Targeted inhibition of coagulation - an anti-inflammatory approach to prolonging organ graft survival

Lead Research Organisation: Imperial College London
Department Name: Dept of Medicine

Abstract

Organ transplantation is a cost-effective treatment for severe kidney, heart and liver disease and patients often return to living a relatively normal life. There is a worldwide effort to increase the supply or organs, so that more patients can benefit, but this has inevitably involved using some organs that previously were deemed medically unsuitable and these organs have suboptimal function. At the same time, transplanted organs don?t last forever. Instead, many suffer an insidious decline in function. In the case of kidney transplantation, most patients with this ?chronic rejection? eventually return to dialysis. This proposal will investigate whether blood-clotting proteins are involved in the inflammatory processes that cause poor performance and premature failure. There is good reason to think that some members of this family will be involved, because of their roles in other types of inflammation. The work being proposed will be entirely in mice, for three main reasons. First, much is already known about the mechanisms of transplant dysfunction in mice and there are many similarities with the same mechanisms in humans. Second, the use of genetically modified strains will greatly simplify the interpretation of many of the results. Third, we have the necessary expertise and knowledge to perform these experiments in rodents. We believe that this work will show the fundamental roles that members of this family of proteins have in determining how well transplanted organs work and how long they last. Although there are many systemic anticoagulants that inhibit the function of these clotting proteins, current therapies can have severe side effects, including a risk of life-threatening bleeding. Therefore, working out a safe way to inhibit the function of these proteins will be vital if the knowledge gained in this project is to be turned into a therapeutic strategy. Our method, which we?ll be able to test in this work, involves targeting the anticoagulants to exactly the cells or tissues where they are needed, thereby avoiding the potentially dangerous side effects. This might be on the transplanted organ, or might be on recipient cells. Either way, we anticipate that once we?ve established the basis for this strategy, new cell-targeted, protein-based treatments could be made and tested almost immediately, using current technology, for pre-clinical testing. Enhancing the early performance of transplanted organs and preventing premature organ failure will have a significant, immediate and lasting impact on the lives of many thousands of patients.

Technical Summary

Although organ transplantation is a therapeutic success, novel solutions are required to prevent premature organ failure, particularly as the donor pool expands to include organs from so-called marginal donors . This proposal will investigate the importance of coagulation proteins (CP) in the inflammatory and immune mechanisms that drive organ dysfunction. It builds on an appreciation that CP have important inflammatory functions and an understanding of the critical role that innate factors play in shaping adaptive immune responses. The specific objectives are to; a) define how CP are involved in ischaemia reperfusion injury; b) investigate the hypothesis that CP play a role in determining whether T cells are activated or tolerised; c) explore the hypothesis that CP play a critical role in antibody-mediated (humoral) rejection through activation of specific protease activated receptors (PAR) as well as through intravascular fibrin deposition; d) explore the role of tissue factor and CP in the recruitment and expansion of neointimal cells in the arteriosclerosis of chronic rejection; e) investigate, in each of the above, whether targeted expression of anticoagulants on relevant donor or recipient cells can minimise allograft dysfunction. A combination of in vitro and in vivo approaches will be used, making optimum use of cells and tissues from relevant gene-knockout (KO) and transgenic mice that are available for this study, including PAR-KO, fibrinogen-KO and strains expressing anticoagulants on CD31+ cells (including endothelial cells) or vascular smooth muscle cells. An important aspect of the work will be to differentiate how donor (graft) and recipient elements contribute to the activation of CP and to distinguish the pathological effects of CP on the graft from those on recipient elements. This will be achieved using a combination of bone marrow reconstitution and appropriate choice of recipient/donor combinations so that the KO or transgenic phenotype is expressed on different cellular components. These studies will determine whether inhibiting CP can limit allograft dysfunction and promote long-term organ survival. Consequently, they will establish the foundation for a novel therapeutic strategy, based on expressing anticoagulant proteins in a highly targeted, cell-specific manner, an approach that would maximise therapeutic benefit but obviate the serious difficulties associated with systemic anticoagulation, most importantly severe bleeding. We anticipate that pre-clinical testing of the strategy could follow immediately on from this project and that it will prove to be safe and effective at enhancing organ performance and prolonging graft survival.

Publications

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Armstrong-James D (2010) Exogenous interferon-gamma immunotherapy for invasive fungal infections in kidney transplant patients. in American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons

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Chen D (2009) Critical roles for thrombin in acute and chronic inflammation. in Journal of thrombosis and haemostasis : JTH

 
Description Co-opted onto BTS council to represent Basic Science
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
 
Description King's Health Accelerator Award
Amount £130,213 (GBP)
Organisation King's College London 
Department King's Commercialisation Institute
Sector Academic/University
Country United Kingdom
Start 08/2016 
End 07/2017
 
Description King's Health Partners Challenge Fund
Amount £46,667 (GBP)
Funding ID R160405 
Organisation King’s Health Partners 
Sector Academic/University
Country United Kingdom
Start 06/2016 
End 05/2017
 
Description MRC Clinical Training Fellowship for Dr Hannah Wilkinson
Amount £278,889 (GBP)
Funding ID MR/P018513/1 
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 10/2017 
End 09/2020
 
Description MRC Project Grant
Amount £1,000,000 (GBP)
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 04/2009 
End 03/2013
 
Description Project Grant
Amount £60,000 (GBP)
Organisation F. Hoffmann-La Roche AG 
Sector Private
Country Global
Start  
 
Description Project Grant/Garfield Weston Foundation
Amount £200,000 (GBP)
Organisation Garfield Weston Foundation 
Sector Charity/Non Profit
Country United Kingdom
Start  
 
Description Project Grant/Roche Organ Transplantation Research Fund
Amount £88,000 (GBP)
Organisation Roche Organ Transplantation Research Foundation (ROTRF) 
Sector Charity/Non Profit
Country Switzerland
Start  
 
Description Wellcome Trust Translation Award (Co-applicant with Richard Smith)
Amount £1,300,000 (GBP)
Funding ID 098300/Z/12/Z 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2012 
End 12/2015
 
Title supply of Tg mice 
Description Mice generated in 1990s under a previous MRC grant held by Robert Lechler are now held by my group 
Type Of Material Model of mechanisms or symptoms - mammalian in vivo 
Year Produced 2011 
Provided To Others? Yes  
Impact New collaboration and line of investigation in liver disease resulted in abstract at international meeting, and seminar by me at St Mary's. Will result in a paper 
 
Description NIH Xenotransplantation at Pittsburgh 
Organisation University of Pittsburgh
Department Thomas E Starzl Transplantation Institute
Country United States 
Sector Academic/University 
PI Contribution Collaborator on NIH-funded Xenotransplantation programme. Latterly, advisor to renewed prgramme
Collaborator Contribution PhD student to work/train in my lab. Collaboration to supply membrane tethered hirulog (thrombalexin) 2013
Impact Multiple papers, reported elsewhere - 1st author Lin CC
Start Year 2006
 
Title Novel Antithrombotic Compounds 
Description Novel cell-tethered anticoagulants that were based in principle on the genetic tethering that we used in our early experiments 
IP Reference WO2011027175 
Protection Patent application published
Year Protection Granted 2011
Licensed No
Impact Has been used to secure Wellcome Trust money to take these compounds through clinical development
 
Title TFPI-Transgenic pig 
Description Work from a previous MRC programme grant on which I was a co-applicant (lead, Professor Robert Lechler), has led directly to the development of a new line of transgenic pig. These animals express human tissue factor pathway inhibitor and have been made and bred for xenotransplantation by the American Company Revivicor 
Type Therapeutic Intervention - Cellular and gene therapies
Current Stage Of Development Initial development
Year Development Stage Completed 2008
Development Status Under active development/distribution
Impact None yet, but expected in near future, as organs from these pigs undergo preclinical testing in primates 
 
Title Thrombalexin 
Description membrane tethered hirulog, developed directly because of our work with the hirudin-trangenic mice. 
Type Therapeutic Intervention - Drug
Current Stage Of Development Refinement. Non-clinical
Year Development Stage Completed 2012
Development Status Under active development/distribution
Impact none yet 
 
Description Frontiers in Transplantation Course 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation workshop facilitator
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A course for clinicians and scientists interested in translational transplantation research. Attended by more than 80 people in 2014. I was highest rated speaker in 2015 and 2017
Second URL relating to 2013 course: https://www.youtube.com/watch?v=ZlzUAzOj47A

Extremely good feedback scores form participants has ensured we will make this an annual event
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015
URL https://www.youtube.com/watch?v=dRnOEYs9hCQ