Effects of Daily Egg Intake in Altering the Capacity of HDL to Modulate Primary T Cell Activation

Objectives: Daily egg consumption alters the immunomodulatory properties of HDL – including the capacity to regulate activation of macrophage and CD4+ T cell lines. Thus, we further investigated whether egg intake could impact HDL's capacity to modulate primary T cell activation, and whether these effects were associated with changes in expression of HDL-related lipid efflux transporters. Methods: Young, healthy men and women (age 18-35y) participated in a 16-week randomized, crossover intervention trial in which they consumed 3 whole eggs/day or 3 egg whites/day for 4 weeks, preceded and separated by 4-week egg-free washout periods. Total T cells were activated with anti-CD3/CD28 antibodies in the presence of a preliminary subset of subject-derived HDL (300 μg/ml) for 24 hours (n = 9), then cells and were collected to assess cellular expansion and expression of genes involved in T cell activation and HDL-related lipid flux. Results: Egg intake did not impact HDL's capacity to modulate activated T cell expansion, viability, or size. Similarly, mRNA expression of STAT5A and STAT5B in activated T cells was not altered by HDL isolated after different egg diets. Conversely, mRNA expression of CD69 was increased by HDL across all egg diets relative to activated control cells lacking HDL treatment, and mRNA expression of IL2 trended toward being increased following the whole egg diet, as compared to the egg white diet. Interestingly, mRNA expression of ABCA1 and ABCG1 were decreased by HDL following the whole egg diet relative to other diet periods. In evaluating individual responses to diet, we observed that changes in HDL-mediated IL2 mRNA expression in activated T cells from the egg white to whole egg period positively correlated with changes in STAT5B and SCARB1 mRNA expression, but negatively correlated with changes in ABCG1 mRNA expression. Conclusions: Our findings suggest that consumption of different egg-based diet may alter HDL's capacity to modulate primary T cell activation, which is associated with changes in the expression of transporters that mediate lipid flux. Funding Sources: This study was funded by an Agriculture and Food Research Initiative Grant from the USDA National Institute of Food and Agriculture and pilot funding from the University of Connecticut.