title: Tumor necrosis factor alpha (TNFalpha)-like factor produced by macrophages in rainbow trout, Oncorhynchus mykiss.
abstract: The presence of a Tumor Necrosis Factor alpha (TNFalpha)-like molecule has been suggested in fish by biological assays and biological and antigenic cross-reactivities with human TNFalpha. In the present study, whether rainbow trout macrophages produce TNFalpha was examined. Murine recombinant TNFalpha (m-rTNFalpha) was used as the standard mammalian TNFalpha. The supernatants were harvested from trout macrophage culture stimulated with lipopolysaccharide (LPS) and then passed through a Polymyxin B column to remove LPS. Results show that trout macrophage culture supernatants exhibit TNF-like activities. The supernatants significantly enhanced neutrophil migration and macrophage respiratory burst activity as assessed by NBT reduction test. The supernatants were also highly cytotoxic to murine L929 cells, which are known to be sensitive to mammalian TNFalpha. The biological activities of TNF in the trout macrophage culture supernatant was determined as 2.6 U ml(-1) in the presence of actinomycin D. This indicates biological cross-reactivity of trout TNFalpha-like factor on mammalian cells. Moreover, these activities were inhibited by a rabbit anti-mTNFalpha antibody. These results suggest that rainbow trout macrophages produce a TNFalpha-like factor that is similar to the mammalian TNFalpha in functions.
authors.affiliation: Tropical Marine Science Institute, National University of Singapore, Singapore. tmsqinqw@nus.edu.sg
authors.forename: Q W
authors.initials: QW
authors.lastname: Qin
authors.forename: M
authors.initials: M
authors.lastname: Ototake
authors.forename: K
authors.initials: K
authors.lastname: Noguchi
authors.forename: G
authors.initials: G
authors.lastname: Soma
authors.forename: Y
authors.initials: Y
authors.lastname: Yokomizo
authors.forename: T
authors.initials: T
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D003601:Cytotoxicity Tests, Immunologic / Q000662:veterinary; D004926:Escherichia coli / Q000235:genetics; D007202:Indicators and Reagents / Q000737:chemistry; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D009504:Neutrophils / Q000276:immunology; D009580:Nitroblue Tetrazolium / Q000737:chemistry; D017686:Oncorhynchus mykiss / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins; D016897:Respiratory Burst / Q000276:immunology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D007202:Indicators and Reagents; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D009580:Nitroblue Tetrazolium