ABSTRACT
ABSTRACT The immune system is composed of a number of organs and cell types, and its development requires the orchestration of a complex series of events. There is concern that exposure to immunotoxic drugs and nondrug chemicals during pre-or postnatal periods of development may result in greater, unique and more persistent effects on the immune system in comparison to exposure as adults. This chapter will address the current landscape of developmental immunotoxicology (DIT), with respect to current regulatory guidance and triggers for developmental immunotoxicity testing, primarily from a pharmaceutical industry perspective. An overview of immune development is presented, focusing on processes common to all mammalian species, and key differences between the immune system of human and that of two major preclinical test species, the rat and monkey, are highlighted. The description of the morphological and physiologic development of the immune system provides a framework to identify processes that may be altered by immunotoxicants. Current methods available for DIT testing are discussed along with specific areas requiring further assay development. Compounds that have been determined to be developmental immunotoxicants are addressed, with a particular emphasis on those where the developing immune system appears more sensitive than that of the adult. Major gaps in our knowledge in the area of DIT are highlighted along with perspectives for the future of DIT.
