IMMUNOLOGY OF THEILERS-MURINE-ENCEPHALOMYELITIS-VIRUS-INFECTION

Theiler's murine encephalomyelitis virus (TMEV) is a single-stranded R NA virus that belongs to the family of picornaviruses. Intracranial in oculation of susceptible mouse strains with TMEV results in biphasic d isease, consisting of early acute disease that resembles poliomyelitis , followed by late chronic demyelinating disease that is characterized by the appearance of chronic inflammatory demyelinating lesions. Susc eptibility to TMEV infection is genetically controlled by three loci: one that maps to the H-2D region of the major histocompatibility compl ex, one to the beta-chain constant region of the T-cell antigen recept or, and one located on chromosome 3. Both early acute and chronic late demyelinating diseases are immunologically mediated. T cells appear t o play an important role in the pathogenesis of the disease. TMEV-indu ced demyelinating disease in mice has extensive similarities with mult iple sclerosis, and it is considered one of the best experimental anim al models for multiple sclerosis.