Towards robust animal models of ANCA-associated Vasculitis

Lead Research Organisation: University of Birmingham
Department Name: Immunity and Infection

Abstract

ANCA-associated systemic vasculitis (AASV) affects 1000 people each year in the UK, approximately half of whom will die or develop permanent kidney failure as a direct result of the disease or its treatment. During the past 20 years, a large body of evidence has been gathered together which suggests that it is a specific antibody termed ANCA which is responsible for initiating damage to blood vessels in the kidney and other organs in this disease. Current treatments are usually effective but they frequently cause serious side-effects such as infection and many patients are left with significant permanent organ damage by the time the disease is brought under control. Furthermore, AASV frequently relapses which requires treatment to be intensified again, further increasing the risk of side-effects. Recently understanding of AASV has been advanced by the development of 2 models which recreate the disease in rats and mice. These have been significant developments because the disease process is a complex one and whereas studying human cells outside of the body (in the test tube) provides important information, it cannot fully represent what happens inside human organs in the same way that the rodent models do. This proposal will further develop and improve the two rodent models so that they better represent the human disease and recreate the conditions where relapses occur. In particular, the proposal will compare damage to the kidney as it occurs in the animals with damage seen in humans, both at the level of the whole tissue and at the levels of cells and genes. These are important experiments because they will help to verify how closely the models reflect human disease and identify any significant differences. From these studies it will be possible to test new therapies in the models with a realistic expectation that they be can transferred to patient treatment where they show promising results. The importance of minimizing the use of animals has been a central theme in the development of this proposal and by carefully designing experiments to address specific scientific questions, the number of animals used and the extent of any suffering will be restricted as far as possible. It is because the human disease that is being studied is a complex, severe and life-threatening condition for which current treatments have significant limitations, that it is necessary undertake some studies in rodents.

Technical Summary

Over the past two decades a paradigm has been developed using experiments with human cells describing potential mechanisms of microvascular injury in ANCA-associated vasculitis (AASV). This disease causes renal failure and lung haemorrhage, and is fatal if untreated. Current treatments are blighted by an unacceptable burden of adverse effects. The main issues to be addressed in this condition are: 1. Development of novel targeted therapies through increased understanding of basic pathogenic mechanisms and 2. Investigation of remission and relapse with a view to assessment of biomarker signatures.

For the first time we are now in a position to begin testing this paradigm using two recently described animal models of AASV: Experimental Autoimmune Vasculitis (EAV, a rat model relying upon immunisation with the ANCA antigen myeloperoxidase, MPO) and Murine Experimental Vasculitis (MEV, a passive mouse model induced by passive transfer of anti-MPO antibodies). We aim to optimise these two models by adjusting antigen dose, administration route or adjuvant components with a view to generating a model representative of human AASV: crescents affecting 50% of glomeruli and reproducible lung haemorrhage. We then plan to further develop the EAV model to mimic relapsing AASV using inflammatory stimulators and/or repeated MPO immunisation. We envisage the EAV model serving as a test bed for novel therapies as it more closely mimics human autoimmune AASV than the passive MEV model. We plan to further develop the MEV model to permit analysis of pathogenic mechanisms of anti-MPO antibody microvascular injury, with focus on the pathophysiologically relevant tissues in the kidney and lung using intravital microscopy of these organs. The optimised MEV model would permit use of the genetically modified mice currently available for probing specific molecular mechanisms.

We then intend to validate the phenotype of tissue injury in EAV and MEV against that seen in human AASV. In addition to standard readouts of histology and renal biochemistry, we will dissect out affected glomeruli and compare them using Affymetrix GeneChip technology and micro-fluidic targeted PCR microarrays to compare gene expression across the three species. We also intend to investigate whether the ANCA effects on neutrophils observed in human systems also pertain in the EAV and MEV models. By developing these two optimised models of AASV we will be well placed to begin translating the findings of the large body of in vitro work towards the clinic for patient benefit.

Publications

10 25 50
 
Description Dissecting the pathogenesis of PR3-ANCA associated vasculitis using humanised mice
Amount € 965,967 (EUR)
Funding ID 11/YI/B2093 
Organisation Science Foundation Ireland (SFI) 
Sector Charity/Non Profit
Country Ireland
Start 07/2012 
End 07/2017
 
Description Dissecting the pathogenesis of PR3-ANCA associated vasculitis using humanised mice
Amount € 965,967 (EUR)
Funding ID 11/YI/B2093 
Organisation Science Foundation Ireland (SFI) 
Sector Charity/Non Profit
Country Ireland
Start 07/2012 
End 06/2017
 
Description Investigating and targeting monocyte-macrophage cellular effectors in ANCA associated vasculitis
Amount £320,000 (GBP)
Funding ID 090048/Z/09/Z 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2011 
End 12/2013
 
Description Probing the metabolic response to vasculitic injury: towards a tool for noninvasive monitoring of immune activation in ANCA vasculitis
Amount € 501,000 (EUR)
Funding ID 20159/12509 
Organisation Health Research Board (HRB) 
Sector Public
Country Ireland
Start 07/2013 
End 07/2018
 
Description St Peters Trust
Amount £49,197 (GBP)
Organisation St Peter's Trust for Kidney, Bladder and Prostate Research 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2009 
End 08/2012
 
Title Murine experimental vasculitis 
Description Amendment of a previous model to allow for passive transfer of antibodies across the placenta rather than preparing and administering them exogenously 
Type Of Material Model of mechanisms or symptoms - mammalian in vivo 
Year Produced 2011 
Provided To Others? Yes  
Impact Major reduction in the number of animals required 
 
Title Rodent GN array data 
Description Expression array of genes in micro-dissected glomeruli derived from mice and rats with vasculitis 
Type Of Material Database/Collection of data 
Year Produced 2012 
Provided To Others? Yes  
Impact Experiments ongoing 
 
Description Agilent metabolomics 
Organisation Agilent Technologies
Country United States 
Sector Private 
PI Contribution Provided samples for use in their LC/MS machine; they derive positive publicity from this
Collaborator Contribution Provided LC/MS technology for assaying metabolites in urine from rats with vasculitis
Impact Experiments ongoing
Start Year 2012
 
Description Biovitrum 
Organisation SOBI Swedish Orphan Biovitrum AB
Country Sweden 
Sector Private 
PI Contribution Optimised rat model of ANCA vasculitis
Collaborator Contribution Provided a large quantity of purified human MPO for use in the model
Impact Publication
Start Year 2008
 
Description Chimeric human ANCA 
Organisation University of Birmingham
Country United Kingdom 
Sector Academic/University 
PI Contribution Paid for services
Collaborator Contribution Generated chimeric human ANCA
Impact Experiments underway
Start Year 2012
 
Description Inter-species affymetrix 
Organisation University of Michigan
Country United States 
Sector Academic/University 
PI Contribution Provided mouse and rat array data
Collaborator Contribution Provided human array data
Impact Experiments ongoing
Start Year 2010
 
Description Inter-species affymetrix 
Organisation University of Zurich
Country Switzerland 
Sector Academic/University 
PI Contribution Provided mouse and rat array data
Collaborator Contribution Provided human array data
Impact Experiments ongoing
Start Year 2010
 
Description investigating ANCA IgG in a humanised chimeric mouse 
Organisation University of Washington
Department Institute for Stem Cell and Regenerative Medicine
Country United States 
Sector Academic/University 
PI Contribution Technical expertise and materials
Collaborator Contribution Testing of human ANCA IgG for effects on the immune system of humanised chimeric mice
Impact Plos 1 paper SFI programme grant
Start Year 2010
 
Description St Peters Trust newsletter 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Participants in your research and patient groups
Results and Impact Summary of research activity in a fundraising newsletter

None as yet
Year(s) Of Engagement Activity 2009