ABSTRACT
Macrophages play a central role in the immune response. They, along with other antigen-presenting cells, process and present antigen to T cells initiating the immune response. 1 Macrophages are not only the major phagocytic cell but are also involved in the synthesis and secretion of at least 100 products, including reactive oxygen metabolites, polypeptide hormones, enzymes and enzyme inhibitors, complement components, and many other im- portant proteins and chemicals. 2 When appropriately stimulated, macrophages are cytotoxic to tumor cells. 3 Of obvious relevance to this chapter is the role of macrophages in the destruction of microorganisms, particularly parasites.
