title: Inhibition of NF-kappa B and oxidative pathways in human dendritic cells by antioxidative vitamins generates regulatory T cells.
abstract: Dendritic cells (DCs) are central to T cell immunity, and many strategies have been used to manipulate DCs to modify immune responses. We investigated the effects of antioxidants ascorbate (vitamin C) and alpha-tocopherol (vitamin E) on DC phenotype and function. Vitamins C and E are both antioxidants, and concurrent use results in a nonadditive activity. We have demonstrated that DC treated with these antioxidants are resistant to phenotypic and functional changes following stimulation with proinflammatory cytokines. Following treatment, the levels of intracellular oxygen radical species were reduced, and the protein kinase RNA-regulated, eukaryotic translation initiation factor 2alpha, NF-kappaB, protein kinase C, and p38 MAPK pathways could not be activated following inflammatory agent stimulation. We went on to show that allogeneic T cells (including CD4(+)CD45RO, CD4(+)CD45RA, and CD4(+)CD25(-) subsets) were anergized following exposure to vitamin-treated DCs, and secreted higher levels of Th2 cytokines and IL-10 than cells incubated with control DCs. These anergic T cells act as regulatory T cells in a contact-dependent manner that is not dependent on IL-4, IL-5, IL-10, IL-13, and TGF-beta. These data indicate that vitamin C- and E-treated DC might be useful for the induction of tolerance to allo- or autoantigens.
authors.affiliation: Department of Immunology, Division of Medicine, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom.
authors.forename: Peng H
authors.initials: PH
authors.lastname: Tan
authors.forename: Pervinder
authors.initials: P
authors.lastname: Sagoo
authors.forename: Cliburn
authors.initials: C
authors.lastname: Chan
authors.forename: John B
authors.initials: JB
authors.lastname: Yates
authors.forename: Jamie
authors.initials: J
authors.lastname: Campbell
authors.forename: Sven C
authors.initials: SC
authors.lastname: Beutelspacher
authors.forename: Brian M J
authors.initials: BM
authors.lastname: Foxwell
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lombardi
authors.forename: Andrew J T
authors.initials: AJ
authors.lastname: George
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D001205:Ascorbic Acid / Q000494:pharmacology*; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D017635:Clonal Anergy / Q000187:drug effects / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000276:immunology; D004338:Drug Combinations; D006801:Humans; D016130:Immunophenotyping; D007424:Intracellular Fluid / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000502:physiology; D010084:Oxidation-Reduction / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D024502:alpha-Tocopherol / Q000494:pharmacology*; D019892:eIF-2 Kinase / Q000037:antagonists & inhibitors / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology
chemical_list: D000975:Antioxidants; D004338:Drug Combinations; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D003907:Dexamethasone; D019892:eIF-2 Kinase; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; D024502:alpha-Tocopherol; D001205:Ascorbic Acid