| Halogenated aromatic hydrocarbons (HAHs) such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), diphenyl ethers (PCDEs), biphenyls (PCBs) and polynuclear aromatic hydrocarbons (PAHs) are industrial compounds and/or chemical combustion by-products which have become widespread environmental pollutants. The biological and biochemical effects of these compounds are thought to be mediated by the Ah receptor. The purpose of these studies was to investigate the immunotoxicity of a number of HAH and PAH congeners and to determine the role of the Ah receptor in HAH-induced immunotoxicity. The research focused on the modulation of the humoral immune response to the T-cell independent antigen trinitrophenyl lipopolysaccharide (TNP-LPS) after exposure to individual congeners or complex mixtures of HAHs or PAHs. Moreover, the interactions between weak Ah receptor agonists and immunosuppressants which act by different mechanisms of action were evaluated using the humoral immune response as an endpoint. Finally, an enzyme-linked immunosorbant assay (ELISA) and an in vitro assay were developed to facilitate the screening for potential immunotoxicants. |
