Immunologic Properties of the Main Encephalitogenic Peptide from the Basic Protein of Human Myelin

Abstract

The encephalitogenic basic protein from human brain was digested with pepsin and encephalitogenic peptides were isolated. Two overlapping peptides containing 15 and 22 amino acids had similar encephalitogenicity as the parent protein. Both peptides induced delayed hypersensitivity to the protein but no detectable circulating antibody in guinea pigs. There was a striking correlation between the occurrence of experimental autoimmune encephalomyelitis and low yields of peritoneal exudate cells. The main encephalitogenic determinant resides within the sequence Ser-Arg-Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-. We postulate that the integrity of this region of the basic protein of myelin is vital to the normal functioning of the central nervous system. These small peptides should be of value in investigating the role of delayed hypersensitivity in autoimmune disease.