Signaling and membrane dynamics during phagocytosis: many roads lead to the phagos(R)ome.

Phagocytosis is the mechanism used by specialized cells such as macrophages, dendritic cells and neutrophils to internalize, degrade and eventually present peptides derived from particulate antigens. This process relies on profound rearrangements of the actin cytoskeleton and the plasma membrane to engulf particles. Recent work has highlighted the early recruitment of internal membranes derived from endocytic compartments and from the endoplasmic reticulum to allow plasma membrane extension at the onset of phagocytosis. This ensures that the phagosome is rapidly provided with the machinery appropriate for later phagocytic functions, including particle degradation and antigen presentation.