Epitope Mapping of Monoclonal Antibody PMab-233 Against Tasmanian Devil Podoplanin

Our plain-English summary of Epitope Mapping of Monoclonal Antibody PMab-233 Against Tasmanian Devil Podoplanin, by M. Sano, M.K. Kaneko, Y. Kato (Monoclonal Antibodies in Immunodiagnosis and Immunotherapy, 2019).

The study

• Authors: M. Sano, M.K. Kaneko, Y. Kato
• Journal: Monoclonal Antibodies in Immunodiagnosis and Immunotherapy
• Published: 2019;38(6):261-265
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The highly O-glycosylated membrane glycoprotein podoplanin (PDPN) is frequently overexpressed in several malignant cancers, such as oral cancer, lung cancer, germinal neoplasia, mesothelioma, and brain tumor. The expression of PDPN is strongly associated with cancer progression and poor prognosis. PDPN possesses three tandem repeats of platelet aggregation-stimulating (PLAG) domains (PLAG1, PLAG2, and PLAG3) and PLAG-like domain (PLD), and binds to C-type lectin-like receptor 2 (CLEC-2) on platelets, followed by PDPN-mediated platelet aggregation. We have previously established a novel anti-Tasmanian devil PDPN (tasPDPN) monoclonal antibody (mAb), PMab-233, which specifically detects tasPDPN using flow cytometry, Western blot, and immunohistochemical analyses. However, the specific binding epitope of tasPDPN for PMab-233 remains to be clarified. Herein, a series of deletion or point mutants of tasPDPN were utilized for investigating the binding epitopes of PMab-233 using flow cytometry. The findings of this study demonstrated that Asp30, Thr33, and Thr34 of tasPDPN, which are located in PLAG1, are responsible for the binding of PMab-233 to tasPDPN.

In plain English

This was a laboratory study, not a study of people or of asbestos exposure. It concerned PMab-233, an antibody the same research group had recently made to detect podoplanin, a protein, from the Tasmanian devil. The authors' introduction notes that podoplanin is found at high levels in several cancers, including mesothelioma, but this study did not examine any cancer. The authors set out to find which part of the Tasmanian devil protein the antibody attaches to. They made altered versions of the protein, either with the front section cut off at different lengths or with single building blocks (amino acids) swapped. They placed these in Chinese hamster ovary cells grown in the lab and tested antibody binding with flow cytometry. The antibody did not bind any of the six shortened versions. Among ten single swaps, it did not bind when amino acid 33 or 34 was changed and bound only weakly when amino acid 30 was changed. The authors concluded that Asp30, Thr33 and Thr34, located in a region called PLAG1, are critical for the antibody's binding.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory experiment (epitope mapping): altered versions of a protein were tested for antibody binding by flow cytometry
• Who was studied: No people or animals. The work used CHO-K1 Chinese hamster ovary cells grown in the lab and made to carry altered versions of Tasmanian devil podoplanin.
• Exposure: No asbestos or other exposure was studied. The study tested binding of the antibody PMab-233, previously made by the group, to Tasmanian devil podoplanin and altered versions of it.
• Main results:
  • PMab-233 did not react with any of the six shortened versions of the protein (dN30, dN40, dN50, dN60, dN70 and dN80).
  • From the shortened versions, the authors inferred that the front end of the antibody's binding region lies between the 27th and 30th amino acids.
  • Of the ten single-swap versions, PMab-233 reacted with L27A, P28A, E29A, A31G, A32G, I35A and D36A, and reacted only weakly with D30A.
  • PMab-233 did not react with the T33A and T34A versions.
• The authors' conclusion: The authors concluded that Asp30, Thr33 and Thr34 of Tasmanian devil podoplanin, located in the PLAG1 domain, are critical for PMab-233 binding.
• Limitations the authors state:
  • The authors stated that they could not examine podoplanin in normal Tasmanian devil tissues, and used lab-grown hamster cells carrying the protein instead.

Topics

Medical terms in this study, explained in our Lexicon: Monoclonal Antibody, Podoplanin (D2-40), Glycoprotein, Lung Cancer, Mesothelioma, Prognosis.

Related studies

• Establishment of Mouse Monoclonal Antibody LpMab-13 Against Human Podoplanin — S. Ogasawara, M.K. Kaneko, et al. (2016)
• Antitumor effect of novel anti-podoplanin antibody NZ-12 against malignant pleural mesothelioma in an orthotopic xenograft model — S. Abe, M.K. Kaneko, et al. (2016)
• Therapeutic efficacy evaluation of radioimmunotherapy with 90 Y-labeled anti-podoplanin antibody NZ-12 for mesothelioma — H. Sudo, A.B. Tsuji, et al. (2019)
• Antitumor activity of chLpMab-2, a human-mouse chimeric cancer-specific antihuman podoplanin antibody, via antibody-dependent cellular cytotoxicity — M.K. Kaneko, S. Yamada, et al. (2017)
• Antitumor activity of anti-C-ERC/mesothelin monoclonal antibody in vivo — K. Inami, M. Abe, et al. (2010)
• A human single-domain antibody elicits potent antitumor activity by targeting an epitope in mesothelin close to the cancer cell surface — Z. Tang, M. Feng, et al. (2013)

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