On the complexity of self.
Self peptides bound to self major histocompatibility complex (MHC) molecules have been implicated both in positive and in negative selection of T cells during intrathymic development. We report here that the novel MHC-restricted monoclonal antibody Y-Ae detects the MHC class II bound form of a major self peptide. Y-Ae binds approximately 12% of the relevant MHC class II molecules on self antigen presenting cells. The peptide detected by Y-Ae is one of several major peptides eluted from the MHC molecule. These data suggest that self peptides presented by self MHC class II molecules at densities sufficient to signal a CD4 T cell are of very limited complexity. Furthermore, as Y-Ae stains antigen presenting cells that mediate negative selection but not thymic cortical epithelial cells that drive positive selection, differential expression of self peptide:self MHC class II complexes may be a key feature of intrathymic selection.
Rudensky AYu
Section of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510.
Rath
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S
Preston-Hurlburt
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Murphy
D B
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Janeway
C A
CA
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000938:Antigen-Presenting Cells / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015153:Blotting, Western; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007108:Immune Tolerance; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D000911:Antibodies, Monoclonal; D001324:Autoantigens; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D010446:Peptide Fragments