title: Vitamin E is an important factor in T cell differentiation in thymus of F344 rats.
abstract: The effect of vitamin E (dl-alpha-tocopheryl acetate) on T cell differentiation in thymus of F344 rats was examined in this study. The rats were divided into three groups: vitamin E-free, regular and high vitamin E groups and fed a diet containing various levels of vitamin E (0, 50, and 585 mg/kg diet) for 7 weeks. The number of thymocytes was significantly lower in the vitamin E-free group relative to the regular group. Although the proportions of both CD4+CD8- and CD4-CD8+ T cells in thymocytes were significantly greater in the high vitamin E group, the proportion of CD4+CD8- T cells inversely decreased in vitamin E-free group compared to that of the regular group. The ratio of CD4+CD8-/CD4-CD8+ T cells increased in the high vitamin E group (p < 0.01) and significantly decreased in the vitamin E-free group (p < 0.001) compared to that of the regular group. Although the marked changes of T cell subsets were not seen in peripheral blood lymphocytes (PBL), the ratio of CD4+CD8-/CD4-CD8+ T cells was significantly lower in the vitamin E-free group and significantly greater in the high vitamin E group compared to that of the regular group. Production of interleukin (IL) 2 by thymocytes following the stimulation with Con A for 48 h increased about threefold in the high vitamin E group compared to the regular group. Conversely, thymocytes from rats fed the vitamin E-free diet showed a significant decrease of IL2 production compared to that of the regular group. Prostaglandin E2 (PGE2) production from thymocytes was significantly lower in the high vitamin E group compared to that of the regular group, whereas thymocytes of rats fed the vitamin E-free diet showed a significant increase of PGE2 production compared to that of rats fed the regular diet. Furthermore, in vitro addition of indomethacin provided a restoration of IL2 production from thymocytes of rats fed the vitamin E-free diet to the level of rats fed the regular diet. These results suggest that vitamin E plays an important role in T cell differentiation in thymus, which may be related to the action of vitamin E as antioxidant.
authors.affiliation: Department of Nutrition, School of Medicine, University of Tokushima, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Moriguchi
authors.forename: H
authors.initials: H
authors.lastname: Miwa
authors.forename: M
authors.initials: M
authors.lastname: Okamura
authors.forename: K
authors.initials: K
authors.lastname: Maekawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kishino
authors.forename: K
authors.initials: K
authors.lastname: Maeda
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D016516:CD4-CD8 Ratio / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D004032:Diet; D015232:Dinoprostone / Q000096:biosynthesis; D005434:Flow Cytometry; D007213:Indomethacin / Q000494:pharmacology; D007376:Interleukin-2 / Q000096:biosynthesis; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D013601:T-Lymphocytes / Q000187:drug effects*; D013950:Thymus Gland / Q000187:drug effects* / Q000276:immunology; D014810:Vitamin E / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D007376:Interleukin-2; D010835:Phytohemagglutinins; D003208:Concanavalin A; D014810:Vitamin E; D015232:Dinoprostone; D007213:Indomethacin