Lack of involvement of CD63 and CD9 tetraspanins in the extracellular vesicle content delivery process.

Extracellular vesicles (EVs) are thought to mediate intercellular communication by transferring cargoes from donor to acceptor cells. The EV content-delivery process within acceptor cells is still poorly characterized and debated. CD63 and CD9, members of the tetraspanin family, are highly enriched within EV membranes and are respectively enriched within multivesicular bodies/endosomes and at the plasma membrane of the cells.

Quantitative Measurement of Extracellular Vesicle Content Delivery Within Acceptor Cells.

Extracellular vesicles (EVs), including exosomes and microvesicles, are thought to transport bioactive molecules from donor to acceptor cells. Although EV uptake has been qualitatively assessed through subcellular imaging, EV content delivery has been rarely addressed due to a lack of adequate methods. Here we present a sensitive bulk assay to quantitatively measure EV uptake and content delivery in mammalian cell.

Quantitative characterization of extracellular vesicle uptake and content delivery within mammalian cells.

Extracellular vesicles (EVs), including exosomes, are thought to mediate intercellular communication through the transfer of cargoes from donor to acceptor cells. Occurrence of EV-content delivery within acceptor cells has not been unambiguously demonstrated, let alone quantified, and remains debated. Here, we developed a cell-based assay in which EVs containing luciferase- or fluorescent-protein tagged cytosolic cargoes are loaded on unlabeled acceptor cells.

Content release of extracellular vesicles in a cell-free extract.

Extracellular vesicles (EVs) transfer molecules from donor to acceptor cells. The EV-content delivery process within the acceptor cell is poorly characterized. We developed a new cell-free assay to assess EV-content release in vitro.