Ectonucleoside triphosphate diphosphohydrolase 1 (CD39) (ENTPD1)

Ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1), widely known as CD39, is a cell-surface enzyme that serves as the rate-limiting step in the hydrolysis of extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) into adenosine monophosphate (AMP) (UniProt P49961). This process is critical in the purinergic signaling pathway, where it initiates the conversion of pro-inflammatory ATP into immunosuppressive adenosine, a transition often referred to as the "adenosine switch" (PMID: 31515460). In the context of oncology, CD39 is frequently overexpressed on tumor cells and regulatory T cells (Tregs), creating an immunosuppressive microenvironment that allows tumors to evade the immune system (PMID: 33011266). Therapeutic strategies targeting ENTPD1 include monoclonal antibodies like TTX-030 and SRF617, which aim to block enzymatic activity to restore the anti-tumor functions of T cells and Natural Killer (NK) cells. While the protein itself is the primary functional target, targeting ENTPD1 mRNA via RNA interference (RNAi) or antisense oligonucleotides is an emerging approach to reduce the overall expression of this enzyme in chronic inflammatory and malignant conditions. Beyond cancer, CD39 plays a vital role in preventing inappropriate platelet aggregation and maintaining vascular health, making its modulation relevant for cardiovascular and autoimmune research.

Other names

CD39NTPDase1ATPDaseLymphoid cell activation antigenEcto-ATP diphosphohydrolase 1Ecto-apyrase

Inhibition of the enzymatic conversion of extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to adenosine monophosphate (AMP), thereby preventing the subsequent formation of immunosuppressive adenosine by CD73.