Effects of individual polybrominated diphenyl ether (PBDE) congeners on harbour seal immune cells in vitro

Effects of polybrominated diphenyl ethers (PBDEs) on the immune system of marine mammals are poorly understood. One important innate immune function of granulocytes is the respiratory burst which generates reactive oxygen species (ROS) used to kill engulfed microorganisms. The present study investigates in vitro the effects of BDE-47, -99 and -153, on the formation of ROS, on intracellular level of thiols, on activity and efficiency of phagocytosis and on apoptosis in granulocytes of harbour seals. Compounds were tested at four different concentrations ranging from 1.5 to 12 microM. Results showed that ROS levels, thiol levels and phagocytosis were all affected when harbour seal cells were exposed to the highest concentration (12 microM) of PBDE congeners. Apoptosis was not affected by PBDEs. The observed effects were similar in adults, pups and in the 11B7501 cell line of harbour seals.