Action of murine gamma (immune)interferon on beta (fibroblast)-interferon resistant L 1210 and embryonal carcinoma cells.

Treatment of leukaemic mouse L 1210 S cells with beta or gamma interferon results in the development of antiviral and anticellular effects, both of which are also induced by interferon in L 1210 R cells selected for their resistance to gamma-interferon. Here we show that treatment of L 1210 S cells with beta or gamma interferon results in the induction of two double-stranded (ds) RNA dependent enzymes which have been described previously in beta and gamma-interferon treated mouse L-929 cells: pppA (2'p5'A)n synthetase and protein kinase(s). Treatment of L 1210 R cells with beta-interferon does not result in the induction of any detectable enhanced pppA (2'p5'A)n synthetase and protein kinase activities whereas gamma-interferon is capable of inducing both of these enzymes. These results indicate that although beta and gamma-interferon induce similar intracellular events, they may have different mechanism of interaction with their target cells. In addition, here we show that similar to the action of beta-interferon, treatment of mouse embryonal carcinoma cells with gamma-interferon results in the induction of pppA (2'p5'A)n synthetase in the absence of any detectable protein kinase activity or any apparent development of antiviral and anti-cellular effects. The significance of this in relation to the mechanism of action of interferon is discussed.