Characterization and Specificity of Humoral Immune Responses to Theiler's Murine Encephalomyelitis Virus Capsid Proteins

Humoral antibody responses to Theiler's murine encephalomyelitis v rus (TMEV) capsid proteins were examined. Rabbit antisera produced against he native BeAn strain of TMEV and against he isolated capsid proteins (VP1, VP2 and VP3) were tested for their ability to bind or neutralize virus and to inhibit the virus-induced haemagglutination f human O + erythrocytes. Western immunoblotting analysis showed that isolated VP1, VP2 and VP3 each primed for a specific antibody response, but that native virions primed for antibodies pecific for VP1 and VP2, but not VP3. Virus neutralization studies revealed that a dominant TMEV neutralizing deter-minant(s) lay on VP 1, as did the haemagglutinating determinant. The possible location of the neutralizing epitopes are discussed on the basis of molecular modelling of the predicted amino acid sequence of TMEV from that of the closely related Mengo virus for which the three-dimensional structure is known. The Theiler's murine encephalomyelitis v ruses (TMEV) are members of the cardiovirus group of the picornavirus family (Pevear et al., 1987). Following intracerebral inoculation, certain mouse strains develop a chronic, inflammatory demyelinating disorder of the centra