Encoding of a homolog of the IFN-gamma receptor by myxoma virus.

Many poxvirus-encoded virulence factors have been identified as proteins that are secreted from infected cells. The major secreted protein (37 kilodaltons) from cells infected with myxoma virus is encoded by the M-T7 open reading frame. This protein has significant sequence similarity to the human and mouse receptors for interferon-gamma (IFN-gamma). Furthermore, the myxoma M-T7 protein specifically binds rabbit IFN-gamma and inhibits the biological activity of extracellular IFN-gamma, one of the key regulatory cytokines in the host immune response against viral infections.