title: Beta-catenin regulates positive selection of thymocytes but not lineage commitment.
abstract: Positive selection and lineage commitment to the cytolytic or helper lineage of T cells result in coordinated expression of MHC class I-restricted TCR and CD8 coreceptor or MHC class II-restricted TCR and CD4 molecule. Positive selection signals also regulate the survival and generation of requisite numbers of cytolytic or Th cells. beta-Catenin is the major transcriptional cofactor of T cell factor and plays a role in thymocyte development. In this study, using mice expressing stabilized beta-catenin and mice with T cell-specific deletion of beta-catenin, we show that beta-catenin regulates positive selection, but not lineage commitment of thymocytes. Furthermore, beta-catenin expression accelerates the timing of mature CD8 thymocyte generation such that CD4 and CD8 single-positive thymocytes mature with the same kinetics during development.
authors.affiliation: Lymphocyte Development Unit, Laboratory of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yu
authors.forename: Jyoti Misra
authors.initials: JM
authors.lastname: Sen
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D019070:Cell Lineage; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000502:physiology*; D051176:beta Catenin / Q000502:physiology*
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D051176:beta Catenin