Apoptosis-mediated immunotoxicity of polychlorinated biphenyls (PCBs) in murine splenocytes.

Polychlorinated biphenyls (PCBs) exhibited immunotoxicity on antibody forming response to T-dependent antigen of sheep red blood cells, primary activation of T cells by mixed lymphocyte response, and lymphocyte proliferation induced by various mitogens. These immunosuppressions were related with the loss of lymphocyte viability which was determined by the propidium iodide method, and this death was proven to be linked with apoptosis which showed DNA fragmentation detected by the diphenylamine method and agarose gel electrophoresis. The degree of DNA fragmentation was increased in a dose- and time-dependent manner in PCB-treated splenocytes. In conclusion, it was assumed that apoptosis was attributable to the immunotoxicity of PCBs in murine splenocytes.