Macrophage cell surface and phagocytic interface

The macrophage cell surface and phagocytic interface, commonly known as the phagocytic synapse, is a specialized junction formed between a macrophage and its target, such as a pathogen or a cancer cell (Niedergang & Chavrier, 2004, PMID: 15549123). This interface serves as a critical decision-making hub where various "eat me" and "don't eat me" signals are integrated to regulate phagocytosis (Chao et al., 2012, PMID: 22446628). A primary component of this interface is the CD47-SIRPα axis; CD47 on the target cell binds to Signal Regulatory Protein Alpha (SIRPα) on the macrophage to inhibit phagocytic activity, acting as an immune checkpoint (Veillette & Chen, 2018, PMID: 29449118). In oncology, many tumors overexpress CD47 to evade macrophage-mediated clearance, making this interface a significant therapeutic target (Feng et al., 2019, PMID: 31110339). Drugs like magrolimab and evorpacept are designed to block this interaction, thereby restoring the macrophage's ability to engulf malignant cells (Advani et al., 2018, PMID: 30380383). Beyond CD47, the interface involves other receptors such as Fc receptors and scavenger receptors that recognize opsonized targets to promote engulfment (Freeman & Grinstein, 2014, PMID: 25145851).

Other names

Phagocytic synapsePhagocytic interfaceMacrophage-target cell interfaceMacrophage-tumor cell synapse

The primary mechanism involves the disruption of the CD47-SIRPα inhibitory axis, which prevents the transmission of 'don't eat me' signals to the macrophage, thereby promoting the phagocytic engulfment of target cells (Veillette & Chen, 2018, PMID: 29449118).