title: Thymocytes can tolerize thymocytes by clonal deletion in vitro.
abstract: Clonal deletion of thymocytes bearing TCR for self antigens is one major mechanism of T cell tolerance induction. Peptide antigen-induced deletion of thymocytes from alpha beta TCR transgenic mice has been studied using single cell suspension cultures. The results show that antigen-presenting immature CD4+CD8+ thymocytes can tolerize antigen-reactive immature thymocytes in vitro by programmed cell death (apoptosis) 6-8 h after antigen exposure. Antigen-induced apoptosis of immature thymocytes was inhibited by antibodies specific for the alpha beta TCR, CD3, CD8, and LFA-1 molecules. This implies that clonal elimination of self-reactive CD4+CD8+ thymocytes does not depend on specialized deleting cell types in the thymus and occurs whenever the TCR of immature thymocytes bind antigen fragments presented by MHC molecules.
authors.affiliation: Department of Pathology, University of Zurich, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Pircher
authors.forename: K P
authors.initials: KP
authors.lastname: Müller
authors.forename: B A
authors.initials: BA
authors.lastname: Kyewski
authors.forename: H
authors.initials: H
authors.lastname: Hengartner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002478:Cells, Cultured; D007108:Immune Tolerance; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell; D014764:Viral Proteins