(P30-041-23) Effects of Egg Consumption on the Capacity of HDL To Modulate T Cell Activation

Objectives: We previously demonstrated that consumption of egg whites vs. whole eggs alters HDL composition and function, and that changes in clinical HDL profiles correlate with peripheral blood mononuclear cell (PBMC) expression of genes involved in T cell activation. Thus, we investigated whether HDL following egg intake could directly regulate T cell activation, and whether T cell effects were associated with changes in HDL composition and efflux capacity.

Methods: Healthy men and women (n = 26) participated in a 16-week randomized, crossover intervention trial in which they followed a 4-week egg-free diet, followed by random assignment to a 4-week diet period in which they consumed 3 whole eggs/day or 3 egg whites/day. Participants were then switched to the alternative egg treatment following a second 4-week egg-free washout period. Fasted blood samples were collected after each diet period to isolate HDL for compositional analysis and Jurkat T cell activation assays on a preliminary subset of subjects.

Results: Independent of egg intake, HDL dose-dependently increased T cell counts and interleukin-2 (IL-2) secretion. These changes were inversely associated with lipid raft formation, with high-dose HDL treatments reducing lipid raft formation relative to control. We next evaluated whether HDL following egg white and whole egg intake differentially impacted T cell activation. While HDL did not impact T cell lipid raft formation or IL-2 production between diet periods, we observed that HDL increased cell viability following both the egg white and whole egg diet period relative to the egg-free diet period, while HDL following the whole egg diet increased average T cell size. Changes in T cell activation measures and total blood lymphocytes between egg white and whole egg diet periods correlated with shifts in the HDL proteome and lipidome, but not efflux capacity or serum sphingosine-1-phosphate levels.

Conclusions: Our findings suggest that HDL can directly and dose-dependently modulate T cell activation and lipid raft formation, and that HDL effects on T cell activation following egg intake correlate with changes in the HDL composition.

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 grant from the University of Connecticut.