Structure and Modulation of Fc and Complement Receptors

Abstract

A striking feature of the professional phagocytes first observed by Metchnikoff (1887) is their ability to bind and ingest foreign particles. In carrying out this vital task, the polymorphonuclear leukocyte (PMN) or macrophage must first recognize the intruder. The mechanism by which cells accomplish this recognition is, for many particles such as Latex or carbon, not well understood, and may not proceed through interaction of the particle with a receptor. On the other hand, many highly dangerous particles, such as bacteria and yeast, are recognized with the aid of opsonins—proteins that bind specifically to the intruder as a signal for phagocytosis (Griffin, 1977). Ingestion of these opsonin-coated particles is triggered by interaction with specific glycoprotein receptors on the cell plasma membrane. This chapter addresses exclusively receptor-mediated phagocytosis.