INDUCTION OF EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS BY CD4(-CELLS SPECIFIC FOR AN ASTROCYTE PROTEIN, S100-BETA() T)

S100 beta protein ia a calcium binding protein that is not only expres sed by astrocytes in the CNS, but also in many other tissues including the eye, thymus, spleen and lymph nodes. Despite this tissue distribu tion, which was expected to induce a firm state of self-tolerance to S 100 beta, the Lewis rat mounts a strong T cell response to this autoan tigen. The pathogenicity of this T cell response was demonstrated by t he adoptive transfer of S100 beta-specific T cells which induced an in flammatory response in the CNS and eye of naive syngeneic recipients. The distribution of lesions in this novel model of EAE resembles that seen in some patients with MS, suggesting that the initial autoimmune insult in MS may be directed against a non-myelin antigen coexpressed in the CNS and extra-neural tissues.