Antigen-induced inhibition of experimental allergic encephalomyelitis. III. Localization of an inhibitory site distinct from the major encephalitogenic determinant of myelin basic protein.

Defined peptide fragments were isolated from the N-terminal half of the myelin basic protein (BP) molecule and employed for antigen-induced inhibition of experimental allergic encephalomyelitis (EAE). Guinea pigs pretreated with peptide 44-89, obtained by limited pepsin digestion and purified by column chromatography, were significantly protected against EAE subsequently induced by sensitization with BP in complete Fruend's adjuvant. Peptide 1-20, derived by cyanogen bromide cleavage, did not inhibit EAE, nor did the synthetic EAE peptide (residues 114-122), although this peptide was only weakly encephalitogenic for guinea pigs. These findings directly support our previous conclusion that different sites on the BP molecule are responsible for induction and inhibition of EAE, and suggest that disease inhibition can be attributed, at least in part, to a site within peptide 44-89.