Figure 3.

The adhesion of CRC Colo-320 cells to exosomes was specifically mediated by integrin α5β1 but not by fibronectin. (A) Western Blot of Colo-320 cells and their exosomes shows lack of expression of fibronectin. As a positive control, abundant fibronectin was detected in a fibroblasts lysate. Blots are representative of three different experiments. (B) Detection by enzyme-linked immunosorbent assay (ELISA) of CD9, CD81 and fibronectin on immobilized exosomes produced by Colo-320 cells. (C) Cell adhesion of Colo-320 cells to immobilized exosomes produced by these same cells was blocked by mAbs specific for integrin β1 or integrin α5, but not for fibronectin. The percentage of cells that remained adhered is indicated as mean ± SEM of four experiments, performed in duplicates. Statistical analysis performed was one-way ANOVA. **** p < 0.0001, ns: not statistically significant.