title: The E delta enhancer controls the generation of CD4- CD8- alphabetaTCR-expressing T cells that can give rise to different lineages of alphabeta T cells.
abstract: It is well established that the pre-T cell receptor for antigen (TCR) is responsible for efficient expansion and differentiation of thymocytes with productive TCRbeta rearrangements. However, Ptcra- as well as Tcra-targeting experiments have suggested that the early expression of Tcra in CD4- CD8- cells can partially rescue the development of alphabeta CD4+ CD8+ cells in Ptcra-deficient mice. In this study, we show that the TCR E delta but not E alpha enhancer function is required for the cell surface expression of alphabetaTCR on immature CD4- CD8- T cell precursors, which play a crucial role in promoting alphabeta T cell development in the absence of pre-TCR. Thus, alphabetaTCR expression by CD4- CD8- thymocytes not only represents a transgenic artifact but occurs under physiological conditions.
authors.affiliation: Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Iannis
authors.initials: I
authors.lastname: Aifantis
authors.forename: Craig H
authors.initials: CH
authors.lastname: Bassing
authors.forename: Annette I
authors.initials: AI
authors.lastname: Garbe
authors.forename: Katie
authors.initials: K
authors.lastname: Sawai
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Alt
authors.forename: Harald
authors.initials: H
authors.lastname: von Boehmer
mesh_terms: D000818:Animals; D016477:Artifacts; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004742:Enhancer Elements, Genetic; D015329:Gene Rearrangement, T-Lymphocyte / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009924:Organ Culture Techniques; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology
chemical_list: D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; C090377:pre-T cell receptor alpha