title: CD4/CD8 lineage commitment in T cell receptor transgenic mice: evidence for precommitment of CD4+ CD8+ thymocytes.
abstract: CD4+ and CD8+ mature T cells arise from CD4+ CD8+ thymic precursors by a process of positive selection that ultimately requires interaction of the T cell receptor (TCR) with self major histocompatibility complex (MHC) molecules. The mechanism of commitment of immature CD4+ CD8+ thymocytes to CD4 or CD8 lineages is controversial. Using TCR transgenic mice, we present evidence that CD4+ CD8+ thymocytes are precommitted to either the CD4 or CD8 lineage, prior to positive selection and independently of TCR specificity for MHC. This lineage precommitment model places important constraints on signaling via CD4 or CD8 coreceptor molecules.
authors.affiliation: Ludwig Institute for Cancer Research, Lausanne Branch, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Crompton
authors.forename: H
authors.initials: H
authors.lastname: Hefti
authors.forename: R K
authors.initials: RK
authors.lastname: Lees
authors.forename: H
authors.initials: H
authors.lastname: Pircher
authors.forename: H R
authors.initials: HR
authors.lastname: MacDonald
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000235:genetics*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta