Modulatory effects of long-chain n-3 fatty acids on cell functions.

In recent years, it has been demonstrated that certain fatty acids are involved in the modulation of immune system functions. The mechanisms responsible for these effects are not fully elucidated, but many hypotheses have described numerous changes in the cell functionality as the main factors capable of altering the immune functions. In the present investigation, we have analysed the potential effects of FFA on cell viability, production of superoxide radicals or proteasome activity in assays in vitro. Thus, different FFA, such as OA, EPA or SA have been incorporated to cellular cultures at a concentration of 100 microM. Phospholipase, cyclooxygenase or lipooxygenase inhibitors abolished the loss of thymocyte viability exerted by EPA, the most immunosuppressive fatty acid. Similarly, measurement of the oxidative process by NBT reduction in cells treated with EPA was markedly increased. Nevertheless, the proteasome activity as a mechanism that participates in T-cell activation was not modified by direct action of the different fatty acids on the in vitro cultures. Overall, these results underline the differential role of several fatty acids (particularly long-chain n-3 polyunsaturated fatty acids) in order to modulate many functions of the immune system.