title: Innate NKTγδ and NKTαβ cells exert similar functions and compete for a thymic niche.
abstract: The transcriptional regulator promyelocytic leukemia zinc finger (PLZF) is highly expressed during the differentiation of natural killer T (NKT) cells and is essential for the acquisition of their effector/memory innate-like phenotype. Staining with anti-PLZF and anti-NK1.1 Abs allows the definition of two subsets of NKTαβ and NKTγδ thymocytes that differ phenotypically and functionally: a PLZF(+) NK1.1(-)  subset composed of mostly quiescent cells that secrete more IL-4 than IFN-γ upon activation and a PLZF(+/-) NK1.1(+)  subset that expresses CD127, NK1.1, and other NK-cell markers, secrete more IFN-γ than IL-4 upon activation and contains a sizable fraction of dividing cells. The size of the NK1.1(+)  population is very tightly regulated and NK1.1(+)  αβ and γδ thymocytes compete for a thymic niche. Furthermore, the relative representation of the PLZF(+)  and NK1.1(+)  subsets varies in a strain-specific manner with C57BL/6 (B6) mice containing more NK1.1(+)  cells and (B6 × DBA/2)F1 (B6D2F1) mice more PLZF(+)  cells. Consequently, activation of NKT cells in vivo is expected to result in higher levels of IL-4 secreted in B6D2F1 mice than in B6 mice. Consistent with this possibility, B6D2F1 mice, when compared with B6 mice, contain more "innate" CD8(+)  thymocytes, the generation of which depends on IL-4 secreted by NKT cells.
authors.affiliation: Institut Pasteur, Unité Limphopoïese, INSERM U668, Paris, France. ppereira@pasteur.fr
authors.forename: Pablo
authors.initials: P
authors.lastname: Pereira
authors.forename: Laurent
authors.initials: L
authors.lastname: Boucontet
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000032:analysis / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D015847:Interleukin-4 / Q000276:immunology; D053699:Interleukin-7 Receptor alpha Subunit / Q000032:analysis / Q000276:immunology; D051741:Kruppel-Like Transcription Factors / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D055651:NK Cell Lectin-Like Receptor Subfamily B / Q000032:analysis / Q000276:immunology; D055611:Natural Killer T-Cells / Q000276:immunology*; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D000950:Antigens, Ly; D053699:Interleukin-7 Receptor alpha Subunit; C527211:Klrb1c protein, mouse; D051741:Kruppel-Like Transcription Factors; D055651:NK Cell Lectin-Like Receptor Subfamily B; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; C513267:Zbtb16 protein, mouse; D015847:Interleukin-4; D007371:Interferon-gamma