Amplification of herpes simplex virus resistance in mouse neuroblastoma (Cl300) cells.

Clones of mouse neuroblastoma (Cl300) cells with increased resistance to herpes simplex virus (HSV) were obtained among survivors after prolonged exposure of partially HSV resistent Cl300 cells to successively increasing multiplicities of infection (MOI) of HSV. The increased restrictedness to HSV of these Cl300 R clones (Cl300 RI and Cl300 RII) as compared to the parental Cl300 cells was demonstrated by a tolerance to higher MOIs of HSV, judged by the appearance of cytopathic effects; by lower yields of progeny virus; and by higher activities of a non-interferon HSV inhibitor. Morphological appearance, cellular growth rate as well as HSV adsorptive capacity of the Cl300 R cells did not differ from that of Cl300 cells. Neither was virus penetration affected. These neuroblastoma Cl300 R cells, demonstrating an amplified resistance to HSV, might serve useful in studies on the regulation of virus replication in HSV latency establishment in neurons.