Figure 1.

Biogenesis and release of exosomes (extracellular vesicles). The formation of exosomes is multistep, and the uptake of exosomes by recipient cells is also multimodal. Early sorting endosomes derived from bud formation at the plasma membrane maturate to multivesicular bodies (MVB) after the cargo sorting and exchange via an endosome-sorting complexes (ESCRT)-independent or ESCRT-dependent pathway. MVBs eventually directly fuse with lysosome and degradation or are transported to the plasma membrane for release. After secretion, recipient cells take up exosomes through fusion with the plasma membrane, receptor-mediated pathway, or endocytosis. ALIX, apoptosis-linked gene 2-interacting protein X; ILVs, intraluminal vesicles.