title: Phenotypic and functional characterization of CD4 T cells expressing killer Ig-like receptors.
abstract: Killer Ig-like receptors (KIR) are commonly found on human NK cells, gammadelta T cells, and CD8 T cells. Although KIR(+) CD4 T cells are found in certain patients, their prevalence in healthy donors is controversial. We now provide definitive proof that such cells are present in most individuals, and report on their frequency, surface phenotype, cytokine profile, and Ag specificity. The number of KIR(+) CD4 T cells detected in peripheral blood increased with age. In contrast with regular KIR(-) CD4 T cells, the majority of KIR(+) CD4 T cells lacked surface expression of CD27, CD28, CCR4, and CCR7, but did express CD57 and 2B4. In addition, KIR were detected on approximately one-tenth of CD28(-) and CD57(+) memory CD4 T cells. In line with the absence of the Th2 marker CCR4, the KIR(+) CD4 cells produced mainly IFN-gamma and little IL-4, IL-10, or IL-17 upon TCR triggering. Furthermore, the KIR(+) population contained cells that responded to recall Ags in an HLA class II-restricted fashion. Together, our data indicate that KIR-expressing CD4 T cells are predominantly HLA class II-restricted effector memory Th1 cells, and that a significant, previously unrecognized fraction of effector memory Th1 cells expresses KIR.
authors.affiliation: Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands. J.van_Bergen@lumc.nl
authors.forename: Jeroen
authors.initials: J
authors.lastname: van Bergen
authors.forename: Allan
authors.initials: A
authors.lastname: Thompson
authors.forename: Arno
authors.initials: A
authors.lastname: van der Slik
authors.forename: Tom H M
authors.initials: TH
authors.lastname: Ottenhoff
authors.forename: Jacobijn
authors.initials: J
authors.lastname: Gussekloo
authors.forename: Frits
authors.initials: F
authors.lastname: Koning
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002999:Clone Cells; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D020869:Gene Expression Profiling; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D006681:HLA-D Antigens / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D051379:Mice; D008822:Mice, Transgenic; D008875:Middle Aged; D008969:Molecular Sequence Data; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000235:genetics; D054340:Receptors, KIR; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D018984:Epitopes, T-Lymphocyte; D006681:HLA-D Antigens; D011971:Receptors, Immunologic; D054340:Receptors, KIR