The Cell Biology of Phagocytosis

Abstract

Engulfment and destruction of invading microorganisms by phagocytosis are critical components of the innate immune response. In addition, phagocytosis is also required for the clearance of apoptotic bodies, an essential aspect of tissue homeostasis and remodeling. Here, we summarize the current knowledge of the cellular and molecular basis of phagosome formation and maturation. We discuss the manner in which phagocytosis is subverted by certain pathogens and consider congenital disorders that affect phagocyte function.

Hypoxic regulation of neutrophil function and consequences for Staphylococcus aureus infection

“…Phagocytic receptor ligation initiates phosphorylation cascades, enabling pseudopod extension by means of dynamic changes in the actin cytoskeleton (reviewed in Ref. [5]). As phagosomes mature, they acquire microbicidal activity by fusion of additional components, including cytosolic granules which contain abundant proteases and antimicrobial peptides.…”

Frustrated Phagocytic Spreading of J774A-1 Macrophages Ends in Myosin II-Dependent Contraction

“…Additionally, the signaling molecules that are involved in connecting Fc-receptor binding events with initiation of the actin polymerization machinery are becoming increasingly well-documented (36). In fact, from a theoretical standpoint, the large number of signaling complexes (for which in vivo rate constants are mostly unknown) makes it difficult to construct all-inclusive models of phagocytosis.…”

“…lamellipodial-like actin protrusions (36). It is possible that tension also stalls filament growth simply via the buildup of pressure at the polymerization front.…”

CD300b regulates the phagocytosis of apoptotic cells via phosphatidylserine recognition

“…[1][2][3][4] If not properly cleared, they become necrotic, pro-inflammatory and immunogenic, potentially leading to the development of autoimmune diseases, such as systemic lupus erythematous (SLE). [5][6][7][8] Therefore, phagocytes possess sensing systems to facilitate the clearance of apoptotic cells.…”

“…[5][6][7][8] Therefore, phagocytes possess sensing systems to facilitate the clearance of apoptotic cells. [1][2][3] Once guided to their location by diffusible 'find me' signals, phagocytes recognize apoptotic cells through their display of characteristic cell surface molecules ('eat me' signals). 4,7 The most common signal promoting phagocytosis is the recognition of phosphatidylserine (PS), which when exposed on the outer leaflet of the plasma membrane signals phagocytes to engulf apoptotic cells.…”