PRNP and infection: Second, PrP expression is upregulated in vitro by infection with adenovirus 5 [156, 157], Epstein–Barr virus (EBV) [158], hepatitis C virus [159, 160], HIV-1 [161], Helicobacter pylori [162], and Mycobacterium bovis [163], as well as by murine leukemia virus (MuLV) and vesicular stomatitis virus [164].