title: Expression of killer cell lectin-like receptor G1 on antigen-specific human CD8+ T lymphocytes during active, latent, and resolved infection and its relation with CD57.
abstract: Killer cell lectin-like receptor G1 (KLRG1) is one of several inhibitory killer cell lectin-like receptors expressed by NK cells and T lymphocytes, mainly CD8(+) effector/memory cells that can secrete cytokines but have poor proliferative capacity. Using multiparameter flow cytometry, we studied KLRG1 expression on CD8(+) T cells specific for epitopes of CMV, EBV, influenza, and HIV. Over 92% of CD8(+) cells specific for CMV or EBV expressed KLRG1 during the latent stage of these chronic infections. CD8(+) T cell cells specific for HIV epitopes were mostly (72-89%) KLRG1(+), even though not quite at the level of predominance noted with CMV or EBV. Lower frequency of KLRG1 expression was observed among CD8(+) cells specific for influenza (40-73%), a resolved infection without a latent stage. We further observed that CD8(+) cells expressing CD57, a marker of replicative senescence, also expressed KLRG1; however, a population of CD57(-)KLRG1(+) cells was also identified. This population may represent a "memory" phenotype, because they also expressed CD27, CD28, CCR7, and CD127. In contrast, CD57(+)KLRG1(+) cells did not express CD27, CD28, and CCR7, and expressed CD127 at a much lower frequency, indicating that they represent effector cells that are truly terminally differentiated. The combination of KLRG1 and CD57 expression might thus aid in refining functional characterization of CD8(+) T cell subsets.
authors.affiliation: Center for AIDS Research, Immunology Core Laboratory, Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA.
authors.forename: Chris C
authors.initials: CC
authors.lastname: Ibegbu
authors.forename: Yong-Xian
authors.initials: YX
authors.lastname: Xu
authors.forename: Wayne
authors.initials: W
authors.lastname: Harris
authors.forename: David
authors.initials: D
authors.lastname: Maggio
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Miller
authors.forename: Athena P
authors.initials: AP
authors.lastname: Kourtis
mesh_terms: D018959:CD57 Antigens / Q000096:biosynthesis* / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism / Q000821:virology*; D002454:Cell Differentiation / Q000276:immunology; D049109:Cell Proliferation; D003587:Cytomegalovirus / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000096:biosynthesis*; D005260:Female; D015497:HIV-1 / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D007110:Immunity, Active; D007156:Immunologic Memory; D016130:Immunophenotyping; D037181:Lectins, C-Type; D008297:Male; D009975:Orthomyxoviridae / Q000276:immunology; D011971:Receptors, Immunologic; D015534:Trans-Activators / Q000096:biosynthesis* / Q000502:physiology; D017735:Virus Latency / Q000276:immunology*; D014779:Virus Replication / Q000276:immunology
chemical_list: D018959:CD57 Antigens; D018984:Epitopes, T-Lymphocyte; C113413:KLRG1 protein, human; D037181:Lectins, C-Type; D011971:Receptors, Immunologic; D015534:Trans-Activators