Posttranscriptional regulation of beta interferon expression in erythroid friend cells treated with gamma interferon

Treatment of Friend erythroleukemia cells (FLC) with gamma interferon (IFN-γ) in the presence of anti-IFN-β antibodies reduces the effectiveness of the antiviral state and the induction of 2′-5′-oligoadenylate synthetase activity, indicating that the antiviral activity of IFN-γ in FLC is in part mediated by the production of IFN-β. Accordingly, IFN-γ induces a less pronounced antiviral state in FLC resistant to IFN-α/β than in wild-type cells. Moreover, while results of run-on assays indicate that both IFN-α and -β genes are constitutively transcribed in these cells, FLC treatment with IFN-γ induces only IFN-β mRNA accumulation. These results indicate that posttranscriptional mechanisms are involved in the regulation of IFN-β and -α expression by IFN-γ. The low amounts of the induced IFN-β synergize with IFN-γ in mounting the potent antiviral effect.