The development of a synthetic scFv monoclonal antibody targeting pro-oncogenic AGR2

Abstract

Event Abstract Back to Event The development of a synthetic scFv monoclonal antibody targeting pro-oncogenic AGR2 M. Aiman Mohtar1*, Teck Yew Low1, Borek Vojtesek2, Rahman Jamal1 and Ted Hupp3 1 UKM Medical Molecular Biology Institute (UMBI), Malaysia 2 Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Czechia 3 Medical Research Council Institute of Genetics and Molecular Medicine (MRC), United Kingdom Background AGR2 is an endoplasmic reticulum (ER)-resident protein that belongs to the protein disulphide isomerase (PDI) family. These enzymes facilitate the rearrangement of disulphide bonds during protein maturation in the ER. AGR2 has emerged as a clinically relevant anti-tumour target since it possesses pro-oncogenic features, promotes metastasis and is overexpressed in diverse types of cancer. One unique molecular function of AGR2 is to drive certain oncogenic client proteins maturation in the ER, such as receptor EpCAM, via a specialised docking site. Methods and Results We developed synthetic single-chain variable fragment (scFv) monoclonal antibodies targeting AGR2. First, recombinant AGR2 protein was used as an antigen for screening a naïve canine phage-scFv library for specific scFvs. After four rounds of screening, nine AGR2-binding scFvs were identified; while subsequent epitope mapping highlighted the presence of four different classes of scFvs. We next selected one scFv that binds strongly to the N-terminal of AGR2 (scFv4) for further studies. We re-designed scFv4 such that the new scFv4 construct contains a C-terminal CD20 epitope tag, and ER postcodes for entry into ER as tools to manipulate the proteins inside the ER. Although all synthetic scFv scaffolds were expressed in AGR2-negative cells, the AGR2-binding scFv with an ER-postcode was selectively degraded in AGR2-positive cells. These data suggest that the expression of scFv scaffolds can be impacted in an AGR2-dependent manner and the presence of AGR2 in cells can suppress the production of a high-affinity binding protein when it is destined for the ER. Conclusion This study demonstrates the successful construction of a novel AGR2-binding scFv scaffold that can be expressed in mammalian cells. These tools were used to show the key determinants that regulate the ability of AGR2 to mediate client protein maturation in the ER and can be potentially manipulated for the development of human monoclonal antibodies for therapeutic treatment of cancer. Keywords: Secretory Pathway, Protein disulfide isomerase (PDI), Endoplasmic Reticulum, Chaperone, Anti cancer Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Oral Presentation Topic: Cancer Citation: Mohtar M, Low T, Vojtesek B, Jamal R and Hupp T (2019). The development of a synthetic scFv monoclonal antibody targeting pro-oncogenic AGR2. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00128 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. M. Aiman Mohtar, UKM Medical Molecular Biology Institute (UMBI), Kuala Lumpur, Malaysia, m.aimanmohtar@ppukm.ukm.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers M. Aiman Mohtar Teck Yew Low Borek Vojtesek Rahman Jamal Ted Hupp Google M. Aiman Mohtar Teck Yew Low Borek Vojtesek Rahman Jamal Ted Hupp Google Scholar M. Aiman Mohtar Teck Yew Low Borek Vojtesek Rahman Jamal Ted Hupp PubMed M. Aiman Mohtar Teck Yew Low Borek Vojtesek Rahman Jamal Ted Hupp Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.