1. Recombinant Proteins
  2. Immune Checkpoint Proteins
  3. Inhibitory checkpoint molecules
  4. CD73/A2aR

CD73/A2aR adenosine signaling is one of the most attractive immunosuppressive pathways, as it dampens T cell-mediated immune responses and promotes tumor immune escape. CD73 is widely expressed by most tissues and is thought to serve as an adhesion molecule for lymphocyte binding to the endothelium and to play an important role as a co-signaling molecule for . However, it is an ecto-enzyme and is expressed on tumor cells and host immunosuppressive cells, where it catalyzes the hydrolysis of AMP into adenosine, favoring tumor progression. Adenosine suppresses antitumor immunity by binding to its receptors, including the A1, A1, A2b and A3 receptors, among which A2aR is the predominant cell surface immune checkpoint. A2aR is expressed on immune cells, including T cells, APCs, NK cells, and on endothelial cells. It is reported that anti-CD73 and anti-A2aR antibodies release T-cell effector functions and synergize with other immune checkpoint blockades, such as anti-PD-1 and anti-CTLA-4 therapies.