title: Cutting edge: selective expression of inhibitory or activating killer cell Ig-like receptors in circulating CD4+ T lymphocytes.
abstract: Apart from NK cells, TCRgammadelta and CD8+ T cells, killer cell Ig-like receptor (KIR) expression was described on a minor subset of CD4+ T cells. However, their functions remain to be elucidated in this latter lymphocyte population. We demonstrated that KIR2DL2/L3 (CD158b) and KIR2DS2 (CD158j) transcripts were synthesized by sorted CD4+CD158b/j+ T cells obtained from healthy individuals. In contrast, we observed that only the inhibitory or activating receptor was expressed at the cell surface according to the donor tested. In CD158b-expressing cells, KIR triggering leads to an inhibition of the CD3-induced cell proliferation and Erk activation, and the receptor exhibits an activation-dependent tyrosine phosphorylation and association with the Src homology 2-containing phosphatase 1. In CD158j-positive cells, KIR-engagement results in an enhanced CD3-mediated cell growth and Erk phosphorylation. Our results suggested that, in contrast to NK cells, the functions of KIR in CD4+ T lymphocytes might derive from a selective expression of their activating or inhibiting forms.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale Unité 841, Department of Immunology, Oncology and Dermatology, Créteil, France.
authors.forename: Natacha
authors.initials: N
authors.lastname: Remtoula
authors.forename: Armand
authors.initials: A
authors.lastname: Bensussan
authors.forename: Anne
authors.initials: A
authors.lastname: Marie-Cardine
mesh_terms: D000911:Antibodies, Monoclonal / Q000502:physiology; D000954:Antigens, Surface / Q000096:biosynthesis / Q000276:immunology / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D020033:Protein Isoforms / Q000096:biosynthesis / Q000276:immunology / Q000502:physiology; D054340:Receptors, KIR / Q000096:biosynthesis* / Q000502:physiology; D054343:Receptors, KIR2DL2 / Q000096:biosynthesis* / Q000097:blood / Q000502:physiology; D054344:Receptors, KIR2DL3 / Q000096:biosynthesis* / Q000097:blood* / Q000502:physiology; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; C515077:KIR2DL2 protein, human; C515078:KIR2DL3 protein, human; C433932:KIR2DS2 protein, human; D020033:Protein Isoforms; D054340:Receptors, KIR; D054343:Receptors, KIR2DL2; D054344:Receptors, KIR2DL3