The cytoskeleton in phagocytosis and macropinocytosis

Cells of the innate immune system, notably macrophages, neutrophils and dendritic cells, perform essential antimicrobial and homeostatic functions. These functions rely on the dynamic surveillance of the environment supported by the formation of elaborate membrane protrusions. Such protrusions-pseudopodia, lamellipodia and filopodia-facilitate the sampling of the surrounding fluid by macropinocytosis, as well as the engulfment of particulates by phagocytosis. Both processes entail extreme plasma membrane deformations that require the coordinated rearrangement of cytoskeletal polymers, which exert protrusive force and drive membrane coalescence and scission. The resulting vacuolar compartments undergo pronounced remodeling and ultimate resolution by mechanisms that also involve the cytoskeleton. Here, we describe the regulation and functions of cytoskeletal assembly and remodeling during macropinocytosis and phagocytosis.

Automated summary

Cells of the innate immune system, such as macrophages, neutrophils, and dendritic cells, rely on dynamic membrane protrusions for essential antimicrobial and homeostatic functions. These protrusions, including pseudopodia, lamellipodia, and filopodia, facilitate the sampling and engulfment of surrounding fluid and particulates through mechanisms that involve extreme plasma membrane deformations and coordinated rearrangement of cytoskeletal polymers. This process ultimately leads to vacuolar compartments that undergo remodeling and resolution through cytoskeletal mechanisms.