title: A subset of CD4+ thymocytes selected by MHC class I molecules.
abstract: To complete their maturation, most immature thymocytes depend on the simultaneous engagement of their antigen receptor [alpha beta T cell receptor (TCR)] and their CD4 or CD8 coreceptors with major histocompatibility complex class II or I ligands, respectively. However, a normal subset of mature alpha beta TCR+ thymocytes did not follow these rules. These thymocytes expressed NK1.1 and a restricted set of alpha beta TCRs that are intrinsically class I-reactive because their positive selection was class I-dependent but CD8-independent. These cells were CD4+ and CD4-8- but never CD8+, because the presence of CD8 caused negative selection. Thus, neither CD4 nor CD8 contributes signals that direct their maturation into the CD4+ and CD4-8- lineages.
authors.affiliation: Laboratory of Cellular and Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
authors.forename: A
authors.initials: A
authors.lastname: Bendelac
authors.forename: N
authors.initials: N
authors.lastname: Killeen
authors.forename: D R
authors.initials: DR
authors.lastname: Littman
authors.forename: R H
authors.initials: RH
authors.lastname: Schwartz
mesh_terms: D000818:Animals; D000941:Antigens / Q000032:analysis; D000950:Antigens, Ly; D000954:Antigens, Surface; D015704:CD4 Antigens / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D016827:CD8 Antigens / Q000032:analysis; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D037181:Lectins, C-Type; D008024:Ligands; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D055651:NK Cell Lectin-Like Receptor Subfamily B; D010641:Phenotype; D011506:Proteins / Q000032:analysis; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis / Q000502:physiology*; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*
chemical_list: D000941:Antigens; D000950:Antigens, Ly; D000954:Antigens, Surface; D015704:CD4 Antigens; D016827:CD8 Antigens; D015395:Histocompatibility Antigens Class I; C527211:Klrb1c protein, mouse; D037181:Lectins, C-Type; D008024:Ligands; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta