Vitamin E-enhanced IL-2 production in old mice: naive but not memory T cells show increased cell division cycling and IL-2-producing capacity.
Aging is associated with reduced T cell function, as demonstrated by decreased T cell proliferation and IL-2 production. These changes respond to supplemental vitamin E both in animals and humans, in part by the reduction of T cell suppressive PGE(2), the production of which by macrophages is increased with age. To evaluate whether vitamin E has a direct PGE(2)-independent effect on T cell responses, T cells purified from the spleens of young and old mice were preincubated with vitamin E or vehicle control. Activation-induced cell division of T cells from old mice was lower than that by young, and the production of IL-2 following 48-h activation was less by T cells from old mice. There was an age-related decline in both the number of IL-2+ T cells and the amount of IL-2 produced per cell. Despite decreased IL-2 protein at 48 h, the expression of IL-2 mRNA at 6 h and IL-2 protein production at 6 and 16 h was greater by T cells from old mice compared with that of young. Age-related decline in cell division and IL-2 production at 48 h was only observed within the naive T cell subpopulation. Vitamin E increased both cell-dividing and IL-2-producing capacity of naive T cells from old mice, with no effect on memory T cells. These data indicate that naive T cells exhibit the greatest age-related defect and show for the first time that supplemental vitamin E has direct immunoenhancing effect on naive T cells from old mice.
Adolfsson
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Nutritional Immunology Laboratory, Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA 02111, USA.
Huber
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BT
Meydani
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D000375:Aging / Q000276:immunology*; D000818:Animals; D002453:Cell Cycle; D002455:Cell Division; D002478:Cells, Cultured; D018960:Hyaluronan Receptors / Q000378:metabolism; D007156:Immunologic Memory; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000235:genetics; D007700:Kinetics; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018448:Models, Immunological; D012333:RNA, Messenger / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014810:Vitamin E / Q000494:pharmacology*; D024502:alpha-Tocopherol / Q000378:metabolism
D018960:Hyaluronan Receptors; D007376:Interleukin-2; D012333:RNA, Messenger; D014810:Vitamin E; D024502:alpha-Tocopherol