title: Potentiation of hydrogen peroxide, nitric oxide, and cytokine production in RAW 264.7 macrophage cells exposed to human and commercial isolates of Bifidobacterium.
abstract: Bifidobacteria have been previously shown to stimulate immune function and this may be mediated by macrophages. The RAW 264.7 cell line was used here as a macrophage model to assess the effects of human and commercial Bifidobacterium isolates on the production nitric oxide (NO), hydrogen peroxide (H2O2) and the cytokines IL-6 and tumor necrosis factor (TNF)-alpha. Thirty three Bifidobacterium strains differentially stimulated the production of H2O2 NO, TNF-alpha, and IL-6 in a dose-dependent manner in 24-h cultures. In the presence of lipopolysaccharide (LPS) the effects of bifidobacteria on NO and H2O2 were masked and were less pronounced at the later stage of incubation. Co-stimulation of macrophages with both LPS and Bifidobacterium increased the production of IL-6 synergistically. In contrast, LPS reduced the ability of the bifidobacteria-induced macrophages to produce TNF-alpha. Our results demonstrated that both human and commercial Bifidobacterium strains can stimulate H2O2, NO, TNF-alpha, and IL-6 production, and this effect was strain-dependent. The in vitro approaches employed here should be useful in further characterization of the effects of bifidobacteria on gastrointestinal and systemic immunity.
authors: Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224, USA.
authors: S Y
authors: SY
authors: Park
authors: G E
authors: GE
authors: Ji
authors: Y T
authors: YT
authors: Ko
authors: H K
authors: HK
authors: Jung
authors: Z
authors: Z
authors: Ustunol
authors: J J
authors: JJ
authors: Pestka
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000276:immunology / Q000502:physiology*; D002478:Cells, Cultured; D016207:Cytokines / Q000032:analysis / Q000096:biosynthesis*; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D005470:Fluorometry; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism*; D015850:Interleukin-6 / Q000032:analysis / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D009569:Nitric Oxide / Q000032:analysis / Q000096:biosynthesis*; D009573:Nitrites / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D015850:Interleukin-6; D008070:Lipopolysaccharides; D009573:Nitrites; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D006861:Hydrogen Peroxide