Effect of the succession of endosulfan exposure and bacterial challenge on DNA integrity and non specific immunity of the three-spine stickleback, Gasterosteus aculeatus

Adrien Marchand (1, 2) , Jean-Marc Porcher (1, 2) , Cyril Turies (1) , Edith Chadili (1, 2) , Stéphane Betoulle (2) , Anne Bado-Nilles (1, 2)

1 INERIS - Institut National de l'Environnement Industriel et des Risques
2 SEBIO - Stress Environnementaux et BIOsurveillance des milieux aquatiques

Endosulfan (C9H6Cl6O3S) is an active substance of phytosanitary products widely found in surface water, groundwater, sediment and rain of many regions in the world and an important source of poisoning in many countries. Endosulfan is known to have genotoxic and immunostimulating effects such as increase of phagocytic capacity. The immune system, in particular innate immune response, seems to be very attractive for biomonitoring due to its connection with organism health status. Indeed, fish weakened by chemical stress might be unable to resist against pathogen aggression. In fact, a connection has been established between the destabilization of the fish immune system, caused by sub-lethal doses of contaminants, and a defect in fish pathogen resistance. In this context, the stresses induced by chemical (chlorpyrifos) and succession of chemical/pathogens (LPS endotoxin) were determined in the three-spined stickleback, Gasterosteus aculeatus, after 4 days of exposure. A loss of DNA integrity was observed after exposure to 1.75 µg.L during 4 days. An increase of splenic leucocytes phagocytic abilities was observed in addition of a reduction of oxidative stress. Moreover, the injection of LPS following endosulfan exposure seems to provoke a destabilization of fish immune system with drastic decrease of phagocytic efficiency and increase of cell mortality by apoptosis. These results may be linked to endocrine disruptor properties of endosulfan and its ability to mimic cytokine signal. This study points out the importance of stress on stress experiments to determine all potential effects of chemical exposure in fish.

Domains: Ecotoxicology

Adrien Marchand, Jean-Marc Porcher, Cyril Turies, Edith Chadili, Stéphane Betoulle, et al.. Effect of the succession of endosulfan exposure and bacterial challenge on DNA integrity and non specific immunity of the three-spine stickleback, Gasterosteus aculeatus. 27. SETAC Europe annual meeting, May 2017, Bruxelles, France. ⟨ineris-01863852⟩