HETEROGENEITY OF RAT ENCEPHALITOGENIC T-CELLS ELICITED BY VARIANTS OFTHE MYELIN BASIC-PROTEIN (68-86) PEPTIDE

By immunizing Lewis rats with myelin basic protein (MBP) peptide varia nts derived from the major encephalitogenic epitope of guinea pig (MBP (68-88) and then isolating encephalitogenic T cells from these animals , we demonstrated that the variant peptides do not elicit the same enc ephalitogenic T cell subsets as those induced by the wild-type peptide or by intact MBP Rather, the pathogenic T cells differed in clonal co mposition as reflected by their heterogeneous responses to a panel of variant peptides and by their T cell receptor usage. Thus, molecules m imicking the MBP(68-88) autoantigen can elicit pathogenic T cell subse ts without necessarily cross-reacting with T cells specific for the or iginal autoantigen. This suggests that a more clonally diverse group o f pathogenic T cells might be involved in EAE than has been apparent f rom studies with intact MBP or its unaltered peptides.