title: Influence of ascorbic acid on the response to mitogens and interleukin production of porcine lymphocytes.
abstract: The influence of ascorbic acid (AA) on lymphocyte functions was examined in vitro and ex vivo in peripheral blood mononuclear cells (PBMC) of vitamin C-deficient pigs, which are unable to synthesise ascorbic acid. AA is accumulated to physiological levels in PBMC in vitro. The cell proliferation induced by T lymphocyte mitogens was unaltered at all AA concentrations tested (0-400 micrograms/ml, i.e., 0-2.3 mM). Conversely, the response to pokeweed mitogen (PWM) which activates T and B lymphocytes was significantly reduced with increasing intracellular and extracellular AA concentrations. The response to lipopolysaccharide (LPS) showed a tendency to increase at low (9 microM) and was significantly reduced at high AA concentrations (> 36 microM). The IL2 production induced by PWM (but not by concanavalin A (Con A) or phytohemagglutinin (PHA)) decreased at high AA (> 142 microM). In contrast, IL6 production induced by mitogens was not dependent on AA concentrations. In concordance with these results, AA-depleted PBMC which were obtained from pigs that were fed an AA-free diet, displayed an increasing response to LPS and PWM. Collectively, the data indicate that ascorbic acid selectively influences the proliferation of B lymphocytes and negatively acts on IL2 production by T lymphocytes when a threshold of saturation is exceeded.
authors.affiliation: Centre de Recherche en Nutrition Animale, Socìeté Chimique Roche, Village-Neuf, France.
authors.forename: J
authors.initials: J
authors.lastname: Schwager
authors.forename: J
authors.initials: J
authors.lastname: Schulze
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology*; D001206:Ascorbic Acid Deficiency / Q000097:blood; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D007376:Interleukin-2 / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D008934:Mitogens / Q000494:pharmacology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013552:Swine; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
chemical_list: D007376:Interleukin-2; D015850:Interleukin-6; D008070:Lipopolysaccharides; D008934:Mitogens; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D003208:Concanavalin A; D001205:Ascorbic Acid