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Individual and combined effects of cadmium and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on the humoral immune response in European eel (Anguilla anguilla) experimentally infected with larvae of Anguillicola crassus (Nematoda)

Published online by Cambridge University Press:  16 April 2004

B. SURES  and
K. KNOPF
B. SURES
Affiliation:
Zoologisches Institut I Ökologie-Parasitologie, Universität Karlsruhe, Kornblumenstrasse 13, D-76128 Karlsruhe, Germany
K. KNOPF
Affiliation:
Leibniz-Institut für Gewässerökologie und Binnenfischerei, Abt. Binnenfischerei, Müggelseedamm 310, D-12587 Berlin, Germany
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Abstract

The individual and combined effects of cadmium (Cd) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on the antibody response of fish against metazoan parasites were tested. Eels experimentally infected with the swim bladder nematode Anguillicola crassus were exposed to sublethal concentrations of Cd and PCB 126. Cd was added to the water resulting in an effective concentration of 21·7±12·8 μg/l (mean±S.D.). PCB 126 was applied orally at a dose of approximately 100 ng PCB 126 per g body weight. At the end of the experiment, 76 days post-infection (p.i.), eels were found to be infected with 2–3 worms. Immunoblot analyses revealed that the body wall of adult worms was the most suitable crude antigen, and was subsequently used for an ELISA to evaluate the immune response of A. anguilla under various conditions. A significant increase of Anguillicola-specific antibodies in the peripheral blood was first detected 61 days p.i., indicating that it was not the invasive larvae but the adult worms which elicit the antibody response. The presence of Cd in the concentrations applied did not appear to modulate the production of antibodies. In contrast, the exposure to PCB 126 resulted in a complete suppression of the antibody response. A similar effect was also found for the combined exposure of the infected eels to Cd and PCB 126. A suppressed immune response, as demonstrated here, may be the reason why hosts exposed to environmental pollution became often much more easily infected than unexposed conspecifics.

Keywords

Anguilla anguillapollutioncadmiumPCB 126parasitesantibody responseimmunosuppression
Type
Research Article
Information
Parasitology , Volume 128 , Issue 4 , April 2004 , pp. 445 - 454
Copyright
© 2004 Cambridge University Press

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