2
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Preventing SARS-CoV-2 infection by blocking a tissue serine protease

      article-commentary

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Currently, there are no proven pharmacologic interventions to reduce the clinical impact and prevent complications of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, the cause of the ongoing Coronavirus Disease of 2019 (COVID-19) pandemic. Selecting specific pharmacological targets for the treatment of viral pathogens has traditionally relied in blockage of specific steps in their replicative lifecycle in human cells. However, an alternative approach is reducing the molecular cleavage of the viral surface spike protein of SARS-CoV-2 to prevent viral entry into epithelial cells.

          Related collections

          Most cited references8

          • Record: found
          • Abstract: found
          • Article: not found

          SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor

          Summary The recent emergence of the novel, pathogenic SARS-coronavirus 2 (SARS-CoV-2) in China and its rapid national and international spread pose a global health emergency. Cell entry of coronaviruses depends on binding of the viral spike (S) proteins to cellular receptors and on S protein priming by host cell proteases. Unravelling which cellular factors are used by SARS-CoV-2 for entry might provide insights into viral transmission and reveal therapeutic targets. Here, we demonstrate that SARS-CoV-2 uses the SARS-CoV receptor ACE2 for entry and the serine protease TMPRSS2 for S protein priming. A TMPRSS2 inhibitor approved for clinical use blocked entry and might constitute a treatment option. Finally, we show that the sera from convalescent SARS patients cross-neutralized SARS-2-S-driven entry. Our results reveal important commonalities between SARS-CoV-2 and SARS-CoV infection and identify a potential target for antiviral intervention.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Clinical evidence does not support corticosteroid treatment for 2019-nCoV lung injury

            The 2019 novel coronavirus (2019-nCoV) outbreak is a major challenge for clinicians. The clinical course of patients remains to be fully characterised, little data are available that describe the disease pathogenesis, and no pharmacological therapies of proven efficacy yet exist. Corticosteroids were widely used during the outbreaks of severe acute respiratory syndrome (SARS)-CoV 1 and Middle East respiratory syndrome (MERS)-CoV, 2 and are being used in patients with 2019-nCoV in addition to other therapeutics. 3 However, current interim guidance from WHO on clinical management of severe acute respiratory infection when novel coronavirus (2019-nCoV) infection is suspected (released Jan 28, 2020) advises against the use of corticosteroids unless indicated for another reason. 4 Understanding the evidence for harm or benefit from corticosteroids in 2019-nCoV is of immediate clinical importance. Here we discuss the clinical outcomes of corticosteroid use in coronavirus and similar outbreaks (table ). Table Summary of clinical evidence to date Outcomes of corticosteroid therapy * Comment MERS-CoV Delayed clearance of viral RNA from respiratory tract 2 Adjusted hazard ratio 0·4 (95% CI 0·2–0·7) SARS-CoV Delayed clearance of viral RNA from blood 5 Significant difference but effect size not quantified SARS-CoV Complication: psychosis 6 Associated with higher cumulative dose, 10 975 mg vs 6780 mg hydrocortisone equivalent SARS-CoV Complication: diabetes 7 33 (35%) of 95 patients treated with corticosteroid developed corticosteroid-induced diabetes SARS-CoV Complication: avascular necrosis in survivors 8 Among 40 patients who survived after corticosteroid treatment, 12 (30%) had avascular necrosis and 30 (75%) had osteoporosis Influenza Increased mortality 9 Risk ratio for mortality 1·75 (95% CI 1·3–2·4) in a meta-analysis of 6548 patients from ten studies RSV No clinical benefit in children10, 11 No effect in largest randomised controlled trial of 600 children, of whom 305 (51%) had been treated with corticosteroids CoV=coronavirus. MERS=Middle East respiratory syndrome. RSV=respiratory syncytial virus. SARS=severe acute respiratory syndrome. * Hydrocortisone, methylprednisolone, dexamethasone, and prednisolone. Acute lung injury and acute respiratory distress syndrome are partly caused by host immune responses. Corticosteroids suppress lung inflammation but also inhibit immune responses and pathogen clearance. In SARS-CoV infection, as with influenza, systemic inflammation is associated with adverse outcomes. 12 In SARS, inflammation persists after viral clearance.13, 14 Pulmonary histology in both SARS and MERS infections reveals inflammation and diffuse alveolar damage, 15 with one report suggesting haemophagocytosis. 16 Theoretically, corticosteroid treatment could have a role to suppress lung inflammation. In a retrospective observational study reporting on 309 adults who were critically ill with MERS, 2 almost half of patients (151 [49%]) were given corticosteroids (median hydrocortisone equivalent dose [ie, methylprednisolone 1:5, dexamethasone 1:25, prednisolone 1:4] of 300 mg/day). Patients who were given corticosteroids were more likely to require mechanical ventilation, vasopressors, and renal replacement therapy. After statistical adjustment for immortal time and indication biases, the authors concluded that administration of corticosteroids was not associated with a difference in 90-day mortality (adjusted odds ratio 0·8, 95% CI 0·5–1·1; p=0·12) but was associated with delayed clearance of viral RNA from respiratory tract secretions (adjusted hazard ratio 0·4, 95% CI 0·2–0·7; p=0·0005). However, these effect estimates have a high risk of error due to the probable presence of unmeasured confounders. In a meta-analysis of corticosteroid use in patients with SARS, only four studies provided conclusive data, all indicating harm. 1 The first was a case-control study of SARS patients with (n=15) and without (n=30) SARS-related psychosis; all were given corticosteroid treatment, but those who developed psychosis were given a higher cumulative dose than those who did not (10 975 mg hydrocortisone equivalent vs 6780 mg; p=0·017). 6 The second was a randomised controlled trial of 16 patients with SARS who were not critically ill; the nine patients who were given hydrocortisone (mean 4·8 days [95% CI 4·1–5·5] since fever onset) had greater viraemia in the second and third weeks after infection than those who were given 0·9% saline control. 5 The remaining two studies reported diabetes and avascular necrosis as complications associated with corticosteroid treatment.7, 8 A 2019 systematic review and meta-analysis 9 identified ten observational studies in influenza, with a total of 6548 patients. The investigators found increased mortality in patients who were given corticosteroids (risk ratio [RR] 1·75, 95% CI 1·3–2·4; p=0·0002). Among other outcomes, length of stay in an intensive care unit was increased (mean difference 2·1, 95% CI 1·2–3·1; p<0·0001), as was the rate of secondary bacterial or fungal infection (RR 2·0, 95% CI 1·0–3·8; p=0·04). Corticosteroids have been investigated for respiratory syncytial virus (RSV) in clinical trials in children, with no conclusive evidence of benefit and are therefore not recommended. 10 An observational study of 50 adults with RSV infection, in which 33 (66%) were given corticosteroids, suggested impaired antibody responses at 28 days in those given corticosteroids. 17 Life-threatening acute respiratory distress syndrome occurs in 2019-nCoV infection. 18 However, generalising evidence from acute respiratory distress syndrome studies to viral lung injury is problematic because these trials typically include a majority of patients with acute respiratory distress syndrome of non-pulmonary or sterile cause. A review of treatments for acute respiratory distress syndrome of any cause, based on six studies with a total of 574 patients, 19 concluded that insufficient evidence exists to recommend corticosteroid treatment. 20 Septic shock has been reported in seven (5%) of 140 patients with 2019-nCoV included in published reports as of Jan 29, 2020.3, 18 Corticosteroids are widely used in septic shock despite uncertainty over their efficacy. Most patients in septic shock trials have bacterial infection, leading to vasoplegic shock and myocardial insufficiency.21, 22 In this group, there is potential that net benefit might be derived from steroid treatment in severe shock.21, 22 However, shock in severe hypoxaemic respiratory failure is often a consequence of increased intrathoracic pressure (during invasive ventilation) impeding cardiac filling, and not vasoplegia. 23 In this context, steroid treatment is unlikely to provide a benefit. No clinical data exist to indicate that net benefit is derived from corticosteroids in the treatment of respiratory infection due to RSV, influenza, SARS-CoV, or MERS-CoV. The available observational data suggest increased mortality and secondary infection rates in influenza, impaired clearance of SARS-CoV and MERS-CoV, and complications of corticosteroid therapy in survivors. If it is present, the effect of steroids on mortality in those with septic shock is small, and is unlikely to be generalisable to shock in the context of severe respiratory failure due to 2019-nCoV. Overall, no unique reason exists to expect that patients with 2019-nCoV infection will benefit from corticosteroids, and they might be more likely to be harmed with such treatment. We conclude that corticosteroid treatment should not be used for the treatment of 2019-nCoV-induced lung injury or shock outside of a clinical trial.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Host cell proteases controlling virus pathogenicity.

              The majority of viral glycoproteins that undergo post-translational proteolysis are cleaved by ubiquitous intracellular proteases; however, a minority are cleaved by secreted proteases available only in a few host systems. The interplay of viral glycoproteins and cellular proteases may have a pivotal role in the spread of infection, host range and pathogenicity.
                Bookmark

                Author and article information

                Contributors
                Journal
                Ther Adv Infect Dis
                Ther Adv Infect Dis
                TAI
                sptai
                Therapeutic Advances in Infectious Disease
                SAGE Publications (Sage UK: London, England )
                2049-9361
                2049-937X
                10 June 2020
                Jan-Dec 2020
                : 7
                : 2049936120933076
                Affiliations
                [1-2049936120933076]Department of Medicine, University of Colorado, Anschutz Medical Center Aurora, CO, USA
                [2-2049936120933076]Department of Medicine, Division of Infectious Diseases, University of Colorado, Anschutz Medical Center, Aurora, CO, USA
                [3-2049936120933076]Department of Medicine, Division of Infectious Diseases, University of Colorado, Anschutz Medical Center, Aurora, CO, USA
                [4-2049936120933076]Department of Medicine, Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, 12700 E 19TH AVE, Mail Stop B168, Aurora, CO, USA
                [5-2049936120933076]Department of Medicine, Division of Infectious Diseases, University of Colorado, Anschutz Medical Center, Aurora, CO, USA
                [6-2049936120933076]Hospital Infantil de México, Federico Gomez, México, City, México
                [7-2049936120933076]Division of Infectious Diseases, Department of Medicine, University of Colorado, Anschutz Medical Center, Aurora, CO, USA
                Author notes
                Author information
                https://orcid.org/0000-0001-9405-5333
                https://orcid.org/0000-0001-7363-8652
                Article
                10.1177_2049936120933076
                10.1177/2049936120933076
                7288835
                e8910c9c-ede9-4615-abef-7e63e1c67e91
                © The Author(s), 2020

                This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License ( https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages ( https://us.sagepub.com/en-us/nam/open-access-at-sage).

                History
                : 10 April 2020
                : 19 May 2020
                Categories
                Commentary
                Custom metadata
                January-December 2020
                ts1

                severe acute respiratory syndrome coronavirus 2 (sars-cov-2),covid-19,serine proteases,covid-19 drug treatment

                Comments

                Comment on this article