Figure 1. Intratumoral Hypoxia→HIF-1α driven and A2A/A2B Adenosine Receptor-mediated suppression of anti-tumor T cells.
Shown are the HIF-1α regulated ecto-enzymes CD39/CD73 which act in tandem to generate extracellular adenosine. Adenosine triggers the accumulation of immunosuppressive intracellular cAMP by signaling through high affinity A2AR and low affinity A2BR. HIF-1α is also shown to suppress cells of the adaptive immune system [20].