Relative Insensitivity of Spleen Cells to Interferon

Spleen cell cultures were markedly resistant to the antiviral effects of interferon. At least 500 times more interferon was required to inhibit vesicular stomatitis virus replication in such cultures as compared to L-929 cells. Inhibition of virus replication was found only when sufficient interferon was employed also to partially inhibit the incorporation of tritiated thymidine. The data suggest that the inhibition of virus replication was due to an inhibition of the stimulating effects of the mitogens on the cells as well as an inhibition of the low levels of thymidine incorporation in nonstimulated cells.