Human Fc gamma receptor II: a standby receptor activated by proteolysis?

Three classes of Fc receptor for IgG have been defined: Fc gamma RI, Fc gamma RII and Fc gamma RII is the most widely distributed, but it has a low affinity for human IgG and its function is not well understood. In this and the following paper, two possible functions of Fc gamma RII are presented. Here, Will Tax and Jan van de Winkel argue that Fc gamma RII may contribute significantly to Fc gamma R-mediated processes, such as the removal of immune complexes and antibody-coated particles, especially in view of the recent finding that the affinity of Fc gamma RII can be upregulated by proteolysis. The following paper considers the role of Fc gamma RII in the context of immune complex regulation of the immune system.