Keynote lecture in the 13th Japanese Society of Immunotoxicology (JSIT 2006) : -Pathophysiological Development and Immunotoxicology: what we have found from research related to silica and silicate such as asbestos-.

Silica and silicates may disturb immune functions such as autoimmunity and tumor immunity, because people who are exposed to the materials sometimes develop autoimmune and malignant diseases, respectively. Although silica-induced disorders of autoimmunity have been explained as adjuvant-type effects of silica, more precise analyses are needed and should reflect the recent progress in immunomolecular findings. A brief summary of our investigations related to the immunological effects of silica/asbestos is presented. Recent advances in immunomolecular studies led to detailed analyses of the immunological effects of asbestos and silica. Both affect immuno-competent cells and these effects may be associated with the pathophysiological development of complications in silicosis and asbestos-exposed patients such as the occurrence of autoimmune disorders and malignant tumors, respectively. In addition, immunological analyses may lead to the development of new clinical tools for the modification of the pathophysiological aspects of diseases such as the regulation of autoimmunity or tumor immunity using cell-mediated therapies, various cytokines, and molecule-targeting therapies. In particular, as the incidence of asbestos-related malignancies is increasing and such malignancies have been a medical and social problem since the summer in 2005 in Japan, efforts should be focused on developing a cure for these diseases to eliminate the nation wide anxiety about these malignancies.