte1, Kamel Khalili1, Barbara
Krynska3,
(presenting author: krynskb@tuhs.temple.edu)
1Department of Neuroscience and Center For Neurovirology, Temple University School
of Medicine;
2Department of Neurology, Temple University School of Medicine;
3Department of Neuroscience and Center For Neurovirology, Department of Neurology,
Center for Neural Repair and Rehabilitation, Shriners Hospitals Pediatric Research
Center, Temple University School of Medicine
JC virus (JCV) is a ubiquitous human polyomavirus and the etiological agent of progressive
multifocal leukoencephalopathy (PML). In addition to its role in PML, which has been
observed with increasing frequency in Multiple Sclerosis patients on monoclonal antibody
therapy, JCV has been association with several human cancers. JCV infection most likely
occurs in childhood and it has been hypothesized that the virus is able to persist
within the bone marrow. However, identification of the bone marrow cell population
that harbor the persistent virus and may therefore facilitate spread of the virus
into different organs, including the brain, has been hampered by the heterogeneity
of cell populations within the bone marrow. We recently isolated a distinct population
of non-hematopoietic bone marrow derived cells from JCV T-antigen transgenic mice.
These cells are of neural crest lineage, and we demonstrate that the expression of
JCV T-antigen can be activated in this population of bone marrow cells upon exposure
to a neural environment. JCV T-antigen positive cells exhibit neural crest characteristics
and demonstrate p75, SOX-10 and nestin positivity. JCV T-antigen positive cells could
be successfully cultured long-term while maintaining their neural crest characteristics.
Furthermore, when these cells are induced to differentiate into neural crest derivatives,
JCV T-antigen expression is downregulated in cells differentiating into bone and maintained
in glial cells expressing GFAP and S100. We conclude that JCV T-antigen can be stably
expressed within a fraction of bone marrow cells differentiating along the neural
crest/glial lineage when cells are cultured in vitro. Thus, we identify a previously
unrecognized bone marrow-derived neural crest stem cell population permissible for
JCV early gene expression suggesting the possibility that these cells could support
viral infection and thus provide clues toward understanding the role of the bone marrow
in JCV persistence and reactivation.
P73
Novel Neuroprotective GSK-3beta Inhibitor Restricts Tat-Mediated HIV-1 Replication
Irene Guendel1, Rachel Van Duyne1,2, Kylene Kehn-Hall1, Mohammed Saifuddin1, Ravi
Das1, Elizabeth Jaworski1, Gavin Sampey1, Svetlana Senina1, Leonard Shultz3, Aarthi
Narayanan1, Hao Chen4, Sergey Iordanskiy1, Benjamin Lepene5, Chen Zeng4,6, Fatah Kashanchi1
(presenting author: fkashanc@gmu.edu)
1Department of Molecular and Microbiology, National Center for Biodefense & Infectious
Diseases, George Mason University;
2The Department of Microbiology, Immunology and Tropical Medicine, The George Washington
University School of Medicine;
3The Jackson Laboratory;
4Department of Physics, The George Washington University;
5Ceres Nanosciences, Inc;
6Department of Physics, Huazhong University of Science and Technology
The implementation of new antiretroviral therapies targeting transcription of early
viral proteins in post-integrated HIV-1 can aid in overcoming current therapy limitations.
Using high throughput screening assays, we have previously described a novel Tat-dependent
HIV-1 transcriptional inhibitor named 6BIO. The screening of 6BIO derivatives yielded
unique compounds that show potent inhibition of HIV-1 transcription. We have identified
a second generation derivative called 18BIOder as an inhibitor of HIV-1 Tat-dependent
transcription in TZM-bl cells and a potent inhibitor of GSK-3beta kinase in vitro.
Structurally, 18BIOder is half the molecular weight and structure compared to its
parental compound 6BIO. More importantly, we also have found differential GSK-3beta
complex present only in HIV-1 infected cells. In uninfected cells GSK-3beta was present
in a complex with a molecular weight of ~300 kDa, which is likely to be composed of
either homo- or hetero-dimers of GSK-3beta in conjunction with possible chaperone
proteins or other bound proteins. However, HIV-1 infected cells displayed an extended
set of smaller molecular weight complexes in addition to the dominant ~300 kDa complex.
18BIOder preferentially inhibits this novel kinase complex from infected cells at
nanomolar concentrations. We observed efficacy of 18BIOder in HIV-1 replication inhibition
in humanized mouse model at both 1.0 and 10 mg/kg as measured through reverse transcriptase
activity from treated animals. Longitudinal measurements over a span of 29 days showed
effective viral suppression at 1.0 mg/kg 18BIOder shortly after treatment. When left
untreated the virus would resume replication, a comparable response to cART which
require daily dosage for effective plasma control of viral load. Finally, we observed
that neuronal cultures treated with Tat protein are protected from Tat-mediated cytotoxicity
when treated with 18BIOder. Overall, our data suggest that HIV-1 Tat-dependent transcription
is sensitive to small molecule inhibition of GSK-3beta.
P74
MODIFICATION OF NEUTROPHIL FUNCTIONS THROUGH CXCL5 REGULATES NEURONAL SURVIVAL
Debjani Guha, Lily Francis, Todd Reinhart, Velpandi Ayyavoo
(presenting author: deg59@pitt.edu)
Dept. of Infectious Diseases & Microbiology, GSPH, University of Pittsburgh
HIV-1 invades the central nervous system (CNS) and establishes infection in brain
by infecting monocytes/macrophages and microglia. HIV-1 infected monocytes/ macrophages
release cytokine/chemokines that recruit other cells into brain. In this study we
focused on the highly expressed chemokine CXCL5, which is a potent chemoattractant
of neutrophils. Neutrophils maintain innate immune surveillance under normal conditions,
whereas, during inflammation they cause tissue damage. To investigate the role of
CXCL5 as well as neutrophils in HIV-1 infected brain monocyte-derived macrophages
(MDMs) were infected with HIV-1 that showed a significant upregulation of CXCL5 both
at the RNA and protein levels compared to uninfected/mock MDM culture. The significant
upregulation of CXCL5 in HIV-1 infected MDMs was partly influenced by overexpression
of IL-1beta, as neutralizing antibody against IL-1beta reduced the expression of CXCL5
more in HIV-1 infected MDM compared to mock infected. The increased production of
CXCL5 was also in part regulated by the phosphorylation status of ERK1/2 and p38.
The association of ERK1/2 and p38 with CXCL5 production was confirmed by blocking
these MAPKs that prevented the elevation of CXCL5 in HIV-1 infected MDMs than in uninfected
cultures. Functional analyses suggest that increased level of CXCL5 was directly correlated
with infiltration of neutrophils in chemotaxis assay. Furthermore, increased level
of CXCL5 and enhanced infiltration of activated neutrophils expressing myeloperoxidase
(MPO) were also observed in brain tissues from HIV-1 positive subjects. To assess
the consequence of MPO on neurons during HIV-1 infection, primary neurons were treated
with HIV-1 infected or control MDM supernatants in the presence or absence of MPO.
Results indicate that MPO reduced neuronal survival in a dose dependent manner. Collectively,
our results suggest that CXCL5 has a profound effect on impairment of innate immune
functions in HIV-1 infected brain through neutrophil infiltration that affects the
final outcome of HIV-1 infection.
P75
IFN activated monocyte-derived exosomes mediate transfer of miRNAs to astrocytes:
Implications for neurocognitive impairment in HIV/HCV-infection
Archana Gupta1, Bing Sun2, Hans Rempel2, Brian Wigdahl3, Lynn Pulliam2
(presenting author: ag434@drexel.edu)
1Department of Microbiology and Immunology, Institute for Molecular Medicine and Infectious
Diseases, Drexel University College of Medicine, Philadelphia, PA, and Department
of Laboratory Medicine, Veterans Affairs Medical Center, San Francisco;
2Department of Laboratory Medicine, Veterans Affairs Medical Center, San Francisco;
3Department of Microbiology and Immunology, Institute for Molecular Medicine and Infectious
Diseases, Drexel University College of Medicine, Philadelphia, PA
We recently reported that 60% of subjects with HCV and virally-suppressed HIV infection
(coinfection) were cognitively impaired. Importantly, we showed that peripheral monocytes
in coinfection had a distinct type-I interferon (IFN) activation profile. Since HCV
is not considered neurotropic, it suggests that indirect viral mechanisms may be responsible
for neural cell dysfunction. Several lines of evidence indicate that exosomes facilitate
cell-to-cell communication wherein host RNA, including miRNAs and proteins can be
transferred to recipient cells. We hypothesized that IFN-activated monocyte/macrophages
mediate neurocognitive impairment in coinfection by the transfer of exosomal miRNAs
to neural cells that subsequently dysregulate their function. In support of our hypothesis,
we show that monocyte-derived exosomes are internalized by primary human astrocytes.
In addition, miRNA profiling of exosomes shed by monocytes from HIV/HCV-infected subjects
revealed that the vesicles were highly enriched in miR-223. Further, we developed
an in vitro model that recapitulated the activation state of monocytes from coinfected
subjects. IFN-activated monocyte-derived exosomes were greatly abundant in miR-223
as well, and when incubated with human astrocytoma cells, resulted in significant
elevation of intracellular miR-223 levels. These results suggest that monocyte-derived
exosomes can transfer miRNAs to neural cells, potentially altering the cellular environment
of the latter. The transfer of miRNAs from activated monocytes to astrocytes via exosomes
may explain, in part, the neurological abnormalities associated with coinfection.
P76
Intra-cerebroventricular (ICV) infusions of HIV envelope glycoprotein gp120 induce
cognitive decline in a rodent model of HIV-associated neurocognitive disorders (HAND)
Chris Gutoskey1, Matt Thomas1, Jed Shumsky1, Vanessa Pirrone2, Brian Wigdahl2, Barry
Waterhouse1
(presenting author: cjg77@drexel.edu)
1Department of Neurobiology and Anatomy, Drexel University College of Medicine;
2Department of Microbiology and Immunology, Drexel University College of Medicine
Discovering the cause and potential therapies for HIV-associated neurocognitive disorders
(HAND) will be of increasing importance as the HIV population continues to age. HAND
is marked by impaired attention and memory as well as decreased cognitive flexibility.
The viral envelope glycoprotein, gp120, has been implicated in the development of
HAND. Previous studies have shown deficits in the acquisition phase of the Morris
Water Maze task following intra-cerebroventricular (ICV) infusions of gp120 in rats.
The present work sought to extend those findings to other domains of cognitive function.
Adult male Fischer-344 rats were implanted bilaterally with cannulae into the lateral
ventricles. After recovery from the surgery, daily infusions of gp120 (50 ng/microliter)
or the bovine serum albumin (BSA) vehicle solution were administered for 7 days. Animals
were food restricted the day after their final infusion and were tested in an attention
set-shifting task, adapted from Birrell and Brown (2002), 20 days later. To succeed
in this task, the animal must discriminate between sensory cues to determine the location
of a food reward. Subjects are also required to ignore cues that were rewarded on
previous trials but which are no longer indicative of reward location. Animals exposed
to gp120 were significantly impaired in reversal learning (within modality shift)
and in their ability to make an extra-dimensional shift (cross-modality switch), suggesting
behavioral inflexibility. Establishing a rat model of HAND that mimics the cognitive
deficits observed in the clinical population will provide insights regarding mechanisms
as well as guide the development of potential therapies. This work is supported by
NIH/NIMH R21 MH097623 and NIMH T32 MH070785.
P77
Targeted quantitative proteomics (SWATH-MS) reveals novel insights for reprogramming
of transcription regulator proteins in HIV-1-infected macrophages
Nicole Haverland, Pawel Ciborowski
(presenting author: pciborowski@unmc.edu)
University of Nebraska Medical Center
Human immunodeficiency virus type 1 (HIV-1) remains a worldwide epidemic and a vaccine
or therapy capable of eradicating the virus is not available. Although HIV-1 infection
is generally associated with the widespread destruction of T-cells, monocytes and
macrophages play an important role in the infection process, serving viral reservoirs
capable of harboring latent virus as well as disseminators of the virus throughout
the body. A novel therapeutic avenue against HIV-1 would be to target host factors,
such as transcription regulators, that are involved in the host response to viral
infection but can be bypassed in normal cellular functioning and this approach could
circumvent the current limitations of antiretroviral therapy. We hypothesized that
transcription regulator proteins - including transcription factors and cofactors,
promoters, enhancers, repressors and proteins involved in chromatin structure and
modification - were differentially expressed in HIV-1-infected macrophages. To test
this hypothesis, we used a novel proteomic platform, SWATH-MS, for the targeted and
quantitative proteomic analysis of transcription regulators capturing quantitative
proteomic data specifically selected for transcription regulator proteins using an
in-house generated database composed of both known and putative transcription regulators.
Using this SWATH-MS approach, we identified and quantified 510 transcription regulators
in uninfected and HIV-1-infected monocyte-derived macrophages. We then applied novel
statistical testing to our proteomics data using methods previously established for
intensity-based microarray data analysis; we identified 61 transcription regulators
that were significantly (p < 0.05) altered following HIV-1 infection. Bioinformatic
analysis of these altered transcription regulators revealed functional enrichment
of proteins involved in chromatin structure and epigenetic modifications. Our findings
highlight a novel subset of transcription regulator proteins that are involved in
HIV-1 infection demanding further investigation. In addition, our study provides a
new experimental paradigm that can be readily applied by a broad group of scientists
for understanding the host response to microbial infection.
P78
Therapeutic Clearance of the Virally Infected Nervous System is Mediated by Noncytopathic
T cell interactions with Resident Microglia
Jasmin Herz, Dorian McGavern
(presenting author: herzjn@mail.nih.gov)
NIH / NINDS
Several viruses can infect the mammalian nervous system, some with devastating consequences,
and others with little or no overt pathology. Adoptive immunotherapy is an approach
that involves administration of anti-viral T cells and has shown promise in clinical
studies for the treatment of CMV, EBV, and adenovirus infections. Our laboratory models
adoptive immunotherapy by transferring anti-viral memory T cells into mice persistently
infected from birth with lymphocytic choriomeningitis virus. Here, we demonstrate
that memory T cells can completely purge the brain of persistently infected mice without
causing blood brain barrier breakdown or severe tissue damage. This is accomplished
by a tailored release of chemoattractants that recruit adaptive immune cells, but
few pathogenic innate immune cells such as neutrophils and inflammatory monocytes.
Interestingly, memory T cells enlist the support of nearly all brain resident myeloid
cells (microglia) by converting them into CD11c-expressing antigen-presenting cells
(APCs). Two-photon imaging studies revealed that anti-viral CD8 T cells are more likely
to decelerate and form stable interactions with brain-resident APCs than CD4 T cells.
Importantly, microglia do not undergo cell death following T cell engagement and appear
to protect themselves by upregulating serine protease inhibitors like Spi-6. We propose
that non-cytopathic viral clearance from the brain by therapeutic memory T cells results
from tailored chemoattractant production and interactions with resident myeloid cells
protected by Spi-6.
P79
RNA-mediated excision of the HIV-1 genome from latently infected cells in nervous
system
Wenhui Hu, Rafal Kaminski, Yonggang Zhang, Fan Yang, Kamel Khalili
(presenting author: whu@temple.edu)
Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine
While the introduction of combined antiretroviral therapy, cART, has greatly improved
survival rates among AIDS patients, a substantial portion of HIV-1 infected individuals
remain at risk for the development of full blown AIDS as a result of reactivation
of latently infected cells, partly due to nonadherence to medication and emergence
of drug resistant viruses. Moreover, HIV-1 positive long term survivors continue to
develop comorbidities including an accelerated aging process, neurocognitive disorders,
heart failure, and others. From the virological point of view, as none of the current
treatments suppress viral gene transcription, it is suspected that low, yet continuous,
levels of viral early proteins with regulatory and pathogenic activities may contribute
to the development of these quality of life-threatening illnesses. Sadly, all efforts
toward the development of vaccines against HIV-1 have not shown promising outcomes.
Thus, curing of AIDS by eradicating the HIV-1 genome in infected subjects requires
a novel strategy that is specific, highly effective, irreversible, and sustained.
Recently, we have adapted a genetic approach using clustered regulatory interspaced
short palindromic repeat-associated system (Cas) and short complementary single-stranded
RNA, called guide RNA (gRNA), which specifically targets the U3 region of the HIV-1
long term repeat (LTR) promoter and precisely excises a segment of the viral regulatory
sequence required for its expression. In addition, the employment of single and multiplex
gRNA in our Cas9 system showed promising results that included eradication of the
entire HIV-1 genome in latently infected microglial cells, thus abrogating viral gene
expression and reactivation. Based on this observation, we propose a working model
for the development of an RNA-guided Cas9 that acts as molecular scissors and, by
disrupting various regions of the LTR and/or removing the entire viral genome, abrogates
reactivation of the virus in macrophages, microglia and astrocytes which serve as
viral reservoirs in the brain. This work was supported by NIH grants R01 MH093271
and P30 MH092177 Comprehensive NeuroAIDS Center Grant awarded to KK.
P80
HIV-1 Tat-induced endolysosome dysfunction in neurons
Liang Hui1, Xuesong Chen1, Norman Haughey2, Jonathan Geiger1
(presenting author: jonathan.geiger@med.und.edu)
1Department of Biomedical Sciences, University of North Dakota, School of Medicine
and Health Sciences;
2Departments of Neurology and Psychiatry, Johns Hopkins School of Medicine
HIV-1 Tat continues to be implicated as a causative agent of HIV-1 associated neurocognitive
disorder (HAND). We found previously that Tat elevates endolysosome pH and alters
the structure and function of neuronal endolysosomes, a prominent and early pathological
feature of HAND. Here, we showed that enlarged neuronal endolysosomes occur in an
inducible HIV-1 Tat transgenic model of HAND and determined underlying mechanisms
whereby HIV-1 Tat induces endolysosome dysfunction. Our observations that HIV-1 Tat
elevates endolysosome pH indicates that HIV-1 Tat escaping from endolysosomes appears
to be linked to proton leakage out of endolysosomes and suggests that a proton-dependent
peptide transporter might be involved. Of the known proton-dependent peptide transporters,
we demonstrated that proton-coupled oligopeptide transporter 2 (Pept2) is present
on neuronal endolysosomes and that siRNA knockdown of Pept2 blocked HIV-1 Tat-induced
enlargement of endolysosomes. Thus, Pept2 might be a proton-dependent peptide transporter
through which HIV-1 Tat affects endolysosome pH and it might be involved in HIV-1
Tat escape from endolysosomes. Elevation of endolysosome pH could also affect endolysosome
calcium homeostasis and we showed that elevation of endolysosome pH not only induces
calcium release from endolysosomes but also activates a novel endolysosome-dependent
calcium influx across plasma membranes, a phenomenon we have termed “acidic store-operated
calcium entry.” Given our observations that HIV-1 Tat elevates endolysosome pH, increases
calcium release from intracellular stores, and enhances calcium influx across the
plasma membranes, HIV-1 Tat could activate this novel endolysosome-dependent calcium
regulatory mechanism. Pept2 may be involved in the actions of HIV-1 Tat on neuronal
endolysosomes and its contribution to the pathogenesis of HAND. (Supported by AG043338,
GM103329, NS065957).
P81
Irradiation-induced cellular stress activates virus replication and apoptosis in HIV-1
infected macrophage model cells and in the brain of infected humanized mice
Sergey Iordanskiy1, Rachel Van Duyne1,2, Gavin Sampey 1, Kelsi Fry1, Fabio Romerio3,
Fatah Kashanchi1
(presenting author: siord6@gmail.com)
1Department of Molecular and Microbiology, National Center for Biodefense & Infectious
Diseases, George Mason University;
2Virus-Cell Interaction Section, HIV Drug Resistance Program, National Cancer Institute
NIH;
3Institute of Human Virology, University of Maryland School of Medicine
The highly active antiretroviral therapy reduces HIV RNA in plasma to undetectable
level. However, the virus continues persistence in resting T cells and CNS reservoirs,
such as perivascular macrophages, microglia and astrocytes. Selective reactivation
and eradication of HIV from CNS reservoirs is a critical problem of current HIV therapy.
The X-ray irradiation (IR), well-defined stress signal, that is widely used for many
therapeutic purposes, has earlier been shown to be capable to activate increased HIV-1
transcription, progeny virion formation and eventual apoptosis of infected cells.
Here, using the HIV-1 infected monocyte-derived macrophage (MDM) model cells (PMA-activated
U1) and NSG humanized mice infected with dual-tropic HIV-1 89.6 strain, we examined
the effect of IR-induced cellular stress on HIV-1 replication and viability of infected
cells. Treatment of both PBMCs and MDM with different IR doses led to dramatic increase
of HIV-1 transcription, as evidenced by presence of Pol II and reduction of HDAC1
on HIV-1 promoter when using ChIP assay. This coincided with increased level of intracellular
HIV-1 RNA. Incubation of IR-treated cells with proteasomal inhibitor ALLN (Calpain
inhibitor 1) resulted in the additional increase of HIV-1 transcription probably due
to Tat protein stabilization. Interestingly, analysis of infectivity of progeny virions
using TZM-bl reporter cells showed decreased infectivity of the virus produced by
irradiated cells, suggesting that along with activation of HIV-1 replication, IR increased
production of defective viral particles. Treatment of HIV-1 infected humanized mice
that did not display viral RNA in the plasma and PBMCs with IR resulted in significant
increase of HIV-1 RNA in plasma, lung and especially brain tissues. Taken together,
our current data suggest that IR-induced cellular stress activates HIV-1 expression
in the infected MDM in different MDM-rich tissues including brain and facilitates
the apoptotic death of infected cells possibly via Tat-dependent phosphorylation of
p53 protein.
P82
Human T-lymphotropic virus type 1 infected cells secrete oncosomes containing Tax
protein
Elizabeth Jaworski1, Aarthi Narayanan1, Rachel Van Duyne1,2, Sergey Iordanskiy1,2,
Mohammed Saifuddin1, Ravi Das1, Philippe Afonso3, Gavin Sampey1, Shabana Shabbeer-Meyering1,
Myung Chung1, Anastas Popratiloff4, Bindesh Shrestha5, Akos Vertes5, Renaud Mahieux6,
Fatah Kashanchi1
(presenting author: msaifuddinbd@yahoo.com)
1Department of Molecular and Microbiology, National Center for Biodefense and Infectious
Diseases, George Mason University;
2The George Washington University Medical Center;
3Unite d'Epidemiologie et Physiopathologie des Virus Oncogenes, Departement de Virologie,
Institut Pasteur. CNRS;
4Department of Chemistry, The George Washington University;
5Center for Microscopy and Image Analysis, The George Washington University Medical
Center;
6Equipe Oncogenese Retrovirale, Equipe labelisee “Ligue Nationale Contre le Cancer”,
International Center for Research in Infectiology
Human T-lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell
leukemia (ATL) and HTLV-1-associated myelopathy (HAM)/tropical spastic paraparesis
(TSP). The HTLV-1 transactivator protein Tax controls many critical cellular pathways
including host cell DNA damage response mechanisms, cell cycle progression, and apoptosis.
Recently, extracellular vesicles called exosomes have been shown to play critical
roles during pathogenic viral infections as delivery vehicles for host and viral components
including proteins, mRNA and miRNA. We hypothesized that exosomes derived from HTLV-1
infected cells contain unique host and viral proteins that may contribute to pathogenesis.
We found that exosomes derived from infected cells contained the oncogenic Tax protein
and pro-inflammatory mediator IL-6, as well as the viral mRNA transcripts, tax, hbz,
and env. We also observed drastic reduction of MCP-1 and RANTES in exosomes from infected
cells. Exosomes from infected cells deliver functional proteins to naive recipient
cells and induce ROS production. Furthermore, we observed that exosomes released from
HTLV-1 infected Tax-expressing cells contributed to enhanced survival of target cells
when treated with FAS antibody. IL-2 dependent CTLL-2 cells that received Tax containing
exosomes were also protected from apoptosis. Similar experiments with PBMCs also showed
protection of the cells in 15 day cultures in the absence of PHA/IL-2. Collectively,
these results suggest that exosomes may play an important role in extracellular delivery
of functional HTLV-1 proteins, especially Tax, and mRNA to recipient cells and contribute
to oncogenesis in the recipient cells.
P83
The use of nanoparticle technology in capturing HIV-1 virions and viral proteins
Elizabeth Jaworski1, Nazly Shafagati1, Rachel Van Duyne1,2, Mohammed Saifuddin1, Sergey
Iordanskiy1, Kylene Kehn-Hall1, Benjamin Lepene3, Fatah Kashanchi1
(presenting author: fkashanc@gmu.edu)
1Department of Molecular and Microbiology, National Center for Biodefense & Infectious
Diseases, George Mason University;
2Department of Microbiology, Immunology, and Tropical Medicine, The George Washington
University Medical Center;
3Ceres Nanosciences
HIV-1 infection results in a chronic but incurable illness since long-term HAART can
keep the virus to an undetectable level. Discontinuation of therapy rapidly increases
virus burden. Moreover, patients under HAART frequently develop various metabolic
disorders and also HIV-associated neuronal disease. Today, the main challenge of HIV
research is the elimination of the residual virus in infected individuals. The current
HIV-1 diagnostics are largely comprised of serological and nucleic acid based technologies.
Our goal is to integrate the nanoparticle technology into a standard research tool
that will allow for highly sensitive detection of HIV infection. Our study demonstrates
that majority of HIV-1 virions and Tat/nef proteins spiked in culture medium can be
captured by nanoparticles. Especially at low concentrations, the nanoparticles provided
dramatic increase in HIV-1 detection levels over standard assays. To determine the
binding specificities of different affinity baits, we incubated target molecules with
nanoparticles at room temperature. After short sequestration, materials were either
eluted using downstream assay buffer or remained attached to nanoparticles prior to
analysis. The unique affinity baits of nanoparticles preferentially bound HIV-1 materials
while excluded albumin. The specific capture of full-length Tat or Tat peptide spiked
in cell culture medium by nanoparticles NT082 and NT084 was measured by WB. Intracellular
Nef protein was captured by NT080, while membrane-associated Nef was captured by NT086.
Whole HIV-1 virus capture was enriched by NT073 and NT086, while NT086 nanoparticle
captured infectious virus as demonstrated by Tat transactivation in TZM-bl cells.
We also demonstrated specific capture of exosomes derived from HIV-1 infected cells
and measured TAR-RNA by qRT-PCR. Collectively, our data indicate that some nanoparticles
selectively capture specific target molecules of HIV-1 infection, and we propose to
use this technology as a platform to enhance HIV-1 detection by concentrating viral
proteins and infectious materials from infected samples.
P84
Detection of HIV-Tat protein in brain and CSF of patients on antiretroviral therapy
Tory Johnson1, Gloria von Geldern2, Richa Tyagi3, Ned Sacktor4, Justin McArthur4,
Scott Letendre5, Rodrigo Hasbun6, Carol Petito7, David Roh7, Ashok Verma7, Avindra
Nath2
(presenting author: tory.johnson@nih.gov)
1NINDS, NIH;
2NINDS, NIH;
3NINDS, NIH;
4Johns Hopkins School of Medicine, Department of Neurology;
5University of California, San Diego;
6University of Texas, Houston;
7University of Miami, Jackson Memorial Hospital
Background: While the effects of HIV-Tat protein on neuro-glial function has been
well studied, the role of Tat in mediating persistent proinflammatory responses in
the CNS in virologically controlled individuals on ART is not well known. Persistent,
low level inflammation can be demonstrated in the majority of individuals with chronic
HIV infection, even when aviremic. Some patients who are well controlled on ART develop
an immune reconstitution inflammatory syndrome (IRIS).
Methods: We immunostained brain biopsy tissue for Tat and p24 antigen, and T cell
markers from two HIV patients on ART who developed CNS- IRIS and compared it to autopsy
brain tissue of seven HIV-infected individuals with good virological control on ART
but without IRIS and one with HIV encephalitis (HIVE) with no ART. Tat levels were
also examined in the CSF of patients on ART (n=31) and in peripheral blood mononuclear
cells (PBMC) infected with HIV and treated with darunavir.
Results: Monocytic infiltrates strongly stained for Tat in both patients with IRIS,
however, p24 immunostaining was negative. In HIV patients without IRIS Tat was present
in 2/7 individuals. The patient with HIVE had Tat and p24 expressing macrophages in
microglial nodules and perivascular regions. In IRIS patients, infiltrates consisted
of CD3 + T-cells which were predominantly CD8+ with few CD4+ cells and occasional
IL-17+ cells. Tat was detected in 13/31 CSF samples by ELISA from HIV-infected individuals
controlled on ART. Tat was confirmed in a subset of CSF samples by Western blot analysis.
Darunavir blocked viral production in HIV-infected PBMC, however Tat production was
unimpaired.
Conclusions: Robust production of Tat was noted in brain of individuals with CNS-IRIS
and in CSF of one third of individuals controlled on ART. While ART can control HIV
replication it does not impact Tat production. Therapeutic development to prevent
Tat production is necessary.
P85
Brain Transferrin Receptor (TFR) RNA Expression is Associated with Neurocognitive
Impairment in HIV/AIDS
Asha Kallianpur1, James Connor2, Christopher Coe3, Benjamin Gelman4
(presenting author: kalliaa@ccf.org)
1Department of Genomic Medicine, Lerner Research Institute, Cleveland Clinic Lerner
College of Medicine & Cleveland Clinic; Cleveland, OH;
2Department of Neurosurgery, Penn State Milton S. Hershey Medical Center, Hershey,
PA;
3Department of Psychology, University of Wisconsin, Madison, WI;
4Department of Pathology, University of Texas Medical Branch, Galveston, TX
Background: Iron dysregulation in the brain is a consistent and poorly understood
feature of neurocognitive disorders, and functional neuronal iron deficiency has been
implicated in certain dementias. We hypothesized that HIV-Associated Neurocognitive
Disorder (HAND) pathophysiology involves brain iron deficiency, reflected by increased
transferrin receptor (TFR) RNA expression in brain.
Methods: Subjects who died of HIV/AIDS and participated in the National NeuroAIDS
Tissue Consortium (NNTC) Study underwent uniform autopsy/neuropathology protocols
and comprehensive neurocognitive assessments within 6 months antemortem. Total RNA
was extracted and purified from frozen brain tissue (frontal neocortex at Brodmann
Area 9); TFR messenger RNA was quantified by RT-PCR. Associations of TFR RNA expression
with HAND and standardized, neurocognitive domain scores were assessed using multivariable
regression to adjust for potential confounders.
Results: Among 300 evaluated decedents from the NNTC Brain Bank (mean age 44, median
CD4 cell count 109/ul), HAND occurred in 243 (81%), ranging from mild neurocognitive
impairment (24%) to dementia (32%). TFR RNA expression levels, available in 274 subjects
(91%), were unrelated to brain viral burden. TFR RNA expression in neocortex was associated
with HAND (p<0.05; p<0.01 for association with dementia) in unadjusted analyses: TFR
RNA levels were 15.4% higher in HAND cases than controls [median (IQR) 0.90 (0.65,
1.20) vs. 0.78 (0.61, 1.0), respectively]. These associations persisted after multivariable
adjustment [odds ratio (OR) 5.8 (95% CI 1.5-22.9, p<0.05) for all HAND cases; OR 2.3
(95% CI 1.1-4.9, p<0.05) for dementia]. Speed of information processing, attention
working memory, and global standardized T-scores were negatively associated with TFR
RNA expression [all p≤0.05; beta-coefficient -4.27 (95% CI -8.3 to -0.23) for global
T-score].
Conclusions: TFR RNA expression in frontal neocortex is independently associated with
both mild and more severe neurocognitive impairment among individuals dying of HIV/AIDS,
suggesting a role for brain iron deficiency in HAND etiology and/or progression.
P86
Interplay of Rad51 and NF-kB pathway stimulates expression of HIV-1 in microglia and
peripheral blood mononuclear cells
Rafal Kaminski, Prasun K. Datta, Hassen Wolllebo, Kamel Khalili
(presenting author: rafalkim@temple.edu)
Department of Neuroscience, Center for Neurovirology, Temple University School of
Medicine, Philadelphia PA
Transcription of the HIV-1 promoter is controlled by a series of ubiquitous and inducible
cellular proteins, some with the ability to enter the nucleus and interact with the
specific DNA sequences spanning the 5` long terminal repeat, LTR. Here, we demonstrate
the ability of Rad51, a key regulator of the homologous recombination pathway of DNA
repair, to stimulate transcription of the HIV-1 promoter spanning within the long
terminal repeat (LTR). Our results show that activation of NF-kB pathway by PMA treatment
or overexpression of its subunit p65, promotes the association of Rad51 with the LTR
sequence. Accordingly, stimulation of the viral promoter by Rad51 relies, in part,
on its interplay with p65 and the NF-kB pathway. Treatment of the cells with PMA that
promotes nuclear entry of Rda51 or inactivation of the NF-kB pathway by a dominant
negative mutant of IkBalpha modulates the ability of Rad51 to stimulate LTR transcription.
Infection of primary peripheral blood mononuclear cells with HIV-1 indices Rad51 expression
and treatment of the infected cells with Rad51 inhibitor suppressed lentiviral replication
in this cells, suggesting the operation of positive feedback pathway between HIV-1
and Rad51. These observations ascribe a new role for Rad51 in transcription of the
HIV-1 genome and offer a new avenue for the development of anti-HIV-1 therapeutics.
Supported by grant to Kamel Khalili. This study utilized services offered by core
facility of the comprehensive neuroAIDS center, CNAC - (NIH P30 MH092177)
P87
Neuroprotective Maraviroc Monotherapy in SIV-infected Macaques: Reduced Replicating
and Latent SIV in the Brain
Kathleen Kelly1, Sarah Beck1, Kelly Metcalf Pate1, Suzanne Queen4, Jamie Dorsey5,
Robert Adams6, Patrick Tarwater2, Joseph Mankowski1
(presenting author: jmankows@jhmi.edu)
1Dept of Molecular and Comparative Pathobiology, Johns Hopkins University;
2Dept of Biostatistics, Texas Tech University School of Medicine;
Given the association between HIV-induced CNS disease and replication of HIV in macrophages
in the brain, CCR5 antagonists could attenuate CNS disease both by limiting HIV replication
in macrophages and by downmodulating inflammatory signaling mediated by chemokine-CCR5
interactions. To determine whether CCR5 inhibition altered CNS disease progression
independent of treatment with other classes of anti-retroviral drugs, CNS outcomes
were compared between SIV-infected animals treated with maraviroc monotherapy versus
untreated SIV-infected animals. SIV RNA and SIV DNA levels in brain were markedly
lower in maraviroc treated, SIV-infected macaques versus untreated SIV-infected macaques,
demonstrating that maraviroc monotherapy limits replication of SIV in the CNS and
may reduce the CNS latent viral reservoir. In addition, maraviroc treatment lowered
monocyte and macrophage activation, represented by CNS CD68 immunostaining and plasma
sCD163 levels, and reduced both TNFalpha and CCL2 RNA expression in brain. Maraviroc
treatment also reduced axonal amyloid precursor protein (APP) immunostaining to levels
present in uninfected animals, demonstrating protection from development of neuronal
dysfunction. Although maraviroc therapy reduced plasma viral load and SIV RNA levels
in spleen, relative decreases were less substantial than CNS declines, underscoring
the importance of assessing CNS-specific outcomes in evaluating efficacy of CCR5 inhibition.
The addition of CCR5 inhibitors to combined anti-retroviral regimens may effectively
prevent neurologic disorders in HIV-infected individuals and also may reduce CNS viral
reservoirs.
P88
Infection by CXCR4-tropic human immunodeficiency virus type 1 (HIV-1) is inhibited
by the cationic cell penetrating peptide derived from HIV-1 Tat
Shawn Keogan, Shendra Passic, Brian Wigdahl, and Fred C. Krebs
(presenting author: keogan42@gmail.com)
Department of Microbiology and Immunology, and Center for Molecular Therapeutics and
Resistance, Center for Sexually Transmitted Disease, Institute for Molecular Medicine
and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA
In the absence of an effective microbicide that reduces or eliminates the risk of
human immunodeficiency type 1 (HIV-1) transmission, the development of new anti-HIV-1
drugs remains a priority. Cell penetrating peptides (CPP), which are short peptides
that are capable of crossing the plasma membrane of a living cell, are under development
as delivery vehicles for therapeutic agents that cannot themselves enter the cell.
One well-studied CPP is the 10-amino acid peptide derived from the human immunodeficiency
virus type 1 (HIV-1) Tat protein. In experiments to test the hypothesis that multiple
cationic amino acids within Tat peptide confer antiviral activity against HIV-1, introduction
of Tat peptide resulted in concentration-dependent inhibition of HIV-1 IIIB (X4) infection
yet minimal antiviral activity against BaL (R5). In contrast, Tat peptide variants
containing arginine substitutions for two non-ionic residues and two lysine residues,
demonstrated a direct relationship between cationic charge and antiviral potency in
HIV-1 inhibition experiments. These studies of Tat peptide as an antiviral agent raise
new questions about the role of Tat in HIV-1 replication and provide a starting point
for the development of CPPs as novel HIV-1 inhibitors.
P89
Extracellular human immunodeficiency virus type 1 viral protein R causes reductions
in astrocytic ATP and glutathione levels compromising the antioxidant reservoir
Katie Kercher1, Adriano Ferrucci1, Eric Cohen2, Michael Nonnemacher1, Brian Wigdahl1
(presenting author: bcondran@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Laboratory of Human Retrovirology, Institut de Recherches Cliniques de Montreal,
and Department of Microbiology and Immunology, University de Montreal
Patients infected with human immunodeficiency virus type 1 (HIV-1) often display neurological
complications in late stage disease and increased viral loads directly correlated
with higher concentrations of extracellular HIV-1 protein r (Vpr) in the blood serum
and cerebrospinal fluid. Additionally, HIV-1-infected patients with a low CD4+ T-lymphocyte
count displayed lower concentrations of reduced glutathione (GSH), the main intracellular
antioxidant molecule, and lower level of survival. Conditioned media obtained from
the human endothelial kidney (HEK) 293T cell line transfected either in the absence
or presence of HIV-1 Vpr contained free Vpr. Exposure of U-87 MG cells to this conditioned
media decreased intracellular levels of both adenosine triphosphate (ATP) and GSH.
These observations were recapitulated using purified recombinant HIV-1 Vpr both in
U-87 MG and primary human fetal astrocytes in a dose- and time-dependent manner. Vpr-induced
oxidative stress could be partly restored by co-treatment with the antioxidant molecule
N-acetyl-cysteine (NAC). In addition, free Vpr augmented production of reactive oxygen
species due to an increase in the level of oxidized glutathione (GSSG). This event
was almost entirely suppressed by treatment with an anti-Vpr antibody or co-treatment
with NAC. These studies confirmed a role for extracellular Vpr in decreasing the levels
of intracellular ATP and GSH in astrocytes. Studies are underway to better understand
the intricate correlation between reductions in ATP and GSH metabolites and the impact
they exert on neuronal survival in end-stage disease. This work is supported by NIH/NINDS
R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P90
HYPERINTENSE CORTICAL T1 SIGNAL IN PML REFLECTS CORTICAL SEGMENTAL ASTROGLIOSIS AND
SEIZURE RISK
Michael Khoury1, David Alsop2, Shruti Agnihotri1, Rolf Pfannl3, Christian Wuethrich1,
Mai-Lan Ho2, David Hackney2, Long Ngo4, Matthew Anderson3, Igor Koralnik1
(presenting author: sagnihot@bidmc.harvard.edu)
1Division of Neurovirology, Department of Neurology, Center for virology and vaccine
research , Beth Israel Deaconess Medical Center;
2Department of Radiology, Beth Israel Deaconess Medical Center;
3Department of Pathology, Beth Israel Deaconess Medical Center;
4Department of Medicine, Beth Israel Deaconess Medical Center
Objective: To determine the frequency of hyperintense cortical T1 signal (HCTS) on
MRI in progressive multifocal leukoencephalopathy (PML) patients, its association
with seizure risk and immune reconstitution inflammatory syndrome (IRIS), and its
pathologic correlate.
Background: PML, caused by JC virus (JCV) affects predominately white matter. Seizures
point to a cortical origin and add to increasing evidence of gray matter involvement
in PML. HCTS is a radiologic marker of cortical laminar necrosis and is described
in hypoxia, hypoglycemia and status epilepticus.
Methods: We reviewed clinical data including seizure history, presence of IRIS, and
MRI scans from PML patients evaluated at our institution between 2003 and 2012. Cases
that were diagnosed either by CSF JCV PCR, brain biopsy or autopsy, and who had MRI
images available were included in the analysis (n=49).We compared pathologic findings
in areas of the brain of two patients displaying HCTS with isointense cortex in the
same individuals.
Results: Of 49 patients, 17 (34.7%) had seizures and 30 (61.2%) had HCTS adjacent
to subcortical PML lesions on MRI. Of the 17 PML patients with seizures, 15 (88.2%)
had HCTS compared to 15/32 (46.9%) patients without seizures (p= 0.006). Of the 20
patients with IRIS, 16 (80.0%) had HCTS compared to 14/29 (49.3%) of those without
IRIS, (p=0.04). HCTS predicted seizures with an odds ratio (OR) of 8.5 (95% confidence
interval (CI) of 1.66 - 43.41). Together, HCTS and IRIS predicted seizures with an
OR of 9.9 (95% CI of 2.5 - 39.3; p=0.001). On histological examination, HCTS areas
showed no evidence of ischemia but were associated with striking demyelination of
sub-cortical U-fibers, significant macrophage infiltration and a pronounced reactive
gliosis in the deep cortical layers.
Conclusions: Seizures are a frequent complication in PML. HCTS is associated with
seizures as well as IRIS, and correlates histologically with cortical segmental astrogliosis.
P91
Hyperperfusion in progressive multifocal leukoencephalopathy is associated with disease
progression and absence of immune reconstitution inflammatory syndrome
Michael Khoury1, Sarah Gheuens2, Long Ngo3, Xiaoen Wang4, David Alsop4, Igor Koralnik1
(presenting author: ikoralni@bidmc.harvard.edu)
1Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess
Medical Center, Harvard Medical School;
2Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess
Medical Center, Harvard Medical School, current affiliation Biogen Idec;
3Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School;
4Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School
Objective: We sought to characterize perfusion patterns of progressive multifocal
leukoencephalopathy (PML) lesions by arterial spin labeling (ASL) perfusion magnetic
resonance imaging and to analyze their association with immune reconstitution inflammatory
syndrome, and survival.
Background: ASL uses magnetic fields to alter the magnetization of water in the inflowing
arterial blood and then measures the effect of the inflow of altered magnetization
on the tissue signal. Because the "tracer" used is the endogenous blood water, ASL
does not require any injections or other contrast agent.
Methods: A total of 22 patients with PML underwent a clinical evaluation as well as
magnetic resonance imaging of the brain within 190 days of symptom onset. The presence
of immune reconstitution inflammatory syndrome was determined based on clinical and
laboratory criteria. Perfusion within PML lesions was determined by arterial spin
labeling magnetic resonance imaging.
Results: We observed intense hyperperfusion within and at the edge of PML lesions
in a subset of subjects. This hyperperfusion was quantified by measuring the fraction
of lesion volume showing perfusion in excess of twice normal appearing gray matter.
Hyperperfused lesion fraction was significantly greater in PML progressors than in
survivors (12.8% vs 3.4% p=0.02) corresponding to a relative risk of progression for
individuals with a hyperperfused lesion fraction ≤ 4.0% of 9.1 (95% CI of 1.4- 59.5).
The presence of hyperperfusion was inversely related to the occurrence of immune reconstitution
inflammatory syndrome at the time of scan (p=0.03). Indeed, within three months after
symptom onset, hyperperfusion had a positive predictive value of 88% for absence of
immune reconstitution inflammatory syndrome.
Conclusions: Arterial spin labeling magnetic resonance imaging recognized regions
of elevated perfusion within lesions of PML. These regions might represent virologically
active areas operating in the absence of an effective adaptive immune response and
correspond with a worse prognosis.
P92
Involvement of BAG3 in AIDS related comorbidity; HIV-1 induced cardiomyopathy
Tijana Knezevic1, Nana Merabova2, Jennifer Gordon2, Joseph Cheung3, Arthur Feldman4,
Matthew Taylor5, Shohreh Amini1, Kamel Khalili2
(presenting author: tijana@temple.edu)
1Department of Biology, College of Science and Technology, Temple University;
2Department of Neuroscience, Center for Neurovirology, Temple University School of
Medicine;
3Department of Medicine, Section of Nephrology and Kidney Transplantation and Center
for Translational Medicine, Temple University School of Medicine;
4Department of Medicine, Section of Cardiology and Department of Physiology, Temple
University School of Medicine;
5Adult Medical Genetics Program, School of Medicine Division of Cardiology, University
of Colorado Anschutz Medical Campus
While long term combined antiretroviral therapy (cART) has greatly improved survival
rates among AIDS patients, a substantial proportion of HIV-1 infected individuals
continue to develop comorbidities including heart failure (HF) secondary to left ventricular
dysfunction at higher rates than non-HIV-1 individuals. The underlying mechanisms
whereby HIV-1 increases susceptibility to HF remain poorly understood. In this respect,
HIV-1 Tat, which is produced and released by the latent viral reservoir and upon its
circulation can be taken up by uninfected cells, has received special attention due
to its ability to induce an array of dysregulatory events that perturb cell and organ
function. We demonstrate that HIV-1 Tat physically associates with BAG3, a stress
induced protein which is involved in protein quality control, and modulates autophagy
and apoptosis. BAG3 is critical for normal cardiac development and maintenance as
BAG3 knockout mice develop left ventricular (LV) dysfunction and have a shortened
lifespan. Furthermore, recent studies have identified a potential role for BAG3 in
patients with HF as heterozygous mutations that decrease the level of BAG3 and lead
to development of a heritable form of dilated cardiomyopathy. Moreover, ventricular
myocardium isolated from failing human hearts examined at the time of heart transplantation
exhibit nearly 50% reduction in BAG3 levels in cardiac tissue, all of which supports
the importance of BAG3 for healthy heart function. BAG3 is an important regulator
of filamin and myopodin and regulates protein turnover by autophagy in cardiomyocytes.
We provide evidence suggesting that the interplay between BAG3 and HIV-1 Tat impacts
the ability of BAG3 to regulate several pathways involved in the structural and functional
integrity of cardiomyocytes. Thus, one can envision a model in which the inactivation
of BAG3, upon its association with HIV-1 Tat, recapitulates the clinical manifestations
seen in patients with heart failure associated with low/dysfunctional BAG3.
P93
TLR2 is essential for immunity against lethal herpes simplex virus encephalitis
Christina Kollias1, Elizabeth Blankenhorn 2, Brian Wigdahl1, Stephen Jennings1
(presenting author: cmk48@drexel.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Department of Microbiology and Immunology, Center for Immunogenetics & Inflammatory
Disease, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine
HSV-1 is a ubiquitous, neurotropic human pathogen that causes diseases ranging from
mild orofacial lesions to potentially fatal encephalitis. Cells present at the infection
site express pattern recognition receptors including Toll-like receptors that detect
infection, produce antiviral cytokines, and limit viral invasion of the nervous system.
We assessed the role of TLR2 in resistance to HSV-1 encephalitis in a natural lip
infection model. Multiple cell types express TLR2, which recognizes HSV-1 glycoproteins.
We show here that TLR2-knockout (Tlr2-/-) mice were highly susceptible to HSV-1-induced
mortality. Their natural killer cells responded normally, but the mice exhibited impaired
dendritic cell and CD8+ T-cell activation. While virus replication within the lips
was not different, HSV-1 spread to the trigeminal ganglia more efficiently in the
Tlr2-/- group. Additionally, CNS entry was exacerbated in the knockouts and viral
loads there positively correlated with disease severity. The elevated CNS viral load
precipitated the up-regulation of inducible nitric oxide synthase. Nitric oxide is
neurotoxic at high concentrations and presumably contributed to the mortality in the
knockout animals. We then assessed the infiltration of leukocytes to the infected
CNS to study their impact on disease. Neutrophils, which contribute to irreparable
inflammation during viral encephalitis, were observed in the cerebral cortex of the
mice exhibiting the most significant signs of disease, irrespective of their TLR2
status. Lastly, we utilized an intracranial infection model to specifically assess
the role of TLR2 within the CNS, but the virus strain utilized proved too virulent
to reveal a phenotypic difference. In summary, TLR2 is critically important for controlling
the level of HSV-1 that spreads to the CNS, and once the virus accesses the brain,
TLR2-independent responses contribute to the heightened inflammation observed in the
knockout animals. In future studies, we will focus on the identification of the responsible
TLR2+ cell type.
P94
Immune activators reduce heme oxygenase-1 expression in primary astrocytes: Possible
role in HIV neurodegeneration
Colleen Kovacsics1, Surendra Ambegaokar1, Alexander Gill1, Benjamin Gelman2, Dennis
Kolson1
(presenting author: collk@mail.med.upenn.edu)
1Department of Neurology, Perelman School of Medicine at the University of Pennsylvania;
2Department of Pathology, University of Texas Medical Branch
Despite the widespread use of antiretroviral therapy, HIV-associated neurocognitive
disorders (HAND) continue to persist, signifying a need for the development of adjunct
therapeutic strategies. We have identified the anti-oxidant and anti-inflammatory
enzyme heme oxygenase-1 (HO-1) as a potential therapeutic target for HAND. Recently
we characterized HO-1 within the prefrontal cortex of HIV+ individuals and found that
HO-1 protein was deficient in HIV+ individuals and correlated with neurocognitive
impairment; however, HO-1 RNA was increased compared to HIV- controls. We have previously
shown that HO-1 protein is also deficient in HIV-infected monocyte derived macrophages
(HIV-MDM) and this deficiency is associated with enhanced glutamate release and neurotoxicity.
To explain the HO-1 protein deficiency observed in HAND patients and to probe mechanisms
by which this deficiency may contribute to neurotoxicity, we examined HO-1 regulation
within astrocytes, which are the predominant source of HO-1 within the brain and are
critical mediators of glutamate handling. Primary rat and human astrocytes were treated
with immune activators relevant to HIV pathogenesis (IFN-gamma, lipopolysachharide
(LPS), TNF-alpha) and HO-1 expression was assessed after acute (1, 6, 24 hours) and
chronic (15 days) exposure. Chronic, but not acute, treatment significantly reduced
HO-1 protein expression in both rat and human astrocyte cultures; HO-1 RNA was not
altered throughout treatment. Furthermore, chronic treatment did not alter the expression
of other antioxidant proteins (NQO1 and GPX1), suggesting that the reduction of HO-1
protein driven by immune activators is specific and not due to global suppression
of the antioxidant response. These results demonstrate that chronic immune activation
suppresses HO-1 protein within astrocytes, and suggest a mechanism by which chronic
HIV infection leads to a global deficiency of HO-1 within the frontal cortex. Reduced
HO-1 within astrocytes may have important functional consequences for glutamate regulation
and subsequent neurodegeneration, which will be addressed in future studies.
P95
TNF-alpha Dependent Degradation of RXR-gamma: Implications for Substance Abuse Disorder
in HIV
Jane Kovalevich, Ahmet Ozdemir, William Yen, Dianne Langford
(presenting author: tdl@temple.edu)
Temple University School of Medicine, Department of Neuroscience
Since the beginning of the AIDS epidemic, HIV infection and substance abuse have been
linked. The risk of contracting HIV and transmitting HIV increases significantly with
cocaine use. Neurocognitive disorders associated with cocaine abuse or with HIV infection
are exacerbated in patients who are HIV+ and use cocaine. Both cocaine and HIV infection
induce pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha)
and ultimately lead to the disruption of numerous neuronal signaling pathways. The
retinoic acid (RA) signaling pathway is important in a number of cellular processes
and in HIV patients this pathway is disrupted. Our data show for the first time that
cocaine and the HIV protein, Tat significantly disrupt this pathway in the CNS. Retinoid
X receptors (RXR) can homodimerize or serve as required heterodimeric partners for
a number of ligand-activated nuclear receptors, which recognize specific DNA sequences
on target genes to regulate transcriptional activation. Our data show that cocaine
significantly down-regulates RXR-gamma in brains of cocaine treated-mice, Tat transgenic
mice and in neurons in vitro. Additionally, genes regulated by RXR signaling such
as neurogranin, which encodes a protein required for adult neuroplasticity, are significantly
down regulated. The cocaine-induced degradation of RXR-gamma is proteasome dependent
and involves nuclear export of the protein. Additionally, our data show that inhibiting
TNF-alpha signaling, or blocking downstream TNF-alpha effectors such as c-jun-NH2-terminal
kinase (JNK), can attenuate the cocaine-mediated decreases in RXR-gamma levels. Data
from our studies provide the first evidence that exposure to cocaine or to Tat disrupts
RXR-gamma signaling in the CNS, and that TNF-alpha activation likely plays a role.
As RXR dysfunction is implicated in a number of neurodegenerative diseases and psychiatric
disorders, our findings may extend to other neuropathological conditions characterized
by a neuroinflammatory component.
P96
Extracellular HIV-1 viral protein R affects astrocytic glyceraldehyde 3-phosphate
dehydrogenase activity and neuronal survival
Fred Krebs1, Adriano Ferrucci2, Michael Nonnemacher1, Brian Wigdahl1
(presenting author: fred.krebs@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Department of Microbiology and Immunology, Drexel University College of Medicine,
School of Biomedical Engineering, Science and Health Systems, Drexel University
Extracellular human immunodeficiency virus type type 1 (HIV-1) viral protein R (Vpr)
is a pleiotropic protein accomplishing several functions within the viral life cycle.
While Vpr has been described extensively as an intracellular protein, very little
is known about its role as an extracellular protein. In fact, HIV-1 Vpr has been detected
in the blood, serum, and cerebrospinal fluid of HIV-1-infected patients, with concentrations
increasingly higher in late-stage disease. To determine the role exogenous Vpr plays
in HIV-associated central nervous system dysfunction, primary human fetal astrocytes
were exposed to recombinant Vpr and a time- and dose-dependent decrease was demonstrated
in two fundamental intracellular metabolites (ATP and glutathione (GSH)). Additionally,
exposure to exogenous Vpr led to increased caspase activity and secretion of proinflammatory
cytokines IL-6 and IL-8 and chemoattractants, monocyte chemotactic protein-1 and migration
inhibition factor. Extracellular Vpr also dampened the glycolytic pathway through
impairment of GAPDH activity, causing a decline in the levels of ATP. The reduction
in intracellular ATP increased reactive oxygen species buildup, decreasing GSH concentrations,
which affected several genes in the oxidative stress pathway. In addition, exposure
of the SK-N-SH neuroblastoma cell line to conditioned medium from exogenous Vpr-treated
astrocytes decreased synthesis of GSH, leading to their apoptosis. These observations
point to a role that Vpr plays in altering astrocytic metabolism and indirectly affecting
neuronal survival. We propose a model that may explain some of the neurological damage
and therefore neurocognitive impairment observed during the course of HIV-1 disease.
This work is supported by NIH/NINDS R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177,
and NIMH T32 MH079785.
P97
Behavioral phenotyping of mice lacking Pur-alpha, an important regulator of HIV-1
mediated neurodegeneration
Jessica Krueger, Jessica Otte, Mary Barbe, Jennifer Gordon
(presenting author: jennifer.gordon@temple.edu)
Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine
Pur-alpha is a highly conserved sequence specific DNA and RNA binding protein with
established roles in DNA replication, RNA translation, cell cycle regulation, and
maintenance of neuronal differentiation. Pur-alpha is also an important mediator of
HIV-1 gene expression through its strong interaction with the regulatory Tat protein
and neurotoxicity associated with Tat is mediated, at least in part, by Pur-alpha.
Post-natal expression of Pur-alpha in the brain is essential to the normal development
of neurons and synaptic formation in the hippocampus and cerebellum as homozygous
deletion of Pur-alpha causes premature death before adolescence. Animals heterozygous
for Pur-alpha demonstrate haploinsufficiency with significantly reduced levels of
Pur-alpha in the brain and expire before one year of age suggesting that chronic reduction
in Pur-alpha leads to neuropathogenic effects. Here we present for the first time
an assessment of the behavioral phenotype of mice heterozygous for the Pur-alpha knockout
allele. Due to the observed motor dis-coordination and cerebellar changes in the model,
the less physically demanding Barnes maze was used to assess spatial learning and
locomotor activity. A reversal protocol on the maze was used to investigate the animals'
retention of spatial memory long-term as well as their capacity for new memory formation.
A second spatial learning paradigm with low but different motor demands, the novel
object location test, was used to further characterize spatial memory function. A
third test probed sensory alterations using a free-two-choice thermal gradient to
assess peripheral nerve changes. Taken together, our findings from our behavioral
and histochemical assays implicated Pur-alpha in the mediation of neurodegeneration
in the context of HIV-1 infection. Thus, the Pur-alpha knockout mice may provide a
well-defined animal model in which to study mechanisms of HIV-1 associated neurological
disorders, including cognitive deficiencies and peripheral neuropathies. Core facility
services supported by CNAC at Temple (NIMH P30 MH092177).
P98
HIV-1 in the CNS in Post-cART era: Impact on Serotonin Status in Different Regions
of Post Mortem Human Brain
Adarsh Kumar1, Raymond Ownby2, Jesus Fernandez1, Eridania Valdes1, Mahendra Kumar1
(presenting author: akumar@med.miami.edu)
1Department of Psychiatry & Behavioral Sciences, Miller School of Medicine, University
of Miami, FL 33101;
2Department of Psychiatry & Behavioral Medicine, Nova Southeastern University, Fort
Lauderdale, FL 33314
Background: HIV-1 associated neurodegeneration, and dysfunctional neurobiological
systems in the CNS in pre- and post-cART era have been investigated in multitudes
of studies, including ours. However, studies are scarce on the impact of HIV-1 on
the CNS serotonin system, the major neurotransmitter system that regulates behaviors.
In an earlier study carried out in the CSF of HIV-1+ individuals in pre-cART era,
we reported a dramatic decrease in 5-hydroxytryptamine (5-HT) concentration without
any change in 5-HIAA. In the post-cART era, however, the impact of HIV-1 in the CNS
serotonin system has remained elusive, although, 30-50% of HIV-1 infected individuals
continue to experience spectrum of neuropsychiatric disorders, including depression,
affecting quality of life, medication adherence and disease progression.
Objectives: To investigate the impact of HIV-1 on CNS serotonin (5-HT) and 5-HIAA
status as well as HIV-1 RNA load in different regions (frontal cortex, basal ganglia,
hippocampus, hypothalamus, raphe nuclei, amygdale, and substantria nigra) of postmortem
brains of HIV-1+ individuals who during life received cART and were evaluated for
neuropsychiatric disorders, compared to 5-HT status in the brain regions of non-infected
individuals.
Results: We found variable changes (%) in 5-HT and 5-HIAA concentrations in different
brain regions of HIV-1+ individuals (5-HT, -13.7%, +4.5%, -9.6%, -8.9%, -0.244%, -9.27%,
+8.2%; 5-HIAA, +3.84%, -2.1%, -4.91%, -1.7%, +4.6%, -4.3%, - 30% respectively), compared
to that in non-infected persons. The variable changes found in 5-HT and 5-HIAA concentrations
in different brain regions of HIV-1+ individuals in this study are contrary to the
dramatic decrease in CSF 5-HT in HIV-1+ individuals in the pre-cART era. Does cART
influence CNS 5-HT turnover?
Conclusion: Our data suggest that serotonin system in the CNS is vulnerable to HIV-1
infection in the post-cART era. Further studies are warranted on the effect of HIV-1
and cART on multiple indices of CNS serotonergic systems.
P99
Role of PINCH in HIV-induced Tauopathy
Dianne Langford1, Ahmet Ozdemir1, Radhika Adiga1, William Yen1, Melissa Wasilewski1,
Alexandra Carides2, Pallavi Chitturi2
(presenting author: tdl@temple.edu)
1Temple University School of Medicine, Department of Neuroscience;
2Center for Statistical Analysis, Department of Statistics, Fox School of Business
Growing evidence points to significant mechanistic overlap between HIV-associated
neurocognitive disorders (HAND) and age-related neurodegeneration. HIV infected individuals
diagnosed decades ago are beginning to face age-related neurodegeneration and combined
with viral infection and long-term exposure to cART, neurodegeneration is exacerbated.
Cellular dysfunction involving accumulation of aberrant proteins, and loss of protein
quality control are among the most important causes for disease and age-related neurologic
decline. Accumulation of hyperphosphorylated Tau (hpTau) is a neuropathological feature
of aging in HIV encephalitis (HIVE) and other neurodegenerative disorders like Alzheimer’s
disease. We have discovered that an adaptor protein called PINCH is important in the
signaling cascade of HIV-related Tauopathy at multiple levels including cell signaling
and as a clinical correlate of CNS disease severity. PINCH is nearly undetectable
in the healthy CNS, but during HIV infection, it is robustly expressed by neurons.
Our in vitro, in vivo and human data show that PINCH binds directly to hpTau and is
associated with loss of Tau solubility in disease. Unique isoforms of PINCH are detectable
in the CSF of HIV patients and pilot data suggest that CSF levels of PINCH may correspond
in part to immune recovery, rather than viral burden. PINCH inhibits the PP1alpha
phosphatase and competes with Tat for binding. Tat induces Tau translocation to the
somatodendritic compartment of human primary neurons, and decreasing PINCH expression
results in the detection of less hpTau. Understanding the contribution of increased
PINCH to HIV-associated Tauopathy may provide a new therapeutic avenue for reducing
levels of hpTau in the brain. Moreover, characterizing the clinical significance of
PINCH in the CSF may warrant including PINCH as a member of biomarker panel to assess
severity or progression of HIV-associated neurocognitive alterations.
P100
CD16+ monocytes are expanded in SIV infection by mechanisms involving increased production
of CD14+ monocytes in bone marrow as well as increased peripheral maturation (CD14+/CD16+)
Gabrielle Lehmicke1, Mark Lewis2, Wendeline Wagner1, Tracy Fischer-Smith1, Jay Rappaport1
(presenting author: lehmicke@temple.edu)
1Temple University;
2Bioqual Incorporated
We previously demonstrated the expansion of CD16+ monocytes in HIV and SIV infection.
Since the percentage of this monocyte subset correlated with viral load and CD4+ T
cell count, we had suggested a role in AIDS and CNS pathogenesis. These cells likely
also promote the persistent macrophage reservoir of viral infection in the CNS as
well as the periphery. Here, we investigated the dynamics of production and clearance
of total (CD14+) and CD16+ monocytes using in vivo BrdU and CFSE labeling in rhesus
macaques infected with SIVMac251. Three groups of animals included SIV+ (N=6), SIV+/CD8
depleted (N=5), and SIV- [N=5(BrdU), 3(CFSE)] . BrdU and CFSE were injected intravenously
3 months post-infection in all groups in order to label proliferating (i.e. in bone
marrow), and peripheral circulating leukocytes, respectively. Blood specimens were
drawn at 30 minutes, 1, 2, 3, 4, 5, and 7 days post-BrdU/CFSE administration and analyzed
by flow cytometry. An increase in the production of BrdU+ monocytes was observed at
day 1 in the SIV+/CD8 depleted macaques. CD14+ monocytes, emerging as BrdU+, were
virtually all CD16- at 24 hours post BrdU administration, despite the increased production
of total CD14+ monocytes in SIV+/CD8 depleted animals at this time point. At subsequent
time points, however, the percentage of CD16+/BrdU+ monocytes increased, peaking at
day 3 in all groups. These results likely suggest an altered distribution of proliferating
monocyte precursors within the bone marrow. Monocyte clearance was similar in all
groups as determined by CFSE labeling. Taken together, our results suggest the importance
of both altered monocyte production (in bone marrow) as well as maturation in peripheral
compartments, leading to the overall expansion of CD16+ monocytes in AIDS. Analysis
of T cell turnover also provided novel insights regarding CD4+ and CD8+ T-cell dynamics
in AIDS.
P101
Coinfection of human herpesviruses 6A (HHV-6A) and HHV-6B demonstrated by digital
droplet PCR
Emily Leibovitch, Giovanna Brunetto, Breanna Caruso, Kaylan Fenton, Joan Ohayon, Daniel
Reich, Steven Jacobson
(presenting author: emily.leibovitch@nih.gov)
National Institutes of Health, NINDS
The human herpesviruses HHV-6A and HHV-6B are widely distributed in the adult population,
though specifically associated with several disorders of the central nervous system
(CNS) including multiple sclerosis (MS). The association of these viruses with neurologic
diseases has been partly established by the detection of elevated viral DNA levels
in patients compared to controls. Despite their high nucleotide homology, HHV-6A and
HHV-6B were recently reclassified as separate species, owing to mounting evidence
of their biological differences. As it is now especially relevant to investigate each
virus separately, we investigated coinfection of HHV-6A and HHV-6B in human biological
material using a novel quantitative PCR technology called digital droplet PCR (ddPCR).
DdPCR enables the absolute quantification of target DNA molecules and is highly sensitive
for low-level targets. To investigate coinfection, we designed an assay to PCR amplify
both viruses with comparable kinetics, such that small amounts of one could be distinguished
in the presence of large amounts of the other. Using this approach, we observed a
heretofore-underappreciated frequency of HHV-6A and HHV-6B coinfection in the serum,
PBMC and saliva of healthy donors. Interestingly, upon comparing adult MS patients
with healthy donors, we detected a significantly elevated frequency of coinfection
in MS saliva. We are currently exploring whether there are clinical correlates to
coinfection, and assessing saliva samples from pediatric MS patients and controls.
Identifying and quantifying both species of HHV-6 may provide clinically relevant
information and as we learn more about each virus in health and disease, the observation
of coinfection may have profound implications.
P102
Transcriptome analysis of HIV-infected peripheral blood monocytes: genes and networks
associated with neurocognitive functioning
Andrew Levine1, Steve Horvath2, Eric Miller3, Elyse Singer4, Paul Shapshak5, Gayle
Baldwin6, Otoniel Martinez-Maza7, Mallory Witt8, Peter Langfelder9
(presenting author: ajlevine@mednet.ucla.edu)
1Department of Neurology, David Geffen School of Medicine at the University of California,
Los Angeles;
2Department of Human Genetics David Geffen School of Medicine at the University of
California, Los Angeles and Department of Biostatistics, University of California,
Los Angeles;
3Department of Psychiatry and Biobehavioral Science David Geffen School of Medicine
at the University of California, Los Angeles;
4Department of Neurology, National Neurological AIDS Bank David Geffen School of Medicine
at the University of California, Los Angeles;
5Department of Medicine (Division of Infectious Disease & International Medicine)
and Department of Psychiatry & Behavioral Medicine. University of South Florida, Morsani
College of Medicine, Tampa;
6Department of Medicine, David Geffen School of Medicine at the University of California,
Los Angeles;
7Departments of Obstetrics & Gynecology and Department Microbiology, Immunology &
Molecular Genetics, David Geffen School of Medicine at the University of California,
Los Angeles. Department of Epidemiology, UCLA Fielding School of Public Health;
8David Geffen School of Medicine at the University of California, Los Angeles. Los
Angeles Biomedical Research Institute at Harbor-UCLA Medical Center;
9Department of Human Genetics, David Geffen School of Medicine at the University of
California, Los Angeles
Immunologic dysfunction, mediated via monocyte activity, has been implicated in the
development of HIVassociated neurocognitive disorder (HAND). We hypothesized that
transcriptome changes in peripheral blood monocytes relate to neurocognitive functioning
in HIV+ individuals, and that such alterations could be useful as biomarkers of worsening
HAND. METHODS: mRNA was isolated from the monocytes of 86 HIV+ adults and analyzed
with the Illumina HT-12 v4 Expression BeadChip. Neurocognitive functioning, HAND diagnosis,
and other clinical and virologic variables were determined. Data were analyzed using
standard expression analysis and weighted gene co-expression network analysis (WGCNA).
RESULTS: Neurocognitive functioning was correlated with multiple gene transcripts
in the standard expression analysis. WGCNA identified two nominally significant co-expression
modules associated with neurocognitive functioning, which were enriched with genes
involved in mitotic processes and translational elongation. CONCLUSIONS: Multiple
modified gene transcripts involved in inflammation, cytoprotection, and neurodegeneration
were correlated with neurocognitive functioning. The associations were not strong
enough to justify their use as biomarkers of HAND; however, the associations of two
co-expression modules with neurocognitive functioning warrants further exploration.
P103
Activation of HERV-K expression in the brain of ALS patients
Wenxue Li, Richa Tyagi, Lisa Henderson, Avindra Nath
(presenting author: liw8@mail.nih.gov)
Section of Infections of the Nervous System, National Institute of Neurological Diseases
and Stroke, National Institutes of Health
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurological disease that affects
both upper and lower motor neurons. Patients develop gradual loss of voluntary muscle
strength and eventually most die of respiratory failure. Most ALS cases are sporadic
, while up to 10% may be inherited. Although a number of gene mutations have been
identified in the familial form of ALS, the etiology of ALS is still largely unclear.
Our group and others have reported that human endogenous retroviruses type K (HERV-K)
is activated in ALS patients, indicating the possible involvement of HERV-K in the
pathogenesis of ALS. HERVs are fossil sequences of retrovirus infection that were
integrated into human germline chromosomes millions of years ago. Most HERVs are defective
because of mutations. However, type K HERV has relatively preserved genomic sequence.
It may be activated and produce viral particles under certain physiological and pathological
conditions. The reverse transcriptase activity of HERVs in serum was detected in some
ALS patients. Increased HERV-K pol gene was also found in the brain of ALS patients.
In this study, we further studied the expression of HERV-K genes in autopsy brain
tissue of ALS patients. Using quantitative real time PCR, we determined the expression
levels of HERV-K gag, pol, and env in frontal cortex. The ALS patients had significantly
higher expression levels of HERV-K genes compared to controls. The expression of three
HERV-K genes correlated with each other. Our results confirmed the activation of HERV-K
in the brain of ALS patients. This warrants further investigation of the activation
mechanism.
P104
Quantifying Spinal Cord Cross-sectional Area in HTLV-1 Associated Myelopathy/Tropical
Spastic Paraparesis and Multiple Sclerosis
Winston Liu, Raya Massoud, Daniel Reich, Govind Nair, Steve Jacobson
(presenting author: winston.w.liu@gmail.com)
National Institutes of Neurological Disorders and Stroke
Human T-cell lymphotropic virus-1 associated myelopathy/tropical spastic paraparesis
(HAM/TSP) and multiple sclerosis (MS) can both lead to progressive inflammatory myelopathy.
Although spinal cord atrophy can be qualitatively detected on routine clinical MRI,
a robust and sensitive method to quantify changes in spinal cord size might improve
characterization of disease severity and progression. Such a method could help develop
an imaging marker for disease, and serve as a surrogate end point in clinical trials.
MRI was performed on 18 HAM/TSP, 9 MS and 10 healthy volunteers on a Siemens 3T Skyra
system equipped with head-neck and spine array coils. Cross-sectional area of the
spinal cord was measured using a novel algorithm developed in-house that traces axial
contours perpendicular to the cord-edge at each point from C1 to T10 vertebral body
segments. Average cross-sectional area in both the T-spine and C-spine were significantly
lower in HAM/TSP patients (C-spine: 50.75 ± 10.02 mm2; T-spine: 24.76 ± 5.01 mm2)
as compared to healthy controls (C-spine: 72.02 ± 5.792 mm2, p<0.0001; T-spine: 38.8
± 6.048 mm2, p<0.0001). However, cross-sectional area was only significantly different
in the T-spine when comparing HAM/TSP with MS patients (C-spine: 61.84 ± 9.54 mm2;
T-spine: 34.84 ± 5.72 mm2, p<0.001). In HAM/TSP, the cross-sectional areas from multiple
cord segments correlated with disease duration (C1-C3, C6, T1-T2), Extended Disability
Status Scale (EDSS) (T2), and Hauser Ambulation Index (T2, T6), but no correlation
was observed between HAM/TSP cross-sectional area and proviral load. MS cross-sectional
area correlated with EDSS (C1-C3, T1-T6). These results suggest that patterns of spinal
cord tissue damage are specific to the underlying disease, a finding that has direct
implications for the use of average cross-sectional spinal cord area as a surrogate
end point for clinical trials. Longitudinal studies are underway to help improve our
understanding of the disease process.
P105
Structural and functional studies of CCAAT/enhancer binding sites within the human
immunodeficiency type 1 subtype C LTR
Kyle Lord, Yujie Liu, Michael Nonnemacher, Brian Wigdahl
(presenting author: kyle.alexander.lord@drexel.edu)
Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine
Human immunodeficiency virus type 1 (HIV-1) subtype C, which is the most predominant
subtype in sub-Saharan Africa as well as in Asia and India, is also the most prevalent
subtype worldwide. A large number of transcription factor families have been shown
to be involved in regulating HIV-1 gene expression in T-lymphocytes and cells of the
monocyte-macrophage lineage. Among these, proteins of the CCAAT/enhancer binding protein
(C/EBP) family are of particular importance in regulating HIV-1 gene expression within
cells of the monocytic lineage during the course of hematologic development and cellular
activation. Few studies have examined the role of C/EBPs in long terminal repeat (LTR)-directed
viral gene expression of HIV-1 subtypes other than subtype B. Within subtype B viruses,
two functional C/EBP sites located upstream of the TATA box are required for efficient
viral replication in cells of the monocyte-macrophage lineage. We report the identification
of three putative subtype C C/EBP sites, upstream site 1 and 2 (C-US1 and C-US2) and
downstream site 1 (C-DS1). C-US1 and C-DS1 were shown to form specific DNA-protein
complexes with members of the C/EBP family (C/EBP alpha, beta, and gamma). Functionally,
within the U-937 monocytic cell line, subtype B and C LTRs were shown to be equally
responsive to C/EBP beta-2, although the basal activity of subtype C LTRs appeared
to be higher. Furthermore, the synergistic interaction between C/EBP beta-2 and Tat
with the subtype C LTR was also observed in U-937 cells as previously demonstrated
with the subtype B LTR. This work is supported by NIH/NINDS R01 NS32092, NIDA R01
DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P106
Moderate neurocognitive decline can be detected over a four-month period using the
HIV-dementia scale
Grace Lu1, Bruce Brew2, Krista Siefried3, Brian Draper4, Lucette Cysique5
(presenting author: bbrew@stvincents.com.au)
1University of New South Wales, St Vincent's Hospital Clinical School Sydney Australia;
2University of New South Wales, St Vincent's Hospital Sydney Australia, St Vincent's
Centre for Applied Medical Research;
3St Vincent's Hospital Sydney Australia;
4School of Psychiatry, University of New South Wales, Sydney Australia;
5University of New South Wales, St. Vincent’s Hospital Clinical School Sydney Australia,
Neuroscience Research Australia Sydney Australia, St. Vincent’s Hospital Sydney Australia,
St. Vincent’s Centre for Applied Medical Research Sydney Australia;
Background: The HIV Dementia scale (HDS) has been recommended as a cross-sectional
screen to identify HIV-associated neurocognitive disorder (HAND) but its longitudinal
usefulness has not been established.
Method: 55 HIV+ participants (aged 57.7±8.3, 96% males) underwent baseline and follow-up
HDS screening at 3.9±1.1 months, a standard neuropsychological (NP) evaluation, and
baseline clinical and laboratory examination. At baseline 49.1% met the gold standard
HAND diagnostic definition. Based on longitudinal published normative standards, 12.7%
showed statistically significant decline (gold standard decline was based on an 80%
confidence interval; 1-tailed to include mild decline). To systematically assess HDS
criterion validity against the NP gold standard, we determined HDS baseline impairment
status based on the three published HDS cut-offs (≤10, ≤14, and demographically-corrected
HDS T-scores<40). To determine statistically significant decline on the HDS (80% confidence
interval; 1-tailed), we developed standard HDS regression-based change scores after
arcsine-root transformation to normalize the data distribution. HDS longitudinal criterion
validity was determined by comparing HDS-based decline to gold standard NP-based decline
using indexes of sensitivity and specificity.
Results: Baseline HDS cut-off ≤14 yielded the highest sensitivity and specificity
(52% sensitivity, 81% specificity) compared to the other cut-offs ≤10 (26% sensitivity,
96% specificity) and T-score <40 (41% sensitivity, 57% specificity). The magnitude
of the HDS reliability was very large r=.76 (p<.0001). We found that 21.8% declined
by the HDS. In cases congruently identified, median raw decline=2.75; median HDS-change
score decline=1.98. The HDS showed 57% sensitivity and 82% specificity in detecting
clinically meaningful decline, signifying that only cases that declined moderately
were congruently identified. Having a HAND diagnosis at baseline (p=0.01) and more
severe HAND diagnosis were associated with greater chance of decline (p<0.03). No
HIV biomarkers were associated with decline.
Conclusions: This is the first study to optimally demonstrate that the HDS reliably
detects at least moderate neurocognitive decline.
P107
Beta-catenin positively regulates key proteins in glutamate cycling in vivo
Victoria Lutgen, Srinivas D Narasipura, Stephanie Min, Maureen Richards, Lena Al-Harthi
(presenting author: victoria_lutgen@rush.edu)
Rush University Medical Center
Neurological disorders including HIV-associated neurocognitive disorders (HAND) have
been linked to abnormal excitatory neurotransmission. Perturbations in glutamate cycling
can have profound impacts on normal activity, lead to excitotoxicity and create or
exacerbate impairments in these diseases. Astrocytes play a key role in excitatory
signaling as they both clear glutamate from the synaptic cleft and house enzymes responsible
for glutamate conversion to glutamine. However, mechanisms responsible for the regulation
of glutamate cycling including the main astrocytic glutamate transporter excitatory
amino acid transporter 2 (EAAT2) or GLT-1 in rodents and glutamine synthetase (GS)
which catalyzes the ATP-dependent reaction of glutamate and ammonia into glutamine,
remains largely undefined. We previously demonstrated that beta-catenin, a transcriptional
co-activator and the central mediator of Wnt/beta-catenin signaling pathway, regulates
both EAAT2 and GS expression in astrocytes in vitro. We assessed here whether beta-catenin
regulates these two proteins in vivo. Towards this end, we injected vivo-morpholinos
(500nM) to knockdown beta-catenin expression or control morpholinos into the prefrontal
cortex (co-ordinates, AP+2.0, ML+/- 0.3, DV 1.0) of 4-6 week old C57 BL/6 male mice
using stereotaxic microinjection technique. Morpholinos, which block the translation
initiation of their gene target, were injected at day 0 and day 3. At day six post
first injection, a small chunk of brain tissue at the injection site was collected,
processed for protein isolation using RIPA buffer and analyzed by western blotting.
We demonstrate that knockdown of beta-catenin resulted in a significant reduction
in GLT-1 and GS protein expression by 99 and 93 percent respectively. These studies
confirm that beta-catenin regulates key proteins responsible for excitatory glutamate
neurotransmission in vivo and reveal the therapeutic potential of Wnt/beta-catenin
modulation in treating diseases with abnormal glutamatergic neurotransmission and
excitotoxicity. This work is supported by R01NS060632 to LA.
P108
Molecular Mechanisms for Alterations in Human Neural Precursor Cell Proliferation
by HIV-1 Tat and Morphine
Shaily Malik, Rinki Saha, Pankaj Seth
(presenting author: pseth@nbrc.ac.in)
Molecular and Cellular Neuroscience, National Brain Research Centre
Co-morbidity of HIV-1 and illicit drugs modulate properties of neural precursor cells
(NPCs). In an attempt to gain insights into the pathways that may mediate such comorbidities,
human fetal brain derived neural precursor cells (hNPCs) were exposed to HIV Transactivating
protein, Tat and illicit opioid, morphine at various doses and time points. Alterations
in hNPC proliferation with Tat and morphine exposure were assessed by Ki67 and BrdU
immunoreactivity of treated cells. Changes in proliferative genes were analyzed at
RNA and protein levels and several molecular mediators were investigated. Using cell
biology and molecular approaches, we observed that chronic treatment of HIV protein,
Tat and morphine affect hNPC proliferation. DNA content analysis by FACS and decreased
BrdU levels in Tat-morphine treated hNPCs indicated perturbations in S-phase of the
cell cycle. HIV-Tat and morphine attenuated Sox2 and CyclinD1 and increased the expression
of p53 and CDK inhibitor, p21 thereby reducing the actively dividing population of
hNPCs. p21 was found to be governed by Extracellular signal-regulated kinase-1/2 (ERK1/2)
while p53 was found to be essential for Tat and morphine induced decrease in NPC proliferation.
The synergy of Tat and morphine induced changes in hNPC proliferation were mostly
observed after chronic exposure as opposed to the acute exposure to these neurotoxic
agents. Interferon-gamma (IFN-g) levels were also elevated in NPCs with Tat and morphine
exposure, leading to altered Signal Transducer and Activator of Transcription (Stat)
levels and derangement of Stat-Sox-2 pathway. Such growth arrest in hNPCs may have
far reaching clinical implications as it may lead to impaired ability of these cells
to maintain their own pool as well as compromise replenishment of damaged brain cells.
Authors acknowledge financial support from Department of Biotechnology, ICMR and NBRC
to PS and University Grants Commission, New Delhi for fellowship to SM.
P109
Activation of endogenous retroviruses of the HERV-W family by Epstein Barr virus in
vitro and in vivo: a dual virus model as the missing link with multiple sclerosis
Giuseppe Mameli1, Luciana Poddighe1, Elena Uleri1, Alessandra Mei1, Caterina Serra1,
Giordano Madeddu2, Roberto Manetti2, Antonina Dolei3
(presenting author: doleivir@uniss.it)
1Department of Biomedical Sciences, University of Sassari;
2Department of Clinical and Experimental Medicine, University of Sassari.;
3Department of Biomedical Sciences, University of Sassari
The immuno-pathogenic phenomena leading to neurodegeneration of multiple sclerosis
(MS) are thought to be triggered by environmental factors operating on predisposing
genetic backgrounds. Among proposed co-factors are EBV, and the potentially neuropathogenic
HERV-W/MSRV/Syncytin-1 endogenous retroviruses. The ascertained EBV-MS links are late
primary infection (possibly with infectious mononucleosis, IM), and high titers of
pre-onset anti-EBNA IgG. During MS, there is no MS-specific EBV expression, while
continuous expression of HERV-Ws occurs, paralleling MS stages, active/remission phases,
and therapy outcome. (A) In vitro data: the expression of HERV-W/MSRV/syncytin-1,
with/without exposure to EBV or to EBVgp350, was studied in PBMC from healthy volunteers
and MS patients, and in astrocytes. Expression of HERV-W/MSRV/syncytin-1 is amplified
in untreated MS patients, and dramatically reduced during therapy. In EBVgp350-treated
PBMC, MSRVenv and syncytin-1 transcription is activated in B cells and monocytes,
but not in T cells, nor in the highly expressing NK cells. (B) In vivo data: hospitalized
young adults with IM symptoms were analyzed for expression of HERV-W/MSRV transcripts
and proteins. Healthy controls were either EBV-negative or latently EBV-infected with/without
high titers of anti-EBNA-1 IgG. HERV-W/MSRV is activated in PBMC of IM patients (2Log10
increase with respect to EBV-negative controls). When healthy controls are stratified
for high, low, or no anti-EBNA-1 IgG titers, a direct correlation occurs with MSRV
expression. Flow cytometry shows increased percentages of cells exposing surface HERV-Wenv
protein, that occur differently in specific cell subsets, and in acute disease and
past infection. Conclusions: in vitro EBV activates the potentially immunopathogenic
and neuropathogenic HERV-W/MSRV/syncytin-1, in cells deriving from blood and brain.
In vivo the two main links between EBV and MS (IM and high anti-EBNA-1-IgG titers)
are paralleled by HERV-W/MSRV activation. These novel findings suggest HERV-W/MSRV
activation as the missing link between EBV and MS, and may open new avenues of intervention.
P110
A Window to the Peripheral Nervous System: Corneal Sensory Nerve Fiber Loss in SIV-infected
Macaques
Lisa Mangus1, Jamie Dorsey1, Jonathan Oakley2, Joseph Mankowski1
(presenting author: lmangus1@jhmi.edu)
1Department of Molecular and Comparative Pathobiology, Retrovirus Laboratory, Johns
Hopkins University;
2Voxeleron
Human immunodeficiency virus-associated peripheral neuropathy (HIV-PN) is currently
the most frequent neurologic complication of HIV infection, affecting most individuals
living with HIV. HIV-PN is a length-dependent small sensory fiber neuropathy typified
by bilateral numbness, tingling, and burning sensations in the lower legs. Because
electrophysiology is insensitive to changes in small unmeylinated fibers, microscopic
evaluation of epidermal nerve fiber density in skin biopsies has become the standard
for diagnosis of HIV-PN. However, longitudinal assessment is limited by the invasiveness
of this technique. While noninvasive assessment of corneal sensory nerves has proven
clinically useful in diagnosing and monitoring other peripheral neuropathic conditions,
such as diabetic neuropathy, corneal nerve alterations in HIV have yet to be characterized.
In this study based in the SIV/macaque model, we first developed a beta-III tubulin
immunostaining protocol for detecting corneal nerves, and then developed both manual
and automated counting methods to measure corneal nerve density. These counting methods
each demonstrated significantly lower subbasal corneal nerve fiber counts among SIV-infected
animals that rapidly progressed to AIDS as compared to slow progressors. Concomitant
with decreased corneal nerve fiber density, rapid progressors had increased levels
of SIV RNA, CD68-positive macrophages, and GFAP expression by glial satellite cells
in the trigeminal ganglia. These findings demonstrate that corneal nerve assessment
has great potential to diagnose and monitor HIV-induced peripheral neuropathy and
set the stage for introducing noninvasive techniques to evaluate PNS damage in the
HIV clinical setting.
P111
Glutamine antagonist, DON, protects mice from acute fatal encephalomyelitis by inhibiting
T-cell growth and proliferation
Sivabalan Manivannan1, Barbara Slusher2, Diane E. Griffin1
(presenting author: smanivan@jhsph.edu)
1Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School
of Public Health,;
2Department of Neurology and Psychiatry and the Johns Hopkins Brain Sciences Institute,
Johns Hopkins School of Medicine
Inflammation in the nervous system is a necessary part of the response to CNS infection,
but also causes neuronal damage in both infectious and autoimmune diseases of the
CNS. Sindbis virus is an enveloped, positive-strand RNA virus that causes acute encephalomyelitis
and fatal paralysis in mice. Adult C56BL/6 mice inoculated with the neurovirulent
strain of Sindbis virus (NSV) succumb to fatal paralysis despite clearing infectious
virus from the central nervous system. We show that low daily doses of the non-reversible
glutamine antagonist, DON (6-diazo-5-oxo-l-norleucine), rescues mice from fatal paralysis
by inhibiting the inflammatory immune response. DON-treated mice fail to induce an
adaptive immune response to the virus in the deep cervical lymph-nodes and show decreased
CD45+ and CD3+ lymphocyte infiltration into the brain and delayed viral clearance
compared to vehicle-treated controls. DON-treated mice show significantly reduced
mRNA expression of neurotoxic and inflammatory cytokines (TNF-alpha, IL-1b, IL-6,
and IFN-gamma) during the course of viral infection in the brain compared to vehicle
controls. Additionally, in vitro studies using purified CD3+ T-cells show that DON
inhibits the growth and proliferation, but not the activation, of primary mouse CD3+
T-cells in response to stimulation with anti-CD3/CD28. Following stimulation, DON-treated
lymphocytes show a defect in S6 phosphorylation, a downstream mTOR pathway target
suggesting impaired protein translation in primary lymphocytes. Stimulated DON-treated
T-cells have lower IL-2 protein production despite having similar levels of IL-2 mRNA
compared to vehicle controls. These studies suggest that small molecules that antagonize
glutamine metabolism are immunomodulatory and could be beneficial in the treatment
of neuroinflammatory diseases.
P112
Effects of HIV Serostatus and Comorbid Drug Dependence on Neurocognition
Eileen Martin1, Raul Gonzalez2, Jasmin Vassileva3
(presenting author: eileen_martin@rush.edu)
1Rush University Medical Center;
2Florida International University;
3University of Illinois
Drug abuse is common among HIV-seropositive persons but questions arise if HIV’s neurocognitive
effects can be distinguished from more nonspecific effects of drug dependence and
associated comorbidities. In a preliminary study, we administered four cognitive neuropsychological
tasks to a sample of 77 HIV- and 25 HIV+ men and women with no history of drug dependence
that were well-matched on demographic characteristics; and 310 HIV- and 137 HIV+ individuals
with lifetime DSM-IV-diagnosed cocaine or opioid dependence. The drug using groups
were well matched on demographic, substance use severity, and potentially confounding
comorbid disorders including PTSD, depression, ADHD and antisocial traits. Current
and nadir CD4 counts and viral suppression did not differ significantly between HIV+
drug users and non-users. All subjects performed motor and cognitive procedural learning
tasks dependent on the integrity of neostriatum and two measures of impulsive behavior
typically performed poorly by drug users. HIV affects neostriatal systems relatively
more than drug dependence, which typically engages ventral/limbic striatal processing;
we reasoned that HIV+ groups would perform procedural learning tasks more poorly than
HIV- groups, regardless of drug history. In a series of HIV Serostatus x Drug History
analyses of variance, we found significant main effects (poorer performance) for Drug
Use but not HIV Serostatus on both inhibitory tasks, p < .05 for each task; and significant
main effects for HIV Serostatus but not Drug History for each procedural learning
task, p = .01 for each test. This demonstration provides proof of concept that theory
driven cognitive neuropsychological tasks may have the capacity to detect effects
of HIV on neurocognition not attributable solely to drug dependence; however, conclusions
that are more definitive will require more sophisticated statistical approaches.
P113
Clinical trial of a humanized monoclonal anti-IL15Rbeta (CD122) antibody, in HTLV-1
associated myelopathy/ tropical spastic paraparesis (HAM/TSP)
Raya Massoud1, Yoshimi Enose-Akahata1, Joan Ohayon1, Kaylan Fenton1, Irene Cortese1,
Steven Jacobson1, Thomas Waldmann2
(presenting author: raya.massoud@nih.gov)
1NINDS/NIH;
2NCI/NIH
CD122 is the common beta subunit shared by the receptors of interleukins-2 and -15
(IL-2, IL-15), two cytokines implicated in the immunopathogenesis of HTLV-1 associated
myelopathy/ tropical spastic paraparesis (HAM/TSP). Several in vitro findings suggest
that CD122 might be a therapeutic target in this condition : HAM/TSP CD8+ T-cells
show increased CD122 expression at baseline and the addition of Mik-Beta1, a monoclonal
antibody against CD122, to cultures of HAM/TSP peripheral blood mononuclear cells
(PBMC) decreases endogenous STAT-5 phosphorylation, spontaneous CD8+T-cell degranulation,
spontaneous lymphoproliferation and reduces the frequency and cytotoxicity of Tax-specific
CD8+T-cells. Based on these findings, we are currently evaluating the safety, clinical
and immunological effects of anti-IL15RBeta monoclonal antibody therapy at 1mg/kg
in patients with HAM/TSP. As of today three subjects have been treated at this dose
and all showed saturation of the CD122 receptor. The therapy seems to be well tolerated
and we have detected a reduction in multiple ex vivo immune activation markers (CD8
spontaneous degranulation, STAT5 phosphorylation and spontaneous lymphocyte proliferation).
Notably, one patient reported resolution of neurogenic bladder symptoms and we observed
objective clinical improvement in two out of three treated patients.
P114
HIV +/- opiate-mediated neurotoxicity: GSK3beta is a potential therapeutic target
Ruturaj Masvekar1, Nazira El-Hage2, Kurt Hauser2,3, Pamela Knapp1,2,3, Joyce Balinang1
(presenting author: masvekarrr@vcu.edu)
1Department of Anatomy and Neurobiology,
2Department of Pharmacology and Toxicology,
3Institutes for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond,
VA 23298
HIV disrupts normal immune system functioning, and can also induce a wide range of
neurological deficits, collectively known as HIV-associated neurocognitive disorder
(HAND). Our previous work has shown that neurotoxic effects induced by the HIV-1 proteins
Tat and gp120 are variably enhanced by co-exposure to morphine, an opiate that preferentially
acts through mu-opioid receptors (MOR). This mimics co-morbid neurological effects
observed in opiate-abusing HIV patients, which occur even in patients receiving HAART.
Previous studies have shown that HIV induces abnormal activation of GSK3beta, leading
to neurotoxicity, but little is known about the role of GSK3beta in HIV-opiate interactive
effects. As tau-immunoreactive tangles have been found in brains of young opiate abusers,
we predict crosstalk between MOR-mediated signaling pathway/s and GSK3beta. To mimic
the disease process more closely, the current studies use supernatant from HIV-infected
monocytes instead of single HIV proteins. U937 human leukemic monocyte lymphoma cells
were infected with HIVSF162, an R5-tropic strain. Supernatants were collected and
p24 levels were measured by ELISA to assess infection. Adjusted titers were added
to cultured murine striatal neurons, in the presence or absence of morphine; all treatments
were carried out either in presence or in absence of GSK3beta-inhibitors (VPA, SB415286
and Calbiochem® GSK3beta Inhibitor XXVI) to determine role of GSK3beta in these processes.
Both lethal and sublethal effects on neurons were assessed in populations, and also
by time-lapse imaging of individual cells over 72 h. Infective supernatants (p24 =
25 pg/ml) induced neurotoxicity, affecting both survival and neuritic arborization;
and for selective neurotoxic measures there were significant interactions with morphine.
Importantly, GSK3beta-inhibitors significantly reduced HIV-mediated neurotoxicity,
and also negated the interactive effects of morphine. Our results suggest that GSK3beta
activation is a point of convergence and therapeutic target for opiate- and HIV-mediated
neurocognitive deficits.
P115
Altered tight junction protein expression in response to prolonged morphine exposure
in an in vitro model of the blood-brain barrier
Monique Maubert1, Marianne Strazza1, Vanessa Pirrone1, Wei Lin2, Rui Feng2, Brian
Wigdahl1, Michael Nonnemacher1
(presenting author: mem446@drexel.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistics, University of Pennsylvania School of Medicine
Approximately one-third of human immunodeficiency virus type 1 (HIV-1) cases resulting
in acquired immunodeficiency syndrome (AIDS) in the United States have been associated
with injection drug use within the HIV-1-positive population. Specifically, opioid
abuse within this population exacerbates disease progression, including increased
viral replication and peripheral viral load, as well as incidence and severity of
neurocognitive impairment, as compared to non-users. The blood-brain barrier (BBB)
is altered as a component of the pathology associated with the processes that ultimately
result in HIV-associated neurocognitive disorders (HAND). HIV-1 proteins, as well
as selected drugs of abuse, have been implicated in compromise of the BBB. Previous
studies have suggested that exposure to mu-opioids alters BBB permeability, resulting
in increased cellular transmigration, as well as overall barrier leakiness. In this
study, a human brain microvascular endothelial cell (hBMEC) line, hCMEC/D3, was utilized
to establish an in vitro transwell model of the BBB to investigate the effects of
chronic (24, 48, or 72 h) morphine exposure on the tight junction proteins (TJPs)
of the BBB. We observed that hCMEC/D3 cells form a confluent monolayer with a basal
rate of passage of a 70 kDa tracer molecule comparable to primary hBMECs. Although
chronic morphine exposure did not induce overall barrier leakiness, changes in mRNA
transcripts of tight junction proteins were observed throughout the course of exposure.
At the protein level, TJP localization was analyzed following cell fractionation and
western immunoblot analysis. Overall, these studies demonstrated that prolonged morphine
exposure induced changes in TJP expression patterns at both the mRNA and protein level.
This work is supported by NIH/NINDS R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177,
and NIMH T32 MH079785.
P116
Acute phase protein lipocalin-2 and disruption of CCR5 signaling cooperate to prevent
microglial activation and neuronal injury by CXCR4-utilizing HIVgp120
Ricky Maung1, Melanie Hoefer1, Ana Sanchez1, Natalia Sejbuk1, Kathryn Medders1, Maya
Desai2, Irene Catalan1, Cari Dowling1, Cyrus de Rozieres1, Gwenn Garden3, Rossella
Russo4, Amanda Roberts5, Roy Williams6, Marcus Kaul1
(presenting author: mkaul@sanfordburnham.org)
1Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute;
2Neuroscience, Aging and Stem Cell Research Center, Sanford-Burnham Medical Research
Institute;
3Department of Neurology, University of Washington, Seattle;
4Department of Pharmacobiology, University of Calabria, Arcavacata di Rende;
5Molecular & Cellular Neurosciences Department, The Scripps Research Institute;
6Bioinformatics Shared Resource, Sanford-Burnham Medical Research Institute
HIV-1 infection continues to cause associated neurocognitive disorders (HAND) despite
the success of combination anti-retroviral therapy (cART). The cellular mechanisms
underlying the development of HAND are poorly understood. Virus-associated or soluble
viral envelope glycoprotein gp120 interacts with CD4 in conjunction with CCR5 and
CXCR4 leading to infection and/or cellular signaling, and we study the role of the
viral co-receptors in HIV-associated brain injury. Mice expressing a CXCR4-utilizing
HIVgp120 as transgene in the brain (gp120tg) share key neuropathological features
with AIDS patients, such as the loss of neurites and synapses, pronounced astrocytosis
and activated microglia. However, the genetic knockout of CCR5 in gp120tg mice abrogates
neuronal injury and microglial activation, but not astrocytosis. In order to further
characterize the protective effect of the CCR5KO we performed a gene expression analysis
for brains of CCR5WT and CCR5KO HIVgp120tg mice and non-tg controls. The microarray
study revealed that brains of HIVgp120tg mice and HIV patients with neurocognitive
impairment, with and without encephalitis (HIVE) share a significant part of differential
gene regulation. Furthermore, brains of CCR5WT and CCR5KO HIVgp120tg mice express
markers of an innate immune response, and one of the most significantly up-regulated
factors is the acute phase protein lipocalin-2 (LCN2). In follow-up in vitro experiments
we found that LCN2 is itself neurotoxic in a CCR5-dependent fashion whereas, as expected,
blockade of CCR5 alone failed to block neurotoxicity of a CXCR4-utilizing gp120. However,
the combination of LCN2 and disruption of CCR5 signaling caused a significant loss
of microglial cells and at the same time completely abrogated neurotoxicity induced
by the CXCR4-utilizing gp120. Altogether our studies identified LCN2 as a potential
novel player in HIV-associated brain injury and provided a mechanism of how CCR5-deficiency
could protect against neurotoxicity of a CXCR4-utilizing HIVgp120. Supported by NIH
grants R01 MH087332, DA026306 and DA029480 (to M.K.).
P117
Apolipoprotein E influences innate immune responses of maturing human neuroepithelial
progenitor cells exposed to HIV-1
Micheline McCarthy1, Rebeca Geffin1, Ricardo Martinez2, Roberto Perez2, Biju Issac3
(presenting author: mmccarth@med.miami.edu)
1Department of Neurology, Miller School of Medicine, University of Miami, Miami VA
Medical Center;
2Miami VA Medical Center;
3Sylvester Comprehensive Cancer Center, Miller School of Medicine, Univ of Miami
HIV enters the brain early during infection and induces a chronic inflammatory state
that can result in neurological abnormalities ranging from mild cognitive dysfunction
to severe encephalitis. To better understand the effects of HIV on neural cells, we
have used an in vitro model consisting of human neuroepithelial progenitor (NEP) cells
that undergo directed differentiation into astrocytes and neurons.
In the presence of HIV-1-containing culture supernatants, maturing neurons having
the apolipoprotein E4 allele have lower total neurite lengths per cell and moderately
reduced levels of neurofilament protein. To investigate whether apolipoprotein E genotype
influences changes in gene expression in HIV-exposed NEP cultures, gene expression
was detected using microarrays with the Illumina HT-12 V4_0_R1 platform array. This
was performed in 4 independent cultures of the apoE3/E3 genotype and 3 independent
cultures of the apoE3/E4 genotype. Through this approach, we identified 32 genes specifically
upregulated with a fold change of ≥ 1.5 during exposure to virus, most related to
interferon induced responses and antigen presentation. Interestingly, this innate
immune response was more robust in the apolipoprotein E3/E3 genotype cultures than
in the apolipoprotein E3/E4 counterparts. Biological processes, as defined by the
gene ontology (GO) program, corroborated these observations, and processes related
to antigen presentation and the actions of interferons were also different among the
apoE cultures. Differences were manifested both in the numbers of genes affected as
well as their significance in the GO processes in which they participate, with apoE3/E3
higher and more significant than apoE3/E4.
These data suggest that maturing NEP cultures respond to HIV by mounting an innate
immune response with a vigor that is influenced by the apolipoprotein E genotype of
the cells.
P118
Increased expression of CD39 and CD73 in frontal white matter of SIV infected rhesus
macaque brain tissue: implications for the immunopathogenesis of AIDS and persistence
of infected reservoirs
Laura McCourt1, Edward J. Gracely2, Olimpia Meucci3, Tracy Fischer-Smith1, Jay Rappaport1,
Wendeline Wagner4
(presenting author: laura.mccourt@temple.edu)
1Temple University School of Medicine;
2Drexel University School of Public Health;
3Drexel University School of Medicine;
4Bioqual Incorporated
CD39 and CD73 are ectonucleotidases that hydrolyze extracellular ATP into ADP/AMP
and adenosine, respectively. Adenosine exerts suppressive effects on effector T cells
via interaction with A2A and A2B receptors and furthermore, promotes M2 polarization
of macrophages via A2B receptors. Conversely ATP exerts immune stimulatory effects.
The hydrolysis of ATP by extracellular CD39 and CD73 has been investigated in the
context of certain tumor microenvironments and has been proposed to provide an important
mechanism for evasion of immune surveillance in cancer. HIV, which establishes chronic
and persistent infection, resistant to eradication via adaptive immune mechanisms,
may also promote immune suppression via the hydrolysis of extracellular ATP. In our
initial pilot studies, CD39 and CD73 levels were evaluated qualitatively and quantitatively
in the frontal white matter of rhesus macaques by immunohistochemistry. CD39 and CD73
are primarily expressed within microglia, perivascular macrophages, and microglial
nodules, the latter in brain tissue from animals with SIV encephalitis. Samples from
macaques with SIV infection with and without encephalitis exhibited increased expression
of CD39 and CD73 compared to uninfected, control specimens. These results suggest
a role for ectonucleotidases in the pathogenesis of AIDS and may provide a mechanism
for the persistence of HIV/SIV infected reservoirs within the CNS and potentially
other compartments.
Acknowledgements: This work was supported by grants from NIH/NIMH 1R01MH090910 and
R01MH101010 to JR. We acknowledge the support from the Comprehensive NeuroAIDS Center
(Kamel Khalili, Ph.D. Program Director, P30MH092177), Basic Science Core II, for providing
Neuropathology consultation services (Yuri Persidsky, M.D., Ph.D.).
P119
Central and Peripheral Markers of Neurodegeneration and Monocyte Activation in HIV-Associated
Neurocognitive Disorders
Jennifer McGuire1, Alexander Gill2, Steven Douglas3, Dennis Kolson4
(presenting author: agill@mail.med.upenn.edu)
1Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA;
Center for Epidemiology and Biostatistics, Perelman School of Medicine at the University
of Pennsylvania, Philadelphia, PA.;
2Department of Neurology, Perelman School of Medicine at the University of Pennsylvania,
Philadelphia, PA.;
3Division of Allergy and Immunology, The Children's Hospital of Philadelphia, Philadelphia,
PA; The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA;
Department of Pediatrics, Perelman School of Medicine at the University of Pennsyl;
4Department of Neurology, Perelman School of Medicine at the University of Pennsylvania,
Philadelphia, PA
Background: HIV-associated neurocognitive disorders (HAND) affect up to 50% of HIV-infected
adults, independently predict HIV morbidity/mortality, and are pathologically associated
with neuronal damage and monocyte activation. CSF neurofilaments (NFL, pNFH) are sensitive
surrogate markers of neuronal damage in other diseases. In HIV, CSF NFL is elevated
in untreated HAD. However, CSF NFL/pNFH expression has not been characterized in milder
forms of HAND (MND, ANI). In addition, the relationship between neurofilaments and
CSF/plasma markers of monocyte activation has not been fully explored.
Objectives: 1. Determine CSF NFL/pNFH expression across HAND stages and neurocognitively
normal (NCN) HIV+ controls. 2. Determine the relationships between CSF NFL/pNFH and
CSF/plasma markers of monocyte activation (sCD14/sCD163/HO-1).
Methods: This retrospective descriptive cross-sectional study included 48 HIV-infected
adults (15 each ANI/MND/NCN; 3 HAD) off ART, enrolled in CHARTER. Biomarkers were
measured by validated ELISAs of CSF (NFL/pNFH), paired CSF/plasma (sCD14/sCD163),
and plasma (HO-1). Intergroup comparisons were performed using Kruskal-Wallis and
Wilcoxan rank-sum tests. Spearman’s correlation coefficients compared different biomarker
profiles.
Results: CSF NFL/pNFH were not significantly different across the different sub-groups
of HAND in this unadjusted viremic cohort. However, among individuals with CD4 nadirs
≤200, CSF NFL levels were elevated in HAD compared with NCN, ANI, and MND. Plasma
sCD163 did not vary significantly across different sub-groups of HAND, in contrast
to previous studies of virologically-suppressed individuals on ART. CSF NFL was significantly
positively correlated with CSF pNFH/sCD163/sCD14.
Conclusion: This study is the first to correlate CSF NFL expression with CSF sCD14/sCD163
in viremic HIV-infected individuals off ART, eliminating unanticipated direct effects
of ART on inflammation and neurodegeneration. In addition, this is the first study
to examine NFL across different sub-groups of HAND. Our results confirm that systemic
HIV replication is strongly correlated with CNS monocyte activation and neurodegeneration
in individuals with a history of severe CD4 depletion.
P120
The novel antiretroviral compound, FX101, reduces virus and provirus burden in cats
chronically infected with FIV LY INFECTED WITH FIV
Rick Meeker1, Lola Hudson2, Heidi Kay3
(presenting author: meekerr@neurology.unc.edu)
1Department of Neurology and Curriculum in Neurobiology, University of North Carolina,
Chapel Hill, NC;
2College of Veterinary Medicine, North Carolina State University, Raleigh, NC;
3Jericho Sciences
Immunodeficiency lentiviruses, including FIV, readily penetrate the host central nervous
system (CNS) and establish a protected reservoir of infection in macrophages and microglia.
These reservoirs have been difficult to control with combined antiretroviral therapy
(CART) due, in part, to limited CNS penetration of current antiretroviral compounds.
Using the FIV model, we explored the therapeutic potential of the novel antiretroviral
compound, FX101, in an effort to reduce or eliminate CNS infection while minimizing
toxicity. FX101 is a proprietary compound that targets a strictly conserved region
of the nucleocapsid protein shared by FIV, SIV, and HIV. Binding of the drug appears
to disrupt virus particle assembly allowing control of infectious virus production
in previously infected cells. FX101 distributes in tissues and has an apparent long
plasma and CSF half-life of 4.2 and 3.3 days, respectively. At a dose of 2 mg/kg,
plasma concentrations peaked at 21.07 uM. CSF concentrations were variable with peak
values ranging from 0.052 to 1.18 uM. Clinical pathology demonstrated no significant
renal, liver, or red blood cell/white blood cell abnormalities. In vitro, neurotoxicity
was relatively low with a median toxic concentration of 20.5 uM. FX101 inhibited FIV
replication in feline macrophages in vitro to 8% of controls. To establish antiviral
efficacy in vivo, six cats, previously intracranially infected with FIV plus 4 sham
infected cats were treated with 2 mg/kg FX101 in 2% DMSO intravenously twice per week
over a 4 week period. Virus load in plasma and CSF and provirus loads were significantly
reduced to 6-23% of baseline and remained at 5-12.5% of original virus burdens even
36 weeks after treatment was completed. These results show that FX101 has significant
antiviral activity which is sustained for long periods and may include effects that
progressively reduce the proviral burden in cells.
Supported by NIH Grant 5R43MH096663
P121
PrPc : Friend or Foe in HIV CNS Pathogenesis?
Bezawit Megra1, Dionna Williams1, Mike Veenstra1, Toni Roberts2, Joan Berman3
(presenting author: bezawit.megra@phd.einstein.yu.edu)
1Department of Pathology, Albert Einstein College of Medicine;
2Department of Medicine, Medical Center, University of Washington;
3Department of Pathology, and Department of Microbiology and Immunology, Albert Einstein
College of Medicine
HIV-1 enters the CNS soon after peripheral infection and causes chronic inflammation
and CNS damage that leads to cognitive impairment in greater than 50% of HIV infected
people even with successful cART treatment. PrPc (protease resistant prion protein)
is the non-pathogenic cellular isoform of human prion protein that is constitutively
expressed in the CNS and is involved in several physiological processes that are disrupted
during HIV neuropathogenesis. PrPc is also expressed on monocytes and brain microvascular
endothelial cells (BMVEC) and is essential for the transmigration of monocytes across
the blood brain barrier (BBB). The surface expression of PrPc is increased in HIV
infected monocytes as detected by flow cytometry analysis. Previously, our laboratory
showed that soluble PrPc (sPrPc) levels are increased in the CSF of people specifically
with HIV associated neurocognitive disorder (HAND). Our in vitro studies also showed
that HIV infection as well as treatment of CNS cells with the chemokine CCL2 caused
increased PrPc shedding. All of these data suggest that sPrPc participates in the
mechanisms that mediate NeuroAIDS. To determine the effect of this shed PrPc on the
transmigration of monocyte across the BBB, we used our in vitro BBB model which consists
of astrocytes and endothelial cells co-cultured on opposite sides of 0.3um pore tissue
culture insert. In these studies we demonstrated that sPrPc treatment blocked the
transmigration of monocytes across the BBB, suggesting that it could be an initial
mechanism of protection against the influx of monocytes across the barrier during
early stages of HIV infection. Thus, PrPc may be both protective and neuroinflammatory
depending upon its temporal and spatial expression during HIV neuropathogenesis.
P122
Secretion of Soluble Insulin Receptor by human neuronal cells correlates with CSF
Cytokine Levels in HIV-seropositive women with HAND
Raissa Menendez-Delmestre1, Yamil Gerena2, Joyce M. Velez1, Richard L. Skolasky3,
Javier Sierra4, Claudia Hernandez4, Claribel Gonzalez1, Valerie Wojna5
(presenting author: raissa.menendez@upr.edu)
1NeuroAIDS Research Program, University of Puerto Rico-Medical Sciences Campus;
2Departments of Pharmaceutical Sciences and Pharmacology, NeuroAIDS Research Program,
University of Puerto Rico-Medical Sciences Campus;
3Department of Orthopaedic Surgery, Johns Hopkins University;
4Department of Biology, University of Puerto Rico-Rio Piedras Campus;
5NeuroAIDS Research Program, Internal Medicine Neurology Division, University of Puerto
Rico-Medical Sciences Campus
Background: HIV-associated neurocognitive disorder (HAND) has been associated with
abnormal glucose metabolism. In our cohort, we showed that high soluble insulin receptor
(sIR) levels positively associated with HAND. Recently, we observed that sIR secretion
from human neuronal cells is influenced by CSF components from HIV-seropositive women.
Our objective was to investigate CSF cytokine levels from HIV-seropositive women and
their influence on sIR secretion from human neuronal cells. Methods: CSF cytokine
levels were determined in 24 HIV-seropositive women stratified by HAND into normal
cognition (NC, n=8), asymptomatic impairment (AI, n=7), and symptomatic impairment
(SI, n=9) and 5 controls. Cytokine levels (TNF-alpha, IFN-gamma, IL-2, IL-4, IL-6,
and IL-10) were quantified by CBA immunoassay kit and flow cytometry. Neuronal cells
(SH-SY5Y cells) were cultured in the presence of cytokines for 24 hours using concentrations
similar to those quantified from the CSF of the HIV-seropositive women. Secreted sIR
levels were assayed by ELISA. Results: CSF levels of TNF-alpha, IFN-gamma, IL-10,
and IL-2 were increased in SI and AI when compared to NC (p<0.05). IL-6 levels were
significantly increased in SI when compared to NC (p<0.05). No significant differences
were observed in IL-4 CSF levels among groups. sIR levels secreted by neurons increased
significantly (p=0.02) after 24hrs exposure to TNF-alpha. Although exposure to IL-10
had slight decrease in sIR secretion this was not significant (p= 0.08). IFN-gamma
and IL-6 did not induce any change in sIR secretion as compared to control. Conclusion:
This study suggests that CSF cytokine levels in HIV-seropositive women alter neuronal
sIR secretion, and may contribute to insulin resistance in HAND patients. Partially
supported by: R21MH095524, R25MH080661, R25MD007607, U54RR026139, G12MD007600, G12RR003051,
U54NS043011, U54MD007587, S11NS046278
P123
Evidence for the Association of BAG3 with Beclin-1 and Induction of Autophagy in Glioma
Cells
Nana Merabova1, Ilker Sariyer1, Michael Weaver2, Caterina Turco3, Kamel Khalili1
(presenting author: mnana@temple.edu)
1Department of Neuroscience, Center for Neurovirology, Temple University School of
Medicine;
2Department of Neurosurgery, Temple University School of Medicine;
3Department of Medicine and Surgery, University of Salerno, Fisciano (SA)
Autophagy is an evolutionary conserved and selective degradation pathway of cellular
components that is important for the maintenance of cell homeostasis under healthy
and pathologic conditions. Here we demonstrate that an increase in the level of BAG3
results in stimulation of autophagy in glioblastoma cells. BAG3 is a member of a co-chaperone
family of proteins that associate with Hsp70 through a conserved BAG domain positioned
at the C-terminus of the protein. Expression of BAG3 is induced by a variety of environmental
changes causing stress to cells. Our results show that BAG3 interacts with Beclin-1,
a key regulator of autophagy, through its unique WW domain positioned at the N-terminus
of the protein. In addition, similar to Beclin-1, BAG3 associates with Bcl2, which
plays an important role in proliferation and apoptosis. Induction of BAG3 and its
association with Beclin-1 diminish interaction of Bcl2 and Beclin-1. Interestingly,
an elevated level of BAG3 also promotes cleavage of caspase 3 suggesting a dual role
for BAG3 in modulating autophagy and apoptosis. These observations place BAG3 in a
unique position suggesting that its interplay with Beclin-1 and Bcl2 has a functional
consequence on coordinating the stage of autophagy and apoptosis in glioma cells.
P124
Attenuation of Attentional Deficits in HIV-1 Transgenic Rats by the Phytoestrogen
Metabolite S-Equol
Landhing M. Moran, Rosemarie M. Booze, Charles F. Mactutus
(presenting author: moranl@email.sc.edu)
Department of Psychology, University of South Carolina
Approximately 50% of HIV-1-positive individuals are afflicted with HIV-1-associated
neurocognitive disorders (HAND), despite the effectiveness of combination antiretroviral
therapy (CART) in reducing the prevalence of more severe neurocognitive impairment
(i.e., dementia). Deficits in executive function are a distinguishing feature of HAND
in the CART era, decaying more rapidly during HIV disease progression than other cognitive
domains. In the present study, ovariectomized female Fischer HIV-1 Tg (n=41) and control
rats (n=43) were tested with a sustained attention task, a component of executive
function. Rats were trained to discriminate signals (illumination for 100, 500, or
1000 msec duration) from non-signals (no illumination) and were reinforced with sucrose
pellets for pressing the lever corresponding to each event (hits and correct rejections
vs. misses and false alarms). A decrease in hits and an increase in misses as a function
of decreased signal duration were observed for both groups; however, the HIV-1 Tg
group was more adversely affected by the shorter signal durations. In contrast to
the performance of controls, the HIV-1 Tg rats did not display differential target
detection (hits vs. misses) at the 500 or 100 msec durations. Subsequently, a daily
oral dose of S-equol (0.05, 0.1, or 0.2 mg, or vehicle), a metabolite produced via
the gut microbiome following ingestion of soy isoflavone daidzein, was administered
to determine its potential therapeutic effects. After 45 days of treatment, the HIV-1
Tg animals that received the 0.2 mg dose of S-equol missed significantly fewer signals
across all stimulus durations compared to their pre-dosing performance. Their improvement
was twofold that of the control group. The phytoestrogen metabolite S-equol may be
useful as a therapeutic for attentional deficits in HAND. Funded by NIH grants DA013137
and HD043680.
P125
The impact of viral infection on the innate immune response within the brain during
chronic neurodegeneration
Lita Murphy1, Dorothy Kisielewski1, Debbie Brown1, Pedro Piccardo1,2, Kris Hogan1,
Rennos Fragkoudis3, John Fazakerley3, Tom Freeman1, Hugh Perry4, Jean Manson1
(presenting author: Lita.Murphy@roslin.ed.ac.uk)
1Neurobiology Division, The Roslin Institute, University of Edinburgh, Easter Bush
Campus, Midlothian;
2Centre for Biologics Evaluation and Research, Food and Drug Administration, Rockville,
MD, USA.;
3The Pirbright Institute, Ash Road, Woking:
4Centre for Biological Sciences, University of Southampton, Southampton General Hospital,
Southampton
Understanding the mechanism and environmental influences which shape the development
of neurodegenerative diseases such as Alzheimer’s is of importance given the trend
for an aging population. The majority of neurodegenerative diseases involve abnormal
protein deposits within the CNS, degeneration of synapses and neurons and the activation
of astrocytes and microglia. It has been suggested that microglia in a brain with
ongoing chronic neurodegenerative disease are susceptible to systemic inflammatory
signals that switch cells from an atypical anti-inflammatory phenotype to one in which
they cause neuronal damage. Defining the impact of environmental factors such as infections
on the diseased brain will have profound implications for protecting neurones. We
are using a well characterised TSE agent, ME7, as a model for neurodegenerative disease.
The locus and timing of the initiation of neurodegeneration by ME7 is under precise
experimental control and rodent models of these diseases display all the features
of a chronic neurodegenerative process. We challenged mice in vivo with a transient
neuroinvasive viral infection, Semliki Forest virus, pre- and post- inoculation with
ME7 to ask if "priming" of the immune system by a viral infection which is cleared
by the host prior to the onset of a neurodegenerative disease would alter the pattern
of progression of the neurodegenerative disease. We observe that co-infection with
SFV during the early phase of neurodegeneration does not change disease incubation
time but does result in a subtle change in clinical disease onset. Interestingly,
we see a significant alteration of early stage disease pathology with a change in
the pattern of PrPSc deposition and gliosis. In addition, we address if viral infection
prior to the onset of chronic neurodegeneration can switch the innate immune response
of microglia from a neuroprotective to a tissue damaging phenotype and exacerbate
neurodegenerative disease progression.
P126
Infiltrating regulatory B (Breg) cells control neuroinflammation following viral brain
infection
Manohar Mutnal, Shuxian Hu, Scott Schachtele, James Lokensgard
(presenting author: mutna001@umn.edu)
Neuroimmunology Laboratory, Center for Infectious Diseases and Microbiology Translational
Research, Department of Medicine, University of Minnesota, MN 55455
In vivo and in vitro experiments were undertaken to elucidate the role of regulatory
B lymphocytes in controlling neuroinflammation following brain infection with murine
cytomegalovirus (MCMV). This unique subset of CD19(+)CD1d(hi)CD5(+) B-cells was found
to infiltrate the brains of chronically infected animals, reaching highest levels
at the latest time point tested (35 d p.i.). B-cell-deficient Jh-/- mice (BKO) displayed
exacerbated neuroimmune responses when compared to infected, wild-type (Wt) animals
as measured by enhanced accumulation and/or retention of CD8+ T lymphocytes within
the brain, as well as increased levels of microglial cell activation (MHC class II).
Conversely, levels of regulatory T-cells (Tregs) were found to be significantly lower
in infected BKO mice when compared to Wt animals. Further experiments showed that
in vitro generated interleukin (IL)-10-secreting Breg cells were able to inhibit cytokine
and chemokine responses from microglia following stimulation with viral antigens.
In addition, these in vitro generated Bregs were also found to promote conversion
of CD4+ T-cells into a regulatory T-cell (Foxp3+) phenotype. Finally, gain-of-function
experiments demonstrated that reconstitution of B-cells into BKO mice restored these
neuroimmune responses to levels exhibited by infected Wt animals. Taken together,
these results demonstrate that regulatory B-cells modulate T lymphocyte as well as
microglial cell responses within the brain, and promote CD4+ T-cell transition into
a Treg phenotype.
P127
HIV anti-retroviral therapy nucleoside reverse transcriptase inhibitors induce mitochondrial
dysfunction, oxidative stress, and premature senescence in primary human fibroblasts
Timothy Nacarelli, Ashley Azar, Elizabeth Crowe, Claudio Torres, Christian Sell
(presenting author: tn332@drexel.edu)
Drexel University College of Medicine
HIV patients are currently treated with highly active anti-retroviral therapy (HAART)
that employs nucleoside reverse transcriptase inhibitors (NRTIs). Although successful
in decreasing the HIV viral-load and rate of infection, NRTIs predispose patients
to an increased risk of developing pathologies associated with aging. These age-related
pathologies are thought to arise from mitochondrial toxicity that is attributed by
NRTI-mediated inhibition of mitochondrial DNA polymerase gamma. The newer generation
of NRTIs currently used in HAART, tenofovir and emtricitabine (TDF/FTC), contain a
decreased inhibitory affinity for DNA polymerase gamma, but mitochondrial toxicity
remains eminent. We postulate that TDF/FTC impair mitochondria in primary human fibroblasts.
Primary human fibroblasts are a relevant model to study aging in vitro, as they contain
a finite proliferative capacity before entering cellular senescence, an irreversible
growth arrest that recapitulates aging at the cellular level. Cellular senescence
is activated by oxidative stress, which could be contributed by reactive oxygen species
(ROS) produced from impaired mitochondria. Therefore, we also examined whether TDF/FTC
increased mitochondrial and cellular ROS and induce premature senescence. Previous
studies in the laboratory shown that treatment with rapamycin, an mTORC1 inhibitor,
promotes mitochondrial homeostasis, decreases oxidative stress, and delays senescence
in aging primary human fibroblasts. We further examined whether rapamycin could alleviate
NRTI-induced effects. After treatment with TDF/FTC, we found that mitochondrial integrity
is impaired, ROS is increased, and premature senescence is induced. However, these
alterations were ameliorated in the presence of rapamycin. Our results demonstrate
that the latest generation of NRTIs impair mitochondria and induce senescence in vitro.
P128
Clopidogrel, a P2Y12 purinoreceptor antagonist, attenuates VZV infection in human
brain vascular adventitial fibroblasts
Maria Nagel1, Ann Wyborny1, Alexander Choe1, Igor Traktinskiy1, Evgenia Gerasimovskaya2
(presenting author: maria.nagel@ucdenver.edu)
1Department of Neurology, University of Colorado School of Medicine;
2Department of Pediatrics, University of Colorado School of Medicine
Varicella zoster virus (VZV) vasculopathy is caused by productive infection of cerebral
arteries leading to pathological vascular remodeling and stroke. Purinergic signaling,
mediated by ATP and its metabolites, has emerged as important in vascular remodeling.
In addition, purinergic signaling is involved in RNA virus infection, but its role
in DNA virus infection is unknown. Thus, we hypothesize that specific purinoreceptors
are involved in VZV infection of cerebral arteries and vascular remodeling. Because
the arterial adventitia is the initial vascular site infected by VZV after virus reactivation,
we treated VZV-infected primary human brain vascular adventitial fibroblasts (BRAFs)
with antagonists of purinoreceptors P2X1, P2X4, P2X7, P2Y2, P2Y6, P2Y11 and P2Y12.
Three days later, viral DNA was quantified by qPCR. Compared to untreated infected
controls, the P2Y11 antagonist significantly down-regulated VZV DNA by 37% and the
P2Y12 antagonist by 69%. Significant differences were not found with other purinoreceptor
antagonists. Because the P2Y12 antagonist (clopidogrel) produced the greatest reduction
of VZV DNA, we also studied its effect on HSV-1 and HSV-2-infected BRAFs. Clopidogrel
significantly down-regulated HSV-1 and HSV-2 by >99% compared to untreated infected
controls. Furthermore, clopidogrel reduced the titer of infectious virus for all three
alphaherpesviruses. Overall, we demonstrated that the P2Y12 purinoreceptor antagonist
decreases VZV, HSV-1 and HSV-2 DNA and infectivity in BRAFs. The clinical effectiveness
of the P2Y12 antagonist clopidogrel remains to be determined.
P129
Exosomes from HIV-1 infected cells carry distinct protein and miRNA components which
control cell survival and apoptosis in recipient cells
Aarthi Narayanan1, Elizabeth Jaworski1, Rachel Van Duyne1,2, Sergey Iordanskiy1,2,
Mohammed Saifuddin1, Ravi Das1, Philippe Afonso3, Gavin Sampey1, Myung Chung1, Anastas
Popratiloff4, Bindesh Shrestha5, Akos Vertes5, Renaud Mahieux6, Fatah Kashanchi1
(presenting author: fkashanc@gmu.edu)
1Department of Molecular and Microbiology, National Center for Biodefense and Infectious
Diseases, George Mason University;
2The George Washington University Medical Center;
3Unite d'Epidemiologie et Physiopathologie des Virus Oncogenes, Departement de Virologie,
Institut Pasteur. CNRS;
4Department of Chemistry, The George Washington University;
5Center for Microscopy and Image Analysis, The George Washington University Medical
Center;
6Equipe Oncogenese Retrovirale, Equipe labelisee “Ligue Nationale Contre le Cancer”,
International Center for Research in Infectiology
Recently, much interest has developed regarding mechanisms of extracellular delivery
of nucleic acids and proteins among virally infected and recipient cells. While the
role of exosomes in viral pathogenesis and disease states remains largely unknown,
it is now widely accepted that exosomes play important roles in intercellular communication,
cellular inflammation, antigen presentation, programmed cell death, and pathogenesis.
HIV-1 encodes its own miRNAs that regulate viral and host gene expression. The most
abundant HIV-1-derived miRNA, first reported by us and later by others using deep
sequencing, is the TAR (Trans-Activation Response element) miRNA. We have recently
found the presence of TAR RNA in exosomes from cell culture supernatants of HIV-1
infected cells and patient sera. We report that transport of TAR RNA from the nucleus
into exosomes is a CRM1-dependent active process. Prior exposure of naive cells to
exosomes from infected cells increased susceptibility of the recipient cells to HIV-1
infection. Exosomal TAR RNA down regulated apoptosis by lowering Bim and Cdk9 proteins
in recipient cells. We found 10^4 -10^6 copies/ml of TAR RNA in exosomes derived from
infected culture supernatants and 10^3 copies/ml of TAR RNA in the serum exosomes
of Highly active antiretroviral therapy (HAART)-treated patients or Long term nonprogressors
(LTNPs). Very recently, we have found that TAR is able to activate cytokines in the
recipient cells by increasing the nuclear accumulation of both p65 and p50 (component
of NFkB complex). This increase may be related to a newly formed IKKb in the TAR treated
cells which may be the result of TLR activation by TAR. We will discuss the effect
of these biochemical steps in the recipient macrophage cells that result in alteration
of cytokines which in part may explain the neuroinflammation observed in AIDS patients
who are under HAART treatment.
P130
Morphine induced expression and subcellular localization of Ferritin Heavy Chain in
rat brain cells
Bradley Nash, Juhi Motiani, Olimpia Meucci
(presenting author: bsn25@drexel.edu)
Drexel University College of Medicine, Department of Pharmacology and Physiology
Ferritin Heavy Chain (FHC), a subunit of the ubiquitously expressed iron storage complex
Ferritin, has recently been shown to be upregulated in the central nervous system
(CNS) in response to HIV/SIV infection and illicit drug abuse. Previous research has
suggested that an unexpected consequence of increased CNS FHC lies in its ability
to inhibit homeostatic signaling of the chemokine receptor CXCR4, resulting in decreased
dendritic spine density in cortical neurons. Interestingly, initial studies indicate
that these changes correlate with disease progression and behavioral symptoms observed
in HIV associated neurocognitive disorders (HAND). Opiates, including morphine and
DAMGO, are able to upregulate FHC in a mu opioid receptor dependent manner, suggesting
a novel avenue of CXCR4 regulation via opioid signaling. Previous experiments have
shown that chronic morphine treatment (both in vitro and in vivo) caused a general
upregulation of FHC in cortical neurons, which corresponded with decreased levels
of phosphorylated, or activated CXCR4, and decreases in the activation of downstream
signals (i.e. ERK1/2 and Akt). However, this interaction has yet to be studied in
other CNS cell types such as astrocytes, which express both CXCR4 and MOR and are
critically involved in neuronal function. Additionally, characterization of morphine-induced
changes in the subcellular distribution of FHC, in neurons or other CNS cells, may
provide clues about the nature of the CXCR4/FHC interaction, and additional roles
of FHC in HAND, and other neurodegenerative diseases.
P131
Tetherin is critical for the resolution of a persistent viral infection
Debasis Nayak, Dorian McGavern
(presenting author: nayakdn@ninds.nih.gov)
NINDS, NIH
Tetherin or bone marrow stromal antigen 2 (BST-2) is an interferon-inducible plasma
membrane protein that has recently emerged as a key innate mammalian restriction factor
which impedes release of enveloped viruses by physically tethering nascent budding
virions to the plasma membrane. Several in vitro studies have demonstrated that BST-2
is a potent antiviral that acts upon many virulent enveloped viruses, such as retroviruses
(HIV), arenaviruses (Lassa), filoviruses (Ebola), paramyxoviruses (Sendai), orthomyxoviruses
(Influenza A), rhabdoviruses (VSV), etc. However, it remains unclear how this important
innate immune protein participates in sequestering a persistent viral infection in
vivo. In this study, we used the lymphocytic choriomeningitis virus (LCMV) clone 13
(CL13) model of persistent viral infection to evaluate the role of BST-2 in facilitating
the transition from an innate to a virus-controlling adaptive immune response. Importantly,
BST-2 knockout mice had an impaired ability to control LCMV CL13 in peripheral tissues
as well as the central nervous system (CNS). Viral clearance was delayed by one month
in the sera and never purged from the CNS. Anatomically, BST-2 expression mapped to
plasmacytoid dendritic cells (DCs), myeloid DCs, and brain resident microglia, consistent
with the impaired ability of BST-2-/- mice to sequester LCMV antigen in the splenic
marginal zone and brain after infection. Analysis of the adaptive immune response
to CL13 revealed that BST-2-/- mice generated less polyfunctional virus-specific CD8+
and CD4+ T cells and showed reduced expansion when compared to wild type control mice,
demonstrating that BST-2 is an important participant in the bridge between innate
and adaptive immunity. Collectively, our data indicate that BST-2 plays an essential
role in controlling a persistent viral infection, which explains why so many viruses
have developed strategies to thwart the activity of this potent antiviral protein
P132
HIV-1 Vpr accessory protein has a negative impact on astrocityc telomerase activity
Diego Ojeda, Mauricio Carobene, Jorge Quarleri
(presenting author: diegosebastianojeda@gmail.com)
INBIRS
HIV-1 Infection leads to a wide spectrum of neurodegenerative diseases. Among central
nervous system cells, astrocytes have been shown to be susceptible to HIV-1 infection.
Vpr is an HIV-1 accessory protein that negatively affects the highly controlled CNS
compartment, inducing astrocytic apoptosis and secretion of neurotoxins that causes
neuronal loss. Telomerase is a cellular ribonucleoprotein complex key in controlling
cellular senescence, and involved in inhibition of apoptosis and improvement of DNA
repair. Considering that HIV-1 has been shown to modify the cellular aging process
by interfering with telomerase activity (TA), the aim of our study was to evaluate
the impact of Vpr protein expression on TA in astrocytes. Vpr coding sequence from
HIV-1 NL4-3 strain was PCR-amplified and cloned into the pEGFP-C3 expression vector.
U373 astrocytic cells were transfected with the pEGFP-Vpr vector, and TA was evaluated
by real-time PCR (expressed as Relative Telomerase Activity, RTA), 48 h post-transfection.
Transfection efficiency, expressed as percentage of GFP-positive cells, was measured
by FACS. Statistical differences were calculated by t-student test. Telomerase activity
(RTA) was found to be significantly reduced in U373 astrocytic cells transfected with
the HIV-1 Vpr-expression vector (25.7% RTA, p<0.05), when compared to untransfected
(considered as 100% RTA) and pEGFP-C3-transfected cells (44.3% RTA). Mean transfection
efficiency for pEGFP-C3 and pEGFP-Vpr transfected cells, was 41% and 39.1%, respectively,
as determined by the percentage of GFP-positive cells evaluated by FACS. Data presented
here indicates that expression of HIV-1 Vpr has a negative impact on astrocityc TA.
Given the critical roles this cell type plays in creating a three-dimensional framework
for the CNS, in maintaining the bloodΓÇôbrain barrier, and in neural metabolism and
activity, the observed phenomenon is relevant in the context of understanding the
astrocyte biology changes that could be involved neurodegenerative process observed
during HIV-1 infection.
P133
Resistance to Apoptosis in HIV-Infected astrocyte as a potential mechanism for viral
Persistence in CNS
Diego Ojeda, Mauricio Carobene, Jorge Quarleri
(presenting author: diegosebastianojeda@gmail.com)
INBIRS
Apoptosis plays a critical role in HIV-1-associated neuropathogenesis. HIV-1 has developed
multiple strategies to modulate apoptosis related-pathways on infected cells thus
promoting its survival and favoring its role as viral reservoirs. HIV-1 establishes
infection in astrocytes of the CNS causing minimal cytopathology in these long-lived
cells. This study aimed to evaluate the HIV infection impact on apoptosis cascade
in infected astrocytes and their neighboring uninfected cells. An HIV infectious molecular
clone pNL43-derived and tagged with the GFP (named HIV-GFP) was constructed. It was
also pseudotyped with the VSV-G glycoprotein by co-transfection of 293T cells. U373
human astrocytic cells were used as in vitro models for astrocyte infection. To detect
apoptotic events at 1 to 6 days post infection (dpi), co-staining with 7AAD and annexin-V
was performed. Single-cell analysis aimed at simultaneously identifying apoptotic-infected
(Ann+/GFP+) and apoptotic-uninfected (Ann+/GFP-) neighbor cells by FACS. The values
were expressed as mean±SD. Statistic analysis was performed by Student T test and
p values <0.001 were considered significant. Initially the level of apoptosis (annexin
V+) at 1 and 2 dpi depicted no differences (p>0.005) between productively infected
astrocytes (13±7.7 and 7.3±9.7 GFP+, respectively) and neighbor uninfected cells (16.5±9.5
and 7.65±6.5 GFP-, respectively). In contrast, when comparing the level of apoptosis
(annexin-V+) at 3, 4, 5 and 6 dpi between infected vs. neighbor uninfected astrocytes
(GFP+/GFP-) a significant decreased (p<0.0001) (12±4/18±6, 14±3.8/26±12.8, 8±2.8/22±10,
and 6±3.6/20±10, respectively) was observed. Such differences were independent of
the level of viral replication (GFP+ cells). HIV infection of astrocytes results in
survival of infected astrocytes and apoptosis of neighbor uninfected cells. Such anti-apoptotic
effect was independent of the viral replication magnitude and its kinetic exhibited
a biphasic pattern according the infection progress. In advances stages of infection
the resistance to apoptosis was more pronounced, which could support the generation
of HIV reservoirs.
P134
Cocaine alters immunomodulatory profiles within HIV-1-infected African American individuals
in the DREXELMED HIV/AIDS Genetic Analysis Cohort
Nirzari Parikh1, William Dampier1, Rui Feng2, Shendra Passic1, Wen Zhong1, Benjamas
Aiamkitsumrit1, Vanessa Pirrone1, Michael Nonnemacher1, Jeffrey Jacobson3, Brian Wigdahl1
(presenting author: np344@drexel.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistics, University of Pennsylvania School of Medicine;
3Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine
This study evaluated the relationship between illicit drug use and HIV-1 disease severity
in HIV-1-infected patients enrolled in the DrexelMed HIV/AIDS Genetic Analysis Cohort.
Since cocaine is known to have immunomodulatory effects, the cytokine profiles of
preferential non-users (PN), cocaine users (PCo) or multi-drug users (MDU) were analyzed
to understand the effects of cocaine on cytokine modulation and HIV-1 disease severity.
Patients within the cohort are assessed approximately every 6 months for HIV-1 clinical
parameters and history of illicit drug, alcohol, and tobacco use. The Luminex human
cytokine 30-plex panel was used for cytokine quantification. Analysis was performed
using a newly developed biostatistical model. Substance abuse was found to be common
within the cohort. Utilizing the drug screens at the time of each visit, it was determined
that the cohort could be categorized as PN, PCo, and MDU. The overall health of the
PN population was better than that of the PCo population, with peak and current viral
loads in PN substantially lower than those in PCo and MDU patients. Among the 30 cytokines
investigated, differential cytokine profiles were established within the three populations.
The Th2 cytokines, IL-4 and IL-10, known to play a critical role during HIV-1 infection,
were positively associated with increasing cocaine use. Clinical parameters such as
latest viral load, CD4+ and CD8+ T-cell counts, and CD4:CD8 ratio were also significantly
associated with cocaine use. Based on these assessments, cocaine use appears to associate
with more severe HIV-1 disease. This work is supported by NIH/NINDS R01 NS32092, NIDA
R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P135
DC-SIGN as potential target for early intervention and transmission of HIV-1
Michael Park1, Thuong Tran1, Rasha El Baz1, Andrea Cuconati2, James Arthos3, Caitlin
Duffy4, Irwin Chaiken4, Dora Schnur5, Fengbin Song2, Patrick Lam6, Charles Reynolds2,
Allen Reitz7, Zafar Khan1, Pooja Jain1
(presenting author: zafar.khan@drexelmed.edu)
1Drexel Institute for Biotechnology and Virology Research, and the Department of Microbiology
and Immunology, Drexel University College of Medicine;
2Institute for Hepatitis and Virus Research, The Hepatitis B Foundation;
3Laboratory of Immunoregulation, National Institute of Allergies and Infectious Disease;
4Department of Biochemistry and Molecular Biology, Drexel University College of Medicine;
5Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center;
6Lam Drug Discovery Consulting, LLC;
7ALS Biopharma, LLC and Fox ChaseChemical Diversity Center, Inc.
DC-SIGN (dendritic cell specific ICAM-3-grabbing non-integrin), a membrane protein
of the C-type lectin family, is found in high levels on monocyte-derived DCs, some
macrophages, and activated B cells. In vivo, DC-SIGN-positive cells have been found
in lymph nodes, tonsils, skin, and the subepithelial regions of the cervix. With respect
to HIV-1 transmission, DC-SIGN has been shown to serve as ligand that efficiently
binds, concentrates, and mediates transfer of virus from the mucosal surface to CD4+
T cells. Subepithelial DCs expressing DC-SIGN have been demonstrated to play an important
role in cervicovaginal transmission of HIV-1. Additional studies have examined the
process of DC-SIGN-mediated transmission of various pathogens, suggesting that targeting
this cell surface molecule may serve as a potential therapeutic strategy. DC-SIGN
binds to mannose and fucose moieties present on the HIV envelope glycoprotein gp120
with high affinity. Blocking this interaction at the site of primary infection could
potentially be prophylactic and/or serve as a potential microbicidal target. We have
developed a novel high throughput screening assay (HTS) to identify inhibitors of
DC-SIGN:gp120 interaction and validated this assay by using quinoxazoline small molecules
that block mannose dimer binding to DC-SIGN demonstrating that HTS of non-carbohydrate
libraries can produce micromolar (or lower) non-carbohydrate hits. Further, we completed
virtual screen of diverse libraries of small molecule inhibitors by docking into the
calcium-binding domain of DC-SIGN crystal structure and subjected virtual hits into
the HTS assay. In addition, we began a novel approach of “binding-site directed lipophilic
mining” for hypothesis-driven drug discovery.
P136
Interplay between macrophage senescence, microRNA expression, and HIV-1 infection
Andrea Partridge, Elizabeth Crowe, Claudio Torres, Julio Martin-Garcia
(presenting author: atp28@drexel.edu)
Drexel University College of Medicine
In the context of HIV-1 infection, senescence is accelerated, facilitating opportunistic
infections and increased viral replication. Cellular senescence is irreversible growth
arrest in the lifetime of a cell. Although increased macrophage tropism and HIV-1
replication has been shown, the contribution of macrophages to this process has not
been clearly established. Changes in microRNA (miRNA) expression during cellular senescence
and/or aging have also been described. MiRNAs seem to contribute to the aging process
at the level of cellular senescence, tissue aging, and lifespan of whole organism.
However, the specific role of miRNAs in macrophages during aging has not yet been
established. Alterations in miRNA profiles during cellular senescence may affect HIV-1
infection, and potentially HIV-1 infection could as well affect cellular senescence
through miRNA modulation. We have induced senescence in primary human macrophages
and THP-1-derived macrophages by oxidative damage (H202 treatment). To confirm the
presence of a senescent phenotype, we used a senescence-associated beta-galactosidase
(SA beta-gal) assay, and western blot analysis of the levels of p16, p21, and p53,
which have been shown to increase in senescent cells. We determined that aged and
senescence-induced macrophages display a senescent-like phenotype that consists of
increased expression of p53, p21, and an enlarged flattened morphology with positive
staining for SA beta-gal. Further studies will include the analysis of the cytokine
and chemokine secretion profile to determine whether or not they exhibit a senescence-associated
secretory phenotype, and the investigation of changes in miRNA profiles due to infection
and senescence.
P137
Pericyte dysfunction in blood brain barrier impairment caused by HIV infection
Yuri Persidsky, Jeremy Hill, Holly Dykstra, Nancy Reichenbach, Slava Rom, Servio Ramirez
(presenting author: yuri.persidsky@tuhs.temple.edu)
Department of Pathology and Laboratory Medicine,Temple University School of Medicine
Despite combined antiretroviral therapy achieving efficient HIV replication control,
neurocognitive complications defined as HAND continue to be highly prevalent in HIV
infection. One of explanations could be constant compromise of blood brain barrier
(BBB) function driven by chronic inflammatory responses documented in HIV infected
individuals even with well-controlled virus replication yet with HAND progression.
Brain endothelial cell injury and its underlying mechanisms have been explored during
last years. However, changes in other cells constituting BBB (like pericytes) have
not been studied in detail in context of HIV-1 infection.We found partial pericyte
loss and down regulation of key receptors on these cells in brain tissue of HIV-1
infected patients (even without detectable HIV-1 in CNS) and HIV-1 infected huNSG
mice that paralleled BBB compromise and neuroinflammation. Primary human brain pericytes
treated with IL-1 beta or TNF-alpha demonstrated decreased secretion of angiopoetin-1/
transforming growth factor-beta 1, diminished expression of PDGF-R beta 1 (controlling
pericyte survival and recruitment to BBB) and connexin 43 (critical for establishing
gap junctions between pericytes and brain microvascular endothelial cells, BMVEC).
Pericytes exposed to IL-1 beta/TNF alpha showed enhanced expression of numerous pro-inflammatory
factors (relevant to HIV-1 neuropathogenesis) and adhesion molecules (ICAM-1, VCAM-1)
paralleling increased adhesion of monocytes to pericyte monolayers. Using BBB models
(composed of BMVEC-pericytes) we showed increased monocyte migration across BBB constructs
in response to relevant chemokine, CCL2. IL-1 beta/TNF alpha treatment of pericytes
diminished their ability to migrate providing potential mechanism of their decrease
in brain tissue of HIV-1 infected patients. Taken together, these data point to a
major decrease in barrier supporting function and enhanced inflammatory responses
in brain pericytes after exposure to relevant cytokines and in brain tissues of HIV-1
infected patients.
P138
Cocaine mediated downregulation of SAMHD1 facilitates HIV-1 infection in CNS cells
Sudheesh Pilakka-Kanthikeel, Andrea Raymond, Venkata Subba Rao Atluri, Vidya Sagar,
Upal Roy, Madhavan Nair
(presenting author: spilakka@fiu.edu)
Dept of Immunology, Institute of NeuroImmune Pharmacology, Herbert Wertheim College
of Medicine, Florida International University, Miami, FL-33199
Human immunodeficiency virus 1 (HIV-1) remains one of the leading causes of death
worldwide. HIV penetrates CNS during early infection, establishing a viral reservoir.
Even though astrocytes are infected by HIV, unlike microglia and brain macrophages,
they are not productively infected. Non-productive infection could be significant
to neuropathogenesis. Although the potent antiretroviral therapies have significantly
improved the morbidity in HIV patients, the biggest challenge is inability of HAART
to eradicate the virus from the reservoirs. The mechanisms governing the establishment
of HIV reservoir in vivo are still not fully understood. The brain is also a target
organ for cocaine. Cocaine enhances HIV-1 expression in susceptible cells, serving
as a co-factor in the susceptibility and progression of infections. Recently identified
restriction factor, SAMHD1, which hydrolyses dNTPs has been shown to restrict HIV
infection in resting CD4+ T cells. Based on the previous reports from literature,
we hypothesized that increased SAMHD1 expression in astrocytes results in suppression
of cellular dNTPs subsequently hampering retrovirus reverse transcription, which in
turn leads to non-productive infection. We examined constitutive expression of SAMHD1
in astrocytes and microglia at the gene and protein level and its modulation by cocaine.
Astrocytes displayed higher expression level of SAMHD1 compared to microglia, suggesting
that SAMHD1 plays a role in astrocytes facilitating them to maintain non-productive
infection. Cocaine degraded SAMHD1, which in turn increased viral replication in astrocytes.
Suppressing the level of SAMHD1 in astrocytes by cocaine reactivates the latent virus
from astrocyte.
P139
HIV-1 LTR single nucleotide polymorphisms (SNPs) correlate with clinical disease parameters
Vanessa Pirrone1, Michael Nonnemacher1, William Dampier1, Benjamas Aiamkitsumrit1,
Jean Williams1, Sonia Shah1, Shendra Passic1, Brandon Blakey1, Wen Zhong1, Brian Moldover2,
Rui Feng3, Jeffrey Jacobson4, Brian Wigdahl1
(presenting author: vanessa.pirrone@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine,
2B-Tech Consulting, Ltd;
3Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistic, University School of Medicine.;
4Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine
The long terminal repeat (LTR) regulates HIV-1 gene expression by interacting with
multiple host and viral factors. Cross-sectional studies in the pre-HAART era demonstrated
that SNPs in C/EBP site I and Sp site III from peripheral blood-derived LTRs increased
in frequency as disease severity increased and correlated with HIV-1-associated dementia.
Current studies focus on the identification of LTR signatures derived from peripheral
blood virus that can be used as molecular markers to identify HIV-1-infected individuals
more prone to developing advanced stage disease and/or neurologic disease. A prospective,
longitudinal study was conducted on 504 HIV-1 seropositive patients currently enrolled
in the DREXELMED HIV/AIDS Genetic Analysis Cohort in Philadelphia, PA. History of
clinical parameters and comorbities were obtained approximately every 6 months. The
collection of extensive clinical parameters on these patients have allowed for cross-sectional
and longitudinal analyses of the impact of these parameters on the development of
SNPs during the course of disease. To date, SNPs have been identified that associated
with CD4 T-cell count and viral load. Of the SNPs identified, SNPs at position 108
were the most significant and correlated with a gain in transcription factor binding.
These results suggest that the HIV-1 genomic swarm may evolve during the course of
disease in response to selective pressures that lead to changes in prevalence of LTR
SNPs that may be predictive of more advanced stage HIV disease and that may result
in alterations in viral function. This work is supported by NIH/NINDS R01 NS32092,
NIDA R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P140
HIV-Tat protein enhances amyloid beta aggregation
Alina Popescu Hategan1, Joseph Steiner1, Emilios Dimitriadis2, Avindra Nath1
(presenting author: alina.popescu@nih.gov)
1NIH/NINDS, Section of Infections of the Nervous System, Bethesda MD;
3NIH/NIBIB, Scanning Probe Microscopy Unit, Bethesda MD
We show that amyloid beta 1-40 aggregation under physiological conditions in the presence
of HIV-Tat protein presents significant structural changes. Atomic force microscopy
imaging shows that the predominant typical singular uniform amyloid fibrils formed
at a 200 micromolar amyloid concentration turn into a population with more double
twisted fibers when 0.08 micromolar HIV-Tat is present and at higher Tat concentrations
(0.4 to 1.8 micromolar) turns into thick unstructured filaments and nonspecifically
aggregated large patches. At a 1:10 molar ratio of HIV-Tat per amyloid beta at incubation,
fibrils are much larger and irregular along the length compared to amyloid fibrils,
their dimensions being similar with those of amyloid fibrils formed at extreme concentrations
(>1 mM), but without the uniformly striated structure. Importantly, the presence of
Tat in the amyloid fibrils significantly increases the neurotoxicity of amyloid fibrils,
as shown in neuronal cell culture experiments. Future studies will involve localization
of Tat molecules throughout the amyloid filaments and aggregates, for a better understanding
of the interaction between HIV-Tat protein and amyloid beta peptide.
P141
Cross-talk between astrocytes and CD8+ T cells impacting activation of astrocytes
and differentiation of CD8+ T cells: Relevance to NeuroHIV
Maureen H. Richards, Melanie S. Seaton, Stephanie Min, Victoria Lutgen, Lena Al-Harthi
(presenting author: maureen_richards@rush.edu)
Department of Immunology/Microbiology, Rush University Medical Center
HIV invades the CNS shortly after infection and despite antiretroviral therapy leads
to a spectrum of neurologic complications termed HIV-Associated Neurocognitive Disorders
(HAND). While extensive studies have probed the cellular and molecular mechanisms
driving HIV-mediated neuropathogenesis, little is known about the complex interaction
between infiltrating immune cells and resident brain cells, especially astrocytes.
We evaluated the interaction between peripheral blood mononuclear cells (PBMCs) and
astrocytes. We show that conditioned media from primary human progenitor-derived astrocytes
(PDAs) induced Beta-catenin expression in PBMCs by 50%, inhibited HIV replication
in T cells by 75% and induced CD4 expression on CD8 T cells to generate a double positive
(DP) T cell phenotype. Depleting PDAs conditioned media of Wnt ligands (Wnt 1, 2b,
3, 5b and 10b) abrogated these responses, indicating that Wnt ligands secreted from
astrocytes mediate these changes in T cells. Conversely, conditioned PBMCs media activated
PDAs as indicated by elevated expression of IFNgamma and HLA-DR, reduced Beta-catenin
expression in PDAs, and enhanced HIV replication in PDAs. These data indicate a feedback
loop whereby activated PBMCs can alter astrocyte phenotype and susceptibility to HIV
infection and astrocytes can alter the phenotype and function of T cell. We propose
a model in which crosstalk occurs between astrocytes and infiltrating immune cells;
shaping the microenvironment of the brain, and perturbing the functional potential
of each cell type. This work is supported by R01NS060632-LA and F32 NS08065701-MR.
P142
Validation and Use of a Navigational Spatial Memory Test (MI) in HIV-Seropositive
Women
Rosa Janet Rodriguez-Benitez1, Miriam Matos1, Rosa Hechavarria1, Karim Garcia2, Myraida
Morales3, Jacob Raber6, Valerie Wojna1
(presenting author: rosa.rodriguez12@upr.edu)
1University of Puerto Rico;
2Carlos Albizu University;
3Oregon and Health Sciences University
PURPOSE: In the era of combined antiretroviral treatment, HIV-seropositive patients
are living longer. With the increase survival, we observe a high prevalence of neurocognitive
impairments. Memory Island (MI) is a computer based test useful in identifying susceptibility
to cognitive impairments especially in spatial learning and memory with the advantage
of being a non-invasive test that can be easily administered. Since MI is not affected
by culture, its validation and characterization in neurocognitive disorders could
represent a good screening test for HAND. The MAIN OBJECTIVE of this study is to determine
the validity and use of MI as a reliable instrument in the characterization of spatial
learning and memory in HIV-seropositive women. DESIGN METHODS: 60 women were evaluated,
44 HIV-seropositive and 16 controls HIV-seronegative, with viral-immune profiles,
MI, and neuropsychological tests. Parametrics and non-Parametrics statistics were
performed. RESULTS: There were no group differences in speed of navigation in the
visible or hidden target trials. During the visible target trials, there were no differences
in ability of the two groups to locate the target location. However, during the “hidden"
trials, HIV-seropositive women required more time and moved longer distance than controls.
Thus, HIV-seropositive women had less efficient acquisition (learning) and worse performance
when compared with HIV-seronegative women. When spatial memory retention was assessed
in the probe trial (no target present), HIV-seropositive women spent less time in
the part of the island (quadrant) that contained the target previously than the controls.
CONCLUSION: The use of MI test is valid in detecting spatial learning and memory deficits
in HIV-seropositive women. While MI resembles the findings of the Morris Water Maze,
serves as a new translational technology and useful valid instrument to spatial and
memory screening.
P143
TLR3 activation on dendritic cells suppresses HIV-1 infection by inducing miR-155
and APOBEC-3G
Fiorella Rossi, Gokul Swaminathan, Julio Martin-Garcia3
(presenting author: fpr23@drexel.edu)
Drexel University College of Medicine
Human Immunodeficiency Virus type-1 (HIV-1) is transmitted predominantly through the
vaginal or rectal mucosa where dendritic cells (DCs) are among the first cells to
interact with the virus. In addition to support viral replication, DCs facilitate
viral dissemination and contribute to HIV-1 pathogenesis by migrating to the lymph
nodes and assisting the infection of CD4+T cells. DCs show less susceptibility to
HIV-1 infection depending on the type of stimuli and maturation stage. Upon DCs maturation,
various cellular host factors such as microRNA-155 (miR-155) and Apolipoprotein B
mRNA editing enzyme 3G (APOBEC-3G) are highly up-regulated. However, these upregulation
in the context of HIV-1-infection has not been elucidated in DCs. Our goal is to determine
the mechanism that explains how maturation of DCs causes suppression of HIV-1 infection
in vitro. Immature DCs were activated with different Toll-like receptor ligands (TLR-L)
to obtain a mature phenotype and determined the expression levels of miR-155, APOBEC-3G,
and the susceptibility of DCs to a HIV-1 recombinant virus (ADA-Fluc). We observed
an upregulation on the expression of both factors upon TLR3 stimulation in comparison
to non-stimulated cells (p=0.003) and other TLR-L. This up-regulation in TLR3-stimulated
DC correlates with increased expression of the maturation markers CD80, CD86, HLA-DR
and CD83 (p=0.03), and a complete suppression of HIV-1 infection (p=0.031). By using
a miR-155 inhibitor and silencing APOBEC-3G, the phenotype reverses to 60% of wild
type infectivity. This suggests that other factors are also involved in suppressing
infection upon TLR3 stimulation. Future studies will address other mechanism(s) involved
in these processes.
P144
M2 macrophages stimulate neural stem/progenitor cell proliferation via a Wnt 5a dependent
pathway: Implications for herpes simplex encephalitis
Jessica Rotschafer, Erin Roach, Dianna Cheney-Peters, Maxim Cheeran
(presenting author: cheeran@umn.edu)
Veterinary Population Medicine department, College of Veterinary Medicine, University
of Minnesota
Activation of macrophages and microglia is a critical component of the host response
following brain damage. Previous studies in our laboratory demonstrated that HSV-1
brain infection stimulates neural stem/progenitor cell (NSC) proliferation between
3 and 6 d p.i., concurrent with macrophage infiltration. In the present study, we
examined the role of macrophage activation phenotypes on NSC proliferation. Evaluation
of infiltrating macrophages [CD45(hi)CD11b(+)] revealed that 68.6±3.3% of the cells
were Ly6C(hi) at 5 d p.i. Expression of an M2 marker, CD206, was five-fold higher
than CD86, an M1 phenotype marker, in Ly6C(hi) macrophages at 5 d p.i, indicative
of an alternative activation phenotype. To determine if macrophage polarization modulated
neurogenesis, NSCs were cultured with supernatants from M1 or M2 polarized bone-marrow
derived macrophages. NSC cultures treated with M2 conditioned media (M2CM) had 4-fold
more proliferating cells compared to those cultured in control media. Cells in all
treatment groups maintained their stem cell phenotype [≥95% nestin(+)] at collection.
M2CM treated NSCs continued to increase in number at 96 h post-treatment with significantly
higher numbers of cells in the G2/M phase of cell division. Transplantation of M2
macrophages into the lateral ventricles of uninfected mice resulted in a 15% increase
in Sox2(+) NSC proliferation and the total number of Sox2(+) NSCs doubled compared
to saline or heat-killed cell controls, at 5 d post-treatment. Interestingly, Wnt5a
expression was significantly increased in M2 polarized macrophages and treatment with
either dickkopf-1, a Wnt5a inhibitor, or Wnt5a neutralizing antibody suppressed NSC
proliferation to control levels. Finally, Wnt5a gene expression in HSV-1 infected
brains increased at 3 d p.i., coinciding with the increase in neurogenesis and M2
macrophage infiltration into the brain. Results from these studies suggest that M2
macrophages promote neurogenesis following herpes virus-induced brain damage and may
provide an avenue for therapeutic intervention.
P145
Persistent CD8 T-cells hinder neurogenesis during chronic Herpes Simplex encephalitis
and render neural stem/progenitor cells refractory to growth stimuli
Jessica Rotschafer, Erin Roach, Maxim CJ Cheeran
(presenting author: rots0006@umn.edu)
Department of Veterinary Population Medicine, College of Veterinary Medicine, University
of Minnesota
Herpes Simplex encephalitis (HSE) is characterized by chronic inflammation, dominated
by the presence of CD8 T-cells. Previous studies in the laboratory showed that neural
stem/progenitor cell (NSC) proliferation was significantly impaired during the chronic
phase of HSE (15 - 30 dp.i.). The current study evaluated the role of CD8(+) T-cells
in modulating this anti-proliferative milieu. At 15 dp.i, approximately 50% of CD8
T-cells in HSV-1-infected brains produced interferon-gamma following virus stimulation.
CD8 T-cells were depleted from mice brains at 15 d p.i, using a neutralizing antibody
to CD8a. CD8 T-cell depletion resulted in a 5-fold increase in CD45(-) nestin(+) NSCs
compared to isotype antibody-treated controls. While CD4(+) T-cell numbers or phenotype
did not change significantly following depletion, an increase in the total number
of infiltrating macrophages (CD45(hi)CD11b(+)) as well as a down-regulation of MHC-II
on microglia was observed. Interestingly, a 3-fold increase in number of CD206(+)infiltrating
macrophages, an M2 macrophage phenotype marker, was seen compared to appropriate controls.
Further analysis of macrophage phenotypes showed that, in the absence of CD8 T-cells,
the ratio of CD206 to CD86 expressing macrophages shifted from 2:1 to approximately
4:1, suggesting that CD8 T-cell depletion promotes an M2 macrophage activation phenotype.
Moreover, gene transcription analysis demonstrated a significant reduction of IFN-gamma
expression in depleted animals, compared to isotype-treated mice. Previous studies
in our laboratory have shown that M2 polarized macrophages enhance NSC proliferation.
However, transplantation of M2 polarized macrophages into the lateral ventricles of
chronically infected mice showed no significant change in neurogenesis. In addition,
cultured NSCs treated with IFN-gamma were refractory to M2 macrophage induced increase
in proliferation. Taken together, these data suggest that CD8 T-cells impair endogenous
NSC proliferation subsequent to HSE in an IFN-gamma dependent manner. These studies
may help identify therapeutic interventions to enhance neurogenesis during viral encephalitis.
P146
Cigarette Smoke Effects on Pro-inflammatory and Oxidative Stress Marker Gene Expression
in HIV Transgenic Rat Brains
Walter Royal, III, Joseph Bryant, Ming Guo, Harry Davis, Christina Preminger, Sandra
Navas-Reyes
(presenting author: wroyal@som.umaryland.edu)
University of Maryland School of Medicine
Objective: Cigarette smoking has been linked to an increased risk of disease progression
in HIV infection, including an increased risk of cognitive impairment. In these preliminary
studies were examined effects of cigarette smoke exposure on the induction of gene
expression of mediators of inflammation and oxidative stress in brains of HIV-1 transgenic
rats.
Methods: 3-6 month old wild-type (WT) and transgenic (TG) Fisher 344/NHsd rats were
exposed to cigarette smoke (CS) from 3R4F research grade cigarettes, which contain
a regular amount of nicotine, in a specially constructed smoking chamber for 5 days
per week for 4 weeks. Frontal cortex and subcortical white matter from the CS-exposed
and non-exposed animals (n=4 rats group) were examined by real-time PCR for IFN-gamma,
TNF-alpha, IL-6, CCL2/MCP-1, CCL-3/MIP-1-alpha, iNOS, the NADPH oxidase isoform dual
oxidase 1 (DUOX1), thioredoxin (TXN) and superoxide dismutase (SOD) gene expression.
Results: INF-gamma gene expression was higher for WT than for TG rats and increased
by CS exposure. TNF-alpha gene expression was increased only in CS+ WT vs CS- WT rats,
and there was no difference in IL-6 expression for either TG or WT rats +/- CS exposure.
In the absence of CS exposure, MCP-1/CCL2 expression was higher for TG than WT rats
and was higher for TG CS+ rats than for all other groups. There was no elevation of
MIP-1-alpha/CCL3 expression with CS exposure. Levels of iNOS and TXN expression were
similar for all groups. However, SOD was decreased by CS in WT rats but was unchanged
in TG rats. Also, CS increased DUOX1 expression in WT rats but did not affect expression
in TG rats.
Conclusions: Increased pro-inflammatory and decreased oxidative stress marker gene
expression resulted from CS exposure in the TG rats. CS effects on oxidative stress
responses in the TG rat may reflect altered sensitivity to nicotine.
P147
Clinical and Laboratory Assessments of Monocyte Function and Associations with Cognition
and Gender among HIV Infected Individuals in Nigeria
Walter Royal III1, Mariana Cherner2, Tricia Burdo3, Christopher Akolo1, Kenneth Williams3,
Kanayo Okwuasaba4, Ajay Bharti5, Scott Letendre5, Ming Guo1, Anya Umlauf5, Min Zhan1,
Lindsay Eyzaguirre1, Alash'le Abimiku1, Joyce Johnson1, William Blattner1
(presenting author: wroyal@som.umaryland.edu)
1University of Maryland School of Medicine;
2University of California San Diego School of Medicine;
3Boston College;
4Institute of Human Virology - Nigeria;
5University of San Diego School of Medicine
Objective: Neurocognitive impairment (NCI) in HIV infection has been linked to nervous
system involvement by virus-infected and activated mononuclear phagocytes. In this
study, associations between levels of markers of monocyte/macrophage activation, levels
of circulating monocytes and the presence of NCI were examined in individuals in Nigeria.
Methods: 160 antiretroviral-naïve seropositive (SP; 97 women and 63 men) and 56 seronegative
(SN; 38 men and 18 women) subjects received a medical assessment and neuropsychological
testing in 7 ability domains. An average global deficit score (GDS), with impairment
indicated by GDS > 0.5, was derived from demographically adjusted test scores. Percentages
of circulating monocytes and HIV RNA measures were performed in a clinical laboratory.
Levels of plasma soluble CD163 and soluble CD14 (which are markers of monocyte/macrophage
activation) were determined by ELISA. Measures were compared for SP and SN and by
gender using t-tests and analysis of variance. Associations between test results were
examined using regression analysis, and analyses of categorical data employed chi-square
tests.
Results: 81.7% of SP had asymptomatic HIV infection. GDS > 0.05 were noted for 9 (16.07%)
SN and 34 (21.25%) SP patients (p=0.4). Among impaired SP, measures were higher for
sCD163 (p=0.03), sCD14 (p=0.0002) and HIV RNA (p=0.02) than for non-impaired subjects.
Higher measures of GDS (p=0.017), sCD163 (p<0.0001), sCD14 (p=0.008) and percent monocytes
(p<0.0001) were noted for SP than for SN subjects. GDS correlated with levels of sCD163
(p=0.02) and sCD14 (p<0.0001). HIV RNA measures were higher for women than men (p<0.0001).
Among women, sCD163 (p<0.05) and sCD14 (p<0.001) levels were higher for SP than for
SN. Among men, sCD14 (p<0.0001) and percent monocytes (p<0.05) were higher for SP
than SN.
Conclusion: Measures of circulating monocytes and monocyte activation can be useful
for detecting evidence of disease activity among clinically stable individuals, particularly
women, with HIV infection.
P148
Development of the Virtual Reality supermarket task for predicting neurocognitive
function in HIV-infected subjects
Giuseppe Russo1, Tracy Fischer-Smith2, Nancy Minniti3, Antonio Giordano1
(presenting author: grusso@temple.edu)
1Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology,
College of Science and Technology, Temple University, Philadelphia, Pennsylvania 19122;
2Department of Neuroscience, Center for Neurovirology, Temple University School of
Medicine, Philadelphia, Pennsylvania 19140;
3Department of Physical Medicine and Rehabilitation, Temple University Hospital, Philadelphia,
Pennsylvania 19140;
Despite the development of combination antiretroviral therapy, HIV-associated neurocognitive
disorders remain prevalent. Traditional neuropsychological (NP) approaches commonly
use paper and pencil-based psychometric tests for impairment assessment. Although
these approaches provide highly standardized control and delivery of performance challenges,
the extent to which these tasks predict everyday functioning is not always clear,
as these tasks do not simulate real world activities, such as managing finances or
remembering appointments. The assessment of neurocognitive ability using tasks to
simulate everyday activities may confer an estimate of the patient’s functioning more
accurate than the one within laboratory conditions. Virtual reality (VR) allows (1)
the user to interact in real time with a pseudo immersing 3D environment by a behavioral
interface; (2) the presentation of close to real life testing environments. The aim
of this study was to design a measure that will detect NP impairment of HIV-infected
subjects in a simulated environment and to analyze how the number of errors detected
in this environment will correlate with NP dysfunction on traditional tests. To this
end, we developed the NP function of an interactive VR supermarket. The facets of
NP functions we expect to correlate with the VR test will be episodic memory and executive
functions tests. This study was supported by a developmental grant from the Comprehensive
NeuroAIDS Center (CNAC NIMH Grant Number P30MH092177) at Temple University School
of Medicine.
P149
In vivo immunogenicity of Tax 11-19 epitope in HLA-A2/DTR transgenic mice: implication
for dendritic cell-based anti-HTLV-1 vaccine
Divya Sagar1, Shet Masih1, Todd Schell2, Steven Jacobson3, Brian Wigdahl4, Pooja Jain1,
Zafar Khan1
(presenting author: pooja.jain@drexelmed.edu)
1Department of Microbiology and Immunology, Drexel University College of Medicine;
2Department of Microbiology and Immunology, The Pennsylvania State University College
of Medicine;
3Viral Immunology Section, Neuroimmunology Branch, National Institutes of Health;
4Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine
Viral oncoprotein Tax plays key roles in transformation of human T-cell leukemia virus
type 1 (HTLV-1)-infected T cells leading to adult T-cell leukemia (ATL), and is the
key antigen recognized during HTLV-associated myelopathy (HAM). In HLA-A2+ asymptomatic
carriers as well as ATL and HAM patients, the Tax(11-19) epitope has exhibited immunodominance.
In this regard, the immunotherapeutic potential of this epitope has been evaluated
in HLA-A2 transgenic mice in the absence and presence of dendritic cells (DCs) given
the recent encouraging observations made with Phase 1 DC-based vaccine trial for ATL.
To facilitate these studies, an HLA-A2/DTR hybrid mouse strain carrying the HLA-A2.1
and CD11c-DTR genes was generated. The CD8+ T-cell immune response was generated against
the Tax(11-19) epitope delivered in the absence or presence of Freund’s adjuvant and/or
DCs. Overall, the results demonstrate that naturally presented Tax epitope could initiate
an antigen-specific CD8+ T-cell response in vivo but failed to do so upon DC depletion.
In addition, the presence of adjuvant potentiated the Tax(11-19)-specific response.
Elevated serum IL-6 levels coincided with depletion of DCs whereas decreased TGF-beta
was associated with adjuvant use. Thus, the Tax(11-19) epitope is a potential candidate
for the DC-based anti-HTLV-1 vaccine and the newly hybrid mouse strain could be used
for investigating DC involvement in human class-I-restricted immune responses.
P150
Dendritic cell trafficking into the central nervous system: involvement of lectin
adhesion receptors and actin polymerization
Divya Sagar1, Jasmine Sharazi1, Catherine Foss2, Zafar Khan1, Martin Pomper2, Pooja
Jain1
(presenting author: divya.sagar@drexel.edu)
1Drexel Institute for Biotechnology and Virology Research and Department of Microbiology
and Immunology, Drexel University College of Medicine;
2Department of Radiology, Johns Hopkins University
In the healthy individual, infiltration of dendritic cells (DCs) into the central
nervous system (CNS) is tightly controlled by the highly specialized blood-brain barrier
(BBB). However, in an inflammatory disease like multiple sclerosis (MS), DCs have
potential to transmigrate across the BBB into the CNS due to the presence of chemoattractants,
particularly CCL2 or MCP-1. Hence, studying the interaction of circulating DCs with
the BBB represents a critical step in cellular trafficking during neuroinflammation.
Near-infrared imaging of DC accumulation into CNS correlated with the severity of
inflammation in EAE (experimental autoimmune encephalomyelitis) model of MS. Ex vivo
histology confirmed the presence of CCL2 in lesions, with DCs emerging from perivascular
spaces. Confocal imaging revealed that CCL2 exposure leads to polymerization of actin
on DCs suggesting a migratory phenotype. During mechanistic studies in BBB model,
DCs exhibited more efficient transmigration than T cells in the presence of CCL2.
Additionally, a paracellular versus transcellular pattern of migration by DCs and
T cells was seen. The unique enrichment of lectin receptors on DCs led to differential
profile for each specific subset of DCs including myeloid (mDC), plasmacytoid (pDC)
and monocyte-derived (MDDC). Subsequently, in the presence of CCL2, each DC subset
was found to utilize a different lectin receptor in order to adhere and transmigrate
across the BBB. At the subcelleular level a cross-talk between actin and lectin pathways
was also established. The prospect of selectively regulating DC entry into the CNS
will open up new possibilities for disease pathogenesis and propagation in MS.
P151
NMR structure-based mutagenesis studies of JC virus agnoprotein revealed the importance
of Leu29, Leu32 and Leu36 in protein stability, dimer/oligomer formation and in viral
DNA replication
Sami Saribas1, Pascale Coric2, Serge Bouaziz2, Mahmut Safak1
(presenting author: saribas@temple.edu)
1Temple University School of Medicine, Department of Neuroscience, Laboratory of Molecular
Neurovirology, Philadelphia PA 19140, USA.;
2University Paris Descartes, Sorbonne Paris City, Laboratoire de Cristallographie
et RMN Biologiques, Paris, France
Agnoprotein is a small and multifunctional regulatory protein of JC virus (JCV) and
plays essential regulatory roles in the viral replication cycle. In the absence of
its expression, JCV is unable to sustain its productive life cycle. We have recently
demonstrated that agnoprotein forms highly stable dimers and oligomers in vivo and
in vitro and the Leu/Ile/Phe-rich hydrophobic domain of the protein plays a key role
in formation of such multimeric structures. Previous mutagenesis analysis of the region
resulted in phenotypes that show defects in viral life cycle. In addition, previous
attempts to determine the 3D structure of agnoprotein have been unsuccessful. Here,
we report the NMR structure of a synthetic agnoprotein peptide encompassing amino
acids Thr17-Glu55 demonstrating that amino acids spanning from Lys22 to Phe39 form
an amphipathic alpha-helix. We have also performed NMR structure-based mutagenesis
studies to identify amino acids critical for agnoprotein multimeric structures and
function. Alanine substitution of three leucine residues; Leu29, Leu32 and Leu36 located
within alpha-helix region resulted in a mutant that exhibits a substantially reduced
level of agnoprotein expression and viral DNA replication. Consistent with these in
vivo findings, in vitro studies with this mutant demonstrated considerably low level
of protein expression in a bacterial expression system and showed defects in monomer,
dimer and oligomer formation. Collectively, these findings suggest that Leu29, Leu32
and Leu36 residues found in the dimer interface of agnoprotein play critical roles
in protein stability, dimer/oligomer formation and in viral DNA replication. Thus,
the dimerization domain of agnoprotein represents a potential target site for developing
novel therapeutics against JCV infections in affected PML patients.
P152
JC virus (JCV) agnoprotein harbors a putative nuclear export signal (NES) and interacts
with a host RNA export factor, CRM1: Evidence for its involvement in nucleo-cytoplasmic
export of JCV transcripts
Sami Saribas, Mahmut Safak
(presenting author: msafak@temple.edu)
Temple University School of Medicine, Department of Neuroscience, Laboratory of Molecular
Neurovirology, Philadelphia, PA, 19140, USA
Viruses have evolved highly sophisticated mechanisms to exploit the host machinery
for their own benefit to produce infectious virions. They achieve this in part by
encoding and utilizing multifunctional proteins in multiple steps of the viral infection
cycle including RNA export. These types of viral proteins have distinct functional
domains used by viruses in such processes. JCV agnoprotein is one of those multifunctional
proteins with multiple properties. For example, it localizes mainly to the perinuclear
area of the infected cells but a considerable amount of it is also found in the nucleus.
This protein is consists of several functional domains, including a bipartite nuclear
localization signal (NLS) and a Leu/Ile/Phe-rich multimerization domain and exhibits
a highly basic nature containing multiple Arg, and Lys residues found at the N- and
C-terminus of the protein. In addition, it specifically interacts with JCV RNA and
harbors a putative NES similar to that of HIV-1 Rev; and treatment of the JCV-infected
cells with a selective CRM1 inhibitor (Leptomycin B) leads to the accumulation of
agnoprotein inside the nucleus, suggesting that it may be involved regulation of the
export of the JCV transcripts in a CRM1-dependent manner. To provide evidence for
such a possibility, a protein-protein interaction study has been performed between
agnoprotein and CRM1 using whole cell extracts from SVG-A cells infected with JCV
and purified CRM1. Results showed that agnoprotein strongly interacts with GST-CRM1,
but not with GST alone, suggesting that the observed interaction between these two
proteins is specific. Collectively, results from these studies support a hypothesis
that agnoprotein may play a regulatory role in nucleo-cytoplasmic export of JCV transcripts
in a CRM1-dependent manner. Our future studies are aimed at investigating the molecular
mechanisms regulated by agnoprotein in export of JCV transcripts.
P153
Functional interplay between Pur-alpha and SF2/ASF controls JC virus gene expression
Ilker Sariyer, Rahsan Sariyer, Jennifer Gordon
(presenting author: isariyer@temple.edu)
Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine, Philadelphia, PA
The majority of the human population is latently infected with JC virus, which causes
the fatal demyelinating disease of the brain, progressive multifocal leukoencephalopathy,
in immunocompromised individuals. The mechanism of viral reactivation and the molecular
switch to activate productive replication is not well understood. Previous studies
have identified Pur-alpha and SF2/ASF, also known as SRSF1, as positive and negative
regulators of JCV gene expression, respectively. Here we studied the functional interplay
between Pur-alpha and SRSF1 in regulation of JCV gene expression at the transcriptional
and splicing levels. Western blot analysis of brain lysates and embryonic fibroblasts
from mice lacking Pur-alpha showed a dramatic increase in SRSF1 levels compared to
wild type mice, pointing to a negative correlation in cellular expression of both
proteins. In addition, overexpression of Pur-alpha in glial cell lines caused a significant
reduction in SRSF1 levels. Next, we tested the effects of Pur-alpha and SRSF1 on JCV
transcription by luciferase assay. As expected, while SRSF1 caused a strong inhibition,
Pur-alpha showed a moderate increase in transcription levels driven by the JCV-early
promoter. Interestingly, we observed that SRSF1 mediated suppression of JCV transcription
was significantly restored by expression of Pur-alpha. These data have revealed a
novel interaction between SRSF1 and Pur-alpha in the regulation of JCV reactivation.
This work was made possible by grants awarded by NIH to IKS and JG.
P154
JC Virus Agnoprotein is Secreted and Uptaken by Glial Cells
Ilker Sariyer, Onder Otlu, Kasra Houshmand, Kamel Khalili
(presenting author: isariyer@temple.edu)
Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine, Philadelphia, PA
The JC virus (JCV) is one of the abundant polyomaviruses which infects the majority
of human population during childhood, and establishes a persistent life-long infection.
JCV replicates in glial cells in the brain, and causes the fatal demyelinating disease,
progressive multifocal leukoencephalopathy (PML). PML is usually seen in patients
with underlying immunocompromised conditions, notably among AIDS patients and those
on chronic immunosuppressive regimens. JCV genome is composed of three functional
regions, including the viral early and late coding regions and viral noncoding regulatory
region. The late leader sequence contains an open reading frame encoding a small regulatory
protein called agnoprotein. Previous studies from mutational analysis suggested that
agnoprotein is required for the sufficient progression of the infection cycle in glial
cells with an unknown mechanism. Here, we have discovered that agnoprotein can be
detected in cell-free fractions of glial cultures infected with JCV, transfected with
expression plasmids or transduced with adenovirus expression system. Moreover, treatment
of cells with Brefeldin A but not Monensin suppressed the secretion of agnoprotein
suggesting that conventional secretion pathway was mainly involved in agnoprotein
secretion. We further demonstrated that the secreted agnoprotein was uptaken by glial
cells. These studies have revealed a novel phenomenon of agnoprotein during the viral
life cycle with a potential of developing diagnostic and therapeutic interventions.
This work was made possible by grants awarded by NIH to IKS and KK.
P155
The activity of HIV-1 Tat and morphine at Toll-like receptor 4: Implications for mechanism
of actions leading to HIVE and HAND
Christina Schier1, Nazira El-Hage1, Elizabeth Podhaizer1, Myosotys Rodriguez2, Pamela
Knapp3, Kurt Hauser1
(presenting author: cjschier@vcu.edu)
1Department of Pharmacology and Toxicology, Virginia Commonwealth University;
2Universidad Central del Caribe, School of Medicine;
3Department of Anatomy, Virginia Commonwealth University
Opiate drug use by HIV-1 positive individuals is reported to exacerbate HIV encephalitis
(HIVE) and HIV-associated neurodegenerative disorders (HAND). It has recently been
suggested that, besides mu-opioid receptors, opiate drugs can also activate Toll-like
receptor 4 (TLR4). Likewise, this receptor is a plausible target for HIV-1 proteins
such as transactivator of transcription (Tat). Therefore, we aimed to clarify the
role of morphine and Tat directly at TLR4 using HEK cell lines that express human
TLR4, MD2 and CD14 [TLR4(+) cells] or only MD2 and CD14 genes [TLR4(-) cells], as
well as an NF-kappaB-inducible reporter which quantifies TLR4 activation. We found
that a 16-h exposure to HIV-1 Tat1-86 (100 nM) increased TLR4 reporter activity, but
under our current conditions at this time point, exposure to (-)-morphine or (+)-morphine
enantiomers (500 nM-5 uM) did not appear to activate the TLR4 reporter; however, higher
doses still need to be tested. Additionally, activity of Tat at TLR4 seems to be specific,
as co-application of the TLR4-selective antagonist, LPS-RS, significantly decreased
Tat- or LPS-EK (TLR4-specific agonist)-induced activity similarly. No significant
activation by Tat or morphine was noted in TLR4(-) cells. Finally, using an ELISA,
we noted that a 24-h exposure to Tat increased MCP-1 production in TLR4(+) cells,
though (-)-morphine did not. We validated the model by confirming the presence of
TLR4 and absence of mu-opioid receptors in the appropriate cell lines using qRT-PCR.
Overall, our current results suggest that, in a TLR4 over-expressing HEK cell model
designed to purely test TLR4 activity, Tat, but not morphine, activated TLR4 and its
signaling pathway. Supported by NIH T32 DA007027, K02 DA027374, and R01 DA034231.
P156
A novel model for proviral HIV-1 latency in neural cells reveals similarities between
HIV-1 latency in the brain and in the immune system
Martha Schneider, Christoph Ziegenhain, Bianca Tigges, Markus Helfer, Ruth Brack-Werner
(presenting author: brack@helmholtz-muenchen.de)
Helmholtz Center Munich, Institute of Virology
Potential carriers of transcriptionally latent HIV-1 proviruses in the immune system
and the central nervous system (CNS) include CD4+ memory T-cells and astrocytes and
possibly also neural progenitor cells. While powerful cell culture models exist for
proviral HIV-1 latency in CD4-positive T-cell reservoirs, comparable models have been
lacking for neural cells. To establish a cell culture model for proviral transcriptional
HIV-1 latency in neural cells, we subjected cells of the human neural stem cell line
HNSC.100 to single-round infections with various Env-defective HIV-1 genomes, including
reporter viruses with GFP-encoding sequences. HIV-1 infection and viral expression
were monitored by quantitative PCR analysis of proviral DNA and viral transcript levels
and by flow cytometry analysis of GFP-expression. Long-term culture led to establishment
of cell populations that had ceased HIV-1 expression but retained HIV-1 proviral DNA.
HIV-1 expression was reactivated by treatment with the proinflammatory cytokine TNF-alpha
and SAHA (suberoylanilide hydroxamic acid), which are potent HIV-1 activators in latently
infected T-cells. Inducible re-activation of HIV-1 expression was maintained over
numerous passages and in differentiated cells and was retained by single-cell clones.
Side-by-side assays with latently infected neural and T-cells (J-Lat) revealed that
reactivation of HIV-1 expression could be blocked in both HIV-1 reservoir cell types
by pretreatment with various small molecules that inhibit activation of NF-kappaB
or the positive transcriptional elongation factor pTEFb. In summary, we report establishment
of a potent cell culture model for persisting latent HIV-1 proviruses in neural cells
and use this model to compare modulation of proviral HIV-1 latency in brain cells
and T-cells. Our results raise the possibility that agents that influence HIV-1 proviral
latency in the immune system may also affect proviral latency in the CNS and provide
proof-of-concept for blocking of reactivation of proviral HIV-1 latency in different
HIV-1 reservoirs by small molecules.
P157
Myocyte enhancer factor-2 (MEF-2) plays critical role in HTLV-1 infection and transformation
of CD4+ T cells
Mohit Sehgal1, Shruti Singh1, Anne Lamontagne2, Edward Harhaj3, Zafar Khan1, Pooja
Jain1
(presenting author: mohit.sehgal@drexel.edu)
1Drexel Institute for Biotechnology and Virology Research and Department of Microbiology
and Immunology, Drexel University College of Medicine;
2Clinical Cell and Vaccine Production Facility, University of Pennsylvania;
3Department of Oncology, Johns Hopkins School of Medicine
The transactivator protein of human T-cell leukemia virus type 1 (HTLV-1), Tax, is
capable of regulating both virus (via transcriptional activation of the viral long
terminal repeat, LTR) and the host transcriptional machinery, however there is no
clear understanding about the involvement of host transcription factors. Herein, we
describe the role of myocyte enhancer factor-2 (MEF-2) in Tax-mediated activation
of HTLV-1 LTR in infected primary CD4+ T cells and the virus-producing cell line,
MT-2. MEF-2 was confirmed by ChIP assay to be recruited to LTR in MT-2 and primary
CD4+ as well as CD4+CD25+ T cells in association with Tax. Furthermore, an increase
in MEF-2 expression was observed upon infection and correlated with Tax and HAT complex
formation, while MEF2 knockdown through shRNA and inhibition of MEF-2 activity by
overexpression of a known repressor, HDAC9, reduced viral mRNA and protein expression
in both primary cells and cell lines. Confocal microscopy also confirmed that MEF-2
colocalizes with Tax in virus producing cell lines. Next, in order to understand the
regulation of MEF-2, we performed comparative protein-DNA array analyses and observed
a global upregulation of many MEF-2 associated transcriptional factors in infected
cells. Additional studies demonstrated the expression of key signaling mediators and
clearly indicated that MEF-2-integrated signaling pathways are activated during HTLV-1
infection, including PI3K/Akt, NF-kappaB, MAPK, TGF-beta and JAK/STAT signaling. Overall,
these studies are the first to describe the involvement and regulation of a novel
transcription factor, MEF-2, during the course of HTLV-1 infection and pathogenesis.
P158
Quality and miRNA control of dendritic cell responses during interferon/ribavirin
therapy in HIV-1/HCV co-infected patients
Mohit Sehgal1, Zafar Khan1, Andrew Talal2, Pooja Jain1
(presenting author: mohit.sehgal@drexel.edu)
1Drexel Institute for Biotechnology and Virology Research and Department of Microbiology
and Immunology, Drexel University College of Medicine;
2School of Medicine and Biomedical Sciences, Buffalo University
HIV-1/HCV co-infection represents a significant burden on global economy and public
health. Up to 30% of HIV-infected patients and 60-90% of HIV-infected injection drug
users are infected with HCV. It is now widely accepted that HIV accelerates the course
of HCV-related chronic liver disease. The current standard treatment for treating
HCV infection in HIV-1/HCV co-infected patients is administration of PEGylated interferon
alpha-2a/2b (PEG-IFNalpha-2a/2b) and an anti-viral drug ribavirin (RBV). Recent breakthroughs
in direct-acting antivirals (DAAs) such as Telaprevir and Boceprevir against HCV genotype
1/2 have provided hope for HCV cure. However, development of viral resistance during
DAA treatment, and drug-drug interaction among protease inhibitors are two key concerns
in the clinical management of infection. Furthermore, Telaprevir or Boceprevir yield
optimal results upon combination with IFN and/or RBV, suggesting IFN/RBV will still
be the backbone of anti-HCV treatment. Plasmacytoid dendritic cells (pDCs) are the
natural producers of type 1 IFN in response to many viral infections including HIV-1.
However, HCV is known to be a weak inducer of IFN-alpha in pDCs and it is not known
how this scenario changes in the presence of HIV. Therefore, we investigated the quality
of DC responses in co-infected patients during the course of IFN/RBV therapy. Further,
to understand the molecular basis of these responses, we analyzed differential expressed
miRNAs and their target mRNAs in sustained virological responders (SVRs) and non-responders
(NRs), pre- and post-treatment. Collectively, results of these studies led to key
immune and molecular correlates of IFN/RBV treatment in HIV-1/HCV co-infected patients.
P159
Regulation of HIV-1 transcription by glycolytic enzyme Pyruvate kinase M2
Satarupa Sen 1, Kamel Khalili2, Shohreh Amini1, Prasun K. Datta2
(presenting author: satarupa.sen@temple.edu)
1Department of Biology, CST Temple University;
2Department of Neuroscience, Center for Neurovirology, Temple University School of
Medicine
Identification of cellular proteins in addition to already known transcription factors
such as NF-kappaB, SP1, and CEBP that interact with the HIV-1 LTR is critical in understanding
the mechanism of HIV-1 replication in monocytes/macrophages. Our studies demonstrate
upregulation of pyruvate kinase isoform M2 (PKM2) expression in HIV-1JRFL infected
PBMCs and during reactivation of HIV-1 in chronically infected U1 cells. Furthermore,
we observed that infection of PBMCs with HIV-1 and reactivation of HIV-1 in U1 cells
results in increased levels of nuclear PKM2. Hence we focused on understanding the
potential role of PKM2 on HIV-1 LTR transactivation. Our studies demonstrate that
over expression of PKM2 in U937 and in TZM-bl cells lead to transactivation of the
HIV-1 LTR reporter construct. Using various deletions constructs of HIV-1 LTR, we
mapped the region spanning between -203 bp to -80 bp to be essential for PKM2 mediated
transactivation. This region contains the NF-kappaB DNA binding site and mutation
of NF-kappaB binding site attenuated PKM2 mediated transactivation of HIV-LTR. Chromatin
immune-precipitation (ChIP) analysis in PMA activated TZM-bl cells demonstrated interaction
of PKM2 with HIV-1 LTR. Our studies suggest that PKM2 is a transcriptional co-activator
of HIV-1 LTR. Hence it opens up another possible target to curb HIV-1 replication
at transcriptional level. This work was supported by the NIH grants to SA and PKD.
The study also utilized services offered by core facilities of the Comprehensive NeuroAIDS
center (CNAC) NIMH Grant # P30MH092177 to KK.
P160
The role of hexokinase in conferring protection to HIV-1 infected macrophages from
apoptosis
Satarupa Sen1, Kamel Khalili2, Prasun K. Datta2, Shohreh Amini1
(presenting author: satarupa.sen@temple.edu)
1Department of Biology, CST, Temple University;
2Department of Neuroscience, Center for Neurovirology, Temple University School of
Medicine
Viruses have evolved various strategies to protect infected cells from apoptosis.
Glycolysis is linked closely to the cell fate and it is known that HIV-1 infected
macrophages are long lived and considered to be viral reservoirs. We provide evidence
that HIV-1 protects infected macrophages from apoptosis by modulating the host glycolytic
pathway. Glycolytic enzyme Hexokinase (HK) and product of its enzymatic activity Glucose
6 phosphate (G-6-P) are known to play a non-metabolic role in resisting and supporting
apoptosis, respectively. Increased association of HK with voltage dependent anion
channel of mitochondrial outer membrane can resist apoptosis by maintaining mitochondrial
membrane integrity. On the other hand increased G-6-P pool in cytoplasm can force
HK to dissociate from mitochondrial membrane and induce apoptosis by cytochrome c
leakage. In this study, we analyzed regulation of HK that converts glucose to G-6-P
and Glucose-6-phosphate-dehydrogenase (G6PD) that converts G-6-P in to fructose 6
phosphate, in response to HIV-1 activation in chronically infected U1 cell line. We
found that HIV-1 replication in U1 cell induces HK expression followed by translocation
of HK from cytoplasm to mitochondria of cell. We also observed that viral replication
increases the enzymatic activity of G6PD. As a consequence, HK can associate strongly
with mitochondrial membrane and this association is kept under tight control by rapidly
turning over G-6-P through increased activity of G6PD enzyme. We also found that treatment
with pentose phosphate pathway blocker Dehydroepiandrosterone (DHEA) which also inhibits
HK and VDAC interaction; reduced viral replication. Hence our work suggests Hexokinase
as a new therapeutic target for intervention to curtail viral persistence in the macrophage.
This work was supported by the NIH grants to SA and PKD. The study also utilized services
offered by core facilities of the Comprehensive NeuroAIDS center (CNAC) NIMH Grant
# P30MH092177 to KK.
P161
Impact of SNPs on regulation of the HIV-1 promoter within a chromatin-based microenvironment
Sonia Shah, Kevin Bloh, Michael Nonnemacher, Vanessa Pirrone, Brian Wigdahl
(presenting author: szs131@gmail.com)
Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine
Selective pressures and the low efficiency of reverse transcriptase lead to genetic
alterations within the human immunodeficiency virus type 1 (HIV-1) genome resulting
in quasispecies that can be differentially regulated and can potentially form niches
within specific cell types and tissues. Previous studies identified a single nucleotide
polymorphism (SNP) within C/EBP site I (3T, C-to-T change at position 3 of the consensus
B site) that correlated with HIV-1-associated dementia. In addition, our current cohort
shows a SNP within Sp site III (5T, C-to-T change at position 5 of the consensus B
site) that occurs as frequently as the consensus subtype B sequence. Stably transfected
cell lines were developed using bone marrow progenitor, T, and monocytic cell lines
to explore the promoter (LTR) phenotype associated with these genotypic changes from
an integrated microenvironment. The LAI LTR was coupled to green fluorescent protein
(GFP), and polyclonal HIV-1 LTR-GFP stable cell lines were developed. To examine the
mechanism of LTR-driven gene expression as well as epigenetic modifications that may
control it, clones were derived from each population of cells. The clones were examined
with respect to basal transcription, cytokine response, and Tat transactivation. Results
have suggested that non-expressing clones containing the 3T5T LTR within TF-1 cell
lines can be induced to express. Additionally, the non-expressing LAI 3T and LAI 5T
Jurkat clone genotypes could be induced into expression. Results demonstrate that
genetic signature, epigenetic modifications to viral and host DNA, and cellular phenotype
may determine the overall level of LTR activity. This work is supported by NIH/NINDS
R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P162
The National NeuroAIDS Tissue Consortium: Status of the Resource
Seth Sherman1, Susan Morgello2, Igor Grant3, Elyse Singer4, Howard S. Fox5, Benjamin
B Gelman6, Diane K Brandt7
(presenting author: ssherman@emmes.com)
1The NNTC Data Coordinating Center, The EMMES Corporation, Rockville, MD;
2Manhattan HIV Brain Bank, Department of Neurology, Mount Sinai Medical Center, New
York, NY;
3California NeuroAIDS Tissue Network, University of California, San Diego La Jolla,
CA;
4National Neurological AIDS Bank Department of Neurology, University of California,
Los Angeles, CA;
5Department of Pharmacology and Experimental Neuroscience, University of Nebraska
Medical Center, Omaha, NE;
6Texas NeuroAIDS Research Center, Department of Pathology, University of Texas Medical
Branch, Galveston, TX;
7NNTC Data Coordinating Center, The EMMES Corporation, Rockville, MD
Background: The National NeuroAIDS Tissue Consortium (NNTC) has served the research
community since 1998 as an NIH-sponsored multi-site repository that distributes antemortem
and postmortem tissue with clinical and serological data from HIV-infected individuals.
The NNTC has recently evolved its tissue bank processes, clinical data, and web resources
to meet the changing needs of the research community it serves.
Methods: The NNTC collects and distributes CNS and systemic samples from HIV sero-positive
and sero-negative individuals. Tissues are provided as embedded, fixed sections or
frozen blocks. Plasma, serum, and PBMCs are also available. Tissue and/or associated
data are available to qualified investigators at no charge beyond shipping expenses.
New web resources available for users include:
Public use data set with documentation
Query tool with download utility
Experimental results from previous NNTC studies
Bioinformatics resources at University of Nebraska
Tissue Bank Holdings:
Fixed Brain Specimens:
745 HIV sero-positive
210 HIV sero-negative
HIV sero-positive brains:
39% have antemortem plasma
28% serum
17% CSF
412 have neurocognitive assessment prior to death
Longitudinal Cohort:
Enrolled:
2117 sero-positive
84 sero-negative cases
HIV sero-positive cases:
603 are active
530 are deceased with autopsy
254 are deceased without autopsy
730 are inactive
1874 have a baseline neurocognitive diagnosis:
20% normal
21% MCMD
12% HIV associated dementia
NNTC Impact:
12,774 specimens of various tissue types have been distributed between 1999 and 2013.
Scientific contributions resulting from the NNTC resources are significant, with close
to 400 publications resulting from the use of the NNTC resources. The resource was
important in 16 investigators securing 25 funded research applications.
Conclusions: The NNTC has become an invaluable resource, expanding the field of NeuroAIDS
research by making available a unique neurologically focused tissue linked to antemortem
clinical data. The website for the NNTC, including user information and cohort description:
www.nntc.org.
P163
Pathogenic Mechanisms of HIV-1/AIDS-Associated Chronic Pain
Yuqiang Shi, Subo Yuan, Bei Li, Benjamin Gelman, Shao-Jun Tang
(presenting author: shtang@utmb.edu)
Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston,
TX 77555
Millions of HIV-1/AIDS patients develop severe chronic pain that drastically deteriorates
their life quality, but the pathogenic mechanism is unclear and effective therapies
are not available. We are interested in elucidating the host mechanisms in CNS that
interact with HIV toxins and contribute to this devastating neurological complication
in HIV patients. We are undertaking an interdisciplinary approach in this line of
research. In the first approach, we focus on analyzing the postmortem nervous tissues
from HIV-1/AIDS patients. The goal is to identify clinically relevant molecular and
cellular abnormalities in the pain-processing pathway. The analyses reveal the critical
HIV-1 protein that may cause this pain syndrome. In the second approach, we are interested
in generating a rodent model for the HIV-1-associated chronic pain, based on the findings
from human specimen analysis. The goal is to establish a clinically relevant animal
model. We have created a mouse model that develops extensive similarities to the pathologies
seen in the HIV-1 patients with chronic pain. In the third approach, we focus on elucidating
the molecular and cellular processes that are critical for the pathogenesis of HIV-1-associated
chronic pain, using the mouse model that we have generated and characterized. We are
currently determining the contribution of synaptic degeneration, glial activation
and Wnt signaling dysregulation to the pathogenesis.
P164
Genotypic and phenotypic characterization of the Envelope glycoproteins of two highly
neurotoxic, CSF-derived, HIV-1 primary isolates
Luz-Jeannette Sierra1, Dennis L. Kolson2, Julio Martin-Garcia1
(presenting author: ls484@drexel.edu)
1Department of Microbiology and Immunology, and Center for Molecular Virology and
Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease,
Drexel University College of Medicine;
2Department of Neurology, University of Pennsylvania School of Medicine
HIV-1 enters the CNS early after systemic infection, leading to a variety of neurocognitive
and motor impairments referred to as HIV-1 associated neurocognitive disorders (HAND).
Macrophages and microglia support productive viral infection in the brain and the
virus subsequently adapt to the CNS environment. Our goal is to elucidate the role
of the HIV-1 envelope glycoprotein (Env) during HIV-1 infection in the CNS. We obtained
viruses derived from the cerebrospinal fluid (CSF) of two HIV-1-infected individuals
with HIV-1-associated dementia, the most severe form of HAND. These isolates are macrophage
tropic (i.e. efficiently infect macrophages, whereas most blood-derived isolates do
not) and highly neurotoxic. We amplified by PCR multiple env genes from these isolates
and have performed extensive genotypic and phenotypic characterization. Interestingly,
a mixture of genotypes and phenotypes has been found. From both viruses, we obtained
a mixture of macrophage-tropic and non-macrophage tropic Env, as well as Env with
various degrees of fusogenicity, ability to use low levels of CD4 for infection, sensitivity
to entry and fusion inhibitors, and sensitivity to neutralizing antibodies directed
against the conserved CD4 binding site. Importantly, some of these Env, in the context
of isogenic recombinant viruses, are able to mediate infection of macrophages and
lead to the production of conditioned medium which causes neurotoxicity in primary
pure neuronal cultures, whereas others do not. Correlations between genetic determinants
and the above reported phenotypes are being further investigated.
P165
Imaging lentiviral reservoirs in vivo based on molecular imaging reporter genes
Jiasheng Song, Won-Bin Young
(presenting author: songj2@upmc.edu)
Molecular imaging laboratory, Department of Radiology, University of Pittsburgh School
of Medicine
HIV-1 infections persist in spite of exposure to highly active antiretroviral therapies
(HAART) due to the latent stage of the virus. The latently infected cells present
a major barrier for curing HIV-1 infections. The identification of viral reservoirs
is essential in monitoring the therapeutic response to HAART including during the
latent stage. Bioluminance imaging (BLI), positron emission tomography (PET), and
magnetic resonance imaging (MRI) are non-invasion imaging techniques that can be employed
to identify viral reservoirs eliminating the need for repeat biopsies in vital organs,
such as the brain. However, during the latency stage there are no detectable viral
proteins for targeted imaging. Our lab has developed a “Trojan Horse” type strategy
where we’ve engineered human, simian, and feline immunodeficiency viruses (HIV, SIV,
FIV) to carry a reporter gene for non-invasive imaging modalities, including BLI,
PET or MRI. The engineered viruses remain replication competent after infecting target
cells for reporter gene expression. The reporter was engineered into the virus either
with or without its own promoter to allow detection of the infected cells during the
latency stage, while the long terminal repeat (LTR) promoter is inactive. We have
demonstrated that the imaging reporter genes are incorporated, expressed and functional
in infected cells and the replication kinetics of engineered lentivirus is comparable
to that of the wild type virus. Currently, we are working towards the evaluation of
the engineered viruses in the individual species: humanized mice (HIV), macaque monkeys
(SIV) or felines (FIV) to further evaluate the use of non-invasive imaging to visualize
the spatial and temporal nature of viral reservoirs and their response to HAART. The
further analyze of these engineered viruses will provide the ability to image viral
reservoirs providing a much needed tool for monitoring and evaluating therapeutic
efficacy.
P166
Effect of antiretroviral therapy on cerebral small vessel disease in HIV infection
Virawudh Soontornniyomkij1, Anya Umlauf2, Sandra Chung3, Megan Cochran4, Benchawanna
Soontornniyomkij1, Ben Gouaux5, Will Toperoff2, Andrea Bucci6, David Moore1, Eliezer
Masliah7, Ronald Ellis8, Scott Letendre9, Dilip Jeste10, Igor Grant2, Cristian Achim1,7
(presenting author: cachim@ucsd.edu)
1Department of Psychiatry, UC San Diego;
2HIV Neurobehavioral Research Programs, UC San Diego;
3School of Medicine, UC San Diego;
4Heritage College of Osteopathic Medicine, Ohio University;
5California NeuroAIDS Tissue Network, UC San Diego;
6John Burns School of Medicine, Honolulu, Hawaii;
7Departments of Pathology and Neurosciences, UC San Diego;
8Department of Neurosciences, UC San Diego;
9Department of Medicine, UC San Diego;
10Stein Institute for Research on Aging, UC San Diego
The benefit of highly active antiretroviral therapy for preventing and treating HIV-associated
neurocognitive disorders (HAND), especially HIV-associated dementia, is well documented.
Nonetheless, the milder forms of HAND remain prevalent and hence are suspected to
be associated with various co-morbid factors including cumulative exposure to antiretroviral
(ARV) medications. We propose that chronic toxic effects of ARV drugs on the cell
components of blood vessel walls can contribute to brain vascular pathology, particularly
cerebral small vessel disease (CSVD, including arteriosclerosis and arteriolosclerosis).
Even at its early stages when a decrease in the cerebral blood flow is not severe
enough to cause infarcts or white matter lesions, CSVD can lead to disturbance of
cerebrovascular autoregulation and deficiency in functional hyperemia. We used multinomial
logistic regression to determine associations between the use of ARV drugs and the
occurrence of CSVD in 144 autopsy HIV-infected cases in the California NeuroAIDS Tissue
Network. Using univariable analysis we found that mild CSVD (vs. absent) was associated
with nucleoside reverse transcriptase inhibitors (NRTIs) or protease inhibitors (PIs)
[odds ratio (OR) 19.23 and 2.84, P=0.003 and =0.06, respectively], but not with any
of the vascular risk factors (i.e., older age [≥50 years], diabetes mellitus, hypertension,
hyperlipidemia, cigarette smoking, and lifetime psychostimulant dependence). On the
other hand, moderate/severe CSVD (vs. absent) was associated with older age and diabetes
(OR 2.56 and 6.55, P=0.035 and =0.01, respectively), but not with any of the ARV-related
predictors. Our findings suggest that the use of NRTIs or PIs may increase the risk
of mild CSVD and consequently neurocognitive impairment. Of particular interest are
further studies of the molecular mechanisms of ARV toxicity to the cell components
of brain vessel walls and identifying potential biomarkers for CSVD in HIV-infected
persons.
P167
The Haptoglobin-Hemoglobin Scavenger Receptor CD163 Enhances HIV Infection in Macrophages
Sergei Spitsin1, Florin Tuluc2, John Meshki1, Steven D. Douglas3
(presenting author: spitsins@email.chop.edu)
1Division of Allergy and Immunology, The Children's Hospital of Philadelphia Research
Institute, Philadelphia, PA 19104;
2Division of Allergy and Immunology, Flow Cytometry Core Laboratory, The Children's
Hospital of Philadelphia Research Institute, Department of Pediatrics, Perelman School
of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
3Division of Allergy and Immunology, The Children's Hospital of Philadelphia Research
Institute, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania,
Philadelphia, PA 19104
The receptor for haptoglobin-hemoglobin complexes, CD163, is expressed on cells of
monocytes-macrophage origin. The membrane-bound molecule is cleaved by proteases and
released in biological fluids in a stable soluble form (sCD163). Plasma levels of
sCD163 are elevated in HIV infected individuals; however, the direct involvement of
membrane-bound or soluble CD163 in HIV pathogenesis is unknown. In this study we demonstrate
that relatively high concentrations of SP (10 microM) trigger intracellular calcium
increase in monocytes, most likely due to the activation of the truncated isoform
of neurokinin 1 receptor (NK1R). SP also enhances CD163 expression on monocytes in
a dose- and time-dependent manner, albeit to a lower extent than IL-10, a cytokine
well known to induce the alternative pathway of monocyte differentiation. The SP-induced
expression of membrane-bound CD163 is accompanied by increased shedding of sCD163
from human monocyte-derived macrophages (MDM) and this effect is inhibited by the
NK1R antagonist, aprepitant. Decreasing the expression of membrane-bound CD163 in
MDM using siRNA resulted in a significant decrease of HIV infection. In order to further
demonstrate that the level of expression of membrane-bound CD163 is important for
HIV infection, we used cell sorting to separate human monocytes expressing high and
low levels of CD163. The productivity of HIV infection was higher in cells expressing
high levels, vs. cells expressing low levels of CD163. Our study indicates that high
levels of membrane-bound CD163 facilitate HIV infection in macrophages.
This work was supported by National Institutes of Health Grants U01-MH 090325, R01-MH
049981, R21-AI 108298 (to SDD)
P168
Prolonged exposure to morphine induces cell adhesion to an in vitro model of the blood-brain
barrier
Marianne Strazza1, Vanessa Pirrone1, Wei Lin2, Rui Feng2, Brian Wigdahl1, Michael
Nonnemacher1
(presenting author: michael.nonnemacher@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistics, University of Pennsylvania School of Medicine
Opioid abuse by human immunodeficiency virus type 1 (HIV-1)-infected individuals leads
to more rapid disease progression, increased viral replication and peripheral viral
load, and increased incidence and severity of neurocognitive abnormalities compared
to non-drug abusers. The blood-brain barrier (BBB) is an obstacle that must be overcome
during neuroinvasion with subsequent development of HIV-associated neurocognitive
disorders (HAND). Previous studies addressing the role of mu-opioids in altering BBB
permeability have suggested that exposure increases cellular transmigration through
an uncharacterized mechanism. In this study, a human brain microvascular endothelial
cell (hBMEC) line, hCMEC/D3, was used to establish an in vitro transwell model of
the BBB to investigate the effects of chronic (24, 48, or 72 h) morphine treatment
on barrier structure and function. We observed that hCMEC/D3 cells form a confluent
monolayer with a basal rate of passage of a 70 kDa tracer molecule comparable to primary
hBMECs. It has also been shown that these cells express mu opioid receptor, and that
prolonged morphine treatment induces changes in mRNA levels of cellular adhesion molecules.
Functionally, an increase in PBMC transmigration and firm adhesion was observed following
prolonged morphine exposure, in the absence of an increase in overall barrier leakiness.
These results have suggested that morphine activates hCMEC/D3 cells leading to a cellular
environment permissive to transmigration. These studies may uncover a mechanism through
which morphine disrupts periphery-CNS homeostasis leading to accelerated HAND. This
work is supported by NIH/NINDS R01 NS32092, NIDA R01 DA19807, NIMH P30 MH092177, and
NIMH T32 MH079785.
P169
A novel role for Toll-Like Receptor-3 in sensing HIV-1 infection: potential implications
in viral replication, immune activation and HIV-1 associated neuropathogenesis
Gokul Swaminathan, Renzo Perales-Linares, Sonia Navas-Martin, Julio Martin-Garcia
(presenting author: gs337@drexel.edu)
Drexel University College of Medicine
Viral particles of HIV-1, the causative agent of AIDS, contain two copies of a ssRNA
genome. Toll-Like Receptors (TLRs) such as endosomal TLRs 7 and 8 have been reported
to sense HIV-1 RNA sequences. The endosomal TLR3 primarily senses dsRNA, a common
viral replication intermediate that is absent during retroviral replication. However,
since HIV-1 ssRNAs contain multiple hairpin-like secondary structures that could potentially
mimic a dsRNA entity, we hypothesized that TLR3 could sense and respond to HIV-1 infection.
No difference in susceptibility to infection with HIV-1 virions pseudotyped with murine
leukemia virus envelope glycoprotein or vesicular stomatitis virus glycoprotein (VSV-g)
was observed between bone marrow-derived macrophages isolated from wild-type and TLR3
knock-out (TLR3KO) mice. However, production of pro-inflammatory cytokines and chemokines,
including type-I IFNs was significantly reduced in BMDMs from TLR3KO mice. Similarly,
in the presence of a TLR3-specific inhibitor, HIV-1 BAL pseudotype infection of human
monocyte-derived macrophages and THP1-derived macrophages resulted in significantly
reduced production of pro-inflammatory cytokines and chemokines. Phosphorylation of
the transcription factor IRF-3 (p-IRF3), is an essential step for TLR3 dependent upregulation
of type-I IFNs. HIV-1 BAL infection upregulated p-IRF3 3-6hrs post infection, however,
inhibition of TLR3, significantly reduced HIV-1 induced p-IRF3 levels. Surprisingly,
HIV-1 BAL infection of human macrophages resulted in significant upregulation of TLR3
mRNA levels and moderate increase in TLR3 protein levels. Finally, infection of 293T
cells stably expressing the murine TLR3, with VSV-g pseudotyped virions, resulted
in significant induction of TNF-alpha and IL-6. Current and future experiments are
aimed at investigating the potential for direct interaction between HIV-1 ssRNA and
TLR3. Overall, this study provides the first known evidence that TLR3 senses and responds
to HIV-1 infection in macrophages. Since TLR3 is a crucial innate immune sensor in
the brain, these results have important implications in HIV-1 neuropathogenesis, inflammation
and other co-morbidities.
P170
Osteopontin Regulates the Expression of Proinflammatory Genes Involved in Macrophage
Activation and Susceptibility to HIV Replication
C. Conover Talbot Jr., David Mohr, Jasmeet Sethi, Haiping Hao, Amanda Brown
(presenting author: abrown76@jhmi.edu)
Johns Hopkins University School of Medicine
Recent studies show that proinflammatory cytokines including osteopontin (OPN, SPP1)
remain elevated in the plasma and cerebrospinal fluid (CSF) in individuals suffering
from HIV-associated neurocognitive disorders (HAND). Beyond its ability to enhance
HIV replication, OPN promotes increased numbers of activated monocytes in the CNS
by facilitating chemotaxis and cell survival. However, the molecular mechanisms by
which OPN mediates its function in the context of HAND remain unexplored. We used
next-generation high-throughput sequencing and transcriptome analyses to identify
the genes and pathways that are differentially regulated in primary human macrophages
knocked down with siRNA against SPP1 (SPP1 KoD) compared to wildtype macrophages.
As predicted by a disruption of SPP1 expression, OPN receptors, the integrins ITGAV
and ITGB3, which signal through NF-kappaB were markedly downregulated. Chemokines
CXCL10, CXCL9, CCL2, CXCL1, CCL13, and CCL7 were up- or downregulated 3-6 fold. TNF-responsive
genes including TRAF1, TANK, TIFAB, TNFSF9, TIFAB, TNFAIP6 and TNFAIP3 and toll-like
receptors -1, -4, -5, -6, and -8 were differentially expressed in SPP1 KoD macrophages.
Key genes involved in cytokine signaling including STAT1, STAT2, NFKBIZ, NFKBID, were
either up- or down modulated in OPN KoD macs. A prominent feature in SPP1 KoD macs
was the differential regulation of 13 members of the mitogen-activated protein kinase
cascade. Interestingly, several members of the host restriction factors that target
HIV including the TRIM and APOBEC proteins were downregulated in SPP1 KoD macrophages.
Unexpectedly, CD163, a biomarker strongly associated with HAND was significantly decreased
in SPP1 KoD macs suggesting a link between proinflammatory gene regulation by OPN
and CD163 expression. Several other host genes implicated in the HIV life cycle were
also differentially regulated. Together, these data suggest that OPN is a potent regulator
of proinflammatory gene expression impacting macrophage activation and host cell resistance
and susceptibility to HIV infection and replication.
P171
Host Immune Responses to JC Virus in Hematopoietic Stem Cell Transplantation (HSCT)
Chen Sabrina Tan1, Thomas Broge2, Sarah Gheuens2, Raphael Viscidi3, Evelyn Borad2,
Jacalyn Rosenblatt4, Michael Wong5, David Avigan4, Igor Koralnik2
(presenting author: ctan@bidmc.harvard.edu)
1Center of Virology and Vaccine Research, Division of Infectious Diseases, Department
of Medicine, Division of NeuroVirology, Department of Neurology, Beth Israel Deaconess
Medical Center, Harvard Medical School;
2Center of Virology and Vaccine Research, Department of Medicine, Division of NeuroVirology,
Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School;
3Johns Hopkins Medical Center;
4Division of Hematology Oncology, Department of Medicine, Beth Israel Deaconess Medical
Center, Harvard Medical School;
5Division of Infectious Diseases, Department of Medicine, Beth Israel Deaconess Medical
Center, Harvard Medical School
Background: JCV causes progressive multifocal leukoencephalopathy(PML) in immunocompromised
patients. Up to 80% of the general population is seropositive for JCV and JCV-specific
cellular immune response is necessary for containment of viral proliferation. The
mechanism of JCV reactivation and immunity in a transplanted immune system remains
unclear.
Methods: We prospectively enrolled 30 patients undergoing allogeneic HSCT, and collected
blood and urine samples before and 3, 6, and 12 months after HSCT. We detected JCV
DNA by PCR in blood and urine samples, performed ELISA for detection of JCV IgM and
IgG, as well as Elispot and ICS for measurement of T-cells responses to JCV. Multivariate
analysis accounted for conditioning regimens, cancer diagnosis, concurrent viremia,
age, and transplant type.
Results: Pre HSCT, JCV DNA was detected in 7/30 urine, 5/30 PBMC and 6/30 plasma samples.
While viruria remained stable after HSCT, viremia was detected in only 1/22 plasma
and none of 22 PBMC samples 12 months after HSCT. Prevalence of anti-JCV IgG was 83%
pre HSCT and remained stable at 72% at 12 months. Anti-JCV IgM was rarely detected.
A significant increase in JCV-specific T cell responses 12 months after HSCT was mediated
by both CD4+ and CD8+ T-cells. While JC viruria correlated directly with detection
of anti-JCV IgG, the cellular immune response to JCV measured by ELISPOT was inversely
correlated with anti-JCV IgG response. Age of the patients and the diagnosis of leukemia
both significantly reduced cellular immune responses to JCV.
Conclusions: JC viruria triggers an antibody response in HSCT. However, an increase
in JCV-specific cellular immune response 12 months after HSCT leads to suppression
of JC viremia, and decrease in JCV humoral immune response. This prospective study
in HSCT patients provides a model of interactions between the host immune response
and viral activation in multiple compartments over time.
P172
Age-dependent susceptibility to La Crosse Virus-induced neurological disease mediated
by TLR3/RLR signaling pathways
Katherine Taylor, Tyson Woods, Clayton Winkler, Karin Peterson
(presenting author: katherine.taylor@nih.gov)
NIH, Rocky Mountain Laboratory, LPVD, Neuroimmunology Unity
Mosquito-borne La Crosse virus (LACV) infections are a leading cause of infectious
encephalitis in children, but adults are generally resistant to neuroinvasive disease.
Age-dependent susceptibility to LACV is also observed in mouse models. Mice younger
than 30 days are susceptible to neurological disease while mice older than 30 days
are resistant. In the current study, we demonstrate that the resistance of adult animals
is dependent on type I IFN responses generated through TLR3 and RIG-I like receptor
(RLR) signaling pathways. These pathways are essential for peripheral virus control
and prevention of spread to the CNS. In particular, TLR3 and RIG-I receptor signaling
in myeloid dendritic cell populations is implicated in virus control. Young mice have
significantly lower numbers of myeloid dendritic cells and generate weaker type I
IFN responses in peripheral tissues following either LACV infection or direct stimulation
with TLR3/RLR ligands compared to older mice. The inability of young mice to generate
strong peripheral type I IFN responses in myeloid dendritic cells following TLR3/RLR
stimulation may explain their increased susceptibility to viral infection, spread
and encephalitis.
P173
Innate immune induced neuronal death during bunyavirus infection is mediated by SARM
Katherine Taylor, Tyson Woods, Karin Peterson
(presenting author: petersonka@niaid.nih.gov)
Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH
Neuronal cell death is a hallmark of various neurological diseases including virus
infections. The innate immune response in the CNS contributes to neuronal damage through
cytokine and neurotoxin production as well as the recruitment of inflammatory cells.
However, the direct role of the innate immune response in mediating cell death during
virus infection of neurons is not known. In the current studies, we identified sterile
alpha and HEAT/Armadillo motif containing 1 (SARM1), a negative regulator of TLR signaling,
as a mediator of bunyavirus-induced neuronal apoptosis. SARM1 was induced in neurons
following La Crosse virus (LACV) infection and inhibition of SARM1 suppressed virus-mediated
neuronal apoptosis. Mechanistic studies demonstrated that SARM1 upregulation was due
to stimulation through MAVS (IPS-1) and that SARM interacted with MAVS on the mitochondria
and induced oxidative damage leading to neuronal apoptosis. This data provides a novel
mechanism for immune mediated neuronal death during virus infection by activation
of pattern-recognition receptors (PRRs) leading to MAVS activation, SARM1 induction
and oxidative stress. Since stimulation of neurons through endosomal TLRs can inhibit
neuronal growth and induce apoptosis, we also analyzed the role of SARM in TLR-mediated
neuronal death. SARM1 was induced by TLR7/TLR9 agonist stimulation of cortical neurons
and TLR-induced neuronal apoptosis was SARM1 dependent. These data indicate that activation
of pattern-recognition receptors on neurons, in the presence or absence of active
virus infection, can lead to neuronal death and that the mechanism of death is through
production of SARM which leads to mitochondrial damage.
P174
Multiomic profiling of Peripheral Immune Response in an SIV Macaque Model of HIV-Associated
Neurological Disease
Ravi Tharakan1, Anne Blackwell2, Ceereena Ubaida Mohien1, David Colquhoun1, Brigitte
Simons3, M. Christine Zink1, David Graham1
(presenting author: rtharak1@jhmi.edu)
1Department of Molecular and Comparative Pathobiology;
2Agilent Technologies;
3AB SCIEX
Purpose: HIV-associated neurocognitive disorder (HAND) is a complication of HIV, in
which HIV-infected individuals suffer a varying degree of neurocognitive impairment.
HAND can occur in both treated and untreated HIV patients, making it a large public
health problem. The etiology of HAND is generally thought to be at least partly neuroinflammatory,
as infected cells in both the periphery and CNS cause immune activation leading to
synaptodendritic damage and neuronal apoptosis. Recently, several labs, including
ours, have found that peripheral inflammation is correlated with the progress of neurocognitive
disease, raising the possibility that peripheral inflammatory mediators may promote
neuroinflammation by crossing into the CNS. Since protein expression, lipid synthesis,
and small molecule metabolism may all be involved in inflammatory cascades, in this
study we determine levels of all three species in the spleen.
Methods: In this study, 6 pig-tailed macaques were dual inoculated with a neurovirulent
molecular clone and an immunosuppressive viral swarm, in which we have shown pig-tailed
macaques to develop AIDS and encephalitis within 84 days. Macaques were sacrificed
at 7 days post-infection and spleen tissue was harvested, then extracted for protein,
lipid and metabolite species. Protein, lipid and metabolite species were then profiled
by mass spectrometry.
Results: Lipidomic profiling by an MS/MS-ALL method found changes in triacylglycerides.
Metabolomic profiling by high-flow LC/MS alignment and then targeted MS/MS found changes
in the nucleotides guanosine and inosine, the small lipid adipic acid, and the small
molecule diethyl oxalopropionate.
P175
HIV and Aging: new graph theoretical models of rs-fcMRI neuropathophysiology
Jewell Thomas, Matthew Brier, Beau Ances
(presenting author: ancesb@neuro.wustl.edu)
Department of Neurology, Washington University in St. Louis
Background: The question whether HIV+ individuals experience aging-related deficits
earlier than healthy individuals or simply experience increased age-associated deficits
across the age-range is unresolved. We present graph theory models of brain functional
connectivity (FC) that add important evidence that HIV may lead to an advanced brain-age
phenotype.
Methods: BOLD resting-state FC scans were collected in HIV+ (N=46) and HIV- (N=59)
participants on a Siemens 3T scanner. These groups had similar demographics, though
the HIV+ group had a higher viral load and lower CD4+ white blood cell count. FC time-series
were sampled in 160 ROIs for each subject and graphs were constructed from cross-correlation
matrices. Clustering coefficient (a measure of local efficiency), path length (a measure
of global efficiency), and modularity (a measure of sub-network structure) were computed
across a range of correlation thresholds for each subject in order to assess the stability
of group differences. Effects of HIV and linear and quadratic effects of age as well
as age by HIV interactions on graph theory topology were assessed using ANCOVA.
Results:Higher clustering coefficient and lower path length were observed for HIV+
(p<.05, FDR). Modularity decreased, suggesting that graph structural changes may explain
changes in efficiency measures. Modularity began to decline earlier in HIV+ individuals
than HIV- individuals and declined as a quadratic effect of age (p<.01). Immune system
strength modulated modularity changes in HIV+ (p<.01).
Conclusions: By investigating graph structure (particularly modularity), we showed
the first fMRI evidence that age-related changes may occur earlier in HIV+ individuals.
Importantly, we showed that modularity decreases were explained by strength of immune
system response (stronger immune activation led to greater decreases). Because immune
activation may be an important underlying cause of brain deficits in both HIV and
aging, our result suggests HIV & aging may both impair brain function through immune
system mechanisms.
P176
The role of the blood brain barrier in amyloid beta uptake by HIV-1-infected brain
Michal Toborek, Ibolya E. Andras
(presenting author: mtoborek@med.miami.edu)
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine
Due to the success of combination antiretroviral therapy (cART), which changed the
clinical picture of HIV infection from acute to chronic disorder, there is a sharp
increase in infected patients 50 years old and older. This increase in age of the
HIV infected population constitutes a new challenge in the HIV epidemic in the affluent
countries. Importantly, older HIV infected patients are more susceptible to neurocognitive
impairments associated with the disease. HIV infected brains are characterized by
increased deposition of amyloid beta (Abeta) in perivascular space, indicating the
importance of brain microvessels in amyloid accumulation. Our research focused on
the mechanisms of HIV-1 interaction with Abeta at the blood-brain barrier level. Exposure
to HIV resulted in accumulation of Abeta in brain endothelial cells, with the prominent
nuclear predisposition. We demonstrated that these effects are dependent on functional
caveolae and can be prevented by inhibition of Ras and the receptor for advanced glycation
end products (RAGE). In additon, HIV-induced nuclear entry of Abeta involves activation
of the dynamin-dependent the EEA1 and TGF-beta/Smad signaling. Using transgenic mice
that express a chimeric mouse/human amyloid precursor protein and a mutant human presenilin
1, we next demonstrated that cerebrovascular toxicity of HIV specific protein Tat
is enhanced in mice with amyloid deposits in the brain. Indeed, exposure to Tat increased
permeability across cerebral capillaries, enhanced disruption of ZO-1 tight junction
protein, and elevated brain expression of MMP-9 in transgenic mice as compared to
age-matched littermate controls. These changes were associated with increased leukocyte
attachment and their transcapillary migration. Supported by MH098891, MH63022, MH072567,
DA027569, and NS39254.
P177
Microvesicles released from astrocytes regulate the peripheral immune response to
CNS inflammation
Luis B. Tovar-y-Romo1, Nino Tabatadze1, Veera Venkata Ratnam Bandaru1, Bezawit Megra2,
Dionna Williams2, Marlene Kanmonge1, David Colquhoun3, Mihyun Bae1, David Graham3,
Daniel Anthony4, Joan W. Berman2, Norman J. Haughey1
(presenting author: llbtyr@gmail.com)
1Department of Neurology, Division of Neuroimmunology, Johns Hopkins University School
of Medicine. Baltimore, MD, USA.;
2Department of Pathology. Albert Einstein College of Medicine. Bronx, NY, USA.;
3Department of Molecular and Comparative Pathobiology, Johns Hopkins University School
of Medicine. Baltimore, MD, USA.;
4Department of Pharmacology, University of Oxford, Oxford, UK
The mechanism by which brain inflammation drives the systemic immune response is currently
unknown. In this study we provide evidence that this neuroimmune axis involves microvesicles
released from brain that enter into peripheral circulation. IL-1beta, TNFalpha and
ATP evoked a rapid and robust efflux of microvesicles from astrocytes. The stimulated
release of these microvesicles from astrocytes involved a stabilization of nSmase2
into ceramide-rich membrane caps that were primarily located to filopodia. Microvesicle
release was blocked by inhibition of IL-1beta receptor binding, or inhibition of nSMase2.
Microvesicles were 65.6 ± 22.2 nm in size, and contained a complex lipid and protein
content that was consistent with exosomes. Using an in vitro BBB-model prepared with
BmuEC with GFAP-GFP expressing astrocytes we determined that microvesicles carrying
GFP as cargo readily crossed endothelial cells with intact tight junctions. Electron
microscopy demonstrated that a small fraction of these exosomes were endocytosed into
endothelial cells through caveolae, with the majority appearing to readily cross as
intact particles, possibly involving local phase transitions in the membrane. We next
determined if the release of these exosomes from the injured brain regulated leukocyte
trafficking. Intrastriatal injections of IL-1beta induced rapid focal generations
of ceramide, and a transmigration of neutrophils to the lesion site within 24h. Genetic
mutation of nSMase2, or simultaneous injections of nSMase2 antagonists (GW4869 or
altenusin) blocked IL-1beta from inducing ceramide, and blocked neutrophil influx.
Purified exosomes isolated from plasma 2h following intrastriatal injections of IL-1beta,
but not exosomes isolated from mice receiving intrastriatal injections of saline,
re-activated neutrophil influx when infused into the tail vein of acceptor mice who
received intrastriatal injections of IL-1beta + altenusin. These data demonstrate
that microvesicles released from astrocytes readily cross the BBB and regulate the
peripheral immune response to CNS inflammation.
P178
Simian varicella virus is present in lymph nodes of rhesus macaques after experimental
reactivation
Vicki Traina-Dorge1, Jennifer Manfredo2, Anna Blackmon2, Mary Wellish2, Stephanie
James2, Xavier Alvarez3, Cecily Midkiff3, Lara Doyle-Meyers4, Brent Palmer5, Eileen
Deharo1, Don Gilden1,1, Ravi Mahalingam2
(presenting author: ravi.mahalingam@ucdenver.edu)
1Division of Microbiology, Tulane University, Tulane National Primate Research Center;
2Department of Neurology, University of Colorado School of Medicine;
3Division of Comparative Pathology, Tulane University, Tulane National Primate Research
Center;
4Veterinary Medicine, Tulane University, Tulane National Primate Research Center;
5Division of Allergy and Clinical Immunology, Department of Allergy, Asthma and Clinical
Immunology, University of Colorado School of Medicine
Clinical, pathological, immunological and virological features of simian varicella
virus (SVV) infection of primates parallel human varicella zoster virus (VZV) infection.
Primary SVV infection of primates causes varicella, after which virus becomes latent
in ganglionic neurons and reactivates. Earlier, we demonstrated experimental reactivation
of SVV after X-irradiation and treatment with tacrolimus and prednisone of latently
infected monkeys. Herein, 5 rhesus macaques were inoculated intrabronchially with
10000 pfu of SVV or SVV-EGFP (SVV expressing green fluorescent protein) and 5 months
later, after the establishment of latency, all monkeys were transported to an irradiation
facility and 4 of them were exposed to a single dose (200 cGy) of X-irradiation and
treated with tacrolimus (80 ug/kg/day) and prednisone (1 mg/kg/day) for the duration
of the experiment; one monkey was not immunosuppressed, but was subjected to the stress
of transportation. Zoster rash developed 7-12 weeks after immunosuppression in all
5 monkeys which were euthanized 24-48 hrs later, and multiple tissues (skin, lungs,
ganglia and lymph nodes) were harvested. In all 5 monkeys, immunohistochemistry revealed
SVV antigens in these tissues. Immunofluorescence and confocal analysis of multiple
lymph nodes corresponding to the area of rash, showed colocalization of SVV proteins
in macrophages and dendritic cells, but not in lymph nodes from a SVV-seronegative
monkey. Detection of SVV proteins was confirmed by Western blot in 2 of 2 lymph nodes
from one monkey and by qPCR detection of SVV DNA in 3 of 3 lymph nodes from another
monkey. These findings suggest that SVV antigens may be transported into draining
lymph nodes where macrophages and dendritic cells present them to activate T cells
directed against SVV.
P179
Recycling HIV Antiretrovirals for inhibition of Human Endogenous Retrovirus-K
Richa Tyagi, Wenxue Li, Danelvis Parades, Avindra Nath
(presenting author: tyagi.richa@nih.gov)
Section of Infections of the Nervous System, National Institute of Neurological Diseases
and Stroke, National Institutes of Health
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterized
by the progressive loss of motor neurons. Its pathogenesis is unclear, although several
mechanisms have been suggested. We previously study showed that Human Endogenous Retrovirus
type K (HERV-K) was activated in the brain of ALS patients, indicating that HERV-K
may be involved in the pathogenesis of ALS. HERVs are genomic sequences of retroviral
origin which were believed to be integrated into germline chromosomes millions of
years ago. Although mostly defective and inactive, some of the HERVs may be activated
under certain physiological and pathological conditions. While no drugs are designed
specifically targeting HERVs, there are a panel of FDA approved HIV antiretroviral
drugs. We hypothesized that HIV antiretroviral drugs may also be effective in inhibiting
the infection and replication of HERVs and may be used for the treatment of HERV-K
activation in ALS. We constructed a plasmid with consensus HERV-K sequence and produced
HERV-K virus for testing the effect of antiretroviral drugs on HERV-K replication.
We first determined the effects of nucleoside and non-nucleotide reverse transcriptase
inhibitors on HERV-K by product enhanced reverse transcription assay (PERT). We found
that Abacavir and Zidovudine could significantly inhibit HERV-K reverse transcriptase
activity at similar effective dosages for HIV-1. To determine the effects of Abacavir
and an integrase inhibitor, Raltegravir on HERV-K viral replication, we pseudotyped
HERV-K with VSV-G and used the pseudotyped HERV-K virus to infect HeLa cells. Replication
of HERV-K was measured by quantitative real time polymerase chain reaction (qRT-PCR).
We found that both Abacavir and Raltegravir blocked the replication of HERV-K at very
low concentration. In summary, we identified several FDA approved antiretroviral drugs
that can effectively inhibit HERV-K virus. These antiretrovirals may open new prospects
for treatment of HERV-K activation in ALS and other neuropsychiatric diseases.
P180
Activation of HERV-W human endogenous retroviruses by JC polyomavirus in human astrocytes:
a novel effect that could contribute to neurodegeneration
Elena Uleri1, Caterina Serra1, Giuseppe Mameli1, Ilker K Sariyer2, Kamel Khalili3,
Antonina Dolei1
(presenting author: doleivir@uniss.it)
1Department of Biomedical Sciences, University of Sassari;
2Department of Neuroscience, Temple University, Philadelphia;
3Department of Neuroscience, Temple University, Philadelphia
Reactivation of the JCV polyomavirus (by not fully explained mechanisms) causes progressive
multifocal leukoencephalopathy in patients severely immunosuppressed or treated with
immunosuppressive antibodies. In most of these diseases, upregulation of HERV-W/MSRV/syncytin-1
endogenous retroviruses was reported. HERV-Ws are potentially neuropathogenic, being
gliotoxic, superantigenic, fusogenic, immuno-disregolatory, etc. We wondered about
JCV/HERV-W interactions, that could contribute to neurodegeneration. To this end human
primary fetal astrocytes and U87MG and SVG cell lines were either infected by JCV-Mad1
strain or transfected with expression plasmids carrying early or late JCV genes, to
monitor the expression of HERV-W/MSRV/syncytin-1 env, or that of constructs carrying
the ERVWE-1/syncytin-1 promoter. Data showed that JCV infection upregulates both MSRV-like
and syncytin env transcripts. Transient transfection experiments showed that both
JCV-early and late proteins stimulate the transcription and the expression of HERV-W/MSRV/syncytin-1
env genes up to the glycosylated form. These data were obtained by RT-Real time PCR
or western blotting analysis. As for the HERV-W promoter activity in presence of JCV
proteins, gene reporter experiments with constructs carrying the full-length syncytin-1
promoter, or promoter deletion mutants, co-transfected with JCV early or late plasmids
were carried out. Data indicate that the full-length promoter is upregulated by both
JCV early and late proteins. Deletion of the upstream (cellular) regulatory region
indicate that the stimulatory effect lies on the 5’LTR (viral) moiety. Due to the
identities between the 5’LTR of MSRV and syncytin-1, it is likely that up-regulation
by JCV antigens of both MSRV and syncytin-1 requires mainly the promoter’s viral moiety.
Given the neuropathogenic properties of HERV-W/env proteins, we wonder whether their
upregulation by JCV in astrocytes could contribute to neurodegeneration. This novel
interaction among JCV and HERV-W may open new avenues in the understanding of neurodegenerative
diseases.
P181
Brain White Matter Lesions link to CVD risk but not HIV Factors in HIV Over Age 60
Victor Valcour, Edgar Busovaca, Lauren Wendelken, Pardis Esmaeili, Katherine P. Rankin,
Iryna Lobach, Howard Rosen
(presenting author: vvalcour@memory.ucsf.edu)
Memory and Aging Center, Neurology Department, University of California San Francisco
Brain white matter hyperintensities (WMH) by magnetic resonance imaging (MRI) are
known to occur with HIV, typically with late disease and linked to dementia. WMH can
also occur with cerebrovascular disease (CVD) in the absence of HIV. Since CVD risk
increases with age and as patients living with HIV age, the underlying mechanisms
and clinical importance of WMH become less clear. Using a customized WMH quantification
pipeline, we measured lesion volume, number of lesions (count) and lobar distribution
of WMH in 65 HIV+ compared to 29 age and gender matched healthy HIV-negative controls.
HIV+ subjects were all over age 60 years (median, range of 63, 60-76) with median
(range) CD4 count of 531 (203-1098) and duration of HIV of 22 (3-31) years. Eighty-eight
percent had suppression of plasma HIV RNA < 400 copies. WMH volume was tightly linked
to WMH count (Spearman's rho=0.89 and 0.75 for HIV+ and HIV-negative, respectively,
p<0.005). The highest WMH volumes, adjusted for intracranial volume (ICV), were seen
in HIV+ subjects (Wilcoxon test of medians, p=0.006). In HIV+ subjects, higher WMH
volume correlated to poorer performance on executive functioning tests (Spearman's
rho=-0.35, p=0.006). WMH volume did not correlate to CD4 count, nadir CD4 count, duration
of HIV, or plasma HIV RNA. In the HIV+ group, subjects who smoke or have hypertension
had higher burden of WMH volume (Wilcoxon test of medians p=0.03 and p=0.04, respectively).
Smoking and HIV status have interactive effect on WMH volume adjusted for age (p=0.04).
Similarly, hypertension and HIV status tend to have an interactive effect (p=0.09).
We conclude that WMH in older HIV+ subjects is more closely related to CVD rather
than HIV risk parameters, and that HIV appears to modulate this effect. These lesions
are linked to cognitive performance. Lifestyle factors remain important targets for
improving cognitive morbidity.
P182
CXCL12 (SDF-1) Mediated Monocyte Transmigration Across the BBB is Regulated by CXCR4
and CXCR7: Implications for NeuroAIDS
Mike Veenstra1, Dionna W. Williams1, Kathryn Anastos2, Joan W. Berman3
presenting author: mike.veenstra@phd.einstein.yu.edu)
1Department of Pathology, Albert Einstein College of Medicine;
2Department of Medicine and Epidemiology & Population Health, Albert Einstein College
of Medicine;
3Department of Pathology and Microbiology & Immunology, Albert Einstein College of
Medicine, Bronx, NY
HIV enters the CNS in infected monocytes within two weeks of peripheral infection.
Once within the CNS, these cells mediate an inflammatory environment that leads to
HIV associated neurocognitive disorders in >50% of infected individuals despite successful
antiretroviral therapy. Increased amounts of CCL2 and CXCL12 are present in the CNS
of individuals with neurocognitive disorders. CCL2 increases the transmigration of
HIV-infected CD14+CD16+ monocytes across the blood-brain-barrier (BBB), but the effect
of CXCL12 on the transmigration of these cells is largely unknown. CXCL12 engages
the HIV co-receptor CXCR4. The finding that CXCL12 also interacts with CXCR7 contributes
to a different understanding of CXCL12 mediated processes. To characterize CXCL12
directed transmigration of CD14+CD16+ monocytes across the BBB, we studied this process
in an in vitro BBB model. To examine mature CD14+CD16+ monocytes, we enrich for this
population in culture. We now demonstrate that these cultured CD14+CD16+ monocytes
transmigrate preferentially across the BBB as effectively to CXCL12 as to CCL2. Moreover,
the expression of CXCR4 and CXCR7 on our cultured monocytes is similar as that on
monocytes from HIV-positive individuals, validating our culture model. CD14+CD16-
and CD14+CD16+ monocytes from HIV-positive individuals express comparable amounts
of CXCR4, but CXCR7 expression is specifically increased on the CD14+CD16+ monocyte
population. These CD14+CD16+ monocytes transmigrate across the BBB to very low concentrations
of CXCL12. CXCL12 is also a potent T cell chemoattractant, yet T cells require higher
CXCL12 concentrations for BBB transmigration. Surface CXCR4 on these monocytes is
decreased after transmigration, but is greatly increased on T cells, suggesting that
CXCR7 may specifically mediate CD14+CD16+ monocyte transmigration across the BBB.
We propose that the significant response of CD14+CD16+ monocytes to CXCL12 when transmigrating
across the BBB is likely mediated by both CXCR4 and, at least in part, CXCR7, having
implications for HIV neuropathogenesis and therapeutics.
P183
SDF-1/CXCL12 induces migration of lymphocytes by a mechanism pannexin1 hemichannels
dependent
Stephani Velasquez1, Juan A. Orellana2, Juan C. Saez3, Eliseo A. Eugenin 1,
(presenting author: stphvelasquez@gmail.com)
1Public Health Research Institute, Department of Microbiology and Molecular Genetics,
Rutgers University;
2Departamento de Neurologia, Facultad de Medicina, Pontificia Universidad Catolica
de Chile;
3Departamento de Fisiologia, Pontificia Universidad Catolica de Chile
In the last few years the role that pannexin hemichannels play in immune cells has
received extensive attention. Our previous work showed that HIV infection induced
a biphasic opening of these channels, an early opening between 5-30 min and a late
opening between 48-120 h after HIV exposure. Our data indicates that opening of panx-1
hemichannels is essential for viral entry and replication, however there function
in physiological conditions is unknown. Thus, we proposed that activation of specific
chemokine receptors results in the physiological opening of pannexin-1 hemichannels
(Panx-1) in T lymphocytes. We determined that treatment of T lymphocytes with SDF-1/CXCL12,
a key chemokine in lymphocyte migration and HIV infection, induces a transient opening
of Panx-1 when compared to HIV, but not connnexin43 hemichannels. Blocking Panx-1
blocked the lymphocyte migration induced by SDF-1/CXCL12, suggesting that opening
of Panx-1 is essential for lymphocyte migration by a mechanism that involves local
release of ATP. Alterations in migration occur in HIV infected cells but also in other
PNS and CNS diseases such as multiple sclerosis (MS). Using a KO mouse model and EAE
(an animal model of MS) we demonstrated that Panx-1 hemichannels are essential for
migration of immune cells into the CNS and PNS. In conclusion our findings demonstrate
that Panx-1 hemichannels play an essential role in HIV infection and in leukocyte
migration into the CNS opening potential new therapeutic targets to block the pathogenesis
of NeuroAIDS and MS.
P184
Virus-induced cellular targets for intrathecal autoimmunity in multiple sclerosis
Jussi Oskari Virtanen1, Jeffrey Kowalak2, Emily Leibovitch1, Naomi Lee1, Yoshimi Enose-Akahata1,
Steve Jacobson1
(presenting author: virtanenjo@ninds.nih.gov)
1NIH/NINDS/Neuroimmunology;
2NIH/NINDS&NIMH/Clinical Proteomics
Viral infections have been associated with autoimmune diseases such as multiple sclerosis
(MS), but the exact mechanisms how viral infection could induce autoimmunity are poorly
characterized. Although molecular mimicry have been suggested as a mechanism, convincing
viral and autoantigen targets have not been identified in MS. Another possibility
is that viral infection could induce and/or modify cellular proteins that are recognized
by the immune system. Human herpesvirus 6 (HHV-6) antigen and nucleic acids have been
found in MS brain lesions suggesting that HHV-6 might participate to the lesion development.
To identify possible intrathecal humoral immune response targets in human HHV-6 infected
cells we used immunoprecipitation based mass spectrometry analysis to identify possible
cellular targets present only in HHV-6 infected cells. Furthermore, we identified
MS brain endogenous IgG protein targets using similar approach. Cerebrospinal fluid
(CSF) IgG pulled 26 unique proteins from infected cells that did not came up with
serum or from non-infected cells. Three of these proteins were identified as MS brain
lesion associated endogenous IgG targets as well. We are in the process of validating
these results with other immunoassays. Our results suggest that HHV-6 infection can
induce cellular proteins that are recognized by MS CSF IgG, and thus, might provide
targets for the autoimmunity in MS.
P185
Intrathecal immune response to HTLV-1 antigens in HAM/TSP
Jussi Oskari Virtanen, Yoshimi Enose-Akahata, Raya Massoud, Steven Jacobson
(presenting author: virtanenjo@ninds.nih.gov)
NIH/NINDS/Neuroimmunology
Human T-lymphotropic retrovirus (HTLV-1) is the causative agent of the central nervous
system disease HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP).
Like patients with multiple sclerosis (MS), a related disease of the central nervous
system, HAM/TSP patients have increased IgG index and oligoclonal bands (OCBs) as
a marker of intrathecal antibody production. In this study, we investigated the specificity
of the cerebrospinal fluid (CSF) and serum antibodies to HTLV-1 antigens by luciferase
immunoprecipitation system (LIPS) assay and the specificity of the oligoclonal bands
to HTLV-1 antigens in HAM/TSP. All of the 22 patients had HTLV-1 gag, env and tax
antibodies in CSF and all but one had OCBs specific to at least one HTLV-1 antigen
studied. Gag- and env-specific OCBs were found more often than tax-specific OCBs in
HAM. Our data shows that in HAM/TSP HTLV-1 antibodies are produced intrathecally and
most of the OCBs are specific for HTLV-1 antigens. Detection of intrathecal antibody
production by LIPS and HTLV-1 antigen specific OCBs by isoelectric focusing and immunoblot
might provide tools to differentiate HAM/TSP patients from HTLV-1 seropositive MS
cases and might suggest the involvement of humoral immune response in the pathogenesis
of HAM/TSP.
P186
Natalizumab-associated progressive multifocal leukoencephalopathy in a patient with
multiple sclerosis: a post mortem study
Christian Wuthrich1, Bogdan F.Gh. Popescu2, Sarah Gheuens1, Michael Marvi3, Ronald
Ziman4, Stephen Pojen Denq5, Mylyne Tham2, Elizabeth Norton1, Joseph E. Parisi6, Xin
Dang1, Claudia F. Lucchinetti7, Igor J Koralnik1
(presenting author: chris_wuthrich@hms.harvard.edu)
1Division of Neurovirology, Department of Neurology, Center for Virology and Vaccine
Research, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical
School;
2Department of Anatomy and Cell Biology, Cameco MS Neuroscience Research Center, University
of Saskatchewan;
3Providence Saint Joseph Medical Center. The Hycy and Howard Hill Neuroscience Institute.
Movement Disorder Center. 501 South Buena Vista Street. Burbank, CA 91505;
4David Geffen School of Medicine. University of California, Los Angeles. 10833 Le
Conte Ave #12138. Los Angeles, CA 90095. Department of Medicine. Northridge Hospital
Medical Center. 18300 Roscoe Blvd. Northridge, CA 91325;
5Buddhist Tzu Chi Medical Center. 1000 South Garfield Avenue, Alhambra, CA 91801;
6Department of Pathology and Laboratory Medicine. Mayo Clinic, 200 First Street SW,
Rochester, Minnesota;
7Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota
Background: Natalizumab, a monoclonal antibody directed against alpha4 integrins,
has to date been associated with 395 cases of progressive multifocal leukoencephalopathy
(PML) worldwide in patients receiving treatment for multiple sclerosis (MS). Due to
the limited number of histological studies, the interplay between MS and PML lesions
has not been investigated.
Objective: We report the clinical, radiological and histological findings of a MS
patient who developed PML after 32 months of natalizumab monotherapy. Following withdrawal
of natalizumab, she received plasma exchange, mefloquine and mirtazapine, but passed
away soon thereafter. Post mortem studies were restricted to examination of the brain
and spinal cord.
Results: Extensive PML lesions, characterized by the presence of JCV DNA were found
in the cerebral white matter and neocortex. Sharply demarcated areas of active PML
lesions contained prominent inflammatory infiltrates composed of approximately equal
numbers of CD4+ and CD8+ T cells, consistent with an immune reconstitution inflammatory
syndrome (IRIS). Conversely, all MS lesions identified were hypocellular, long-standing
inactive plaques characterized by myelin loss, relative axonal preservation, and gliosis,
and importantly, were devoid of JCV-DNA and active inflammation.
Conclusions: This case demonstrates the coexistence of chronic inactive MS and PML
lesions harboring active JCV infection.Chronic inactive MS lesions were separate and
distinct from nearby PML lesions. Furthermore, IRIS greatly affected the shape and
appearance of PML lesions but did not involve MS lesions. Whether PML may alter the
nature of active MS lesions remains to be determined.
P187
Rapid NLRP3 Inflammasome Activation in Microglia during HIV/AIDS contributes to Neurovirulence
John Walsh, Stacey Reinke, Ferdinand Maingat, William Branton, David Broadhurst, Christopher
Power
(presenting author: chris.power@ualberta.ca)
Department of Medicine, University of Alberta
Human immunodeficiency virus type 1 (HIV-1) infection causes activation of innate
immune pathways in the brain, often with ensuing neurovirulence that is evident as
neuronal injury and death with accompanying neurobehavioral disorders. The specific
innate immune genes that drive early inflammatory responses to HIV-1 remain uncertain
in brain cells but activation of inflammasomes in myeloid cells with subsequent cleavage
and release of interleukin (IL)-1beta represent important pathogenic components underlying
multiple inflammatory disorders. To investigate inflammasome expression and function
in the human brain during HIV-1 infection, inflammasome-associated genes were examined
showing that IL-1beta, IL-18 and caspase-1 were induced in brains from HIV-infected
persons, largely detected in activated brain myeloid cells. Cultured human microglia
constitutively expressed inflammasome-associated genes including IL-1beta, caspase-1,
NLRP3, NLRP1, AIM2 and ASC, unlike human astrocytes and neurons. HIV-1 induced pro-IL-1beta
in human microglia at 4 hr post-infection with appearance of the cleaved form and
peak IL-1beta release at 24hr, which was prevented by the caspase inhibitor, YVAD-fmk.
Exposure of microglia to soluble HIV-1 gp120 mediated IL-1beta induction and subsequent
release by microglia. HIV-dependent release of IL-1beta from a human myeloid cell
line, THP-1, was also inhibited by NLRP3 deficiency and high extracellular [K+]. In
vivo infection by feline immunodeficiency virus (FIV) caused induction of multiple
inflammasome-associated genes in microglia, which was accompanied by neuronal loss
and neurobehavioral impairments; multivariate analyses of FIV-infected and uninfected
animals disclosed that IL-1beta, NLRP3 and Caspase-1 represented key molecular determinants
in the development of neurovirulence. Thus, inflammasome activation was an early and
integral aspect of HIV/AIDS neuropathogenesis and might represent a potential target
for therapeutic interventions.
P188
Activation of the OAS-RNase L pathway by murine coronavirus is organ specific and
muted in the CNS
Susan Weiss1, L. Dillon Birdwell1, Joshua Thornbrough1, Yize Li1, Ling Zhao1, Ruth
Elliott1, Robert Silverman2
(presenting author: weisssr@upenn.edu)
1Department of Microbiology, Perelman School of Medicine, University of Pennsylvania;
2Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic
Murine coronavirus (MHV) accessory protein, ns2 is a phosphodiesterase that inhibits
activation of the interferon(IFN)-induced oligoadenylate synthetase(OAS)-RNase L pathway
and facilitates viral replication in macrophage lineage cells and induces hepatitis.
However, efficient MHV replication in the brain and subsequent encephalitis are independent
of enzymatically active ns2. Compared to the liver and other peripheral organs, the
CNS expresses lower basal levels of IFN-stimulated genes including several OASs, which
are required for RNase L activation. Thus, we hypothesized that expression of OAS
in the CNS was not sufficient to activate RNase L after MHV infection. Indeed, an
MHV mutant expressing an inactive ns2 protein (ns2H126R) replicates to a similar extent
as wild type (wt) virus in the CNS. We have compared replication of wt and ns2H126R
in bone marrow derived macrophages with primary microglia, neurons, astrocytes and
oligodendrocytes. In contrast to restriction of ns2H126R replication in macrophages
and microglia, wt and ns2H126R replicated with similar kinetics in the other primary
cells. In addition, ns2H126R induced RNase L activity, as assessed by ribosomal RNA
(rRNA) cleavage, in myeloid-derived cells but failed to do so in other cell types.
Parenchymal cells pretreated with IFN restricted wt and ns2H126R to similar extents
indicating that inhibition is not due to RNase L activity. However, astrocytes and
neurons are competent for RNase L activity as they cleave rRNA when transfected with
poly I:C. Thus, RNase L activation depends on the virus, kinetics of infection and
IFN induction. Furthermore, expression of relatively high levels of OAS genes is necessary
but not sufficient for induction of an effective RNase L antiviral response. Activation
of RNase L is muted in the CNS perhaps to prevent the potentially destructive effects
of unrestricted activity in nonrenewable cells.
P189
JAM-A and ALCAM are Critical to the Transmigration Across the BBB of CD14+CD16+ Monocytes
Isolated from HIV Seropositive Individuals: Implications for NeuroAIDS
Dionna W. Williams1, Kathryn Anastos2, Susan Morgello3, Joan W. Berman4
(presenting author: dionna.williams@phd.einstein.yu.edu)
1Department of Pathology, Albert Einstein College of Medicine;
2Departments of Medicine and Epidemiology & Population Health, Albert Einstein College
of Medicine;
3Department of Neurology, Neuroscience, and Pathology, Mount Sinai School of Medicine;
4Department of Pathology and Microbiology and Immunology, Albert Einstein College
of Medicine
HIV enters the CNS early after primary infection and results in HAND, or HIV associated
neurocognitive disorders, in 40-70% of HIV infected individuals despite successful
combined antiretroviral therapy (cART). Monocytes are critical cells involved in HAND
as they bring virus into the CNS upon transmigration across the blood brain barrier
(BBB). A subset of circulating mature monocytes that express surface CD14 and CD16
is highly susceptible to HIV infection and accumulates in the brain of those with
HAND. The mechanisms by which these mature monocytes transmigrate across the BBB are
not fully understood. We previously demonstrated using an in vitro culture system
that diapedesis of CD14+CD16+ monocytes across the BBB is facilitated by the junctional
proteins ALCAM, JAM-A, CD99, and PECAM-1. We now characterize the CD14+CD16+ monocyte
subset in HIV infected individuals from the Manhattan HIV Brain Bank and the Women’s
Interagency HIV Study cohort. We found that this monocyte population was present in
significantly greater numbers irrespective of cART status, viral load, CD4 count,
and gender as compared to individuals without HIV. We determined that CD14+CD16+ monocytes
from these people preferentially transmigrated across our in vitro model of the human
BBB in response to CCL2, a potent monocyte chemoattractant elevated in the CNS of
HIV infected people with HAND. CD14+CD16+ monocytes isolated from HIV seropositive
individuals had higher surface expression of ALCAM, JAM-A, and PECAM-1 relative to
HIV seronegative people. Blocking antibodies to ALCAM and JAM-A inhibited the transmigration
of these CD14+CD16+ monocytes to baseline levels, suggesting their importance in facilitating
monocyte transmigration across the BBB. Targeting the increased junctional proteins
present on CD14+CD16+ monocytes derived from HIV infected people, which preferentially
infiltrate the CNS, represents a novel therapeutic strategy which may reduce the ongoing
chronic neuroinflammation which occurs during HIV neuropathogenesis.
P190
Differential roles of mature and proNGF in the regulation of human macrophage activation
by HIV
Kimberly Williams, Dierdre Killebrew, Gillian Clary, Youmei Xie, Rick Meeker
(presenting author: williaks@email.unc.edu)
University of North Carolina- Chapel Hill
HIV activation of macrophages and microglia cells in the central nervous system (CNS)
triggers the secretion of unknown neurotoxins, which are thought to be the cause of
neuronal damage. Macrophage phenotype is controlled extensively by extracellular signals
but the influence of brain derived signals on macrophage phenotype is poorly understood.
We have recently shown that human macrophages and monocytes express p75 and TrkA neurotrophin
receptors and respond to the natural ligand, Nerve Growth Factor (NGF). Flow cytometry
showed a decrease in receptors p75 and TrkA on human monocytes after stimulation with
HIV virions and ProNGF +/- HIV while NGF +/- HIV increased both receptors. Stimulation
of macrophages with HIV also caused prolonged calcium accumulation that was blocked
by pretreatment with NGF. ProNGF pretreatment however resulted in spikes of calcium
activity in macrophages that was blocked with a neutralizing antibody to the HIV Co-Receptor,
CXCR4 suggesting interactions between neurotrophin and chemokine receptors . NGF and
proNGF also had opposing effects on macrophage neurotoxin secretion as assessed by
calcium dysregulation in rat cortical neurons. HIV virions resulted in increased neurotoxic
activity of the macrophage conditioned medium. Pretreatment with NGF partially suppressed
while ProNGF exacerbated neurotoxicity. Rearrangement of actin cytoskeleton of macrophages,
polarity and podosome location were also seen with neurotrophin and HIV stimulation.
ProNGF stimulation resulted in an increase in the polarization of podosomes compared
to NGF. As with neurons where signaling of the pro and mature forms of neurotrophins
results in opposing actions, the pro and mature forms of NGF may also exert opposing
regulation of monocyte/macrophage phenotypes. Based on these data we conclude that
mature NGF promotes a less destructive macrophage phenotype while proNGF may increase
neurotoxicity. Pharmacological control of these interactions may provide new therapeutic
avenues for the treatment of HIV-associated cognitive disorders.
[NIH Grant R01 MH085606]
P191
Use of drugs of abuse impact HIV-1 LTR single nucleotide polymorphisms (SNPs) in the
DrexelMed HIV/AIDS Genetic Analysis Cohort
Jean Williams1, William Dampier1, Michael Nonnemacher1, Vanessa Pirrone1, Benjamas
Aiamkitsumrit1, Adam Wojno1, Shendra Passic1, Brandon Blakey1, Wen Zhong1, Brian Moldover2,
Rui Feng3, David Downie4, Sharon Lewis4, Jeffrey Jacobson4, Brian Wigdahl1
(presenting author: jean.williams@drexelmed.edu)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2B-Tech Consulting, Ltd;
3Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistic, University School of Medicine.;
4Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine
The current clinical studies have focused on the identification of LTR SNPs derived
from peripheral blood (PB) of patients enrolled in the DrexelMed HIV/AIDS Genetic
Analysis Cohort in Philadelphia to identify HIV-1-infected individuals more prone
to developing advanced disease and/or neurologic dysfunction. Patient demographics
and clinical parameters including drug use, CD4/CD8 T-cell count, and viral load are
performed at every visit. Drug abuse is common within this cohort with cocaine use
being favored. The cohort can be categorized into non-users (PN), preferential cocaine
(PC), and multidrug users (MDU). SNPs have been identified that associated with CD4
T-cell count and viral load. SNPs were also identified that are unique to each drug
abuse category. Using an in silico sensitivity analysis, we were able to determine
significant differences in transcription factor footprints at the Lef-1 site with
a variation from an A-to-G at position 321 to be significantly different between the
PN and PC and PN and MDU subcohorts. Additionally, an A-to-G alteration at position
286 within C/EBP site II was found to be significant in both the psychomotor and constructive
neuropsychologically impaired patients. In previous studies, we have shown this position
to have an increased affinity for C/EBP beta, increased HIV-1 basal LTR activity,
a decreased prevalence in PB-derived LTRs from patients with increased disease progression,
but an increased prevalence in brain-derived LTRs. These results suggest that cocaine
may be applying selective pressure with respect to the genetic architecture of the
LTR within these critical binding sites. This work is supported by NIH/NINDS R01 NS32092,
NIDA R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P192
Leukocyte CNS infiltration precedes neurological disease following La Crosse virus
infection
Clayton Winkler, Tyson Woods, Karin E. Peterson
(presenting author: clayton.winkler@nih.gov)
Laboratory of Persistent Viral Diseases, Rocky Mountain Labs, NIAID, NIH
La Crosse virus (LACV) is a primary cause of pediatric arbovirus encephalitis United
States resulting in severe neurologic symptoms and even death. LACV encephalitis is
characterized by perivascular infiltration of leukocytes into the central nervous
system (CNS) and neuronal death. However, the mechanisms leading to leukocyte infiltration
and the role of those cells in LACV pathogenesis remains unclear. Intravenous injection
of Evans blue dye demonstrated increased vascular leakage into the CNS at 5 days post
infection (dpi), which is prior to the onset of neurological disease. Brain endothelial
cells at this time point showed decreased expression of CD31, a primary component
of endothelial tight junctions, as well as increased expression of Ccl2, Ccr2 and
Cxcl11, which are involved in leukocyte recruitment. These findings suggest CNS blood
vessels in LACV infected animals are permissive to cellular infiltration prior to
neurological signs. Examination of CNS infiltrates determined that activated monocytes/macrophages,
CD4+ and CD8+ T cells were present at 5dpi, with numbers peaking at neurological disease
onset. Inflammatory monocytes/macrophages were by far the predominant infiltrating
population and were found in close association with areas of neuronal infection suggesting
they may be relevant to neurological disease. Concordantly, depletion of T cells,
which are present in low numbers, did not alter the kinetics or onset of the disease
suggesting their infiltration is not critical for neurological disease development.
Interestingly, Rag1-/- mice were more susceptible to LACV CNS infection than wildtype
controls suggesting B cells antibody responses have a protective role in disease pathogenesis.
However, B cell infiltration was not observed, suggesting their role in LACV-induced
neurological disease is distant from the CNS. Collectively, while the role of infiltrating
monocytes/macrophages is still under investigation, we conclude adaptive immune cell
infiltration into the CNS does not appear to influence the development of LACV-induced
neurological disease.
P193
Increased HIV-1 DNA in CSF cells is associated with decreased CSF oxidative stress
in HIV-seropositive Hispanic women
Valerie Wojna1, Joyce Velez1, Dianedis Toro Nieves1, Yolanda Rodriguez1, Marangely
Huertas2, Richard Skolasky3, Melissa Agsalda4, Marines Plaud1, Calribel Gonzalez1,
Loyda Melendez1, Bruce Shiramizu4
(presenting author: valerie.wojna1@upr.edu)
1University of Puerto Rico, Medical Sciences Campus;
2University of Puerto Rico;
3Johns Hopkins University;
4University of Hawaii
Background: HIV-associated neurocognitive disorders (HAND) persist in spite of antiretroviral
therapy. Recent data demonstrated high HIV-1 DNA in circulating activated monocytes
is associated with HAND. These activated monocytes with HIV-1 DNA migrate to the brain
and may represent CSF viral reservoirs. Studies have shown a correlation between oxidative
stress and HAND. Therefore we proposed to determine the relationship between HIV-1
DNA in CSF cells, oxidative stress, and HAND.
Methods: A retrospective review was performed on prospectively collected clinical
data and samples from a cohort of 27 HIV-seropositive Hispanic women, stratified by
cognitive impairment into normal (n=8), asymptomatic (n=6), mild impairment (n=6),
and HAD (n-7). HIV-1 DNA was measured in CSF cells using real time PCR. The CSF oxidative
stress markers 3-NT were detected by dot-blot analysis while the protein carbonyls
(PC) with oxy- and dot-blot. Cognitive performance was determined by the established
criteria. Parametric and non-parametric statistics were used.
Results: A positive association was observed between higher HIV-1 DNA copy/cell in
CSF cells and use of cART (p=0.007). When controlling for cART use there was a negative
correlation between higher HIV-1 DNA in CD14+ blood cells with worse performance in
Trail Making B (TMB, p=0.049) and verbal memory (p=0.036) tests. This negative correlation
was also observed in the CSF cells with higher HIV-1 DNA copy/cell and lower CSF levels
of 3NT (p=0.015) and PC (p=0.014).
Conclusions: Increased HIV-1 DNA in CD14+ correlated with worse cognitive performance
while increased HIV-1 DNA in CSF cells correlated with lower CSF oxidative stress
levels. Findings may suggest persistence of CSF viral reservoirs containing latent
virus.
Grant support U54MD008149, U54 RR022762; partially by U54MD007587, S11NS46278, U54NS43011,
P20RR11126, G12RR03051, F31AI081450, R01NS053345, U54MD007584
P194
Epigenetic regulation of JC virus
Hassen Wollebo, Kamel Khalili, Mahmut Safak, Martyn White
(presenting author: siraj123@temple.edu)
Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine, Philadelphia
The human polyomavirus JC (JCV) is the etiologic agent of the rare devastating neurologic
disease Progressive multifocal leukoencephalopathy. Globally, the prevalence of infection
with JCV is high and JCV is believed to persist in a latent state after primary infection.
Even though JCV is common in the population, PML is extremely rare which suggest that
the virus is very tightly regulated by cell-mediated immunity. Previously our laboratory
and others have shown that the JCV promoter and its transcriptional activity are regulated
by multiple transcriptional factors. Here we provide evidence that JC virus promoter
activity under goes another level of regulation by epigenetic events involving protein
acetylation. We have found that histone deacetylase inhibitors profoundly stimulate
the transcription of both the early and late JC virus promoters in transient transfection
experiments and in stable early and late reporter cell lines. This suggests that the
acetylation status of histones may be an important mechanism controlling the latency/
reactivation status of JCV.
P195
Statins are a promising candidate adjunctive therapy for prevention or treatment of
HIV-1 associated neurocognitive disorders (HAND)
Anjana Yadav1, Lorraine Kolson2, Michael Betts3, Dennis Kolson2, Ronald Collman1
(presenting author: ayadav@mail.med.upenn.edu)
1Department of Medicine, University of Pennsylvania School of Medicine;
2Department of Neurology, University of Pennsylvania School of Medicine;
3Department of Microbiology, University of Pennsylvania School of Medicine
HIV-1 associated neurocognitive disorders (HAND) result from indirect effects mediated
by activated blood monocytes that traffic to the brain, and activated and/or infected
brain macrophages that release inflammatory chemokines and cytokines (including MCP-1)
and neurotoxic mediators (such as glutamate). HAND remains a major problem even among
patients on antiretroviral therapy (ART) with effective viral suppression, and has
been linked to persistent immune activation and inflammation. Statins are HMG-CoA
reductase inhibitors with pleiotropic immunomodulatory properties mediated by effects
on intracellular signal transduction pathways. We first investigated the immunomodulatory
effects of lipophilic statins (simvastatin & atorvastatin) on human monocyte/macrophage
activation in vitro. Statin treatment reduced the CD16+ and CD163+ monocyte populations
following LPS and MCP-1 stimulation, and strongly suppressed MCP-1, IL-8, MIP-1alpha
production by activated PBMC. Statin treatment also strongly inhibited monocyte chemotaxis
to MCP-1. Further, we demonstrated that statins inhibited production of the neurotoxin
glutamate by HIV-1 infected macrophages, and also had a direct neuroprotective effect
on rat neurons exposed to macrophage-HIV supernatants. We then carried out a small
open label in vivo pilot study of five HIV+ / ART+ subjects treated with Atorvastatin
for 12 weeks followed by a 4-week washout period. In this small number of subjects,
atorvastatin treatment was associated with a trend towards decreased total CD14+ monocytes,
reduced CD16 mean fluorescent intensity on CD14+ monocytes , and decline in plasma
hsCRP during the treatment period. These observations suggest the potential of statins
as a candidate adjuvant treatment to prevent HAND through modulation of monocyte/macrophage
function and through its anti-inflammatory effects, and warrant a larger randomized
clinical trial with a longer treatment period.
P196
SIGMA-1 RECEPTOR PROTECTS AGAINST HIV TAT-MEDIATED ER STRESS RESPONSE IN ASTROCYTE:
IMPLICATION FOR HAND
Lu Yang1, Tomohisa Mori2, Shilpa Buch1
(presenting author: lu.yang@unmc.edu)
1Department of Pharmacology and Experimental Neuroscience, University of Nebraska
Medical Center;
2Department of Toxicology, School of Pharmacy and Pharmaceutical Sciences, Hoshi University,Tokyo
Although ART can effectively suppress viral suppression, expression of viral proteins
such as Tat remains unaffected. This in turn, could lead chronic activation of glia
resulting in neuroinflammation. ER stress has recently been implicated to play an
important role in the impairment of CNS homeostasis in HIV+ patients. In response
to ER stress, cells activate a set of tightly controlled regulatory programs, the
unfolded protein response (UPR), to restore normal functioning of the ER. However,
if ER stress is sustained and the adaptive UPR fails to eliminate unfolded/misfolded
proteins, balance shifts to apoptosis as a mechanism for clearing stressed proteins.
We hypothesized that Tat mediated activation/apoptosis of astrocytes involves the
ER stress response. Our preliminary data demonstrates that HIV Tat induced ER stress
in astrocytes, with activation of the three UPR pathways-PERK, ATF6 & IRE1. This was
accompanied by disruption of calcium homeostasis, generation of reactive oxidative
stress (ROS) & induction of apoptosis. Of particular interest is the chaperone Sigma-1
Receptor (sigma1-R) that is critical for ER stress. Intriguingly, overexpression of
sigma1-R in astrocytes significantly decreased Tat-mediated ROS generation & inhibited
the expression of pro-apoptotic CHOP protein. Reciprocally, knocking down sigma1-R
resulted in decreased expression of the anti-apoptotic Bcl2 & increased cellular apoptosis.
Sigma1-R could be envisioned as a critical modulator of glial cell survival and may
be an important target for therapeutic intervention in HAND.
P197
A novel host restriction factor NIBP suppresses HIV-1 transcription/reactivation
Yonggang Zhang, Fan Yang, Rafal Kaminski, Fang Li, Kamel Khalili, Wenhui Hu
(presenting author: zygote@temple.edu)
1Department of Neuroscience and Center for Neurovirology, Temple University School
of Medicine;
NIBP (NIK- and IKK2-Binding Protein) is a novel protein that enhances cytokine-induced
NFkB activation and is required for neuronal differentiation. TNFalpha and IL-1beta
are well known to stimulate NFkB activation, which contribute to cytokine-induced
HIV-1 reactivation. We hypothesize that NIBP may regulate HIV-1 infection and reactivation
via NFkB signaling. To test this, we performed HIV-1 long terminal repeat (LTR) driven
firefly-luciferase reporter assay using mouse brain neural stem/progenitor cells and
human fibroblast with NIBP deletion. To our surprise, NIBP overexpression in mouse
neural stem/progenitor cells significantly inhibited constitutive and TNFalpha-induced
LTR promoter activation. Such inhibition was independent of NFkB signaling be-cause
NFkB site-deletion LTR mutant inhibited TNFalpha-induced LTR activation but did not
prevent NIBP-induced inhibition. This was validated in other cells and species including
human fibroblast and breast cancer cells as well as rabbit colonic smooth muscle cells.
Interestingly, LTR-luciferase activity was increased in NIBP deletion fibroblast cells
from patient with mental retardation and overexpression of NIBP in these fibroblasts
rescued such inhibition. NIBP is known to interact with bovine viral diarrhea virus
non-structural protein 5A (NS5A), which hijacks NIBP-mediated NFkB activation. Co-immunoprecipitation
assay in HEK293T cells cotransfected with Flag-tagged NIBP and CFP-tagged TAT or YFP-tagged
Vpr vectors showed that both NIBP(1148aa) and NIBP(960aa) interact with TAT but only
NIBP(1148aa) interacts with Vpr. These data suggests that NIBP may act as a novel
restriction factor to suppress HIV-1 transcription/reactivation through interacting
with HIV-1 viral proteins. Such interaction may hijack NIBP-mediated NFkB activation.
Since NIBP is highly expressed in HIV-1 non-permissive neurons but not in permissive
microglia/macrophage and T cells, NIBP gene therapy may serve as a novel approach
to treat NeuroAids.
P198
Impact of Aging on markers of HIV-1 disease
Wen Zhong1, Vanessa Pirrone1, Michael Nonnemacher1, Shendra Passic1, Nirzari Parikh1,
Benjamas Aiamkitsumrit1, William Dampier1, Peter Katsikis2, Yvonne Mueller2, Christian
Sell3, David Libon4, Brian Moldover5, Rui Feng6, Jeffrey Jacobson7, Brian Wigdahl1
(presenting author: lain_d_h@163.com)
1Department of Microbiology and Immunology, Center for Molecular Virology and Translational
Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University
College of Medicine;
2Department of Microbiology and Immunology, Center for Immunology and Vaccine Sciences,
Institute for Molecular Medicine and Infectious Disease, Drexel University College
of Medicine,
3Department of Pathology, Drexel University College of Medicine;
4Department of Neurology, Drexel University College of Medicine;
5B-Tech Consulting, Ltd;
6Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and
Biostatistics, University of Pennsylvania School of Medicine;
7Division of Infectious Diseases and HIV Medicine, Department of Medicine, Drexel
University College of Medicine
The introduction of HAART has resulted in significantly lower mortality rates, culminating
in an HIV epidemic that increasingly affects older adults, emphasizing the importance
of understanding the risk factors associated with aging and HIV-1 infection. Additionally,
immune failure commonly occurs with both aging and HIV infection. Current studies
focus on the impact of age on LTR signatures that correlate with HIV-1 clinical parameters
including CD4+ and CD8+ T-cell count and viral load (VL). A prospective, longitudinal
study was conducted on 458 HIV-1-seropositive patients currently enrolled in the DrexelMed
HIV/AIDS Genetic Analysis Cohort in Philadelphia, PA. History of illicit drug, alcohol,
and medication use, CD4+ and CD8+ T-cell count, and viral load, along with patient
history including age, were collected approximately every 6 months. Using a linear
mixed model for longitudinal data, we determined that there were viral SNPs that significantly
correlated with increasing age. Additionally, age modified the SNP effect with respect
to CD4+ T-cell counts and VL to different degrees. Both HIV-1 infection and age are
also known to have immunomodulatory effects. The cytokine profiles of adult and aged
individuals were analyzed to understand the impact of age and HIV-1 infection on cytokine
modulation and HIV-1 disease severity. Interestingly, among the 30 cytokines investigated,
the cytokine profiles appeared different between these two populations. In addition,
there appeared to be a number of SNPs that correlated with the age effect on cytokine
levels. In conclusion, age, in the context of HIV-1 infection, appears to impact viral
gene expression and immune activation. This work is supported by NIH/NINDS R01 NS32092,
NIDA R01 DA19807, NIMH P30 MH092177, and NIMH T32 MH079785.
P199
Rats genetically expressing HIV-1 viral proteins exhibit increased synaptosomal [3H]dopamine
uptake in prefrontal cortex and striatum
Jun Zhu, Adrian Gomez, Narasimha Midde
(presenting author: zhuj@sccp.sc.edu)
Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy,
University of South Carolina, Columbia, SC
The central dopamine (DA) neurotransmission plays a crucial role in the development
of neurocognitive dysfunction in patients with HIV-1 associated neurocognitive disorders
(HAND). We have demonstrated that HIV-1 Tat protein in vitro inhibits DA transporter
(DAT) allosterically and modulates cocaine binding sites on DAT in rat striatal synaptosomes
and cells expressing human DAT. To understand how in vivo expression of HIV-1 viral
proteins influences DAT function, kinetic analysis of [3H]DA uptake in prefrontal
cortex (PFC) and striatum, and [3H]WIN35,428 binding in striatum were determined in
HIV-1 transgenic (HIV-1Tg) and Fisher 344 rats. Compared to Fisher 344 rats, the maximal
velocity (Vmax) of DAT-mediated [3H]DA uptake into prefrontal and striatal synaptosomes
in HIV-1Tg rats was increased by 34% and 32%, respectively, whereas the Km values
for DA uptake were reduced in striatum but not in PFC of HIV-1Tg rats. In addition,
HIV-1Tg rats exhibit decreased maximal binding sites (Bmax) of [3H]WIN35,428 and increased
DA uptake turnover rate (Vmax/Bmax) in striatum, compared to Fisher 344 rats. To explore
the potential mechanism(s) underlying alteration of DAT function in HIV-1Tg rats,
our ongoing study is to determine whether the increased DA uptake in both regions
is due to redistribution of membrane DAT or changes in DAT-associated proteins in
membrane microdomains. Collectively, these results suggest that neuroadaptive changes
have occurred in the HIV-1Tg rats that might help to compensate for HIV-1 viral protein-induced
inhibition of the DAT function. Supported by grant from the NIH to Jun Zhu (R01DA035714)
P200
The SIV/Macaque Model: Proof of Concept for HIV Eradication
M. Christine Zink1, Lucio Gama1, Janice Clements1, Celina Abreu2, Amilcar Tanuri2
(presenting author: mczink@jhmi.edu)
1Johns Hopkins University School of Medicine;
2Division of Genetics - Federal University of Rio de Janeiro, Rio de Janeiro, RJ,
Brazil
We have developed an SIV/pigtailed macaque model that results in rapid development
of CNS disease and AIDS that provides a robust model for testing of antiretroviral
and neuroprotective therapeutic strategies. We have also demonstrated that we can
obtain suppression of plasma vRNA to below detectable levels using combinations of
three different classes of antiretroviral drugs that are CNS penetrant or nonpenetrant.
In the last few years, a number of HIV-infected patients have experienced at least
functional cures (the Berlin Patient, the Mississippi Child, the French Cohort), ceasing
antiretroviral therapy without viral reactivation or development of disease. This
has initiated a search for ways to duplicate these natural experiments. Recently a
number of compounds that are able to activate HIV DNA have been suggested as coadjuvant
to cART therapy. It is proposed that the antiretroviral drugs would prevent viral
spread while host lymphocytes would kill reactivated infected cells expressing viral
proteins. We have been investigating a hexanoate derivative of Ingenol (Kyo-IIB),
a phorbol ester isolated from Euphorbia tirucalli. Kyo-IIB treatment of resting CD4+
T cells isolated from virus suppressed SIV-infected macaques led to a significant
increase in reactivated latent cells and viral RNA transcription. In a pilot trial
in SIV-infected macaques, Kyo-IIB was administered in escalating doses orally BID
for one week each, alternated with off-treatment weeks. Activation markers in blood
leukocytes and plasma viral load increased during treatment and decreased during the
washout periods. In contrast to other phorbol esters, Kyo-IIB is less toxic and can
be orally administered to animals with no apparent side effects. We plan to treat
virus suppressed SIV-infected macaques with Kyo-IIB to determine the ability of the
compound to reactivate SIV in vivo and reduce the number of SIV latently infected
resting CD4+ T cells, monocytes, and macrophages as proof-of-concept for a functional
HIV cure.
P201
Development of SIV Latently Infected Primary Macrophages and Astrocytes
Meredith Zoch, Sarah Price, Jeanne Sisk, Lucio Gama, Janice Clements
(presenting author: mzoch1@jhmi.edu)
Department of Molecular and Comparative Pathobiology, Johns Hopkins University School
of Medicine, Baltimore, MD 21205
A major barrier to the eradication of HIV is the persistence of virus in latent reservoirs.
CD4+ T cells have been widely studied, and resting CD4+ T cells are considered the
major latent reservoir in HIV and SIV infections. HIV and SIV replicate in activated
CD4+ T cells, but a small percentage of these cells become resting memory cells and,
if infected, harbor latent virus. Monocytes, macrophages, and microglia in the brain
have been shown to support HIV and SIV infection. In both HIV and SIV infected individuals
on combination antiretroviral therapy, viral DNA is found in the brain, and ongoing
changes in the brain suggest that the virus is persistent and latent. Because of the
recent focus on the eradication of HIV, identification of all latent viral reservoirs
has become crucial. However, little is understood about mechanisms of HIV or SIV latency
in myeloid cells. In the CNS, the astrocyte, the most abundant cell in brain, is also
infected with HIV and SIV but infection is not productive. In order to characterize
viral latency in macrophages, microglia, and astrocytes, we are developing in vitro
primary cell latency models. In order to recapitulate the environment in the CNS,
cytokines are being used to determine their role in establishing viral latency in
macrophages, microglia, and astrocytes.
P202
Glutamate receptors mediate stage-specific effects of HIV-1 Tat on the viability and
phenotype of oligodendroglia
ShiPing Zou1, Kurt Hauser2, Pamela Knapp1
(presenting author: szou@vcu.edu)
1Department of Anatomy & Neurobiology, Virginia Commonwealth University;
2Department of Pharmacology and Toxicology, Virginia Commonwealth University
Myelin pallor is frequently reported in HIV patients, and can occur in the CNS prior
to other evidence of a disease process. Oligodendrocytes (OLs) are the myelinating
cells of the CNS; they are highly vulnerable to excitotoxicity due to the fact that
1) NMDA receptors (NMDA-Rs) expressed on OLs are weakly blocked by Mg2+1, and 2) AMPA
receptors (AMPA-Rs) on OLs lack the Ca2+-impermeable GluR2 subunit2,3. We hypothesized
that HIV-1 Tat (transactivator of transcription) activates NMDA-Rs and AMPA-Rs, which
in turn leads to Ca2+ influx and OL injury. Our repeated measure experiments established
that 100 nM Tat1-86 is toxic to immature OLs, but not mature OLs. On the other hand,
mature OLs exposed to 100 nM Tat exhibit reduced myelin-like membrane area, indicating
potential injury to cell morphology and function. To investigate if these effects
are mediated via Ca2+, Fura-2 AM was used to quantify [Ca2+]i within individual cells.
Both mature (O4+, MBP+) and immature OLs (O4+, MBP-) exposed to 1-100 nM Tat showed
a dose-dependent, gradual increase in [Ca2+]i up to ~600 nM vs. ~100 nM in control,
and this high [Ca2+]i level was maintained during a 1 h experimental period. This
Tat-induced [Ca2+]i increase is completely abolished in Ca2+-free medium, suggesting
extracellular Ca2+ as the primary source. The NMDA-R antagonist MK801 reduces Tat-induced
[Ca2+]i increase in both immature and mature OLs. Surprisingly, AMPA/KA-R antagonist
CNQX also attenuates Tat-induced Ca2+ influx in OLs, suggesting both NMDA-R and AMPA/KA-R
on OLs were activated by HIV-1 Tat. Importantly, both MK801 and CNQX block Tat-induced
immature OLs death, but only MK801 reverses Tat-induced mature OL membrane area change.
These results add to evidence suggesting that OLs are targets of HIV, and also suggest
that viability and phenotypic changes in immature and mature OLs, respectively, may
involve different Ca2+-mediated glutamatergic mechanisms.
Author Index
Aron Aronow, 22, 23
Aarthi Narayanan, 73, 82, 13
Ada Francia, 24
Adam Wojno, 192
Adarsh Kumar, 99
Aditya Bade, 14
Adrian Gomez, 200
Adriana Bora, 31
Adriano Ferrucci, 90, 97
Ahmet Ozdemir, 96, 100
Ajay Bharti, 26, 148
Akos Vertes, 82, 130
Alash'le Abimiku, 148
Alessandra Mei, 110
Alessia Bachis, 13
Alex M. Dickens, 51
Alexander Choe, 29, 69, 129
Alexander Gill, 7, 70, 95, 120
Alexandra Carides, 100
Alfredo Garzino-Demo, 27
Alina Popescu Hategan, 141
Allen Reitz, 136
Allyssia Boelk, 13
Amanda Brown, 171
Amanda J. Morgan, 25
Amanda Roberts, 117
Amber Paul, 1
Amilcar Tanuri, 201
Ana Sanchez, 117
Anastas Popratiloff, 82, 130
Andrea Bucci, 167
Andrea Cuconati, 136
Andrea Partridge, 137
Andrea Raymond, 139
Andrew D. Miller, 36
Andrew G. MacLean, 36
Andrew Levine, 22, 23, 103
Andrew Miller, 30
Andrew Talal, 159
Anjana Yadav, 196
Ann Ragin, 22, 23
Ann Wyborny, 129
Anna Bellizzi, 24
Anna Blackmon, 179
Anna Heintzman, 69
Anna Teresa Palamara, 24
Anne Blackwell, 175
Anne Lamontagne, 158
Antonina Dolei, 110, 181
Antonio Giordano, 149
Anya Umlauf, 26, 148, 167
Apurva Kulkarni, 57
Archana Gupta, 75
Arthur Feldman, 93
Asha Kallianpur, 86
Ashley Azar, 128
Ashok Verma, 85
Avindra Nath, 9, 15, 31, 67, 85, 104, 141, 180
Ayman Bodair, 30
Ayuna V. Dagdanova, 84
Barbara Krynska, 72
Barbara S. Slusher, 19, 61, 62, 112
Barry Waterhouse, 60, 76
Beau Ances, 176
Bei Li, 164
Ben Gouaux, 167
Benchawanna Soontornniyomkij, 55, 167
Benedikt Kaufer, 71
Benjamas Aiamkitsumrit, 4, 11, 44, 135, 140, 192, 199
Benjamin Lepene, 73, 83
Benjamin B Gelman, 7, 33, 66, 70, 86, 95, 163, 164
Bezawit Megra, 122
Bezawit Megra, 178
Bianca Tigges, 157
Biju Issac, 118
Bill Switzer, 38
Bindesh Shrestha, 82, 130
Bing Sun, 75
Biswajit Das, 5, 6
Bogdan F.Gh. Popescu, 187
Bradley Nash, 131
Brandon Blakey, 4, 11, 140, 192
Brandon Bullock, 12
Breanna Caruso, 38, 102
Brenna Duffy, 60
Brent Palmer, 179
Brian Augelli, 72
Brian Daniels, 46
Brian Draper, 107
Brian Frantz, 4
Brian Moldover, 4, 11, 44, 140, 192, 199
Brian Wigdahl, 4, 11, 43, 44, 52, 75, 76, 89, 90, 94, 97, 106, 116, 135, 140, 150,
162, 169, 192, 199
Bridgette Jeanne Billioux, 28
Brigitte Simons, 175
Bruce Brew, 107
Bruce Shiramizu, 3, 194
C. Conover Talbot Jr., 171
Caitlin Duffy, 136
Calribel Gonzalez, 194
Camilla Carloni, 48
Camilo Rojas, 61, 62
Cari Dowling, 117
Cari Fritz-French, 64
Carlo Amorin Daep, 8
Carol Petito, 85
Carolina Ionete, 40
Caroline Anderson, 9
Caterina Serra, 110, 181
Caterina Turco, 124
Catherine Foss, 151
Cecilia Shikuma, 3
Cecily Midkiff, 179
Ceereena Ubaida Mohien, 31, 175
Celina Abreu, 201
Charles Eberhart, 69
Charles F. Mactutus, 25, 125
Charles Grose, 16
Charles Reynolds, 136
Chelsea Bleckwehl, 32
Chen Sabrina Tan, 32, 172
Chen Zeng, 73
Chigo Eze, 28
Chris Gutoskey, 60, 76
Christian Sell, 128, 199
Christian Wuethrich, 91, 187
Christina Kollias, 52, 94
Christina Preminger, 147
Christina Schier, 156
Christoph Ziegenhain, 157
Christopher Akolo, 148
Christopher Coe, 86
Christopher Power, 1, 188
Christopher Power, 188
Claribel Gonzalez, 67, 123
Claudia Avalos, 12
Claudia F. Lucchinetti, 187
Claudia Hernandez, 123
Claudia Hilera, 67
Claudio Torres, 128, 137
Clayton Winkler, 173, 193
Colleen Kovacsics, 7, 70, 95
Cory Teuscher, 20
Cristian Achim, 53, 55, 167
Cynthia Munro, 22, 23
Cyrus de Rozieres, 117
Dan Barouch, 32
Dan Duiculescu, 53
Danelvis Parades, 180
Daniel C. Anthony, 51, 178
Daniel Reich, 102, 105
Davey Smith, 26
David Alsop, 91, 92
David Alvarez, 5, 6
David Avigan, 172
David Broadhurst, 188
David Colquhoun, 175, 178
David Downie, 192
David Graham, 175, 178
David Hackney, 91
David Holman, 46
David J. Nolan, 36
David Libon, 199
David Mohr, 171
David Moore, 167
David R. Graham, 31
David Roh, 85
Debasis Nayak, 132
Debbie Brown, 126
Debjani Guha, 74
Deepika Dinesh, 30
Denis Chatelain, 69
Dennis Kolson, 7, 33, 66, 70, 95, 120, 165, 196
Diane Griffin, 19, 112
Diane K Brandt, 163
Dianedis Toro Nieves, 194
Dianna Cheney-Peters, 145
Dianne C. Daniel, 84
Dianne Langford, 96, 100
Diego Franciotta, 37, 48
Diego Ojeda, 133, 134
Dierdre Killebrew, 191
Dilip Jeste, 167
Dionna W. Williams, 3, 35, 122, 178, 183, 190
Divya Sagar, 150, 151
Don Gilden, 16, 71, 69, 179
Donatella Maria Rodio, 24
Dora Schnur, 136
Dorian McGavern, 78, 132
Dorothy Kisielewski, 126
Edgar Busovaca, 182
Edward Harhaj, 158
Edward J. Gracely, 119
Edward M. Johnson, 84
Edward Makarov, 14
Eileen Deharo, 179
Eileen Martin, 22, 23, 113
Elena Anzivino, 24
Elena Colombo, 37
Elena Uleri, 110, 181
Eliezer Masliah, 167
Eliseo Eugenin, 8, 35, 39, 56, 184
Elizabeth Blankenhorn, 20, 94
Elizabeth Crowe, 128, 137
Elizabeth Jaworski, 73, 82, 83, 130
Elizabeth Norton, 187
Elizabeth Podhaizer, 156
Ellen M. Tedaldi, 68
Elyse Singer, 103, 163
Emilios Dimitriadis, 141
Emily Leibovitch, 28, 102, 185
Emma Wall, 20
Eric Cohen, 90
Eric Miller, 22, 23, 103
Erica L. Gray, 57
Eridania Valdes, 99
Erin Roach, 145, 146
Erin Shirk, 12
Eugene Major, 59
Eva-Maria Ratai, 36
Evelyn Borad, 172
Evelyn Bord, 40, 45
Evgenia Gerasimovskaya, 129
Fabio Romerio, 81
Fan Yang, 79, 198
Fang Li, 198
Fatah Kashanchi, 58, 73, 81, 82, 83, 130
Fengbin Song, 136
Ferdinand Maingat, 1, 188
Fiorella Rossi, 144
Florin Tuluc, 168
Francesca De Simone, 47
Francesca Elia, 37, 48
Francis Novembre, 34
Francois Villinger, 34
Frank Bearoff, 20
Fred C. Krebs, 89, 97
Gabrielle Lehmicke, 101
Gavin Sampey, 73, 81, 82, 130
Gayle Baldwin, 103
Gillian Clary, 191
Giordano Madeddu, 110
Giovanna Brunetto, 28, 38, 102
Girish Hemashettar, 34
Giuseppe Mameli, 110, 181
Giuseppe Russo, 149
Glen Baker, 1
Gloria von Geldern, 9, 85
Gokul Swaminathan, 41, 144, 170
Govind Nair, 105
Grace Lu, 107
Gratiela Tardei, 53
Gregory Antell, 11
Gwenn Garden, 117
Haiping Hao, 171
Hamid Akbarali, 63
Hans Rempel, 75
Hao Chen, 73
Harry Davis, 147
Hassen Wolllebo, 87, 195
Heidi Kay, 121
Holly Dykstra, 138
Howard Gendelman, 14
Howard Rosen, 182
Howard S. Fox, 163
Hugh Perry, 126
Ibolya E. Andras, 177
Igor Grant, 17, 51, 53, 463, 167
Igor Koralnik, 32, 40, 45, 91, 92, 172, 187
Igor Traktinskiy, 129
Ilker Sariyer, 47, 72, 124, 154, 155, 181
Irene Catalan, 117
Irene Cortese, 114
Irene Guendel, 73
Irene M. Dustin, 28
Irwin Chaiken, 136
Iryna Lobach, 182
Italo Mocchetti, 13
Jacalyn Rosenblatt, 172
Jaclyn Knibbe, 14
Jacob Raber, 143
Jacob Sloane, 40
Jacqueline Bowlin, 16
Jacqueline S. Coley, 35
James Arthos, 136
James Connor, 86
James Lokensgard, 127
James T. Becker, 22, 23
Jamie Dorsey, 88, 111
Jane Kovalevich, 96
Jane Libbey, 42
Janice Clements, 12, 201, 202
Jasmeet Sethi, 171
Jasmin Herz, 78
Jasmin Vassileva, 113
Jasmine Sharazi, 151
Javier Sierra, 123
Jay Rappaport, 101, 119
Jayasri Das Sarma, 29
Jean Manson, 126
Jean Williams, 11, 44, 140, 192
Jeanne Sisk, 202
Jed Shumsky, 76
Jeffrey Jacobson, 4, 11, 44, 135, 140, 192
Jeffrey Kowalak, 185
Jennifer Gordon, 72, 93, 98, 154
Jennifer H. Campbell, 36
Jennifer Manfredo, 179
Jennifer McGuire, 120
Jennifer P. Bharucha, 27
Jeremy Hill, 138
Jeremy J. Martinson, 22
Jessica Krueger, 98
Jessica Otte, 72, 98
Jessica Rotschafer, 145, 146
Jesus Fernandez, 99
Jewell Thomas, 176
Jiasheng Song, 166
Jiri Forejt, 20
Joan Berman, 122
Joan Ohayon, 102, 114
Joan W. Berman, 3, 35, 65, 178, 183, 190
John Fazakerley, 126
John Meshki, 168
John Schreiber, 28
John Walsh, 188
Jonathan Carter, 45
Jonathan D. Geiger, 15, 80
Jonathan Karn, 5, 6, 58
Jonathan Oakley, 111
Jorge Quarleri, 133, 134
Joseph Bryant, 147
Joseph Cheung, 93
Joseph E. Parisi, 187
Joseph Hardardt, 68
Joseph Mankowski, 21, 88, 111
Joseph Steiner, 141
Joshua Lisinicchia, 33, 66
Joshua Thornbrough, 189
Joy Ngwainmbi, 63
Joyce Balinang, 115
Joyce Johnson, 148
Joyce M. Velez, 123, 194
Juan A. Orellana, 184
Juan C. Saez, 184
Juhi Motiani, 131
Julio Martin-Garcia, 4, 41, 137, 144, 165, 170
Jun Zhu, 200
Jussi Oskari Virtanen, 185, 186
Jussi Virtanen, 54
Justin McArthur, 9, 17, 31, 85
Kalamo Farley, 58
Kamel Khalili, 49, 72, 79, 87, 93, 124, 155, 160, 161, 181, 195, 198
Kanayo Okwuasaba, 148
Kareem Zaghloul, 28
Karim Garcia, 143
Karin Peterson, 173, 174, 193
Kasra Houshmand, 155
Katherine P. Rankin, 182
Katherine Taylor, 173, 174
Kathleen Kelly, 88
Kathryn Anastos, 183, 190
Kathryn Medders, 117
Katie Kercher, 90
Kaushiki Biswas, 29
Kaylan Fenton, 102, 114
Kelly Metcalf Pate, 88
Kelsi Fry, 81
Kenneth Johnson, 33
Kenneth S. Shindler, 29
Kenneth Williams, 26, 36, 148
Kenta Matsuda, 34
Kevin Bloh, 162
Kevin Egan, 52
Kimberly Williams, 191
Kory Johnson, 59
Kris Hogan, 126
Krista Siefried, 107
Kristen N. Fantetti, 57
Kristofer Jennings, 33, 66
Kurt Hauser, 58, 63, 115, 156, 203
Kyle Lord, 106
Kylene Kehn-Hall, 73, 83
L. Dillon Birdwell, 189
Landhing M. Moran, 125
Lara Doyle-Meyers, 179
Larisa Poluektova, 14
Laura McCourt, 119
Laure Case, 20
Lauren A. O'Donnell, 57
Lauren Wendelken, 182
Lawrence C. Kenyon, 29
Lawrence Kingsley, 22, 23
Lee Campbell, 13
Lena Al-Harthi, 108, 142
Leonard Shultz, 73
Liang Hui, 80
Lillian Cruz-Orengo, 46
Lillie Lopez, 35
Lily Francis, 74
Linda Chang, 31
Lindsay Eyzaguirre, 148
Lindsay Festa, 60
Lindsey Gerngross, 18, 68
Ling Zhao, 189
Lisa Henderson, 104
Lisa Mangus, 111
Lishomwa C. Ndhlovu, 3
Lita Murphy, 126
Lola Hudson, 121
Long Ngo, 91, 92
Lorraine Kolson, 7, 196
Loyda Melendez, 194
Lu Yang, 197
Lucette Cysique, 107
Lucia Nencioni, 24, 37
Luciana Poddighe, 110
Lucio Gama, 12, 201, 202
Luis B. Tovar-y-Romo, 178
Luke Ollila, 30
Luminita Ene, 53
Luz-Jeannette Sierra, 165
Lynn Pulliam, 75
M. Christine Zink, 175, 201
Madhavan Nair, 139
Mahendra Kumar, 99
Mahmut Safak, 152, 153, 195
Mai-Lan Ho, 91
Mallory Witt, 103
Manohar Mutnal, 127
Manuela Morreale, 24
Marangely Huertas, 194
Marcus Kaul, 117
Margaret J. Wortman, 84
Maria Nagel, 69, 129
Maria Nica, 53
Mariana Cherner, 148
Mariana Cherner, 26, 148
Mariana Figuera Losada, 61, 62
Marianne Strazza, 116, 169
Marines Plaud, 194
Marion Stein, 40
Mark Lafferty, 27
Mark Lewis, 101
Mark P. Mattson, 15
Markus Helfer, 157
Marlene Kanmonge, 178
Martha Schneider, 157
Martin Pomper, 151
Martyn White, 195
Mary Barbe, 98
Mary Wellish, 179
Matt Thomas, 76
Matteo Gastaldi, 37, 48
Matthew Anderson, 91
Matthew Brier, 176
Matthew Cusick, 42
Matthew Rimbey, 4
Matthew Taylor, 93
Maureen McCarthy, 71
Maureen Richards, 108, 142
Mauricio Carobene, 133, 134
Maxim Cheeran, 145, 146
Maya Desai, 117
Megan Cochran, 167
Melanie Hoefer, 117
Melanie S. Seaton, 142
Melissa Agsalda-Garcia, 3
Melissa Agsalda, 194
Melissa Wasilewski, 100
Meredith Zoch, 202
Michael Betts, 196
Michael Boska, 14
Michael Ferenczy, 59
Michael Khoury, 91, 92
Michael Marvi, 187
Michael Nonnemacher, 4, 11, 43, 44, 90, 97, 106, 116, 135, 140, 162, 169, 192, 199
Michael Park, 136
Michael Weaver, 124
Michael Wong, 172
Michal Toborek, 177
Micheline McCarthy, 118
Michelle M. Mielke, 17, 51
Michelle Potter, 19
Mihyun Bae, 15, 178
Mike Veenstra, 122, 183
Min Zhan, 148
Ming Guo, 147, 148
Ming Li, 12
Miriam Matos, 143
Mohammed Saifuddin, 73, 82, 83, 130
Mohit Sehgal, 158, 159
Monique Anderson, 10
Monique Maubert, 116
Mudit Tyagi, 58
Mylyne Tham, 187
Myosotys Rodriguez, 156
Myounghwa Lee, 15
Myraida Morales, 143
Myriam M. Gorospe, 15
Myung Chung, 82, 130
Nagagopal Venna, 2
Nana Merabova, 93, 124
Nancy Minniti, 149
Nancy Reichenbach, 138
Naomi Lee, 185
Narasimha Midde, 200
Naresha Saligrama, 20
Natalia Sejbuk, 117
Natalie Chen, 41
Nazira El-Hage, 58, 115, 156
Nazly Shafagati, 83
Neal Shah, 30
Ned Sacktor, 9, 22, 23, 31, 85
Nelly Khmeleva, 69
Nicholas Baird, 16
Nicole A. Renner, 36
Nicole Haverland, 77
Nikolaus Osterrieder, 71
Nino Tabatadze, 178
Nirzari Parikh, 4, 44, 135, 199
Norman Haughey, 15, 17, 31, 51, 61, 80, 178
Nyater Ngouth, 10
Ola Selnes, 23
Olga Latinovic, 27
Olimpia Meucci, 60, 119, 131
Onder Otlu, 47, 155
Otoniel Martinez-Maza, 103
Pallavi Chitturi, 100
Pamela Knapp, 63, 115, 156, 203
Pankaj Seth, 109
Paolo Fortina, 29
Pardis Esmaeili, 182
Pascale Coric, 152
Pasquale Ferrante, 37, 48
Patric S. Lundberg, 84
Patricia Vance, 7
Patrick Autissier, 36
Patrick Lam, 136
Patrick Tarwater, 88
Paul Castellano, 39
Paul Pozniak, 49
Paul Shapshak, 103
Pawel Ciborowski, 77
Pedro Piccardo, 126
Peter Abbink, 32
Peter Dickie, 1
Peter J. Gaskill, 35, 65
Peter Katsikis, 199
Peter Langfelder, 103
Philip Boyer, 69
Philip Kinkel, 40
Philippe Afonso, 130
Philippe Afonso, 82
Pooja Jain, 136, 150, 151, 158, 159
Pornpun Vivithanaporn, 1
Prachi Sharma, 34
Prasanta Dash, 14
Prasun Datta, 49, 50, 87, 160, 161
Pratima Agarwal, 69
Priya Ganesan, 57
R. Gilberto González, 36
Rachel Van Duyne, 73, 81, 82, 83, 130
Radhika Adiga, 100
Rafal Kaminski, 79, 87, 198
Raghothama Chaerkady, 31
Rahsan Sariyer, 154
Raissa Menendez-Delmestre, 67, 123
Randall Cohrs, 16, 29, 71
Raphael Viscidi, 172
Rasha El Baz, 136
Raul Gonzalez, 113
Ravi Das, 73, 82, 130
Ravi Mahalingam, 179
Ravi Tharakan, 175
Raya Massoud, 10, 38, 54, 105, 114, 186
Raymond Ownby, 99
Rebeca Geffin, 118
Reena Deutsch, 51
Renaud Mahieux, 82, 130
Rennos Fragkoudis, 126
Renzo Perales-Linares, 170
Ricardo Martinez, 118
Richa Tyagi, 85, 104, 180
Richard Moxley,IV, 31
Richard Skolasky, 67, 123, 194
Rick Meeker, 121, 191
Ricky Maung, 117
Rinki Saha, 109
Robert Adams, 88
Robert Fujinami, 42
Robert Mathey, 19
Robert Poppiti, 69
Robert Silverman, 189
Roberto Bergamaschi, 37
Roberto Manetti, 110
Roberto Perez, 118
Robyn Klein, 46
Rodrigo Hasbun, 85
Rojas Roxana, 6
Rolf Pfannl, 91
Ronald Collman, 196
Ronald Ellis, 53, 167
Ronald Ziman, 187
Rosa Hechavarria, 67, 143
Rosa Janet Rodriguez-Benitez, 143
Rosemarie M. Booze, 25, 125
Rossella Russo, 117
Roxana Radoi, 53
Roy Williams, 117
Rui Feng, 11, 44, 116, 135, 140, 169, 192, 199
Ruth Brack-Werner, 157
Ruth Elliott, 189
Ruth Ruprecht, 34
Ruturaj Masvekar, 115
Ryan Fassnacht, 58
Ryan O’Donnell, 30
Sagarika Banerjee, 50
Samantha Molsberry, 22, 23
Sami Saribas, 152, 153
Sandra Chung, 167
Sandra Navas-Reyes, 147
Sandra Reynolds, 22, 23
Sankar Addya, 29
Santhi Gorantla, 14
Sara Cioccolo, 24
Sarah Beck, 21, 88
Sarah Gheuens, 92, 172, 187
Sarah Inati, 28
Sarah J. Bertrand, 25
Sarah Price, 202
Satarupa Sen, 160, 161
Satinder Dahiya, 43
Satish Deshmane, 49, 50
Scott Letendre, 17, 26, 51, 55, 85, 148, 167
Scott Schachtele, 127
Sebastian Perez, 67
Serena Delbue, 37, 48
Serge Bouaziz, 152
Sergei Spitsin, 168
Sergey Iordanskiy, 73, 81, 82, 83, 130
Servio Ramirez, 138
Seth Sherman, 163
Shabana Shabbeer-Meyering, 82
Shaily Malik, 109
Shao-Jun Tang, 164
Shaona Acharjee, 1
Sharon Lewis, 192
Shawn Keogan, 89
Shendra Passic, 4, 11, 44, 89, 135, 140, 192, 199
Shet Masih, 150
Shilpa Buch, 197
ShiPing Zou, 203
Shohreh Amini, 93, 160, 161
Shruti Agnihotri, 2, 45, 91
Shruti Singh, 158
Shuxian Hu, 127
Siddappa Byrareddy, 34
Silvia Carluccio, 24, 37, 48
Simona Pontecorvo, 24
Simona Ruta, 53
Simone Dallari, 37
Sivabalan Manivannan, 112
Slava Rom, 138
Sonia Navas-Martin, 170
Sonia Shah, 11, 140, 162
Spyridon Chalkias, 40
Srimoye Banerjee, 18
Srinivas D Narasipura, 108
Stacey Reinke, 188
Stephani Velasquez, 184
Stephanie Batson, 40
Stephanie Cross, 7, 70
Stephanie James, 179
Stephanie Milne, 6
Stephanie Min, 108, 142
Stephen Jennings, 52, 94
Stephen Pojen Denq, 187
Steve Horvath, 103
Steve Jacobson, 28, 105, 185
Steven B. Harrod, 25
Steven Douglas, 120, 168
Steven Jacobson, 10, 38, 54, 102, 114, 150, 186
Steven Wolinsky, 22
Subo Yuan, 164
Sudheesh Pilakka-Kanthikeel, 139
Sudhir Penugonda, 22
Surendra Ambegaokar, 7, 95
Susan Morgello, 163, 190
Susan V. Westmoreland, 36
Susan Weiss, 189
Suzanne Gartner, 27
Suzanne Queen, 12, 21, 88
Svetlana Senina, 73
Swati Thorat, 34
Sylvia Fitting, 63
Tatro Erick, 55
Tatyana Russo, 4
Tetyana Buzhdygan, 33, 66
Thomas Broge, 32, 172
Thomas Goodwin, 71
Thomas Marcotte, 51
Thomas Waldmann, 114
Thuong Tran, 136
Tijana Knezevic, 93
Timothy D. W. Claridge, 51
Timothy Nacarelli, 128
Tina M. Calderon, 35
Todd Reinhart, 74
Todd Schell, 150
Tom Freeman, 126
Tomohisa Mori, 197
Toni Roberts, 122
Tory Johnson, 85
Tory Johnson, 9
Tracy Fischer-Smith, 18, 68, 101, 119, 149
Tricia Burdo, 26, 30, 36,148
Tyler Clement, 33, 66
Tyson Woods, 173, 174, 193
Umberto Girolami, 34
Unsong Oh, 10
Upal Roy, 139
Valentina Pecchenini, 48
Valeria Pietropaolo, 24
Valerie Wojna, 67, 123, 143, 194
Vanessa Hirsch, 34
Vanessa Pirrone, 4, 11, 44, 76, 116, 135, 140, 162, 169, 192, 199
Veera Venkata Ratnam Bandaru, 15, 17, 178
Velpandi Ayyavoo, 74
Venkata Subba Rao Atluri, 139
Vicki Traina-Dorge, 179
Victor Valcour, 182
Victoria Baxter, 19
Victoria Lutgen, 108, 142
Victoria Pelak, 69
Vidya Sagar, 139
Vikram D Durairaj, 69
Vipulkumar Patel, 33, 66
Virawudh Soontornniyomkij, 167
Walter Royal III, 147, 148
Walter Royal, 26
Wei Lin, 116, 169
Wen Zhong, 4, 11, 44, 135, 140, 192, 199
Wendeline Wagner, 101, 119
Wenhui Hu, 79, 198
Wenxue Li, 104, 180
Will Toperoff, 167
William Blattner, 1, 4, 11, 26, 44, 135, 140, 148, 188, 192, 199
William H. Theodore, 28
William Tyor, 64
William Yen, 96, 100
Winston Liu, 105
Won-Bin Young, 166
Wuyuan Lu, 27
Xavier Alvarez, 179
Xiaoen Wang, 92
Xin Dang, 40, 45, 187
Xuesong Chen, 15, 80
Yamil Gerena, 67, 123
Yize Li, 189
Yoelvis Garcia-Mesa, 6
Yolanda Rodriguez, 194
Yonggang Zhang, 79, 198
Yoshimi Enose-Akahata, 10, 54, 114, 185, 186
Youmei Xie, 191
Yuetsu Tanaka, 10
Yujie Liu, 106
Yuqiang Shi, 164
Yuri Persidsky, 138
Yutong Liu, 14
Yvonne Mueller, 199
Zafar Khan, 136, 150, 151, 158, 159