Immune-modulation by polyunsaturated fatty acids

Polyunsaturated fatty acids (PUFAs) are precursormolecules for eicosanoids such as leukotrienes and prostaglandins. Furthermore, PUFAs can alter immune cell function via various mechanisms, including modulation of receptor functions. Immune modulating properties of different dietary fatty acids (FA) (saturated, w-3/w-6 polyunsaturated) were investigated in two mouse models (1) the vaccination model, in which the Delayed Type Hypersensitivity (DTH) response and other immune parameters were studied in C57BL/6 mice and (2) the ovalbumine (OVA)- induced model for experimental allergic asthma in BALB/c mice. 3 wk-old mice were put on different diets two weeks before vaccination (model 1) or sensitization (model 2) until the end of the experiment. In model 1, the DTH- response was highest in mice fed the diet with the highest w-3 PUFA content, indicating that these PUFAs contribute to a boosted Th1-response to vaccination. In model 2, mice fed this latter diet had a less severe acute allergic skin response (ASR), suggesting that w-3 PUFAs in this diet may lessen the Th2-response. In addition, the most severe ASR was observed in mice fed a saturated FA diet, indicating that a diet with high levels of saturated FA may contribute to an increased severity of allergic symptoms.