10 - Immunotoxicology Testing In Vitro

Abstract

This chapter presents an overview of immunology and immune system cells and their functions, and describes the use of in vitro methods in immunotoxicology testing. The immune system is a highly complex entity involving a large number of cell types from varying lineages and is dependent for its normal function on subtle interactions between these cell types requiring both cell-cell contact and communication via soluble mediators and their receptors. Thus the whole immune system does not readily lend itself to modeling with in vitro techniques. Even though there have been great advances in cell culture technologies in recent years, with better understanding of the demands of cells for essential cytokines or growth factors for normal functioning, it is difficult to envisage any in vitro system that could mimic several of the properties of the whole immune system in vivo. Therefore, to make any progress in this field, it is necessary to break down immune function into a series of compartments, often related to known pharmacotoxicological effects of drugs and chemicals on specialized immune responses, from which can be developed appropriate in vitro systems to model specific facets of the immune system. In terms of immunotoxicology in vitro, there are many systems employed using isolated lymphocytes or monocytes which can be used in the process of drug development to assist in screening candidate molecules for efficacy or for potential undesirable side-effects. There are tremendous economic benefits in identifying proper in vitro models for the assessment of all categories of immunotoxicity, which in time would lead to the establishment of test procedures compatible with regulatory requirements.