Microbial peptides and superantigens in the pathogenesis of autoimmune diseases of the central nervous system.

The mechanisms by which microbial peptide antigens and superantigens might initiate and perpetuate autoimmune responses against antigens of the central nervous system are discussed. A model will be proposed that includes the initial activation of naive T lymphocytes through T cell receptor-mediated recognition of microbial antigens presented by MHC class II molecules. This event might be followed by re-activation of autoreactive T cells by bacterial and viral superantigens. Both mechanisms could lead to acute and relapsing autoimmune disease.