title: Vitamin E and immunity.
abstract: Vitamin E is a potent antioxidant and has an ability to modulate host immune functions. This chapter consists of five parts: (1) vitamin E deficiency and immunity, (2) vitamin E supplementation and immunity, (3) vitamin E and the decreased cellular immunity with aging, (4) vitamin E and T-cell differentiation in the thymus, and (5) vitamin E and acquired immune deficiency syndrome (AIDS). In vitamin E deficiency most of the immune parameters show a downward trend, which is associated with increased infectious diseases and the incidence of tumors. In contrast, vitamin E supplementation has various beneficial effects on the host immune system. The decreased cellular immunity with aging or during the development of AIDS is markedly improved by the intake of a high vitamin E diet. In addition, vitamin E plays an important role in the differentiation of immature T cells in thymus. Vitamin E deficiency induces the decreased differentiation of immature T cells, which results in the early decrease of cellular immunity with aging in spontaneously hypertensive rats. Conversely, vitamin E supplementation induces a higher differentiation of immature T cells via increased positive selection by thymic epithelial cells, which results in the improvement of decreased cellular immunity in the aged. Furthermore, vitamin E supplementation induces the early recovery of thymic atrophy following X-ray irradiation. Taken together, these results suggest that vitamin E is an important nutrient for maintaining the immune system, especially in the aged.
authors.affiliation: Department of Nutrition, Faculty of Human Life Science, Yamaguchi Prefectural University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Moriguchi
authors.forename: M
authors.initials: M
authors.lastname: Muraga
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000178:diet therapy / Q000276:immunology; D000375:Aging / Q000276:immunology* / Q000502:physiology; D000818:Animals; D019587:Dietary Supplements; D006801:Humans; D007111:Immunity, Cellular / Q000502:physiology; D051379:Mice; D051381:Rats; D013950:Thymus Gland / Q000276:immunology / Q000502:physiology; D014810:Vitamin E / Q000276:immunology* / Q000502:physiology; D014811:Vitamin E Deficiency / Q000276:immunology*
chemical_list: D014810:Vitamin E