title: Clustering class I MHC modulates sensitivity of T cell recognition.
abstract: T cell recognition of peptide-MHC is highly specific and is sensitive to very low levels of agonist peptide; however, it is unclear how this effect is achieved or regulated. In this study we show that clustering class I MHC molecules on the cell surface of B lymphoblasts enhances their recognition by mouse and human T cells. We increased clustering of MHC I molecules by two methods, cholesterol depletion and direct cross-linking of a dimerizable MHC construct. Imaging showed that both treatments increased the size and intensity of MHC clusters on the cell surface. Enlarged clusters correlated with enhanced lysis and T cell effector function. Enhancements were peptide-specific and greatest at low concentrations of peptide. Clustering MHC class I enhanced recognition of both strong and weak agonists but not null peptide. Our results indicate that the lateral organization of MHC class I on the cell surface can modulate the sensitivity of T cell recognition of agonist peptide.
authors.affiliation: Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Fooksman
authors.forename: Gigi Kwik
authors.initials: GK
authors.lastname: Grönvall
authors.forename: Qing
authors.initials: Q
authors.lastname: Tang
authors.forename: Michael
authors.initials: M
authors.lastname: Edidin
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000235:genetics / Q000276:immunology*; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002784:Cholesterol / Q000172:deficiency; D003432:Cross-Linking Reagents / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D019281:Dimerization; D004306:Dose-Response Relationship, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000819:agonists / Q000172:deficiency / Q000276:immunology / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
chemical_list: D003432:Cross-Linking Reagents; D018984:Epitopes, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D002784:Cholesterol