Plant- and Animal-Derived Dietary Sources of Phosphatidylcholine Have Differential Effects on Immune Function in The Context of A High-Fat Diet in Male Wistar Rats

Abstract

BackgroundPhosphatidylcholine (PC) derived from eggs has been shown to beneficially modulate T cell response and intestinal permeability under the context of a high-fat diet. ObjectivesThe objective of this study was to determine whether there is a differential effect of plant and animal-derived sources of PC on immune function. MethodsFour-week-old male Wistar rats were randomly assigned to consume 1 of 4 diets (n = 10/group) for 12 wk, all containing 1.5 g of total choline/kg of diet but differing in choline forms: 1—Control Low-Fat [CLF, 20% fat, 100% free choline (FC)]; 2—Control High-Fat (CHF, 50% fat, 100% FC); 3—High-Fat Egg-derived PC (EPC, 50% fat, 100% Egg-PC); 4—High-Fat Soy-derived PC (SPC, 50% fat, 100% Soy-PC). Immune cell functions and phenotypes were measured in splenocytes by ex vivo cytokine production after mitogen stimulation and flow cytometry, respectively. ResultsThe SPC diet increased splenocyte IL-2 production after PMA+I stimulation compared with the CHF diet. However, the SPC group had a lower proportion of splenocytes expressing the IL-2 receptor (CD25+, P < 0.05). After PMA+I stimulation, feeding EPC normalized splenocyte production of IL-10 relative to the CLF diet, whereas SPC did not (P < 0.05). In mesenteric lymph node lymphocytes, the SPC diet group produced more IL-2 and TNF-α after PMA+I stimulation than the CHF diet, whereas the EPC diet group did not. ConclusionsOur results suggest that both egg- and soy-derived PC may attenuate high-fat diet-induced T cell dysfunction. However, egg-PC enhances, to a greater extent, IL-10, a cytokine involved in promoting the resolution phase of inflammation, whereas soy-PC appears to elicit a greater effect on gut-associated immune responses.