The neuroimmunology of multiple sclerosis: Possible roles of T and B lymphocytes in immunopathogenesis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous s ystem white matter. The association of the disease with MHC genes, the infl ammatory white matter infiltrates, similarities with animal models, and the observation that MS can be treated with immunomodulatory and immunosuppres sive therapies support the hypothesis that autoimmunity plays a major role in the disease pathology. Evidence supports activated CD4(+) myelin-reactiv e T cells as major mediators of the disease, in addition, a renewed interes t in the possible contribution of B cells to MS immunopathology has been sp arked by nonhuman primate and MS pathological studies. This review focuses on the immunopathology of MS, outlining the hypothetical steps of tolerance breakdown and the molecules that play a role in the migration of autoreact ive cells to the CNS. Particular focus is given to autoreactive T cells and cytokines as well as B cells and autoantibodies and their role in CNS path ogenesis in MS.