title: Natural killer (NK) cell activating factor produced by a human T-cell hybridoma.
abstract: A human T-cell hybridoma (KC8-1.10), whose culture supernatant augments peripheral blood lymphocytes (PBL)-mediated spontaneous cytotoxicity against K562 cells, was established. This activity [natural killer (NK) cell activating activity] appears to be not due to interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) for the following reasons: 1) KC8-1.10 produced negligible or small amounts of IFNs and IL-2. 2) The NK cell activating activity in the KC8-1.10 culture supernatant was not neutralized by anti-IFN-gamma antiserum and stable even after pH 2 treatment for 24 hr, which is known to destroy IFN-gamma activity. 3) IL-2-dependent cell line absorbed IL-2 more efficiently than it absorbed the NK cell activating activity, and the latter activity was not retained by Blue Sepharose column in contrast with IL-2. The NK cell activating factor in the KC8-1.10 culture supernatant appears to be a glycoprotein, because the activity was abolished with pronase treatment or with boiling for 5 min and because the activity was retained by concanavalin A- and Pisum sativum agglutinin-agarose. Finally it was found that the NK cell activating activity requires Leu 11b+ cells to exert its effect.
authors.affiliation: Division of Chemical Toxicology and Immunochemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Yoshimatsu
authors.forename: T
authors.initials: T
authors.lastname: Osawa
mesh_terms: D003602:Cytotoxicity, Immunologic / Q000502:physiology; D006801:Humans; D006825:Hybridomas / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008222:Lymphokines / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D008222:Lymphokines; D007371:Interferon-gamma