PT03 Persistent Organic Pollutants (POPs)
Exhibit Hall
8:00 AM - Tuesday
(PT022) Differential immunotoxicity of a coplanar and noncoplanar polychlorinated biphenyl (PCB) congener in bluegill sunfish (Lepomis macrochirus).
Duffy, J.1, Li, Y.1, Zelikoff, J.1, 1 New York University, School of Medicine, Tuxedo, New York, USA
ABSTRACT- Polychlorinated biphenyls (PCBs) are a well-studied class of environmental contaminants known to be immunotoxic for both mammals and fish. Depending upon the particular structure of a PCB congener (i.e., coplanar or noncoplanar), different degrees and/or types of immunotoxic effects have been observed in exposed species. For this study, the effects of a single intraperitoneal (i.p.) exposure of bluegill sunfish (Lepomis macrochirus) to either a coplanar (PCB 126) or noncoplanar (PCB 153) PCB congener on host immunocompetence was determined by examining non-specific and cell-mediated immune parameters. Specifically, phagocyte-mediated extracellular superoxide (O2.-) production as well as mitogen-stimulated T- and B-lymphocyte proliferation were examined using kidney or spleen cells recovered from fish on 3, 7, 14 or 21 d post-PCB exposure. While both PCB congeners enhanced extracellular O2.- production by kidney phagocytes at 3 d post-exposure, only PCB 153 had significant effects on lymphocyte proliferation. Mitogen-induced proliferation of both T- and B-lymphocytes was suppressed (compared to controls) as early as 3 d and up to 14 d post-PCB 153 exposure. Results from this study demonstrate that structurally different PCB congeners, thought to act by different mechanisms to produce toxicological effects in exposed species, can differentially impact the fish immune response. Moreover, in this case, noncoplanar PCB 153 appears more immunotoxic than coplanar PCB 126. This work was supported by a Hudson River Foundation Graduate Fellowship and USACEHR contract no. DAMD 17-99-9011.
Key words: immunotoxicity, polychlorinated biphenyls, fish