Antibody-dependent cell phagocytosis (ADCP)

Antibody-dependent cell phagocytosis (ADCP) is a mechanism by which antibody-opsonized target cells activate the FcRs on the surface of macrophages to induce phagocytosis, resulting in the internalization and degradation of the target cell through acidification of the phagosome. ADCP is an important mechanism of action for several biologics, however this activity has been difficult to demonstrate and measure by in vitro assays. ADCP provides a mechanism for clearance of virus and virus-infected cells, it also facilitates antigen presentation, and stimulates secretion of inflammatory mediators. ADCP can be completed by monocytes, macrophages, neutrophils, and dendritic cells, through FcγRI-III, of which FcγRIIa (CD32a) on macrophages represent the predominant pathway.

At FlowMetric, we have developed ADCP assays using cell lines and also primary cells to evaluate therapeutic antibody candidates with reproducible results.