Differentially expressed genes during spontaneous lytic switch of Marek's disease virus in lymphoblastoid cell lines determined by global gene expression profiling

Eight members of the Herpesviridae family commonly infect humans, and close to 100% of the adult population is infected with at least one of these. The five that cause the most health concerns are: herpes simplex virus (HSV) type 1 and 2, Epstein–Barr virus (EBV), cytomegalovirus (CMV), and varicella zoster virus (VZV). In addition, there are human herpes virus (HHV) types 6–8. The review starts by introducing possible viral strategies in general. The particular biology and host relationship of the various human herpesviruses, including their pathology, are examined subsequently. Factors that contribute to the maintenance of latency and reactivation of viral replication are discussed. There will be special reference to how these viruses exploit and contribute to pathology in the oral cavity. Reactivation does not necessarily imply clinical symptoms, as reflected in the asymptomatic shedding of EBV and CMV from oral mucosa. The immune response and the level of viral output are both important to the consequences experienced.

A virus was isolated from the peripheral blood lymphocytes of patients with exanthem subitum, cultured successfully in cord blood lymphocytes, and shown to be antigenically related to human herpesvirus-6 (HHV-6). Morphological features, as studied by thin-section electronmicroscopy, resembled those of herpes group viruses. Convalescent-phase serum samples, tested against the new viral antigen and HHV-6 antigen, showed seroconversion. The results strongly suggest that the newly isolated virus is identical or closely related to HHV-6 and the causal agent for exanthem subitum.