The immunopathogenesis of MS is discussed in the light of data recently obtained in Experimental Autoimmune Encephalomyelitis (EAE), a myelin specific experimental autoimmune disease reflecting the first, inflammatory phase of MS plaque generation. EAE is caused by CD4+ T cells specific for defined myelin protein, like MBP and PLP. In rats and mice there is a marked dominance of the autoantigenic peptide epitopes on the one hand, and the T cell receptor V regions on the other. During T cell mediated EAE, clonotypically counterregulatory CD8+ T cells are induced, which specifically neutralize the encephalitogenic T clones.