Interferon-mediated increased lysis of L-cells by vesicular stomatitis virus

Abstract

L-929 cells have been cultivated for more than 6 months in the presence of interferon. These L-cells, referred to as L-int cells, were found to be more susceptible to the lytic properties of vesicular stomatitis virus (VSV) than normal L-929 cells. This phenomenon has been demonstrated by the production of clear plaques as opposed to cloudy plaques as well as the increased release of cell incorporated ³H-thymidine after VSV infection. The L-int cells were also signicantly more susceptible than L-929 cells to the cytotoxic properties of DEAE-dextran, protamine sulfate, and methylated albumin.This interferon-induced change to L-cells is not stable. Increased susceptibility to VSV lysis is lost after 4–6 cell generations in the absence of interferon, and increased susceptibility to DEAE-dextran is lost after 16–24 cell generations in the absence of interferon. Moreover, the increased sensitivity to VSV lysis and polycation cytotoxicity can be induced after overnight treatment of L-929 cells with interferon.