title: Requirement for diverse, low-abundance peptides in positive selection of T cells.
abstract: Whether a single major histocompatibility complex (MHC)-bound peptide can drive the positive selection of large numbers of T cells has been a controversial issue. A diverse population of self peptides was shown to be essential for the in vivo development of CD4 T cells. Mice in which all but 5 percent of MHC class II molecules were bound by a single peptide had wild-type numbers of CD4 T cells. However, when the diversity within this 5 percent was lost, CD4 T cell development was impaired. Blocking the major peptide-MHC complex in thymus organ culture had no effect on T cell development, indicating that positive selection occurred on the diverse peptides present at low levels. This requirement for peptide diversity indicates that the interaction between self peptides and T cell receptors during positive selection is highly specific.
authors.affiliation: Molecular and Cellular Biology Program of the University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA 98195, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Barton
authors.forename: A Y
authors.initials: AY
authors.lastname: Rudensky
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D000949:Histocompatibility Antigens Class II / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010455:Peptides / Q000276:immunology* / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II; D010455:Peptides; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins