Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Beyond toxicity: aryl hydrocarbon receptor-mediated functions in the immune system. | Journal of Biology Opinion Beyond toxicity aryl hydrocarbon receptor-mediated functions in the immune system Brigitta Stockinger Address Division of Molecular Immunology MRC National Institute for Medical Research Mill Hill London NW7 1AA UK. Email bstocki@ Abstract The aryl hydrocarbon receptor is a ligand-activated transcriptional regulator that binds dioxin and other exogenous contaminants and is responsible for their toxic effects including immunosuppression. New evidence suggests however that the aryl hydrocarbon receptor has a physiological role in the immune system and the immunosuppressive effects of dioxin may reflect a more subtle disruption of the regulatory interactions between immune cells. The aryl hydrocarbon receptor AhR also called the dioxin receptor is a transcriptional regulator best known for mediating the toxicity of environmental contaminants most notably halogenated polycyclic aromatic hydrocarbons such as dioxin. AhR has been studied extensively for its pathological role in response to environmental pollution and there is a wealth of knowledge regarding its signalling components as well as its structural features and pharmacological effects. Although many aspects of AhR-mediated toxicity have been described the molecular mechanisms underlying these are not well understood. AhR is conserved across vertebrate and invertebrate species playing a role for instance in the development of the nervous system in Caenorhabditis elegans while in Drosophila the AhR homolog spineless is involved in development of antennae and legs as well as in aspects of color vision 1 .The intrinsic physiological functions of AhR in mammals have been delineated from the phenotype of the AhR knockout mouse 2-4 . These mice show reduced fertility smaller livers possibly resulting from vascular defects 1 and portal fibrosis. The strong conservation of AhR in so many species as well as the mutant phenotype suggest that it has roles beyond those of mediating .