Integrins in sEV bind to laminin through conventional integrin–laminin interactions. (A and B) TIRF images of sEV-PC3-CD63Halo7-TMR stained with anti-activated integrin β1 HUTS-4 (A) and anti-integrin β1 P5D2 (B) on uncoated glass (top) or laminin-coated glass (bottom). (C) Colocalization ratio of fluorescent spots of sEVs stained with the antibody to those of sEV-PC3-CD63Halo7-TMR (n = 10 images). (D) Western blot analysis of sEVs derived from WT, integrin α6 KO, integrin α6-rescued, and integrin α6 R155A-expressing PC3 cells. (E) Fluorescence images of the sEVs derived from WT, integrin α6 KO, integrin α6-rescued, and integrin α6 R155A-expressing PC3 cells bound to laminin on glass. (F) Quantification of sEVs bound to laminin on glass under the conditions described in E (n = 8 images). Data are presented as the mean ± SE. n.s., nonsignificant difference; ***P < 0.001 according to Welch’s t test (two-sided). In F, due to the necessity of multiple statistical tests, the significance level was corrected by the Bonferroni method and determined to be 0.0125 (=0.05/4). Source data are available for this figure: SourceData F5.