Induction of lytic plaques by murine leukemia virus in murine sarcoma virus-transformed nonproducer mouse cells persistently infected with mouse hepatitis virus MHV-S.

Kirsten murine sarcoma virus-transformed, nonproducer BALB3T3 (K-BALB) cells were persistently infected with mouse hepatitis virus, MHV-S. The cultures developed plaques after infection with murine leukemia viruses. If the murine leukemia virus-infected cultures were further submitted to the UV-XC assay, comparable numbers of XC plaques were obtained. The sensitivity to murine leukemia viruses, as determined by the UV-XC assay, was higher in MHV-S-infected cells as compared to uninfected K-BALB cells.