Herpes simplex virus persistence in mouse neuroblastoma (C 1300) cell cultures: role of interferon.

The Mp strain of herpes simplex virus type 1 (HSV1) induced a persistent infection in the mouse C 1300 neuronal cell line (clone N 115). C 1300 cultures infected at an MOI of 0.01 or 0.001 survived the initial infection and continued to produce infectious virus and viral antigens for 185 days and 31 days, respectively. Viral antigens were not detected in cultures no longer producing infectious virus; these "cured" cultures had comparable susceptibility to reinfection with HSV as previously uninfected C 1300 cells. While significant amounts of interferon were produced by C 1300 cells when challenged with Newcastle Disease Virus (NDV) or when treated with poly I:C, HSV-induced interferon could not be detected in either the acutely or persistently infected cell lines. The persistent state was not significantly altered by the addition of 1,000 units/ml of murine interferon alpha plus beta (MuIFN alpha + beta), nor was it affected by the addition of antibody to MuIFN. It appears that IFN does not play an important role in the establishment and/or maintenance of viral persistence in this neuronal system.