title: Mega-dose Vitamin C modulates T cell functions in Balb/c mice only when administered during T cell activation.
abstract: Previously we reported that a mega-dose of Vitamin C enhanced the initial stage of delayed-type hypersensitivity reaction in Balb/c mice. In this study its effects were further evaluated as follows. Mice were administered Vitamin C intraperitoneally at 0.625 mg/day or at 5mg/day for variable days before, during, or after being sensitized with DNFB. T cells were isolated in each group and examined. When stimulated antigen-specifically or non-specifically in vitro, mice showed elevated thymidine uptake and a shift of cytokine secretion profiles toward Th1, i.e., elevated levels IL-2, TNF-alpha, and IFN-gamma, and lowered level of the Th2 cytokine IL-4, only when Vitamin C was administered during sensitization. T cells from those mice administered Vitamin C before sensitization or after challenge showed the same T cell properties as those from PBS-treated mice. Mice were also given 0.625 mg/day of Vitamin C during primary and/or secondary immunizations with KLH and secondary specific antibody titers in sera were measured. The total specific antibody titer was lowered in Vitamin C-treated animals whenever treatments were administered, and this was entirely attributed to decreased levels of IgG1 and IgE antibodies. Based on these results, we suggest that an exogenously administered mega-dose of Vitamin C shifts immunity in Balb/c mouse toward Th1 and that these affects occur only when Vitamin C is administered during T cell activation.
authors.affiliation: Tumor Immunity Medical Research Center, Seoul National University College of Medicine, Seoul 110-799, South Korea.
authors.forename: Kahwa
authors.initials: K
authors.lastname: Noh
authors.forename: Hyunja
authors.initials: H
authors.lastname: Lim
authors.forename: Sung-Kyu
authors.initials: SK
authors.lastname: Moon
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Kang
authors.forename: Wang Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Dongsup
authors.initials: D
authors.lastname: Lee
authors.forename: Young-il
authors.initials: YI
authors.lastname: Hwang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D004139:Dinitrofluorobenzene / Q000276:immunology; D004342:Drug Hypersensitivity / Q000276:immunology; D006433:Hemocyanins / Q000276:immunology; D006968:Hypersensitivity, Delayed / Q000139:chemically induced / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007249:Inflammation / Q000188:drug therapy; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D016207:Cytokines; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D006433:Hemocyanins; D004139:Dinitrofluorobenzene; C032808:keyhole-limpet hemocyanin; D001205:Ascorbic Acid