Receptor diffusion and mechanical coupling as determinants of the cellular internalization of particulate material

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Synopsis

Phagocytosis is a specialized process that enables cellular ingestion and clearance of microbes, dead cells and tissue debris that are too large for other endocytic routes.  As such, it is an essential component of the immune response and tissue homeostasis.  However, ingestion of particulate materials exceeding several microns represents a monumental task for phagocytic cells.  It requires a profound reorganization of the cell morphology around the target in a controlled manner, which is limited by biophysical constraints.  Experimental and theoretical studies have identified critical aspects associated with the interconnected biophysical properties of the receptors, the membrane and the actin cytoskeleton that can determine the success of large particle internalization.  Using quantitative live cell imaging, we uncovered molecular mechanisms that underpin the biophysical properties of surface receptors and enable phagocytic cells to bind and fold their membrane around large particulate materials.