Nonclassical HLA-G molecules are classical peptide presenters.

摘要: Abstract Background: The physiological functions of the classical HLA (human leukocyte antigen) molecules, HLA-A, HLA-B and HLA-C, are to present peptides T cells inhibit activity natural killer cells. In contrast, nonclassical HLA-molecules, such as HLA-E, HLA-F HLA-G, remain be established. expression HLA-G is largely limited placental trophoblast, where it might mediate protection fetus from rejection by mother. Achieving aim understanding function should facilitated information on biochemical properties especially their potential ability act peptide receptors. Results To study presentation we used stably transfected LCL721.221 a source molecules analysed spectrum extracted individual pool sequencing. Our results indicate that like associated with wide array derived cellular proteins. Peptides presented usually consisted 9 amino acids, adhered specific sequence motif, anchor residues at position 2 (isoleucine or leucine), 3 (proline) carboxy-terminal (leucine). Thus, ligand motif follows principles motifs, although displays its own unique features. Peptide-binding assays indicated two three were sufficient for binding, ligands identified bound, not only but also HLA-A2. This was surprising, because binding pockets HLA-A2 overlap in recognize positions 9. Likewise, some, all, could bind HLA-G. Conclusion Nonclassical essentially same way do. We determined specifically recognized HLA-G; basic features described XI/LPXXXXXL. help elucidate role fetal–maternal interface. Most likely, this protect fetal lysis cells, possibly foreign class has yet been identified.