Immune-evasive interferon

As previously mentioned, interferons are cytokines produced by cells to protect them from viral infection, and anti-interferon strategies are a part of the immune evasion repertoire of most viruses. These mechanisms include the production of soluble versions of interferon receptors, which act as decoys. These decoys bind and inactivate interferons before they reach their destination - normal, membrane-bound receptors.22... 

Myxomatosis is associated with general immunosuppression of the host and thus MV was a prime candidate to encode immune evasion molecules. Initial work identified the MV M-T7 gene encoding a 37 kDa glycoprotein that is abundantly secreted from infected cells. The M-T7 ORF showed significant similarity to the extracellular binding domain of human and mouse interferon-y receptors (IFN-yRs), and was shown to bind to and inhibit the biological activity of rabbit IFN-y in a species specific manner. ... 

Interferon was first described by Isaacs and Lindenmann as a soluble factor that interfered with viral replication in cultured cells (Isaacs and Lindenmann 1957). A large body of work has now shown that the IFNs are a family of soluble proteins that serve to mediate antiviral effects, to regulate cell growth, and to modulate the activation of immune responses. The innate antiviral activities of IFNs are exceedingly potent and rapid. It is, therefore, not surprising that so many viruses have evolved ways to either preclude the synthesis of IFNs or evade downstream antiviral events. Such evasion allows for the virus to spread before the development of a specific adaptive immune response and likely represents a pivotal determinant of virulence for the invading virus. 

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