Vitamin E and immune response in the aged: molecular mechanisms and clinical implications.
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.
Meydani
Simin Nikbin
SN
Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA. simin.meydani@tufts.edu
Han
Sung Nim
SN
Wu
Dayong
D
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
D014810:Vitamin E; D015232:Dinoprostone