Immunoglobulins reactive with myelin basic protein promote CNS remyelination

We tested the hypothesis that immunoglobulins directed against a CNS autoantigen, myelin basic protein, may promote remyelination in the course of a chronic, immune-mediated demyelinating disease. SJL/J mice infected chronically with Daniel's strain of Theiler's virus served as an experimental model of MS. The spinal cords of these mice exhibit extensive primary demyelination and inflammation with minimal spontaneous remyelination. Treatment with whole antiserum or affinity-purified mouse immunoglobulins directed against rat or rabbit myelin basic protein increased new myelin synthesis as measured by quantitative morphometry. Electron microscopy revealed numerous oligodendrocytes in remyelinated CNS lesions and a relative lack of inflammatory cells. Viral antigen persisted in the spinal cord despite enhanced CNS-type remyelination. These findings indicate that immunoglobulins reactive with myelin autoantigens have the potential to promote myelin repair.