Modulation of interleukin production by ascorbic acid.
We studied the influence of ascorbate (vitamin C) on peripheral blood mononuclear cells (PBMC) of pigs with hereditary deficiency in ascorbate synthesis. Groups of animals were depleted of, or supplemented with dietary ascorbate for up to 5 weeks. B lymphocytes and T lymphocyte subsets differed in the two experimental groups only marginally and transiently as determined by analysis of cell surface markers. The proliferative response of PBMC to B and T lymphocyte mitogens was lower in depleted as compared to supplemented animals. Interleukin (IL)-2 and IL-6 were determined by bioassays and were secreted within few hours after mitogenic activation of PBMC which contained normal physiological concentrations of ascorbate. IL-2 production peaked at about 24 h of in vitro culture after Con A activation, but it lasted for 2-3 days after PWM activation. The production of IL-2 and IL-6 were compared during systemic depletion and supplementation with ascorbate. Depleted PBMC produced IL-2 which accumulated in cultures instead of being rapidly consumed by IL-2 dependent cell growth. This suggests that cellular ascorbate influences the production of IL-2. Secretion of IL-6 by mitogen activated PBMC was also affected by prolonged dietary ascorbate depletion. The results suggest that ascorbate levels exert an early effect on immune homeostasis via reactive oxygen intermediates (ROI)-dependent expression of interleukin genes, since the transcription factor NF-kappa B is sensitive to ROI and regulates the expression of interleukin genes.
Schwager
J
J
Centre de Recherche en Nutrition Animale, Société Chimique Roche S.A. Village-Neuf, France. Joseph.Schwager@Roche.com
Schulze
J
J
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology*; D001206:Ascorbic Acid Deficiency / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis*; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008934:Mitogens / Q000494:pharmacology; D010641:Phenotype; D017382:Reactive Oxygen Species / Q000378:metabolism; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
D007376:Interleukin-2; D015850:Interleukin-6; D007378:Interleukins; D008934:Mitogens; D017382:Reactive Oxygen Species; D001205:Ascorbic Acid