Copper induced immunomodulation in the marine mussel, Mytilus edulis

The effects on the immune response of the mussel, Mytilus edulis, of short- term in-vivo exposure to copper were investigated under laboratory-controll ed conditions. Parameters measured concentrated on the ability of the blood cells to destroy invading pathogens and included changes in the number and character of the: circulating haemocytes, peroxidase and phenoloxidase enz yme activity in the blood cells, intra- and extracellular superoxide radica l production, phagocytosis and uptake of neutral red. Copper concentrations of 0.02 and 0.05 ppm were found to increase significantly the total number of circulating haemocytes, while 0.2 and 0.5 ppm decreased the proportion of eosinophilic to basophilic cells, Intracellular superoxide production si gnificantly decreased on exposure to 0.5 ppm copper, whereas phagocytic act ivity was stimulated at 0.2 ppm but not at 0.5 ppm. Copper exposures of 0.2 and 0.5 ppm reduced the percentage of haemocytes showing binding of lectin s from Galanthus nivalis and Helix pomatia compared with haemocytes from mu ssels not dosed with copper. No significant alterations were found in perox idase and phenoloxidase activity, binding of wheat germ agglutinin or uptak e of neutral red. The results are discussed in the light of elucidating the possible relationship between environmental contaminants and increased dis ease susceptibility in aquatic organisms. The benefits of using a multi-ass ay approach to monitoring environmental pollution using such methods are hi ghlighted. (C) 1999 Elsevier Science B.V. All rights reserved.