Alternative peptide repertoire of HLA-E reveals a binding motif that is strikingly similar to HLA-A2.

Autor: Lampen MH; Department of Clinical Oncology, Leiden University Medical Center, The Netherlands., Hassan C, Sluijter M, Geluk A, Dijkman K, Tjon JM, de Ru AH, van der Burg SH, van Veelen PA, van Hall T
Jazyk: angličtina
Zdroj: Molecular immunology [Mol Immunol] 2013 Jan; Vol. 53 (1-2), pp. 126-31. Date of Electronic Publication: 2012 Aug 13.
DOI: 10.1016/j.molimm.2012.07.009
Abstrakt: The non-classical HLA-E is a conserved class I molecule that mainly presents monomorphic leader peptides derived from other HLA class I molecules. These leader peptides comprise an optimized sequence for tight and deep binding into the HLA-E groove. In a TAP-deficient environment, as it can be generated during viral infection or in tumor tissue, loading of the classical leader peptide sequences is hampered leading to an alternative HLA-E peptide repertoire. In this study, we characterized this alternative peptide repertoire using cells in which TAP activity is inhibited. We identified more than 500 unique peptide sequences carried by HLA-E and found that their binding motif is different from the dominant leader peptides. Hydrophobic amino acids were only found at positions 2 and 9, in close resemblance to the peptide binding motif of HLA-A*0201. HLA-E-eluted peptides were indeed able to bind this classical HLA class I molecule. Our findings suggest that the dominant leader peptides uniquely conform to HLA-E, but that in their absence a peptide pool is presented like that of HLA-A*0201.
(Copyright © 2012 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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