title: Lack of proliferative capacity of human effector and memory T cells expressing killer cell lectinlike receptor G1 (KLRG1).
abstract: Adaptive immunity necessitates the proliferation of lymphocytes. In the mouse, we have previously shown that antigen-experienced T cells that have lost their proliferative potential express the killer cell lectinlike receptor G1 (KLRG1). By using a newly generated monoclonal antibody specific for human KLRG1, we now demonstrate that expression of KLRG1 also identifies T cells in humans that are capable of secreting cytokines but that fail to proliferate after stimulation. Furthermore, our data show that proliferative incapacity of CD8 T cells correlates better with KLRG1 expression than with absence of the CD28 marker. In peripheral blood lymphocytes (PBLs) from healthy adult donors, KLRG1 was expressed on 44% +/- 14% of CD8 and 18% +/- 10% of CD4 T cells. KLRG1 expression was restricted to antigen-experienced T cells. Here, KLRG1(+) cells were preferentially found in the CCR7(-) effector T-cell pool. Besides T cells, a significant portion (approximately 50%) of human natural killer (NK) cells expressed KLRG1. Interestingly, these KLRG1(+) NK cells were found exclusively in the CD56(dim) NK-cell subset. Thus, the expression of KLRG1 identifies a subset of NK cells and antigen-experienced T cells in humans that lack proliferative capacity.
authors.affiliation: Institute for Medical Microbiology and Hygiene, Department of Immunology, University of Freiburg, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Voehringer
authors.forename: Marie
authors.initials: M
authors.lastname: Koschella
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Pircher
mesh_terms: D000911:Antibodies, Monoclonal; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D037181:Lectins, C-Type; D008213:Lymphocyte Activation / Q000276:immunology*; D011971:Receptors, Immunologic / Q000032:analysis* / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015534:Trans-Activators
chemical_list: D000911:Antibodies, Monoclonal; C113413:KLRG1 protein, human; C451496:Klrg1 protein, mouse; D037181:Lectins, C-Type; D011971:Receptors, Immunologic; D015534:Trans-Activators