title: Participation of CD4 coreceptor molecules in T-cell repertoire selection.
abstract: During thymocyte development, progenitor cells bearing both CD4 and CD8 coreceptor molecules mature into functional T lymphocytes that express these proteins in a mutually exclusive way. Although T-cell specificity is determined primarily by the structure of the T-cell antigen receptor (TCR) heterodimer, a developmentally regulated process acts to ensure that cells bearing class II-restricted TCRs are CD4+ and those bearing class I-restricted TCRs express only CD8. To investigate this maturation process, we have engineered transgenic mice in which CD4 is expressed in all thymocyte subsets and in all peripheral T cells. Peripheral CD4+8+ T lymphocytes from these mice react with both class I and class II alloantigens. Moreover, expression of the CD4 transgene disrupts the positive selection of doubly transgenic thymocytes bearing a class I-restricted TCR specific for the male (H-Y) antigen. Hence the CD4 coreceptor participates directly in T-cell repertoire selection.
authors.affiliation: Department of Microbiology, University of British Columbia, Vancouver, Canada.
authors.forename: H S
authors.initials: HS
authors.lastname: Teh
authors.forename: A M
authors.initials: AM
authors.lastname: Garvin
authors.forename: K A
authors.initials: KA
authors.lastname: Forbush
authors.forename: D A
authors.initials: DA
authors.lastname: Carlow
authors.forename: C B
authors.initials: CB
authors.lastname: Davis
authors.forename: D R
authors.initials: DR
authors.lastname: Littman
authors.forename: R M
authors.initials: RM
authors.lastname: Perlmutter
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis*; D015704:CD4 Antigens / Q000502:physiology*; D016827:CD8 Antigens; D005260:Female; D005786:Gene Expression Regulation; D006183:H-2 Antigens / Q000502:physiology; D006182:H-Y Antigen / Q000276:immunology; D064532:Histocompatibility Antigen H-2D; D015395:Histocompatibility Antigens Class I / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011993:Recombinant Fusion Proteins; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D015704:CD4 Antigens; D016827:CD8 Antigens; D006183:H-2 Antigens; D006182:H-Y Antigen; D064532:Histocompatibility Antigen H-2D; D015395:Histocompatibility Antigens Class I; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011993:Recombinant Fusion Proteins