Citation

Quantitative assessments using single-molecule imaging and super-resolution microscopy revealed that all extracellular vesicle subtypes derived from four distinct tumor cell lines, regardless of size, bind to laminin predominantly via CD151-facilitated integrin heterodimers and GM1, but not as much to fibronectin.Tumor-derived extracellular vesicles (EVs) have attracted significant attention, yet the molecular mechanisms that govern their specific binding to recipient cells remain elusive. Our in vitro study utilizing single-particle tracking demonstrated that integrin heterodimers comprising ?6?4 and ?6?1 are responsible for the binding of small-EV (sEV) subtypes to laminin. EVs derived from four distinct tumor cell lines, regardless of size, exhibited high binding affinities for laminin but not for fibronectin, although fibronectin receptors are abundant in EVs and have functional roles in EV-secreting cells. Our findings also revealed that the robust binding of integrins in EVs to laminin is preserved by CD151 rather than by talin-1 inside-out signaling and is inhibited by a molecule that associates with CD151 via cholesterol. The sEV-laminin interaction is also induced by GM1. Super-resolution movie observation revealed that sEV integrins bind only to laminin on living recipient cells. Thus, we demonstrated that all EV subtypes bind to laminin predominantly via CD151-facilitated integrin heterodimers and GM1.