Transforming growth factor-beta inhibits the antiviral action of interferons in human embryonic fibroblasts.

Transforming growth factor-beta (TGF-beta) at concentration of 10 ng/ml inhibited the development of the interferon-alpha- (IFN-alpha) or IFN-gamma-induced antiviral state in quiescent human embryonic fibroblasts. The action of the cytokines was dose-related; TGF-beta had no direct effect on the replication of either vesicular stomatitis virus (VSV) or encephalomyocarditis virus (EMCV) used as the challenge viruses in the IFN assays. We suggest that despite the fact that TGF-beta acts mainly as a "negative" growth factor, its interactions with IFNs in the antiviral assays resemble known effects of the typical "positive" peptide growth factors.