title: Coexpression of Fc gamma receptor IIIA and interleukin-2 receptor beta chain by a subset of human CD3+/CD8+/CD11b+ lymphocytes.
abstract: In this study we identify and characterize a subset of human peripheral blood T cells, present in all individuals, that has features previously described for T cells either separately or in special circumstances. These cells are found in purified suspensions of resting peripheral blood lymphocytes within the CD8+ T lymphocytes, express alpha beta T cell receptor (TCR), and can be identified and isolated because of high-density expression of surface CD11b (TCR alpha beta +/CD3+/CD8+/CD11b+ cells). They coexpress constitutively the IL-2 receptor beta chain, Fc gamma RIIIA, and CD56. Although they do not mediate spontaneous cytotoxicity, CD3+/CD8+/CD11b+ cells have cytotoxic potential, demonstrated in redirected cytotoxicity assays with P815 target cells in the presence of anti-Fc gamma RIII (CD16) or anti-CD3 monoclonal antibodies. Stimulation of CD3+/CD8+/CD11b+ cells with rIL-2 induces proliferation, cytotoxicity against NK-sensitive and NK-resistant target cells, and expression of surface activation antigens, including IL-2 receptor alpha chain (CD25). CD3+/CD8+/CD16+/CD56+ cell clones with cytotoxic functions including those mediated by engagement of surface CD16 were obtained by limiting-dilution cloning of purified CD3+/CD8+/CD11b+ cells in the presence of rIL-2 and autologous feeder cells. Our data support the hypothesis that the CD3+/CD8+/CD11b+/CD16+ cells represent a discrete peripheral blood lymphocyte subset that could be the physiological counterpart of that expanded in several pathological conditions and in large granular lymphocyte lymphocytosis.
authors.affiliation: Istituto Nazionale per la Ricerca sul Cancro, IST, Laboratorio di Immunologia Clinica, Genova, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Zupo
authors.forename: L
authors.initials: L
authors.lastname: Azzoni
authors.forename: R
authors.initials: R
authors.lastname: Massara
authors.forename: A
authors.initials: A
authors.lastname: D'Amato
authors.forename: B
authors.initials: B
authors.lastname: Perussia
authors.forename: M
authors.initials: M
authors.lastname: Ferrarini
mesh_terms: D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology*; D019002:CD56 Antigen; D016827:CD8 Antigens / Q000276:immunology*; D006801:Humans; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D016177:Macrophage-1 Antigen / Q000276:immunology*; D017452:Receptors, IgG / Q000096:biosynthesis*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D019002:CD56 Antigen; D016827:CD8 Antigens; D016177:Macrophage-1 Antigen; D017452:Receptors, IgG; D015375:Receptors, Interleukin-2