Feedback activation of CD73-Adenosine axis attenuates the antitumor immunity of STING pathway

The cGAS-STING pathway, a crucial component of innate immunity, has garnered attention as a potential therapeutic target for tumor treatment, but targeting this pathway is complicated by diverse feedback mechanisms of the cGAS-STING pathway. In this study, we demonstrated that STING activation enhanced the expression of CD73 and the subsequent production of adenosine in immune cells and cancer cells. Mechanistically, the feedback activation of CD73 depended on the type I IFN/IFNAR axis induced by STING activation. Furthermore, the combination of STING agonist and anti-CD73 mAb markedly blocked tumor growth in vivo by promoting the infiltration of CD8+ T cells and reducing the accumulation of Foxp3+ regulatory T cells (Tregs) in the tumor microenvironment. Our work provides a rationale for the combination of STING agonists and CD73 inhibitors in cancer immunotherapy.