Interferon-induced proteins and their mechanisms of action.

Interferons modulate a number of biological functions including cell growth and differentiation, the immune response, and virus replication. The antiviral activity of interferons (IFNs), the property that led to their discovery, is mediated by multiple cellular proteins. Among the IFN-induced cellular proteins with antiviral activity are the protein kinase PKR, the enzymes of the 2', 5'-oligoadenylate pathway, and the Mx proteins. The antiviral activities of these proteins differ significantly against viruses of the myxoviridae, rhabdoviridae, and picornaviridae virus families.