title: Vitamin E and immune response in the aged: molecular mechanisms and clinical implications.
abstract: Nutritional status has been indicated as a contributing factor to age-related dysregulation of the immune response. Vitamin E, a lipid-soluble antioxidant vitamin, is important for normal function of the immune cells. The elderly are at a greater risk for vitamin E intake that is lower than recommended levels. Vitamin E supplementation above currently recommended levels has been shown to improve immune functions in the aged including delayed-type hypersensitivity skin response and antibody production in response to vaccination, which was shown to be mediated through increased production of interleukin (IL)-2, leading to enhanced proliferation of T cells, and through reduced production of prostaglandin E(2), a T-cell suppressive factor, as a result of a decreased peroxynitrite formation. Vitamin E increased both cell-dividing and IL-producing capacities of naive T cells, but not memory T cells. The vitamin E-induced enhancement of immune functions in the aged was associated with significant improvement in resistance to influenza infection in aged mice and a reduced risk of acquiring upper respiratory infections in nursing home residents. Further studies are needed to determine the signaling mechanisms involved in the upregulation of naive T-cell function by vitamin E as well as the specific mechanisms involved in reduction of risk for upper respiratory infections.
authors.affiliation: Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA. simin.meydani@tufts.edu
authors.forename: Simin Nikbin
authors.initials: SN
authors.lastname: Meydani
authors.forename: Sung Nim
authors.initials: SN
authors.lastname: Han
authors.forename: Dayong
authors.initials: D
authors.lastname: Wu
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D015232:Dinoprostone / Q000378:metabolism; D006801:Humans; D007107:Immune System / Q000187:drug effects* / Q000276:immunology*; D007239:Infections / Q000178:diet therapy / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014810:Vitamin E / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D014810:Vitamin E; D015232:Dinoprostone