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Viruses have been found to induce inflammatory demyelinating lesions in central nervous system (CNS) tissue of both animal and man, either by natural infections or after vaccination. At least two different pathogenic mechanisms have been proposed for these changes, a cytopathic viral infection of oligodendroglia cells with subsequent cell death, and a host immune reaction against virus and brain antigens. We now report the occurrence of cell-mediated immune reactions against basic myelin proteins in the course of coronavirus infections in Lewis rats. Infection of rats with the murine coronavirus JHM leads to demyelinating encephalomyelitis developing several weeks to months postinfection. Lymphocytes from these diseased Lewis rats can be restimulated with basic myelin protein (BMP) and adoptive transfer of these cells leads to lesions resembling those of experimental allergic encephalomyelitis (EAE) in recipients, which can be accompanied by a mild clinical disease. This model demonstrates that a virus infection in CNS tissue is capable of initiating an autoimmune response which may be of pathogenic importance.

SUMMARYCoronavirus JHM contained six major proteins, four of which were glycosylated. The proteins were gpl70, gp98, gp65, p60, gp25 and p23. Sac(-) cells infected with JHM shut off host cell protein synthesis, and the synthesis of three major (150K, 60K and 23K) and three minor (65K, 30K and 14K) polypeptides was detected by pulse-labelling with aSS-methionine. Antiserum directed against purified virus proteins specifically immunoprecipitated the three major intracellular species and also the 65K minor species. During a chase period, species 150K and 23K were processed and three new immunoprecipitable species, 170K, 98K and 25K appeared. The intracellular species 170K, 98K, 65K, 60K, 25K and 23K co-electrophoresed with virion proteins.Two-dimensional gel electrophoresis of infected cell polypeptides showed that the 60K, 23K, 25K and 14K species were relatively basic polypeptides whilst the 98K and 170K were relatively acidic and heterogeneously charged polypeptides. Additionally, a charge-size modification of the 23K species during processing was detected, which was not apparent using one-dimensional gel analysis.