Tolerance controls encephalitogenicity of αB-crystallin in the Lewis rat

The myelin-associated protein, αB-crystallin, is considered a candidate autoantigen in multiple sclerosis (MS). In the present study, we examined the potential of αB-crystallin to induce experimental autoimmune encephalomyelitis (EAE) in Lewis rats. Attempts to induce EAE with either bovine, rat or murine αB-crystallin or αB-crystallin peptides consistently failed. Immunization with either autologous rat or murine αB-crystallin did not trigger any antigen-specific T cell response. Immunization with bovine αB-crystallin or a synthetic peptide representing the cryptic epitope 49-64 did trigger T cell responses but these failed to crossreact with autologous rat αB-crystallin. Examination of lymphoid tissues of the Lewis rat revealed constitutive expression of αB-crystallin in thymus, spleen, and peripheral lymphocytes. Our data show that in Lewis rats, constitutive lymphoid expression of αB-crystallin is associated with a state of nonresponsiveness to autologous αB-crystallin that effectively controls the development of EAE in response to this myelin antigen. Copyright (C) 2000 Elsevier Science B.V. Chemicals/CAS: Autoantigens; Crystallins; Immunodominant Epitopes; Peptide Fragments; RNA, Messenger