Positive Health Online

Abstract

MARKO and COLLEAGUES, Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA evaluated the effect of in vitro supplementation with vitamin E upon T cell signalling events of CD4+ T cells.

Background

Supplemental vitamin E alleviates age-related defects in interleukin (IL)-2 production, T cell proliferation, and immune synapse formation.

Methodology

Here, we evaluated the effect of in vitro supplementation with 46 mumol/L of vitamin E on T cell receptor-proximal signaling events of CD4(+) T cells from young (4-6 mo) and old (22-26 mo) C57BL mice. Aged murine CD4(+) T cells stimulated via CD3 and CD28, tyrosine 191 of the adaptor protein Linker for Activation of T cells (LAT), was hypo-phosphorylated. Supplementation with vitamin E eliminated this difference in the tyrosine phosphorylation of LAT.

Results

By using a flow cytometric assay, the age-related differences in the activation-induced phosphorylation of LAT were observed in both naive and memory T cell subsets. In addition, supplementation with vitamin E eliminates the age-related differences in LAT phosphorylation in both T cell subsets. Neither age nor vitamin E supplementation altered the fraction of LAT entering the membrane compartment.

Conclusion

Furthermore, neither age nor vitamin E influenced the phosphorylation of Lck and Zap70, indicating that associated changes in LAT phosphorylation were not caused by alterations in activation states of the upstream kinases Lck and Zap70.

References

Marko MG, Pang HJ, Ren Z, Azzi A, Huber BT, Bunnell SC and Meydani SN. Vitamin E reverses impaired linker for activation of T cells activation in T cells from aged C57BL/6 mice. Journal of Nutrition. 139(6):1192-7. Jun 2009. Source: NLM. PMC2714384 [Available on 06/01/10]