title: Deletion of self-reactive thymocytes occurs at a CD4+8+ precursor stage.
abstract: As T cells develop in the thymus, they become tolerant of self-antigens. A major advance in the understanding of how this process occurs was the direct demonstration that cells bearing autoreactive T-cell receptors (TCRs) are physically eliminated from the population of functionally mature T cells present in both the thymus and periphery. We have sought to determine the developmental stage at which autoreactive T cells are eliminated by examining the expression of V beta 17a anti-I-E TCRs under various experimental conditions. In vivo antibody blockage of the CD4 molecule on developing thymocytes of I-E+ C57BR mice was found to inhibit the deletion of V beta 17a-bearing cells from the CD4-8+ single positive thymocyte subset. This result provides strong evidence that deletion of potentially autoreactive T cells occurs at a CD4+8+ precursor stage, that the non-clonally distributed accessory molecules (CD4, CD8) are significant participants in the self-recognition process that leads to clonal elimination, and that thymic class II major histocompatibility complex (MHC) molecules can influence the repertoire of CD4-8+ cells.
authors.affiliation: Laboratory of Cellular and Molecular Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20894.
authors.forename: B J
authors.initials: BJ
authors.lastname: Fowlkes
authors.forename: R H
authors.initials: RH
authors.lastname: Schwartz
authors.forename: D M
authors.initials: DM
authors.lastname: Pardoll
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D051379:Mice; D008817:Mice, Mutant Strains; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015728:Receptors, HIV; D011991:Receptors, Virus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D001323:Autoantibodies; D011948:Receptors, Antigen, T-Cell; D015728:Receptors, HIV; D011991:Receptors, Virus