Fig. 6
From: Tumor extracellular vesicles mediate anti-PD-L1 therapy resistance by decoying anti-PD-L1
TEVs inhibit the antitumor effect of αPD-L1 on human tumors by consuming αPD-L1. a PC3 cells (1 × 105) were coincubated with αPD-L1CV and EVs from the sera of three lung tumor patients in 100 μl of medium for 30 min. Then, PD-L1 on the cells was detected by flow cytometry. b CFSE-labeled CD8+ T cells were stimulated with 2 μg ml-1 anti-CD3 and anti-CD28 for 24 h and then coincubated with 5 × 104 PC3 cells and αPD-L1CV with 10 μg of the indicated EVs in 200 μl of medium for 48 h. Then, the CFSE dilution was measured by flow cytometry. c–f, NOD-SCID mice with PC3 tumors were intratumorally injected with 1 × 106 preactivated human peripheral blood mononuclear cells once when the tumor size reached 80–100 mm3. Two days later, the mice were intravenously injected with 10 μg of αPD-L1 or αPD-L1Exe with or without 20 μg of EVs-TT (c–e), or the mice were intravenously injected with αPD-L1 according to the indicated strategies (f) every 2 days. The interaction of αPD-L1 and tumor PD-L1 was detected by PLA on Day 20 (c), the tumor sizes were monitored every other day (d, f), and CD8+ T cells in TTs were detected by immunofluorescence (e). Scale bar, 20 μm. Representative results from two independent experiments are shown (n = 3 except for n = 5 in i, l). *P < 0.05; ***P < 0.001; ns not significant (one-way ANOVA followed by Tukey’s test except for unpaired two-tailed Student’s t test in (c); mean and s.d.)
