Dioxins and the Immune System: Mechanisms and Consequences of Interference

Dioxins and chemically related halogenated aromatic hydrocarbons (HAHs) interfere with several components of the immune system, including cells and soluble factors. Dioxins and HAHs, in particular the infamous 2,3, 7,8-tetrachlorodibenzo-p-dioxin, or "Seveso dioxin", bind to the cytosolic Ah (arylhydrocarbon) receptor, turning it into a transcription factor for a variety of genes. Affected by dioxin action are growth and differentiation patterns of lymphoid cells including stem cells, thymocytes, B cells and others. Growth factors and cytokines are directly or indirectly modulated by Ah-receptor-binding chemicals. In this issue leading experts summarize the current knowledge on the molecular biology of the Ah receptor, the effects on stem cells, thymus development, the humoral immune response, growth factors and cytokines. It is the only collection of current data on the immunotoxicology of dioxins in a concise form, presenting ideas and hypotheses that are crucial for a rational risk assessment of these ubiquitous environmental pollutants. Authoritative and up-to-date, this publication will make essential reading for immunologists and toxicologists. Furthermore, people involved in environmental health policy, risk assessment and public relations will find it very useful.

Table of Contents:
Part 1 Molecular biology of the Ah receptor: Ah receptor - a novel ligand-activated transcription factor, Y. Fujii-Kuriyama et al. Part 2 T cells and thymus as targets of dioxin action: proliferation inhibition and CD4/CD8 thymocyte subset skewing by in vivo exposure of C57BL/6 mice to Ah receptor-binding 3,3',4,4',-tetrachlorobiphenyl, C. Esser et al; the intrathymic target cell for the thymotoxic action of 2,3,7,8-tetrachlorodibenzo-p-dioxin, C. De Heer et al; 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated gene expression in the immature rat thymus, M.J. Olnes et al. Part 3 B cells as targets of dioxin action: mechanisms of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced disruption of B-lymphocyte signalling in the mouse - a current perspective, J.G. Karras and M.P. Holsapple. Part 4 Cytokine involvement in dioxin toxicity: dioxin-enhanced expression of interleukin-1 beta in human epidermal keratinocytes - potential role in the modulation of immune and inflammatory responses, H. Yin et al; modulation of growth factor expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin, O. Dohr et al. Part 5 Risk assessment: immunotoxicity of polychlorinated biophenyls - present status and future considerations, H. Tryphonas; risk assessment for possible effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related substances on components and functions of the immune system, R. Neubert et al. (Part Contents).