Differential Sensitivity of Rauscher Murine Leukaemia Virus (MuLV-R) to Interferons in Two Interferon-Responsive Cell Lines

Abstract
The effect of interferon on the replication of vesicular stomatitis virus (VSV) and type-C oncornavirus in 2 Balb/c mouse cell lines, JLS-V5 [derived from embryo thymus and bone marrow cells] and JLS-V9R, infected with MuLV-R was examined. VSV replication was inhibited 3-fold (0.5 log10) in both cell lines by 10-20 units of interferon/ml. In JLS-V5 cells, C-type virus yields, as measured by 3H-uridine incorporation and reverse transcriptase activity, were also reduced 3-fold by 10-20 units of interferon/ml. In JLS-V9R cells, C-type virus replication was refractory to interferon at concentrations up to 1 .times. 104 units/ml. Infectious C-type virus transmitted from JLS-V9R cells to Balb/3T3 cells was as sensitive to interferon as virus transmitted from JLS-V5 cells, indicating that resistance of C-type virus in JLS-V9R cells is a feature of the cells rather than of the virus strain.