Scientists have characterized the MHC- and TCR-binding residues of
myelin oligodendrocyte glycoprotein 38-51 peptide
April 9, 2004
"Myelin oligodendrocyte glycoprotein (MOG) is a major experimental autoimmune encephalomyelitis (EAE) antigen in H-2b mice and a potential autoantigen in multiple sclerosis. How well MOG peptides bind to MHC and how TCR recognize the peptide/MHC complex have important implications for thymic selection as well as T cell activation in the periphery. In this study, we have characterized amino acids in the MOG38-51 peptide important for peptide binding to I-Ab, and for TCR recognition of the peptide/MHC complex," researchers in New Zealand and the United States report.
"We found that the amino acids R41, F44, R46 and V47 constituted the major TCR contact residues, as alanine substitution at these positions abrogated T cell responses without decreasing their binding affinity to I-Ab," stated Troels R. Petersen and collaborators at the Malaghan Institute of Medical Research in New Zealand and Harvard University and the La Jolla Institute for Allergy and Immunology in the U.S. "In addition, G38 and W39 were found to be minor TCR contact residues. Finally, substituting tyrosine for alanine at position 40 decreased binding to I-Ab by approximately 50% and prevented induction of T cell responses in C57BL/6J mice upon immunization."
"Thus, Y40 is the dominant MHC-binding residue of the MOG38-51 peptide and most likely occupies the p1 pocket of I-Ab," concluded the researchers. "Our results could be useful to design peptides with altered agretopes and epitopes of the MOG38-51 peptide to study their therapeutic potential in the EAE model."
Petersen and associates published their study in the European Journal of Immunology (Characterization of MHC- and TCR-binding residues of the myelin oligodendrocyte glycoprotein 38-51 peptide. Eur J Immunol, 2004;34(1):165-173).
The information in this article comes under the major subject areas
of Multiple Sclerosis, Autoimmmune Disease, Autoimmune Encephalomyelitis,
Proteomics, Neurology, and Neuroscience.
Copyright © 2004, Drug Week