Latek R R, Petzold S J, Unanue E R
Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
Proc Natl Acad Sci U S A. 2000 Oct 10;97(21):11460-5. doi: 10.1073/pnas.210384197.
Selection of particular antigen-derived peptides by class II MHC molecules determines the population of complexes represented on the antigen-presenting cell surface and available for T cell receptor engagement. This discriminating selection process results from unique interactions between the spectrum of peptides generated during antigen processing and the MHC molecules. Here, we examined the selection of peptides by the class II MHC, I-A(k). Our results indicate that although peptide primary anchors are key in MHC binding, auxiliary anchors are a powerful regulatory component in the selection of peptides by I-A(k). Study of the segments surrounding the dominant hen egg white lysozome(48-61) epitope demonstrates that auxiliary anchors also are involved in determining the binding register of I-A(k) along an extended peptide. In addition, we found that unique combinations of auxiliary anchors can act in concert to modulate the binding of peptides to I-A(k).
II类主要组织相容性复合体（MHC）分子对特定抗原衍生肽段的选择，决定了抗原呈递细胞表面所呈现的、可供T细胞受体结合的复合体群体。这种具有区分性的选择过程源于抗原加工过程中产生的一系列肽段与MHC分子之间独特的相互作用。在此，我们研究了II类MHC分子I-A(k)对肽段的选择。我们的结果表明，虽然肽段的主要锚定位在MHC结合中起关键作用，但辅助锚定位是I-A(k)选择肽段时的一个强大调节成分。对优势鸡卵清溶菌酶（48 - 61）表位周围片段的研究表明，辅助锚定位也参与决定I-A(k)沿着延伸肽段的结合位置。此外，我们发现辅助锚定位的独特组合可以协同作用，调节肽段与I-A(k)的结合。
