Project Number: 1950-51000-058-03
Project Type: Specific Cooperative Agreement

Start Date: Oct 01, 2006
End Date: Sep 30, 2011

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.

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 naive 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 naive 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.