Fig. 3

GFP-fused nanobodies H1 and H6 compete with anti-CD9 for EV epitopes. The binding of anti-CD9-PE to EVs (from either SKBR3 or HEK 293 cells) immobilized on latex beads was monitored by flow-cytometry in the presence of (gray) or absence of (red) the VHH-GFP constructs H1 (reported as an example), H6, B1 (CD9-neg/EV-pos clone), and nbVHH (irrelevant non-binding control nanobody). Latex beads are slightly autofluorescent (data not shown). The inhibition rate was calculated by analysis of variance, using the Kruskal–Wallis test followed by the Tukey’s post hoc test (p < 0.05). The error bars indicate standard deviations for triplicate measurements