title: CD161 (NKR-P1A) costimulation of CD1d-dependent activation of human T cells expressing invariant V alpha 24 J alpha Q T cell receptor alpha chains.
abstract: A population of human T cells expressing an invariant V alpha 24 J alpha Q T cell antigen receptor (TCR) alpha chain and high levels of CD161 (NKR-P1A) appears to play an immunoregulatory role through production of both T helper (Th) type 1 and Th2 cytokines. Unlike other CD161(+) T cells, the major histocompatibility complex-like nonpolymorphic CD1d molecule is the target for the TCR expressed by these T cells (V alpha 24(invt) T cells) and by the homologous murine NK1 (NKR-P1C)+ T cell population. In this report, CD161 was shown to act as a specific costimulatory molecule for TCR-mediated proliferation and cytokine secretion by V alpha 24(invt) T cells. However, in contrast to results in the mouse, ligation of CD161 in the absence of TCR stimulation did not result in V alpha 24(invt) T cell activation, and costimulation through CD161 did not cause polarization of the cytokine secretion pattern. CD161 monoclonal antibodies specifically inhibited V alpha 24(invt) T cell proliferation and cytokine secretion in response to CD1d+ target cells, demonstrating a physiological accessory molecule function for CD161. However, CD1d-restricted target cell lysis by activated V alpha 24(invt) T cells, which involved a granule-mediated exocytotic mechanism, was CD161-independent. In further contrast to the mouse, the signaling pathway involved in V alpha 24(invt) T cell costimulation through CD161 did not appear to involve stable association with tyrosine kinase p56(Lck). These results demonstrate a role for CD161 as a novel costimulatory molecule for TCR-mediated recognition of CD1d by human V alpha 24(invt) T cells.
authors.affiliation: Department of Cancer Biology, Hematology/Oncology, Beth Israel-Deaconess Medical Center, Boston, Massachusetts 02215, USA. mexley@bidmc.harvard.edu
authors.forename: M
authors.initials: M
authors.lastname: Exley
authors.forename: S
authors.initials: S
authors.lastname: Porcelli
authors.forename: M
authors.initials: M
authors.lastname: Furman
authors.forename: J
authors.initials: J
authors.lastname: Garcia
authors.forename: S
authors.initials: S
authors.lastname: Balk
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018949:Antigens, CD1 / Q000502:physiology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis*; D000954:Antigens, Surface / Q000276:immunology / Q000502:physiology*; D003602:Cytotoxicity, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D051379:Mice; D055651:NK Cell Lectin-Like Receptor Subfamily B; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis*; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D018949:Antigens, CD1; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; C527203:KLRB1 protein, human; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D016693:Receptors, Antigen, T-Cell, alpha-beta; C045084:invariant chain