Phagocytic cell surface and associated uptake machinery

The phagocytic cell surface and associated uptake machinery refers to a complex system of receptors and signaling molecules that mediate the recognition and engulfment of large particles, such as pathogens and apoptotic cells [IUPHAR/BPS Guide to Pharmacology]. This machinery includes various classes of receptors, such as Fc receptors, complement receptors, scavenger receptors, and C-type lectins, which work in concert to initiate phagocytosis [Nature Reviews Immunology, 2018]. Beyond recognition, the machinery involves intracellular signaling pathways, including Rho GTPases and actin-remodeling proteins, that drive the physical engulfment process [Journal of Cell Science, 2012]. In healthy tissues, this system is essential for immune defense and the maintenance of homeostasis through the clearance of cellular debris [IUPHAR/BPS Guide to Pharmacology]. However, in diseases like cancer, the machinery is often subverted; for instance, tumor cells may overexpress CD47, a "don't eat me" signal that interacts with SIRPα on macrophages to inhibit phagocytosis [Frontiers in Oncology, 2020]. Therapeutic strategies targeting this machinery often focus on blocking these inhibitory checkpoints or enhancing pro-phagocytic signals to promote the destruction of malignant cells or infectious agents [Annual Review of Immunology, 2020]. Clinical candidates like magrolimab target the CD47-SIRPα axis, while other approaches utilize Fc receptor modulation to improve the efficacy of therapeutic antibodies [Nature Reviews Drug Discovery, 2019]. Safety concerns associated with these therapies include the potential for off-target effects, such as the destruction of healthy red blood cells, leading to anemia [Frontiers in Oncology, 2020].

Other names

Phagocytic receptorsEngulfment machineryPhagocytosis-associated proteinsPhagocytic uptake system

Modulation of phagocytic activity through the blockade of inhibitory signals (e.g., CD47-SIRPα axis) or the activation of pro-phagocytic receptors (e.g., FcγR) to enhance the clearance of target cells or pathogens.