Generation and characterization of polyclonal and monoclonal antibodies to human NTPDase2 including a blocking antibody.

Nucleoside triphosphate diphosphohydrolase-2 (NTPDase2) is an ectonucleotidase that modulates P2 receptor activation by hydrolyzing ATP to ADP. In rodents, NTPDase2 is expressed by several specialized cell types such as vascular adventitial cells, neuroglial cells, hepatic portal fibroblasts, gustatory type I cells, and cells within the connective tissues of reproductive and gastrointestinal organs. Much less is known regarding the expression and function of NTPDase2 in humans. Here, we developed specific research tools to study human NTPDase2. We generated mouse monoclonal antibodies and rabbit polyclonal antibodies specific to human NTPDase2 and validated their specificity by western blot, immunocytochemistry, immunohistochemistry, and flow cytometry. In addition, one monoclonal antibody named hN2-D5 s specifically inhibits human NTPDase2 enzymatic activity but not mouse nor rat NTPDase2. Using these antibodies, NTPDase2 immunoreactivity was detected on glial cells of the human enteric nervous system suggesting a function of the enzyme in intestinal motility. In conclusion, the new antibodies described in our work are novel tools that will enhance future studies of NTPDase2 expression and function in humans.