Long double stranded RNA is present in scrapie infected cells and tissues

Despite decades of research efforts, the nature of the infectious agent causing scrapie and other Transmissible Spongiform Encephalopathies (TSE) remains an enigma. The protein-only prion hypothesis posits that an abnormal conformer of a host protein is the infectious agent. Virus and virino theories include host-independent nucleic acids in the genome of the infectious agent, in addition to the protein component (a host protein in the case of virino, and a viral protein in the case of a virus). Viral or sub-viral nucleic acids have long been sought in scrapie to explain the existence of multiple agent strains. Despite a plethora of different approaches to the search, no scrapie-specific nucleic acid sequences have been found in infected cells or tissues. Most viruses induce synthesis of long double stranded RNA (dsRNA) during their replication in cells, and thus the presence of long dsRNA would be an indication of viral infection in cells. J2 monoclonal antibody against long dsRNA is a useful tool for easy screening of cells and tissues for the presence of suspected viral infection; however, this antibody has not previously been used for testing of scrapie infected tissues. Here, we present evidence for long dsRNA in scrapie infected cells and tissues. Such dsRNA is also found in scrapie free tissue culture cells. We believe this may be the first evidence of viral infection in scrapie susceptible and infected cells.