Project

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Xeno2Cure - advanced engineering and testing of organ donor pigs

Applicant Rieben Robert
Number 198577
Funding scheme Sinergia
Research institution Department for BioMedical Research Universität Bern
Institution of higher education University of Berne - BE
Main discipline Interdisciplinary
Start/End 01.04.2021 - 31.03.2025
Approved amount 2'656'900.00
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All Disciplines (4)

Discipline
Interdisciplinary
Veterinary Medicine
Immunology, Immunopathology
Animal Breeding

Keywords (2)

xenotransplantation; genetic modification of pigs

Lay Summary (German)

Lead
Zusammenarbeit zwischen Forschungsteams in Bern, Genf und München soll die Xenotransplantation näher an die klinische Anwendung bringen
Lay summary
Die Xenotransplantation von Organen von Schweinen in menschliche Patienten wäre eine Möglichkeit, um den gravierenden Mangel an menschlichen Spenderorganen zu beheben. Mittels genetischer Veränderung der Spendertiere sollen Organe von Schweinen so an das menschliche Immunsystem angepasst werden, dass die Abstossung deutlich vermindert und durch gängige Immunsuppressiva unterdrückt werden kann. Bisher wurden neue, zusätzliche genetische Veränderungen jeweils zu bereits bestehenden Genveränderungen hinzugefügt, was zu grossen Schwierigkeiten bei der anschliessenden Züchtung stabiler, genetisch veränderter Schweine-Stämme führt. Eine stabile Zuchtpopulation von genetisch veränderten Tieren ist aber wichtig für verlässliche präklinische Studien.

In diesem SINERGIA Projekt sollen Schweine mit mehreren genetischen Veränderungen hergestellt werden, deren Organe für präklinische und später klinische Versuche der Schwein-zu-Mensch Xenotransplantation zur Verfügung stehen. Im Gegensatz zu anderen, laufenden Projekten, sollen die genetisch modifizierten Spenderschweine hier von Grund auf neu entworfen und die Auswirkungen der verschiedenen Genveränderungen zuerst in vitro in neuartigen Zellkulturmodellen untersucht werden. Basierend auf den Erkenntnissen der in vitro Tests werden dann Schweine mit den vielversprechendsten Kombinationen von genetischen Veränderungen gezüchtet und stehen für präklinische Tests zur Verfügung. Im Rahmen dieses Projekts sind insbesondere Perfusionsexperimente geplant, in denen Extremitäten von Schweinen über eine Herz-Lungen-Maschine mit menschlichem Blut versorgt werden. Diese Experimente simulieren die kurzfristigen Effekte, die der Kontakt von menschlichem Blut mit den Blutgefässen der Schweine haben wird und können damit die Wirkung eines Grossteils der voraussichtlich nötigen genetischen Veränderungen untersuchen. Dank der Struktur der komplett neu entworfenen genetischen Veränderungen lassen sich rasch und effizient neue Genkombinationen testen und optimal für Schwein-zu-Mensch Xenotransplantation geeignete Schweine züchten.
 
Direct link to Lay Summary Last update: 29.03.2021

Responsible applicant and co-applicants

Employees

Project partner

Associated projects

Number Title Start Funding scheme
67001 Molecular Mechanisms and Inhibition of Human Cell-Mediated Immune Response against Porcine Endothelial Cells. 01.06.2002 Project funding (Div. I-III)
138376 Transgenic strategies to overcome cellular rejection in pig-to-human xenotransplantation 01.04.2012 Project funding (Div. I-III)
109921 Molecular Mechanisms and Inhibition of Human Innate Immune Responses against Porcine Endothelial Cells 01.01.2006 Project funding (Div. I-III)
156193 Endothelial cell protection in xenotransplantation and ischemia / reperfusion injury: Assessing the effect of multiple transgenes and the pathophysiological role of the plasma cascade systems 01.10.2014 Project funding (Div. I-III)
52198 Inhibition of Human Natural Killer (NK) Cell-mediated Cytotoxi- city against Porcine Endothelial Cells (EC). (zu SCORE B) 01.03.1998 Project funding (Div. I-III)
51983 Inhibition of Human Natural Killer (NK) Cell-mediated Cytotoxi- city against Porcine Endothelial Cells (EC). (SCORE B) 01.03.1998 Ambizione
159594 Strategies to promote tolerance and reduce rejection in rat-to-mouse xenotransplantation models 01.06.2015 Project funding (Div. I-III)

Abstract

The overall aim of this project is to generate pigs with multiple genetic modifications available for testing in experimental pig-to-baboon and later on in clinical pig-to-human xenotransplantation. In order to achieve this, we propose to re-design genetically modified donor pigs ‘from scratch’ and assess the functional consequences of the combined genetic modifications on a cellular level in vitro before pigs are produced from these modified cells. Pigs will then be bred based on the genetic modifications which were proven in vitro to have the best functional phenotype. Finally, ex vivo perfusion studies of limbs of these animals with human blood will be performed to further assess the suitability of the respective genetic modifications in potential xenograft organ donor pigs.This project combines animal genetics and biotechnology with immunology, in particular humoral and cellular innate immunity, but also direct T cell activation by endothelial cells (EC). In addition, biomedical engineering tools like microfluidic techniques for 3D culture of EC under pulsatile flow will be used. Only this synergistic combination of disciplines and approaches will allow for the breakthrough, which is necessary to functionally understand and correctly design in a hypothesis-driven, bottom-up approach the optimal set of genetic modifications required to make porcine organs compatible enough with human physiology and the human immune system to allow clinical xenotransplantation.The three teams involved in this application have known each other and collaborated on different occasions for many years. The group of Eckhard Wolf and Nikolai Klymiuk at the LMU Munich is one of the world’s leading teams in genetic engineering of pigs. They have produced genetically modified pigs as models for human diseases and have also bred the pigs which were used as organ donors for the currently longest lasting orthotopic heart xenotransplantations in baboons (195 days, Nature 2018). These pigs carried only three genetic modifications, namely a knockout of the alpha-Gal transferase gene (GGTA1), combined with transgenic expression of the human complement regulator CD46 (hCD46) as well as human thrombomodulin (hTBM). In this project, we propose the development of optimized xenograft organ donor pigs which carry these genetic modifications after targeted integration to ensure that the donor pigs can be efficiently propagated by breeding without Mendelian segregation of the transgenes. Additional xenoprotective transgenes will be placed into the GGTA1 locus using an innovative gene stacking approach and functionally evaluated using our unique pipeline of in vitro and ex vivo tests. The proposed experiments will make an essential contribution to clinical translation of organ xenotransplantation.
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