Adenosine Generated by Regulatory T Cells Induces CD8⁺ T Cell Exhaustion in Gastric Cancer through A2aR Pathway

Figure 2

Antagonists of ectonucleotidases CD39 and CD73 affect the activity of Tregs to synthesize adenosine from ATP. (a) Tregs (3 × 10⁴/well) were incubated in 96-well plates for 30 min with vehicle (DMSO), 250 μΜ ARL67156 (CD39 antagonist), α,β-methylene-ADP (CD73 antagonist) (100 μM), or ARL67156 + α,β-methylene-ADP, a negative control without the Treg and treated with an equal volume of vehicle. Then, exogenous ATP (20 μM) was added, and the concentration of unhydrolyzed ATP was detected 10 to 100 min after treatment (, , and vs Tregs). (b) The concentration of adenosine was also detected 10 to 100 min after treatment (, , and vs Tregs). In ANOVA, all experiments are repeated at least five times.