Roles of Prion Protein in Virus Infections

The normal cellular prion protein, designated PrPC, is a membrane glycoprotein expressed most abundantly in brains, particularly by neurons, and to a lesser extent in non-neuronal tissues including lungs. Conformational conversion of PrPC into the amyloidogenic isoform is a key pathogenic event in prion diseases. We recently found that PrPC has a protective role against infection with influenza A viruses (IAVs) in mice by reducing reactive oxygen species in the lungs after infection with IAVs. The antioxidative activity of PrPC is probably attributable to its function to activate antioxidative enzyme Cu/Zn-superoxide dismutase, or SOD1, through regulating Cu content in lungs infected with IAVs. Oxidative stress could play a pivotal role in the pathogenesis of a wide range of viral infections. Here, we introduce our and others' studies on the role of PrPC in viral infections, and raise the attractive possibility that PrPC might be a novel target molecule for development of antioxidative therapeutics against not only IAV infection but also other viral infections.