title: Identification of human T cell hybridoma-derived macrophage activating factor as interleukin-2.
abstract: Macrophages are activated by a two-step mechanism involving at least two kinds of factors, a priming and a triggering factor, to become cytotoxic to various tumor cells. In the present study, we purified macrophage-activating factor for cytotoxicity I (MAF-C I), defined as a priming macrophage activating factor (MAF), by about 1,600-fold from the culture supernatant of a human T cell hybridoma, H3-E9-6, by a series of chromatographic procedures. We identified MAF-C I activity released from H3-E9-6 cells as interleukin-2 (IL-2) from the following findings. (i) The physicochemical properties of MAF-C I and IL-2 were almost identical. (ii) Purified MAF-C I active fraction also showed T cell proliferating activity. (iii) MAF-C I activity in the purified fraction was completely neutralized by anti-IL-2 antibodies. (iv) Human recombinant IL-2 (rIL-2), at a suboptimal dose, and lipopolysaccharide (LPS) synergistically induced monocyte-mediated cytotoxicity.
authors.affiliation: Division of Chemical Toxicology and Immunochemistry, Faculty of Pharmaceutical Sciences, University of Tokyo.
authors.forename: N
authors.initials: N
authors.lastname: Higashi
authors.forename: M
authors.initials: M
authors.lastname: Higuchi
authors.forename: N
authors.initials: N
authors.lastname: Hanada
authors.forename: J
authors.initials: J
authors.lastname: Oeda
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Osawa
mesh_terms: D003602:Cytotoxicity, Immunologic; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007376:Interleukin-2 / Q000302:isolation & purification*; D008213:Lymphocyte Activation; D008262:Macrophage Activation; D016215:Macrophage-Activating Factors / Q000302:isolation & purification*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D016215:Macrophage-Activating Factors