Identification of I-A beta-chain residues critical for T cell recognition of peptide antigens.
Major histocompatibility complex (MHC)-restricted recognition of antigen by T lymphocytes involves the formation of a complex composed of the T cell receptor, antigen, and restricting MHC molecule. To elucidate the interactions occurring within the antigen recognition complex, we have evaluated the ability of a panel of cell lines expressing mutated I-Ak molecules to function in the recognition by T hybridoma cells of two distinct peptide antigens. Our results indicate that while alterations along the entire length of the proposed helical structure in the carboxyterminal half of the beta 1 domain interfere with the I-Ak-restricted recognition of human fibrinopeptide B, mutations which affect recognition of hen egg lysozyme/I-Ak fall almost exclusively in the central portion of the helix. On the basis of these and previous results, we propose a "T cell receptor-mediated peptide exchange model" for formation of the antigen recognition complex.
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Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor 48109.
McKean
D J
DJ
Thomas
D W
DW
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D005345:Fibrinopeptide B / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D008969:Molecular Sequence Data; D009113:Muramidase / Q000276:immunology; D009154:Mutation; D010455:Peptides / Q000032:analysis / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology; D014162:Transfection
D000949:Histocompatibility Antigens Class II; D010455:Peptides; D011948:Receptors, Antigen, T-Cell; D005345:Fibrinopeptide B; D009113:Muramidase