Microvesicle uptake by peripheral blood monocytes. Shown are confocal images from GM-CSF–treated donor monocytes stained with D384, a phospholipid membrane dye (red stain; top left panel) and SytoRNA Select, an RNA-select stain (green stain; bottom left panel). After 48 hours, microvesicles from GM-CSF–stimulated monocytes were collected. Based on previous studies,39 100 000 microvesicles/mL were incubated with unstained naive recipient cells. Cells were imaged using the Zeiss LSM 510 multiphoton confocal microscope. Background fluorescence was subtracted using unstained cells. Transfer of fluorescent microvesicles from the GM-CSF–stimulated cells was apparent in the recipient cell membranes and cytoplasm as indicated by the appearance of the red dye as well as transferred RNA as indicated by the green stain (right panel). The differential interference contrast (DIC) was used to visual the morphology of the cells without fluorescence. Data are representative of 3 independent monocyte donors and 3 monocyte recipients.
