Virus-host cell interaction in rat C6 glial cell cultures persistently infected with herpes simplex virus

The virus-host cell interaction in a rat C6 glial cell line persistently infected with herpes simplex virus type 1 (HSV1) was examined. The C6 cultures infected at an MOI of 10 or 0.01 exhibited virally induced cytopathology and produced infectious virus and viral antigens for 108 and 50 days, respectively. Infectious virus was continually present in the supernatant fluids of persistently infected cultures, with only a minority of the cells having viral CPE or viral antigens at any given time. There was no obvious pattern of periodic cyclical viral replication in these cultures; no predictable regularity in the fluctuations of virus production was evident. 'Cured' cultures were as susceptible to re-infection with HSV1 as previously uninfected cultures; thus, there was no selection of a subpopulation of C6 cells resistant to subsequent challenge with HSV1. The virus recovered from persistently infected cultures was more infectious for C6 cells relative to HeLa cells than was the original virus stock. Significant levels of interferon were not detected in HSV1-infected C6 cultures during either the acute or persistent phases of infection or in 'cured' cultures.