Figure 8.

Antibody-dependent cellular phagocytosis (ADCP) mediated by macrophages. Antibodies targeting macrophages either block receptor-ligand pairs involved in immune checkpoints or recruit macrophages closer to tumor cells to promote ADCP. The FcγR receptor on macrophages binds to the Fc domain of antibodies, facilitating ADCP. Tumor cells evade immune responses by expressing CD47, which interacts with the SIRPα receptor on macrophages to deliver a “don’t eat me” signal. Antibodies binding to CD47 disrupt the SIRPα/CD47 axis, restoring phagocytic activity. The top left diagram illustrates how antibodies bind to tumor-associated antigens (TAA) and FcγR to promote ADCP. The bottom left diagram demonstrates how antibodies are designed to bind both FcγR and TAA while simultaneously blocking CD47 to enhance phagocytosis. Once tumor cells are engulfed by macrophages, phagosomes are formed, which fuse with lysosomes to create phagolysosomes, breaking down tumor cells.