title: Reduction of macrophage-mediated tumor cytotoxicity by pretreatment with GM-CSF.
abstract: The effect of granulocyte/macrophage colony stimulating factor (GM-CSF) on macrophage activation by interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS) was studied in a murine model system. When peritoneal macrophages were pretreated with GM-CSF for 24 hrs, a strong reduction of IFN-gamma-induced tumor cytotoxicity and LPS-triggered tumor necrosis factor-alpha (TNF-alpha) release was found. In contrast, GM-CSF treatment of macrophages for only 4 to 8 hrs enhanced TNF-alpha production. These data suggest that GM-CSF may affect macrophage activation in a biphasic manner in that a time period of enhanced responsiveness to IFN-gamma is followed by a longlasting period of refractoriness.
authors.affiliation: Institute of Immunology, University of Marburg, W.-Germany.
authors.forename: S
authors.initials: S
authors.lastname: Heidenreich
authors.forename: J H
authors.initials: JH
authors.lastname: Gong
authors.forename: M
authors.initials: M
authors.lastname: Nain
authors.forename: D
authors.initials: D
authors.lastname: Gemsa
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000276:immunology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D008811:Mice, Inbred DBA; D011994:Recombinant Proteins / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D003115:Colony-Stimulating Factors; D006133:Growth Substances; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor