Critical Epitope of Anti-Rabbit Podoplanin Monoclonal Antibodies for Immunohistochemical Analysis

Monoclon Antib Immunodiagn Immunother. 2016 Apr;35(2):65-72. doi: 10.1089/mab.2015.0078. Epub 2016 Mar 15.

Abstract

Podoplanin (PDPN) is a type I transmembrane sialoglycoprotein, which is expressed in several normal cells, including lymphatic endothelial cells throughout the body, podocytes of the kidney, and lung type I alveolar cells of the lung. We have established many monoclonal antibodies (mAbs) against human PDPN, mouse PDPN, and rat PDPN. In addition, we recently produced an anti-rabbit PDPN mAb, PMab-32, which was established by immunizing mice with recombinant proteins of rabbit PDPN. Herein, we compared the reactivity of PMab-32 with that of newly established anti-rabbit PDPN mAbs, PMab-33 and PMab-21, against normal tissues in immunohistochemistry. PMab-32 reacted with podocytes, type I alveolar cells, and lymphatic endothelial cells, whereas PMab-33 detected only podocytes and type I alveolar cells but not lymphatic endothelial cells. PMab-21 was not useful in immunohistochemistry. We identified the epitope of PMab-32 and PMab-33 as Ser61-Ala68 of rabbit PDPN using western blot and flow cytometric analyses. In contrast, the epitope of PMab-21 was identified as Leu44-Glu48, which is corresponding to platelet aggregation-stimulating (PLAG) domain, indicating that Ser61-Ala68 of rabbit PDPN is a more appropriate epitope for immunohistochemistry compared with PLAG domain. PMab-32 could be useful for uncovering the function of rabbit PDPN.

MeSH terms

  • Alveolar Epithelial Cells / immunology
  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibody Specificity / immunology*
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Epitope Mapping
  • Epitopes / immunology*
  • HEK293 Cells
  • Humans
  • Immunohistochemistry
  • Membrane Glycoproteins / immunology*
  • Mice
  • Podocytes / immunology
  • Rabbits
  • Rats
  • Species Specificity

Substances

  • Antibodies, Monoclonal
  • Epitopes
  • Membrane Glycoproteins
  • PDPN protein, human