Fig. 1.

The biogenesis and uptake of EVs. Exosome biogenesis pathway starts with the formation of early endosome by endocytosis at the plasma membrane. ILVs are generated by inward budding of the multivesicular body (MVB, also known as late endosome) lipid bilayer membrane. MVB can fuse with the plasma membrane under the regulation of multistep processes including MVB trafficking along microtubules and docking at the plasma membrane for exosome secretion. Alternatively, MVBs fuse with lysosomes for degradation. Unlike exosomes, microvesicles are released directly by budding from the plasma membrane. EVs in extracellular space bind to the surface of recipient cells through protein-protein or receptor-ligand interactions, leading to the internalization of EVs by recipient cells through fusion or endocytosis. EV contents are then released into the recipient cells to manipulate various biological processes