title: Functional killer Ig-like receptors on human memory CD4+ T cells specific for cytomegalovirus.
abstract: Although very few CD4(+) T cells express killer Ig receptors (KIR), a large proportion of CD4(+) T cells with a late memory phenotype, characterized by the absence of CD28, does express KIR. Here, we show that KIR expression on CD4(+) T cells is also associated with memory T cell function, by showing that the frequency of CMV-specific cells is higher in CD4(+)KIR(+) than CD4(+)KIR(-) T cells. In addition, engagement of an inhibitory KIR inhibited the CMV-specific proliferation of these CD4(+)KIR(+) memory T cells, but had no detectable effect on cytokine production. Our data reveal that, in marked contrast with CD8(+) T cells, the activity of a subset of CMV-specific CD4(+) T cells is modulated by HLA class I-specific KIR. Thus, the CMV-induced down-regulation of HLA class I may in fact enhance memory CMV-specific CD4(+) T cell responses restricted by HLA class II.
authors.affiliation: Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, the Netherlands. J.van_Bergen@lumc.nl
authors.forename: Jeroen
authors.initials: J
authors.lastname: van Bergen
authors.forename: Engelina M C
authors.initials: EM
authors.lastname: Kooy-Winkelaar
authors.forename: Henrike
authors.initials: H
authors.lastname: van Dongen
authors.forename: Floris A
authors.initials: FA
authors.lastname: van Gaalen
authors.forename: Allan
authors.initials: A
authors.lastname: Thompson
authors.forename: Tom W J
authors.initials: TW
authors.lastname: Huizinga
authors.forename: Mariet C W
authors.initials: MC
authors.lastname: Feltkamp
authors.forename: René E M
authors.initials: RE
authors.lastname: Toes
authors.forename: Frits
authors.initials: F
authors.lastname: Koning
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D002460:Cell Line; D003587:Cytomegalovirus / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D054340:Receptors, KIR / Q000276:immunology* / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism / Q000821:virology
chemical_list: D018106:CD28 Antigens; D054340:Receptors, KIR