Differential expression of cellular prion protein (PrP) in mouse hepatitis virus induced neuroinflammation.

The cellular prion protein (PrP) is an extracellular cell membrane protein. Due to its diversified roles, a definite role of PrP has been difficult to establish. During viral infection, PrP has been reported to play a pleiotropic role. Here, we have attempted to envision the function of PrP in the neurotropic m-CoV-MHV-RSA59-induced model of neuroinflammation in C57BL/6 mice. A significant upregulation of PrP at protein and mRNA levels was evident in infected mouse brains during the acute phase of neuroinflammation. Furthermore, investigation of the effect of MHV-RSA59 infection on PrP expression in specific neuronal, microglial, and astrocytoma cell lines, revealed a differential expression of prion protein during neuroinflammation. Additionally, siRNA-mediated downregulation of prnp transcripts reduced the expression of viral antigen and viral infectivity in these cell lines. Cumulatively, our results suggest that PrP expression significantly increases during acute MHV-RSA59 infection and that PrP also assists in viral infectivity and viral replication.