Establishment of a novel anti-mouse CD73 monoclonal antibody C73Mab-9 by CBIS method

Cluster of differentiation 73 (CD73), also known as 5'-nucleotidase ecto, is a glycosyl-phosphatidylinositol-anchored cell surface molecule that belongs to the 5'-nucleosidase family. CD73 metabolizes extracellular AMP into adenosine and inorganic phosphate. CD73 plays a vital role in cancer-immune evasion by facilitating adenosine production. Therefore, the development of specific anti-CD73 antibodies is desired to clarify the biological and pathological functions of CD73. Moreover, developing antibodies against mouse CD73 (mCD73) is also essential for preclinical experiments. This study successfully established an anti-mCD73 monoclonal antibody (clone C73Mab-9, rat IgG2a, lambda) using the Cell-Based Immunization and Screening (CBIS) method. In flow cytometric analysis, C73Mab-9 is confirmed to recognize mCD73 in mCD73-overexpressed CHO-K1 (CHO/mCD73), MUSS, and NMuMG cells. The dissociation constant values of C73Mab-9 were 7.6 × 10−9 M for CHO/mCD73 and 1.2 × 10−9 M for MUSS cells, respectively. Furthermore, C73Mab-9 detected mCD73 in western blot analysis. Therefore, the C73Mab-9, established by the CBIS method, is helpful for basic research and is expected to contribute to preclinical studies.