Age-associated changes in immune and inflammatory responses: impact of vitamin E intervention

J Leukoc Biol. 2008 Oct;84(4):900-14. doi: 10.1189/jlb.0108023. Epub 2008 Jul 2.

Abstract

Aging is associated with dysregulated immune and inflammatory responses. Declining T cell function is the most significant and best-characterized feature of immunosenescence. Intrinsic changes within T cells and extrinsic factors contribute to the age-associated decline in T cell function. T cell defect seen in aging involves multiple stages from early receptor activation events to clonal expansion. Among extrinsic factors, increased production of T cell-suppressive factor PGE(2) by macrophages (Mphi) is most recognized. Vitamin E reverses an age-associated defect in T cells, particularly naïve T cells. This effect of vitamin E is also reflected in a reduced rate of upper respiratory tract infection in the elderly and enhanced clearance of influenza infection in a rodent model. The T cell-enhancing effect of vitamin E is accomplished via its direct effect on T cells and indirectly by inhibiting PGE(2) production in Mphi. Up-regulated inflammation with aging has attracted increasing attention as a result of its implications in the pathogenesis of diseases. Increased PGE(2) production in old Mphi is a result of increased cyclooxygenase 2 (COX-2) expression, leading to higher COX enzyme activity, which in turn, is associated with the ceramide-induced up-regulation of NF-kappaB. Similar to Mphi, adipocytes from old mice have a higher expression of COX-2 as well as inflammatory cytokines IL-1beta, IL-6, and TNF-alpha, which might also be related to elevated levels of ceramide and NF-kappaB activation. This review will discuss the above age-related immune and inflammatory changes and the effect of vitamin E as nutritional intervention with a focus on the work conducted in our laboratory.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Aged
  • Aging / immunology
  • Aging / physiology*
  • Animals
  • Antigen-Presenting Cells / immunology
  • Dinoprostone / metabolism
  • Humans
  • Infections / epidemiology
  • Infections / immunology
  • Inflammation / immunology*
  • Inflammation / physiopathology*
  • Inflammation / prevention & control
  • Middle Aged
  • Models, Animal
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology*
  • Vitamin E / therapeutic use

Substances

  • Vitamin E
  • Dinoprostone