Project Number: 1950-51000-058-00
Project Type: Appropriated

Start Date: May 01, 2004
End Date: Apr 30, 2009

Objective:
LAB:Nutrition, aging, immune function and inflammatory response in health and disease Determine the mechanisms of vitamin E-induced enhancement of T cell function in the aged. Determine the efficacy of vitamin E in reducing the pathogenesis of secondary bacterial infection following influenza infection. Determine the role of adipocytes and obesity in age-related immune and inflammatory dysregulation and pathologies associated. Determine the effect and mechanisms of food components and their interaction with age and genetic background on immune function and infectious diseases. LAB:Vascular biology Determine at molecular and cellular levels the mechanisms by which the antioxidant components of foods (vitamins E, carotenoids and polyphenols such as catechins) singly and interactively modulate development of atherosclerosis and angiogenesis. Determine the effect of components of foods-vitamin E, carotenoids, lipids and polyphenols such as catechins, as well as their synergistic interactions in preventing and in reducing the risk of atherosclerosis, specifically when they are incorporated into the diet of animal models early in life compared to middle and later ages.

Approach:
LAB:Nutrition, aging, immune function and inflammatory response in health and disease The mechanism of vitamin E-induced enhancement of T cell function will be determined by investigating the effect of age and vitamin E supplementation on T cell receptor induced immune synapse formation using confocal microscopy of single and two-colored stained naïve T cells from young and old mice supplemented with or without vitamins. The mechanism of E-induced enhancement of effective immune synapse formation will further be determined by investigating the effect of age and vitamin E on the association of critical signaling molecules with membrane lipid domains known as lipid rafts using Western blots of phosphorylated and non-phosphorylated forms, of existing proteins, and S-methionine metabolic labeling of newly synthesized proteins. The mechanism of E-induced changes in association with the above key signaling molecules with lipid rafts will be determined by investigating the effect of age and vitamin E on palmitoylation of LAT (linker for activation of T Cells) and Lck (a Src family kinase) in young and old naïve T cells using metabolic labeling. In addition, sphingolipid and cholesterol composition of lipid rafts will be determined using HPLC and tandem mass spectrometry. The effect of vitamin E on downstream signaling molecules will be determined by focusing on Ca2+ mobilization and NFAT, NFKB, and AP-1 activities. The efficacy of vitamin E in preventing secondary bacterial infection in aged mice will be tested by feeding young and old C57BL/6 mice with adequate (30 ppm) or high (500 ppm) levels of E and determining viral and bacterial titers as well as morbidity and mortality after primary influenza A or S. aureus infection, or following a secondary S. aureus infection subsequent to an influenza infection. Preliminary experiments will be conducted to determine the underlying mechanisms. LAB:Vascular Biology The effect of mixed tocopherols at the concentrations commonly found in human plasma and after vitamin E supplementation will be examined in a cell culture system for modulation of immune and endothelial cell interaction and inflammatory cytokines. In this system, the interaction of vitamin E with avenathramide , a flavonoid found in oats, will be also tested for anti-atherogenic and anti-inflammatory action. The molecular mechanism of green tea catechins' inhibition of angiogenesis will be tested in a cell culture system using Matrigel and 3D gel. This effect of green tea will be investigated in vivo using the Matrigel plug assay in young and aged mice. The effect of vitamin E supplementation started from early, middle, and late age on the inhibition of atherosclerosis will be determined in LDL receptor null mice, which will be fed medium or high fat/cholesterol diets. The potential inhibitory effect of dietary vitamin E on the inhibition of atherosclerosis will be further tested in mice models when vitamin E is combined with lycopene, a carotenoid found in tomato, and with epigallocatechin gallate, the major catechin of green tea.