Dietary (n-6) and (n-3) fatty acids and energy restriction modulate mesenteric lymph node lymphocyte function in autoimmune-prone (NZB x NZW)F1 mice

We previously showed that dietary fish oil (FO) and energy restriction (R) have beneficial antiinflammatory properties in the peripheral blood and spl eens of (NZB x NZW)F1 (B/W) lupus-prone mice. Furthermore, unsaturated fatt y acids also were shown in the past to influence mesenteric lymph node (MLN ) lymphocyte function in healthy young rats. The MLN play a pivotal role in mediating food allergy. To date, the effect of R on intestinal immunity is not well understood; therefore we determined the effect of diet on MLN lym phocyte function. Mice were given either free access to a 5 g/100 g corn oi l (CO) or fish oil (FO) diet or the same corn oil (CR) or fish oil (FR) die ts restricted to 60% of the intake of the control group. At the age of 4 (y oung) and 8 told) mo, MLN lymphocytes were isolated and B- (CD19(+)) and T- lymphocyte subsets (CD4(+) and CD8(+)) were determined by flow cytometry. A dditional MLN lymphocytes were placed in culture with or without concanaval in A and culture supernatants collected after 72 h for cytokine and immunog lobulin (Ig) quantitation by ELISA. Aging significantly (P < 0.05) decrease d both CD4(+) and CD8(+) T-lymphocytes. Spontaneous and activation-induced interleukin-4 (IL-4), IL-10, and interferon-gamma secretion were greater wh ile IL-2 was lower in CO-fed old mice compared to CO-fed young mice. In con trast, GR or FO alone partially blunted the age-dependent alterations in T- lymphocyte ratios including cytokine and Ig secretion, whereas the FR diet significantly (P < 0.005) normalized the accelerated aging effects on these immune variables. We show for the first time that FR is a far more potent anti-inflammatory therapy than either GR or FO alone in modulating MLN lymp hocyte function.