Publications [#278113] of Chi Wei C. Chan

Papers Published

1. Tan, PH; Sagoo, P; Chan, C; Yates, JB; Campbell, J; Beutelspacher, SC; Foxwell, BMJ; Lombardi, G; George, AJT, Inhibition of NF-kappa B and oxidative pathways in human dendritic cells by antioxidative vitamins generates regulatory T cells., J Immunol, vol. 174 no. 12 (June, 2005), pp. 7633-7644, ISSN 0022-1767 [15944264], [doi]
   (last updated on 2026/02/09)

   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.

   Keywords:
   Antioxidants • Apoptosis • Ascorbic Acid • Cell Differentiation • Cells, Cultured • Clonal Anergy • Dendritic Cells • Dexamethasone • Down-Regulation • Drug Combinations • Humans • Immunophenotyping • Intracellular Fluid • NF-kappa B • Oxidation-Reduction • Protein Kinase C • Reactive Oxygen Species • Signal Transduction • T-Lymphocytes, Regulatory • alpha-Tocopherol • antagonists & inhibitors • antagonists & inhibitors* • drug effects • eIF-2 Kinase • immunology • immunology* • metabolism • metabolism* • p38 Mitogen-Activated Protein Kinases • pharmacology • pharmacology* • physiology