In vitro effects of different chlorinated contaminants on porcine macrophages

Macrophages are important component of the immune system responsible for triggering innate immune response, and engulfing microorganisms. Moreover, they play an important role for the clearance of apoptotic cells and the tumor immuno-surveillance and in induction and maintenance of the inflammatory process by the expression of different cytokines as well as producing nitric oxide. Although it is well known that different environmental pollutants, such as polychlorinated biphenyls (PCBs) and polychlorodibenzo-p-dioxin (PCDD), may affect immune functions, only few studies have been carried out to date about the effects of these chemicals in macrophages (Webster et al., 2000; Park et al., 2005; Choen et al., 2009); while, at our knowledge, no study investigated the effects of these contaminants in porcine macrophages. The aim of the current study was to evaluate the effects of three non dioxin-like PCB congeners (PCB 138, PCB 153 and PCB 180) and TCDD, alone and differently combined, on porcine macrophages cell line (3D4/31). The results of the current study showed that ndl-PCBs and TCDD reduced significantly cell viability only at the highest tested concentrations (50-100 µM and 1 µM, respectively); such an effect was not linked to apoptosis induction or cell cycle arrest. The contemporary presence of more than one contaminant differently combined did not induce any enhancement of effects on 3D4/31 cell line. These data highlighted the need to continue the evaluation of toxicity of environmental contaminants especially those still poorly studied such as ndl-PCB.