Coronavirus induction of class I major histocompatibility complex expression in murine astrocytes is virus strain specific

M ouse hepatitis viruses (MHV) 1 are members of the Coronaviridae, which cause gastrointestinal, neurological, and respiratory diseases in a wide variety of mammalian species (1) (2) (3) (4) (5) (6) (7) . Although some MHV strains, such as A59 and MHV-3, can cause both gastrointestinal and neurological disease in mice and rats, many tend to induce pathology that is restricted to either system, prompting their classification as hepatotropic or neurotropic. There has been considerable interest in the study of the more neurotropic strains of MHV, such as JHMV and A59, because of their ability to produce demyelinating lesions that resemble the demyelinating plaques observed in the human neurological disease, multiple sclerosis (MS). In addition, MHV and human coronavirus iso- 1013 lates are capable of inducing demyelination in primates (8) , and coronavirus RNA and antigen have been detected in demyelinating lesions in the brains of MS patients (9, 10) .