Immunotoxicology of regional lymphoid tissue: the respiratory and gastrointestinal tracts and skin.

The area of immunotoxicology has grown significantly over the past decade. Most of the research on methods development and validation and mechanisms of action have focused on the systemic immune system (i.e, spleen, thymus). However, since the regional/mucosal immune system plays an important role in host resistance and is also potentially exposed to significant levels of chemicals, it should also be considered a potential target. The objective of this symposium was to increase the awareness and importance of examining the effects of xenobiotics on the regional/mucosal immune response. The speakers presented an overview of the rapidly growing field of regional immunology with emphasis on the respiratory tract, gut, and skin. The complex intercellular distribution and limited number of immune cells within the various regional lymphoid tissue have resulted in the use of a variety of methods to study the immune response of these tissues. These methods and results of studies which examined the effects and mechanisms of action of chemicals and uv light on the regional immune response were discussed.