title: Synergistic induction of tumor necrosis factor alpha by bacterial lipopolysaccharide and lipoteichoic acid in combination with polytetrafluoroethylene particles in a murine macrophage cell line RAW 264.7.
abstract: The induction of tumor necrosis factor alpha (TNF-alpha) by polytetrafluoroethylene (PTFE) particles (5-50 microns) and by bacterial lipopolysaccharide (LPS) and lipoteichoic acid (LTA) was examined in RAW cell cultures. Twenty-four-hour culture supernatants from the treated and control cells were assayed for TNF-alpha using a mouse L929 cell cytotoxicity assay. Untreated RAW cells produced low levels of endogenous TNF-alpha in the culture supernatants. Addition of 0.5 ng to 1 microgram/ mL LPS or 1 ng to 1 microgram/ml LTA increased the TNF-alpha production by 7-3570-fold and 2-815-fold, respectively. Addition of 1-5 mg PTFE increased the TNF-alpha production by 6-17-fold over the untreated control cell levels. The cells exposed to PTFE and 0.5 ng/mL LPS or 5 ng/mL LTA produced TNF-alpha levels that were significantly higher than those produced by any inducer alone. Thus, both LTA, a Gram-positive bacterial cell wall component and LPS, a Gram-negative bacterial cell wall component, can induce TNF-alpha production, which is further enhanced by PTFE particles in RAW cells.
authors.affiliation: Center for Biologics Evaluation and Research, Rockville, MD 20852-1448, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Chapekar
authors.forename: T G
authors.initials: TG
authors.lastname: Zaremba
authors.forename: R K
authors.initials: RK
authors.lastname: Kuester
authors.forename: V M
authors.initials: VM
authors.lastname: Hitchins
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001681:Biological Assay; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D013293:Enterococcus faecalis; D004926:Escherichia coli; D007700:Kinetics; D007739:L Cells; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages; D051379:Mice; D011138:Polytetrafluoroethylene / Q000494:pharmacology*; D013211:Staphylococcus aureus; D013682:Teichoic Acids / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis* / Q000494:pharmacology
chemical_list: D001672:Biocompatible Materials; D008070:Lipopolysaccharides; D013682:Teichoic Acids; D014409:Tumor Necrosis Factor-alpha; C009900:lipoteichoic acid; D011138:Polytetrafluoroethylene