Epitope Mapping of Antipig Podoplanin Monoclonal Antibody PMab-213.

Podoplanin (PDPN), a type I transmembrane sialoglycoprotein, is expressed on lymphatic endothelial cells, podocytes of the kidneys, and type I alveolar cells of the lungs. PDPN, a platelet aggregation-inducing factor, comprises three platelet aggregation-stimulating (PLAG) domains (PLAG1, PLAG2, and PLAG3) in the N-terminus and PLAG-like domains in the middle of the PDPN protein. We have previously reported a mouse antipig PDPN (pPDPN) monoclonal antibody (mAb) clone, PMab-213, which was developed using the Cell-Based Immunization and Screening (CBIS) method. PMab-213 is very useful in flow cytometry, Western blotting, and immunohistochemical analyses; however, the binding epitope of PMab-213, which was developed by CBIS method, remains to be elucidated. Therefore, this study aimed to investigate the epitope of PMab-213 using enzyme-linked immunosorbent assay, flow cytometry, and immunohistochemical analyses. The results revealed that the critical epitopes of PMab-213 are Pro53, Arg54, Arg56, and Tyr60 of pPDPN.