title: Beryllium-stimulated production of tumor necrosis factor-alpha by a mouse hybrid macrophage cell line.
abstract: Chronic beryllium disease (CBD) results from exposure to the light-weight metal beryllium (Be). In vitro stimulation of bronchoalveolar lavage cells from CBD subjects causes the production of high levels of TNF-alpha, IFN-gamma and IL-6. We tested the hypothesis that Be-stimulation might induce the production of TNF-alpha by macrophage cell lines. We observed that H36.12j cells (12j), a mouse hybrid macrophage cell line, but not other mouse and human macrophage cell lines, produced TNF-alpha upon Be-stimulation. The response was maximal at 100 microM BeSO4 and did not occur when 12j cells were stimulated with either aluminum sulfate or cobalt sulfate. Beryllium-stimulated the production of 725+/-25 pg/ml (mean +/- SEM) TNF-alpha protein by 12j cells as measured by ELISA of culture supernatants after 24 h. As measured by RT-PCR, Be-stimulated 12j cell TNF-alpha protein production was accompanied by an increased intracellular TNF-alpha mRNA at 3 and 24 h. The addition of 10U or 100U of rMu-IFN-gamma to Be-stimulated 12j cells further increased TNF-alpha production 1.5-4 fold (1.6+/-0.1 ng/ml) respectively. Bacterial lipopolysaccharide (LPS, 1 microg/ml) stimulated production of TNF-alpha in 12j culture supernatants after 6 h (515+/-151 pg/ml). This early versus late TNF-alpha production suggests that LPS and Be both stimulate 12j cell TNF-alpha synthesis, but through different pathways. We report for the first time, the direct effects of Be stimulation on the ability of 12j cells to produce TNF-alpha. The 12j cell line, contrasted with other macrophage hybrids that do not respond to Be-stimulation, may provide a useful tool to evaluate the mechanisms by which Be stimulates macrophage cytokine production, and by which T cell derived IFN-gamma amplifies TNF-alpha production in granulomatous diseases.
authors.affiliation: Department of Medicine, National Jewish Medical and Research Center, Denver, CO 80220, USA. sawyerr@njc.org
authors.forename: R T
authors.initials: RT
authors.lastname: Sawyer
authors.forename: L A
authors.initials: LA
authors.lastname: Kittle
authors.forename: H
authors.initials: H
authors.lastname: Hamada
authors.forename: L S
authors.initials: LS
authors.lastname: Newman
authors.forename: P A
authors.initials: PA
authors.lastname: Campbell
mesh_terms: D000818:Animals; D001608:Beryllium / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D006822:Hybrid Cells; D007202:Indicators and Reagents; D007371:Interferon-gamma / Q000096:biosynthesis; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis; D013268:Stimulation, Chemical; D014158:Transcription, Genetic / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D016207:Cytokines; D007202:Indicators and Reagents; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D001608:Beryllium