Autoimmune T cells: immune recognition of normal and variant peptide epitopes and peptide-based therapy.

Experimental autoimmune encephalomyelitis (EAE) results from T helper (TH) cell recognition of myelin basic protein (MBP). We have characterized TH cell reactivity in B10.PL and PL/J (H-2u) mice to 39 N-terminal MBP peptide derivatives of different lengths and with individual amino acid substitutions. The peptide determinant of murine MBP can be divided into a minimal stimulatory core region (residues 1-6) and a tail region (residues 7-20) that alters the structure of the core region to affect both T cell recognition and MHC binding. Core recognition by B10.PL and PL/J mice is highly similar but in one case strain dependent. Peptide analogs that do not stimulate MBP-specific TH cells but bind to the I-Au molecule competitively inhibit T cell reactivity to MBP in vitro and prevent the induction of EAE in vivo.