Serum-Free Cultures of Mouse LM Fibroblasts as a Tool for Biochemical and Genetic Studies in the Cellular Responses to Interferon

LM cells continuously growing in the absence of serum and exogenous lipids have been used for studies on the mechanism of action of interferon (IFN). Several of its biological activities, namely the inhibition of virus and cell growth and the increased cytotoxicity to Poly(rI).Poly(rC) (=dsRNA), are shown to be increased in such conditions. None of these three effects of IFN depends on an active prostaglandin biosynthesis, as previously proposed, since cells in our conditions are lacking the necessary precursors.