The Effects of some Different Metabolic Inhibitors on Interferon Superinduction

Three different inhibitors of RNA synthesis, actinomycin, ~-amanitin and camptothecin, and five different inhibitors of protein synthesis were able to superinduce interferon production in human diploid fibroblasts treated with poly(rI), poly(rC). Camptothecin was shown to be a reversible inhibitor of virus induced inter-feron formation. It also substantially reduced the interferon yield from human diploid fibroblasts which had been superinduced with actinomycin D and cyclo-heximide. This suggests that the previously reported failure of camptothecin to inhibit interferon production in human diploid cells after induction with poly(rI).poly(rC) is the result of two mutually opposing effects: a marked in-hibition of interferon messenger RNA synthesis, but a stimulation of the activity of the interferon messenger RNA that is formed