Fig. 1.

Modification with gp350 increases the uptake of 293T-EVs by tumor CD21⁺ B cells. (A-D) Mock or Flag-gp350 overexpression plasmids were transfected into 293T cells, and 48 h later, EVs were separated from the supernatants of these cells. The EV morphology was detected by TEM. Scale bar, 100 nm (A). The EV grain distribution was detected using nanoparticle tracking analysis (B). The indicated proteins in the EVs were detected by immunoblotting (C). Flow cytometry was applied to analyze flag-gp350 proteins on the EVs (D). (E) PKH26-labeled K562 or Raji cells were incubated with CFSE-labeled 293T-EVs/Mock or 293T-EVs/gp350 (10 µg/ml) at 4 degrees Celsius for 1 h, and the EVs on the cells were then detected by fluorescence microscopy. Scale bar, 10 µm. (F) Raji or K562 cells were maintained with 10 µg/ml PKH26-labeled 293T-EVs/Mock or 293T-EVs/gp350 at 37 degrees Celsius for 1 h, and the EV uptake was then detected by flow cytometry. ns: not significant; ***P < 0.001 (unpaired Student's t test). Typical outcomes from three independent trials are given (mean ± SD) (n = 3-5).