Immune Cell Membrane Protrusions as Sensory Organelles

Immune cells possess a remarkable set of complementary surface protrusions, such as microvilli, podosomes, filopodia, and lamellipodia, which play pivotal roles in the sensing of and responding to varied environmental cues. These dynamic structures maximize the surface area-to-volume ratio of immune cells, which in turn enhances cell-cell and cell-matrix interactions, while generating pulling and pushing forces, allowing immune cells to integrate biochemical and physical cues from their surroundings. This review discusses recent insights into the structures and dynamics of different protrusions, the molecular machinery behind mechanosensing, the differential role of protrusions for different subsets of immune cells, and the cutting-edge technology that has advanced our understanding of those protrusions.