Neurotropic influenza A virus infection causes prion protein misfolding into infectious prions in neuroblastoma cells

Misfolding of the cellular prion protein, PrP C , into the amyloidogenic isoform, PrP Sc , which forms infectious protein aggregates, the so-called prions, is a key pathogenic event in prion diseases. No pathogens other than prions have been identified to induce misfolding of PrP C into PrP Sc and propagate infectious prions in infected cells. Here, we found that infection with a neurotropic influenza A virus strain (IAV/WSN) caused misfolding of PrP C into PrP Sc and generated infectious prions in mouse neuroblastoma cells through a hit-and-run mechanism. The structural and biochemical characteristics of IAV/WSN-induced PrP Sc were different from those of RML and 22L laboratory prions-evoked PrP Sc , and the pathogenicity of IAV/WSN-induced prions were also different from that of RML and 22L prions, suggesting IAV/WSN-specific formation of PrP Sc and infectious prions. Our current results may open a new avenue for the role of viral infection in misfolding of PrP C into PrP Sc and formation of infectious prions.