A Rat Anti-Mouse CD39 Monoclonal Antibody for Flow Cytometry.

By converting extracellular adenosine triphosphate to adenosine, CD39 is involved in adenosine metabolism. The extracellular adenosine plays a critical role in the immune suppression of the tumor microenvironment. Therefore, the inhibition of CD39 activity by monoclonal antibodies (mAbs) is thought to be one of the important strategies for tumor therapy. In this study, we developed novel mAbs for mouse CD39 (mCD39) using the Cell-Based Immunization and Screening (CBIS) method. One of the established anti-mCD39 mAbs, C 39 Mab-2 (rat IgG 2a , lambda), reacted with mCD39-overexpressed Chinese hamster ovary-K1 (CHO/mCD39) and an endogenously mCD39-expressed cell line (SN36) by flow cytometry. The kinetic analysis using flow cytometry indicated that the dissociation constant ( K D ) values of C 39 Mab-2 for CHO/mCD39 and SN36 were 5.5 × 10 -9 M and 4.9 × 10 -9 M, respectively. These results indicated that C 39 Mab-2 is useful for the detection of mCD39 in flow cytometry.