MONOCYTE-BASED GENE THERAPY FOR ACUTE NEUTROPHIL-MEDIATED TISSUE INJURY

Lead Research Organisation: University of Edinburgh
Department Name: MRC Centre for Inflammation Research

Abstract

This proposal is aimed at developing new treatments for lung diseases caused by excessive activation of cells used by the body to fight infection (neutrophils). In particular, a condition called adult respiratory distress syndrome is fatal in 40% of cases despite modern treatment, and survivors have considerable long-term problems..
The research involves manipulating another defence cell, the monocyte. Monocytes are recruited to inflamed sites alongside neutrophils and are amenable to therapeutic modification. I shall boost monocytes by providing extra copies of a protective gene called elafin. Elafin efficiently neutralises the main toxic product of neutrophils and makes monocytes switch off inflammation. I shall therefore insert elafin into human monocytes in order to reduce the toxic effects of ‘activated‘ neutrophils. I shall extend these findings to mice with the aim of reducing lung injury caused by neutrophils. These pre-clinical studies will lay the grounds for future clinical application in humans. Importantly, the principles of this proposal can be extended not only to other lung diseases associated with neutrophil malfunction (e.g. emphysema, bronchitis, cystic fibrosis) but to all causes of inflammation involving the neutrophil. The work therefore has potential implications for psoriasis, arthritis, peritonitis, and a host of other conditions

Technical Summary

Neutrophil-mediated lung injury (NMLI) is central to the pathogenesis of conditions such as acute
lung injury and adult respiratory distress syndrome (ARDS). Mortality from these conditions
approaches 40%. Therefore new neutrophil-directed therapeutic strategies are required. Human
neutrophil elastase (HNE) is the key effector of NMLI. Because monocytes specifically access
inflamed alveoli, manipulation of circulating monocytes to express anti-elastases(such as secretory leukocyte protease inhibitor (SLPI) and elafin) has therapeutic potential. I propose that antielastase production by native monocytes is negligible, that monocytes mature into antielastase expressing macrophages in the inflamed lung,that this defence mechanism is overwhelmed in ARDS, and that genetic augmentation of antielastases in monocytes can obviate NMLI. In support of this I have demonstrated novel and consistent protective effects mediated by alveolar macrophages (AMs) but not monocytes against neutrophil-mediated epithelial injury in vitro. This protective effect by AMs is temporally associated with an increase in SLPI secretion. Against this background I aim to address
three key hypotheses:
1. Interaction with neutrophils specifically stimulates generation of protective levels of SLPI from
autologous AMs but not autologous blood monocytes in vitro.
2. Monocytes transfected with adenovirus encoding human elafin (Ad-elafin) consistently protects the lung against neutrophil-mediated injury in vitro and in vivo.
3. Adoptively transferred monocytes traffic rapidly and selectively to the inflamed lung where they differentiate to a macrophage phenotype capable of expressing SLPI. Using primary autologous cells isolated from healthy volunteers and patients with ARDS, I shall assess whether protective effects of AMs on NMLI are SLPI-dependent by transfecting AMs with SLPI siRNA. Human monocytes will be transfected with Ad-elafin to confer consistent protection in vitro.
Extending these studies to an in vivo setting, murine monocytes will be transfected with elafin and adoptively transferred to mice with established NMLI. In the same model, trafficking of adoptively administered monocytes will be assessed dynamically and non-invasively using ‘fluorine’ MRI. To determine the fate of the administered cells, I will administer monocytes isolated from transgenic GFP mice, then isolate these cells to determine phenotype.
This project offers unique training opportunities in cell and molecular biology, gene therapy, animal models of lung inflammation and ‘cutting edge’ imaging techniques. From a scientific perspective the proposal will dissect mechanisms by which monocytes and macrophages interact with neutrophils in vitro and in vivo. The development of a novel, targeted ‘monocyte-based gene therapy’ approach provides a potential strategy for the future treatment of NMLI.

Publications

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Barr LC (2013) A randomized controlled trial of peripheral blood mononuclear cell depletion in experimental human lung inflammation. in American journal of respiratory and critical care medicine

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Conway Morris A (2009) C5a mediates peripheral blood neutrophil dysfunction in critically ill patients. in American journal of respiratory and critical care medicine

 
Description Preclinical imaging for college of medicine
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Participation in advisory committee
 
Description MRC Developmental Pathway Funding Scheme (DPFS)
Amount £625,000 (GBP)
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start 07/2010 
End 08/2012
 
Description MRC Models of Disease (multimodal imaging of inflammation)
Amount £750,000 (GBP)
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start 07/2009 
End 08/2012
 
Description The Sir Jules Thorn Charitable Trust, Project Grant, Clinical Trial
Amount £375,000 (GBP)
Organisation Sir Jules Thorn Charitable Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 07/2009 
End 08/2011
 
Description Wellcome Trust HICF award- optical imaging in lung infection/inflammation
Amount £1,300,000 (GBP)
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 08/2011 
End 09/2015
 
Title Establishing an in vivo optical imaging facility 
Description Tendering, assessemnet and training the institute to use new equipment to expedite preclinical in vivo imaging 
Type Of Material Improvements to research infrastructure 
Provided To Others? No  
Impact potential collaborations 
 
Title Protease detector 
Description Chemical agent that detects protease activity in vitro and in vivo 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact Applied for further funding 
 
Description Academic collaboration with University of Regensberg - Matthias Mack 
Organisation University Hospital Regensburg
Country Germany 
Sector Hospitals 
PI Contribution Collaborating on developing clinical asset for monocyte depletion for COVID-19
Collaborator Contribution The humanised antibody technology is from Regensberg
Impact developing clinical trial protocols and MHRA meetings
Start Year 2010
 
Description Molecular imaging probe generation 
Organisation University of Edinburgh
Department School of Chemistry
Country United Kingdom 
Sector Academic/University 
PI Contribution I run all of the in vivo optical molecular imaging and train new members of staff
Collaborator Contribution Developing optical molecular imaging reagents and tools for applcation in animals and man
Impact further MRC DPFS award- 625K Wellcome Trust HICF award- £2M University Spin-Off company
Start Year 2006
 
Description visit to GSK and Astra Zeneca 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Participants in your research and patient groups
Results and Impact spoke to diverse groups in pharma

collaborations established
Year(s) Of Engagement Activity 2009,2010