Effect of dietary n-3 fatty acids on interleukin-2 and interleukin-2 receptor alpha expression in activated murine lymphocytes.

Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) suppress interleukin-2 (IL-2) secretion and impair T-lymphocyte proliferation. To determine the mechanism of action, mice were fed diets containing either safflower oil (control diet enriched in linoleic acid, 18:2n-6), EPA, DHA or arachidonic acid (20:4n-6). Splenic lymphocytes were isolated and concanavalin A-induced kinetics of IL-2 and IL-2 receptor alpha mRNA expression were determined by relative competitive-PCR. EPA and DHA did not affect IL-2 mRNA expression but suppressed IL-2 receptor alpha mRNA levels. These data show, for the first time, the selective effects of dietary EPA and DHA on T-lymphocyte gene expression.