Overlap in the repertoires of peptides bound in vivo by a group of related class I HLA-B allotypes

摘要: Abstract Background: Polymorphism among class I molecules of the major histocompatibility complex (MHC) confers allotypic specificity on peptides that these bind and present to cytotoxic T lymphocytes. Evolution new human HLA alleles usually involves gene recombination events replace a segment one allele with homologous region another. In this study, impact evolutionary changes has been assessed by comparison peptide-binding specificities six related HLA-B allotypes. Results Endogenous bound ∗ 5401, 5501, 5502, 5601, 6701 0702 were characterized. Despite differing 1–9 amino-acid residues comprising their sites, all allotypes share dominant preference for have proline at position 2. results in selection carboxy-terminal secondary anchor residues, but are sufficiently similar there is overlap repertoires Complete sequence determination individual revealed four could be isolated from two or more Members closely HLA-B22 family — 5502 5601 show only minor differences specificities. This marked similarity reflected functional level, as alloreactive lymphocytes generated against 5401 5501 exhibited cross-reactive recognition. Conclusion The isolation identical endogenously demonstrates vivo different We speculate shared binding 2 reflects selective pressure retain specificity, which may based upon peptide availability vivo. Characterization between simplify development peptide-based vaccines targeted cells, single would effective humans types.