title: U937 cells stimulated with opsonised zymozan particles provide a convenient laboratory source of tumour necrosis factor alpha.
abstract: The U937 cell line has been shown to generate tumour necrosis factor alpha (TNF-alpha) in response to soluble stimuli such as PMA and LPS, but only after treatment with GM-CSF. We report here the generation of TNF-alpha from U937 cells following phagocytosis of opsonised zymozan particles without the need for pre-treatment with GM-CSF. The release of TNF-alpha from U937 cells was demonstrated by a specific radioimmunoassay, L929 cell killing and neutrophil 'priming'. The biological activities in the cell supernatant were inhibited by TNF-alpha antiserum. Phagocytosis was required for TNF-alpha production. Non-opsonised zymozan or latex particles which were not phagocytosed or pretreatment with cytochalasin B, which inhibited phagocytosis of opsonised zymozan particles, all failed to trigger TNF-alpha production. Phagocytosis failed to trigger detectable IL-1 generation, and production of IL-6 was insufficient to produce biological effects on neutrophils. The U937 supernatant thus provides a source of human TNF-alpha which can be generated conveniently and cheaply for experimental investigations.
authors.affiliation: University Department of Surgery, University of Wales College of Medicine, Heath Park, Cardiff, UK.
authors.forename: W G
authors.initials: WG
authors.lastname: Jiang
authors.forename: M C
authors.initials: MC
authors.lastname: Puntis
authors.forename: M B
authors.initials: MB
authors.lastname: Hallett
mesh_terms: D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D007378:Interleukins / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D009895:Opsonin Proteins / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology; D011863:Radioimmunoassay; D011994:Recombinant Proteins / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000276:immunology; D015054:Zymosan / Q000276:immunology*
chemical_list: D007378:Interleukins; D009895:Opsonin Proteins; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D015054:Zymosan