title: Expression of inhibitory receptors Ly49E and CD94/NKG2 on fetal thymic and adult epidermal TCR V gamma 3 lymphocytes.
abstract: Ly49 and CD94/NKG2 inhibitory receptors are predominantly expressed on murine NK cells, but they are also expressed on a subpopulation of peripheral CD8 memory TCR alphabeta lymphocytes. In this study we demonstrate that Ly49E and CD94/NKG2 receptors are expressed on mature TCR Vgamma3(+) cells in the fetal thymus. Expression correlated with a memory phenotype, such as expression of CD44, 2B4, and IL-2Rbeta (CD122), and absence of IL-2Ralpha (CD25) expression. No expression of Ly49A, C, D, G2, or I receptors was observed. This phenotype is similar to that of fetal thymic NK cells. Skin-located Vgamma3 T cells, the progeny of fetal thymic Vgamma3 cells, also expressed CD94/NKG2 and Ly49E but not the other members of the Ly49 family. The development and survival of Ly49E(+) or CD94/NKG2(+) Vgamma3 T lymphocytes was not dependent upon expression of MHC class I molecules. The cytotoxicity of TCR Vgamma3 cells was inhibited when Qdm, the ligand for CD94/NKG2, was presented by Qa1(b)-transfected target cells. Also, upon cross-linking of CD94/NKG2 with mAb 3S9, TCR Vgamma3 thymocytes were prevented from killing FcgammaR(+) P815 target cells. These effects were most pronounced in the CD94/NKG2(high) subpopulation as compared with the CD94/NKG2(low) subpopulation of Vgamma3 cells. Our data demonstrate that Vgamma3 T cells expressing inhibitory Ly49E and CD94/NKG2 receptors are mature and display a memory phenotype, and that CD94/NKG2 functions as an inhibitory receptor on these T lymphocytes.
authors.affiliation: Department of Clinical Chemistry, Microbiology, and Immunology, University of Ghent, University Hospital, Ghent, Belgium.
authors.forename: Katrien
authors.initials: K
authors.lastname: Van Beneden
authors.forename: An
authors.initials: A
authors.lastname: De Creus
authors.forename: Frederik
authors.initials: F
authors.lastname: Stevenaert
authors.forename: Veronique
authors.initials: V
authors.lastname: Debacker
authors.forename: Jean
authors.initials: J
authors.lastname: Plum
authors.forename: Georges
authors.initials: G
authors.lastname: Leclercq
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D000950:Antigens, Ly / Q000096:biosynthesis*; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D015536:Down-Regulation / Q000276:immunology; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology* / Q000378:metabolism; D005333:Fetus; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000502:physiology; D007156:Immunologic Memory; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000378:metabolism; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055650:NK Cell Lectin-Like Receptor Subfamily A; D051920:NK Cell Lectin-Like Receptor Subfamily D; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis*; D011971:Receptors, Immunologic / Q000096:biosynthesis*; D055630:Receptors, NK Cell Lectin-Like; D055607:Receptors, Natural Killer Cell; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D001613:beta 2-Microglobulin / Q000172:deficiency / Q000235:genetics / Q000502:physiology
chemical_list: D015703:Antigens, CD; D000950:Antigens, Ly; D015395:Histocompatibility Antigens Class I; C527088:Klra1 protein, mouse; C527093:Klra5 protein, mouse; C497870:Klrd1 protein, mouse; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D055650:NK Cell Lectin-Like Receptor Subfamily A; D051920:NK Cell Lectin-Like Receptor Subfamily D; D016692:Receptors, Antigen, T-Cell, gamma-delta; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like; D055607:Receptors, Natural Killer Cell; D001613:beta 2-Microglobulin