Experimental allergic encephalomyelitis(EAE) is an induced autoimmune disease mediated by CD4+ T lymphocytes. Analysis of T cell receptors of myelin basic protein-specific encephalitogenic T cell clones derived from six different PLN (H-2”) or (PL/J x SJL) Fl (H-2Uxs) mice revealed a limited heterogeneity in primary structure. In vivo, the majority of T lymphocytes recognize the N-terminal MBP-nonapeptide in association with I-AU and utilize the VB8 gene element. cDNA-sequencing showed that all T cell receptors from a panel of such T cell clones, grown in vitro, share the same V, gene segment. Despite heterogeneity in the DJ regions, the clones unexpectedly display a striking similarity in fine specificity, Based on these results, prevention and reversal of autoimmune disease with VB8-specific monoclonal antibodies was achieved.