Immunomodulation by polyunsaturated fatty acids: mechanisms and effects

Abstract

Polyunsaturated fatty acids (PUFAs) modulate immune responses, thereby exerting beneficial effects in a variety of inflammatory disorders. PUFAs of the n-3 series that are found in marine fish oils are particularly effective. A variety of molecular mechanisms have been found to explain how PUFAs could interfere with immune cell function. PUFAs alter eicosanoid (prostaglandin, leukotriene) synthesis, orphan nuclear receptor activation (e.g. peroxisome proliferator-activated receptors, liver X receptors) and T lymphocyte signaling by changing the molecular composition of special signaling platforms called lipid rafts. This review discusses these mechanisms in detail with respect to their probable relevance in vivo. In addition, the effects of PUFAs on the immune system in general are summarized, as are clinical effects in rheumatoid arthritis, inflammatory bowel disease and sepsis.