PW12 Pesticide II
Exhibit Hall
8:00 AM - Wednesday
(PW200) Effects of pesticides on antibody response and cytokine transcription of juvenile Chinook salmon (Oncorhynchus tshawytscha).
Eder, K1, Adkison, M1, Werner, I1, 1 UC Davis, Davis, CA, 95616
ABSTRACT- Results from U.S. National Water-Quality Assessment (NAWQA) studies show, that contamination from pesticides is widespread in streams and ground water throughout the nation's agricultural and urban areas, often times exceeding guidelines for the protection of aquatic life. Environmental pollution has been associated with a higher incidence of disease in fish. Pesticides have been shown to have an immunosuppressive effect on fish, but relatively little is known concerning the toxic effects of specific chemical pollutants on immune defense mechanisms. The objective of our study was to examine the immune response of pesticide-treated salmon to an administered antigen, and to measure the transcription of several cytokines in responding fish. We exposed juvenile Chinook salmon to sublethal concentrations of two widely used insecticides, the organophosphate chlorpyrifos and the pyrethroid esfenvalerate, followed by immediate immunization to dinitrophenylated-keyhole limpet hemocyanin (DNP-KLH) by intraperitoneal injection. Serum- and tissue samples were collected six, eight and ten weeks after immunization. The expression of four cytokines was quantitated by real-time TaqMan PCR. Antibody titers in serum samples were determined by enzyme-linked immunosorbent assay (ELISA). The number of individuals producing a measurable antibody response to DNP-KLH increased with weeks passed after immunization. In comparison to unexposed fish, fewer salmon were categorized as antigen-responsive when pre-treated with esfenvalerate and chlorpyrifos. In addition, esfenvalerate-exposed fish had significantly lower antibody titers eight weeks after immunization. Cytokine induction patterns in response to pesticide treatments and immunization will be discussed.
Key words: pesticide, Oncorhynchus tshawytscha, antibody response, cytokine