DIETARY POLYUNSATURATED FATTY-ACID EFFECTS ON IMMUNE CELLS OF THE PORCINE LUNG

The effects of various dietary polyunsaturated fatty acids (PUFAs) on the function of immune cells of the porcine lung was studied. Groups o f six pigs were fed diets containing 10.5 % corn oil [CO; enriched in linoleic acid (18:2, n-6)], linseed oil (LO; enriched in alpha-linolen ic acid (18:3, n-3)], menhaden oil (MO; enriched in eicosapentaenoic ( 20:5; n-3) and docosahexaenoic (22:6; n-3) acids], linseed + corn oil (1:1; LC), and menhaden + corn oil (1:1; MC) for 28-30 days. Basal lev els of alveolar macrophage (m phi) tumor necrosis factor-alpha (TNF-al pha) production were higher (P < .05) for LC- and MC-fed pigs than for CO- and LO-fed pigs. Lipopolysaccharide (LPS)-stimulated LC and MC m phi s produced more TNF than m phi s from pigs fed CO, LO, and MO diet s. Macrophages from pigs receiving the CO and LC diets had higher (P < .05) levels of leucine aminopeptidase than m phi s from the other die tary groups. Lipopolysaccharide did not increase m phi nitrite product ion over basal levels except in the MO diet group. However, LPS-stimul ated m phi s from the CO, MO, and LC dietary groups produced more nitr ite than m phi s from MC-fed pigs. Alveolar lymphocytes from pigs rece iving the MC diet produced more T cell growth factors than LO and MO m phi s. Alveolar m phi s from the different dietary groups did not dif fer in their capacity for non-immune-mediated phagocytosis of fluoresc ent latex beads. These results indicate that dietary PUFAs can modulat e some functions of porcine alveolar immune cells and that this may pr ove significant for host response to respiratory disease agents.