Viral inhibition of interferon signal transduction.

The type I and II interferons (IFNs) are potent stimulators of antigen processing and presentation and are essential in antiviral immunity. IFNs upregulate the transcription of major histocompatibility complex (MHC) class I and II molecules, associated antigen-processing proteins, and induce the production of direct antiviral effector molecules such as 2',5'-oligoadenylate synthetase, double-stranded-RNA-dependent protein kinase and Mx proteins. It is increasingly evident that viruses have evolved mechanisms to globally inhibit the actions of IFNs through disruption of their signal transduction pathways. Herein, we review the ability and novel mechanisms of several diverse viruses to inhibit IFN-induced JAK/STAT signal transduction. Copyright 2000 S. Karger AG, Basel