CO-REGULATION OF MACROPHAGE INFLAMMATORY PHENOTYPE BY IRF5 AND RELA

Lead Research Organisation: University of Oxford
Department Name: NDORMS

Abstract

Inflammation is a normal and self-limiting physiological response to infection and injury but can lead to extensive tissue damage and disability when elicited in excess or sustained. Pathological consequences of chronic inflammatory responses include a variety of diseases with huge social impact ranging from autoimmune diseases, such as rheumatoid arthritis to many forms of cancer. Macrophages are cells of the immune system which patrol the body and have the ability to recognise a number of different signals released during infection and damage. They are of central importance in the pathogenesis of chronic inflammatory diseases. Depending on the type of signal they receive, macrophages can acquire "aggressive" inflammatory phenotype and will destroy invading threats and defective cells. They secrete inflammatory molecules and set up an environment for expansion of other types of immune cells with inflammation propagating features. Other signals give rise to more "peaceful" macrophages that promote the growth and repair of damaged regions. For example, synovial lesions in rheumatoid arthritis are characterised by the pre-dominant presence of aggressive macrophages.

Recently my laboratory has made a potentially therapeutically important discovery and identified a molecular switch, called 'IRF5' that controls the aggressive phenotype of macrophages: it is highly expressed in aggressive macrophages and induces a characteristic gene expression and inflammatory molecule secretion profile. It is crucially important for establishing an inflammatory environment, associated with a number of autoimmune and inflammatory diseases, and promotes development of memory immune cells which produce even more harmful inflammatory mediators. We have also explored modes of IRF5 regulatory function and demonstrated that they involve functional and physical interactions with another molecular switch, called NF-kB RelA, which is important for proper immune function of both aggressive and peaceful macrophages. This project will test the hypothesis that interfering with IRF5, and in particular with its interactions with RelA, will override signals influencing aggressive macrophage development at sites of inflammation and promote their transformation into more peaceful phenotype, thus reducing inflammation.

Our aim is to ascertain:

1. which inflammatory molecules produced by aggressive macrophages are regulated by IRF5 and RelA and how is this control achieved on the molecular level?

2. can we block direct interactions between IRF5 and RelA and would this reduce production of the inflammatory molecules identified above?

The outcome of this study is expected to be the proof-of-principle demonstration of a new approach to controlling sustained inflammatory cytokine production, based on modulation of the recently identified major molecular switch. The follow up studies will look into the possibilities of other ways of modulating its activity and function, using chemicals, amendable to drug development. Taking account the essential role of macrophages in any immune and inflammatory condition, identification of major molecular switches that determine aggressive or peaceful function of macrophages may hold the key to new therapeutic interventions. It is an important area of research, as it may result in new class of treatment for a wide range of immune conditions. For example, blocking the function of these switches would dampen down damaging inflammation present in autoimmune diseases, while alternatively, inducing their function would boost the immune system in people with immunosuppression.

Technical Summary

Macrophages are immune cells that produce inflammatory mediators and are of central importance in the pathogenesis of chronic inflammatory diseases. The state of macrophage activation depends on the environmental factors and can change from pro- (M1) to anti-inflammatory (M2). M1 macrophages mediate resistance to pathogens and tissue destruction, whereas M2 macrophages promote tissue repair and remodelling as well as tumour progression. Mechanisms that control the switch of macrophage states present an attractive target for designing new therapeutic interventions that would modify sustained inflammatory macrophage activities without affecting their homeostatic function.

We have recently discovered that the transcription factor IRF5 is a major factor defining the pro-inflammatory M1 macrophage polarization. It directly regulates the secretion of specific inflammatory mediators characteristic of M1 macrophages (e.g. IL-12, IL-23, TNF, IL-1), that subsequently set up the environment for expansion of Th1/Th17 cells. We have also mapped molecular mechanisms of IRF5 function in regulation the TNF gene expression, such as direct binding to DNA and indirect recruitment via the formation of a protein complex with RelA. This proposal employs the state of the art functional genomics approaches (e.g. ChIP-Seq, RNA-Seq, EMSA-Seq) and established biochemical techniques (e.g. peptide mapping of protein-protein interaction interface) to identify a subset of genes important for M1 macrophage polarization and co-dependent on RelA-IRF5 interactions and to design molecules capable of breaking these interactions.

The proof of principle modulation of M1 macrophage polarization via interfering with RelA-IRF5 interactions may pave ways to future chemical drug design, which will selectively target the inflammatory response, ideally without having a deleterious effect on innate immunity which is an essential first line of defence against microbes.

Planned Impact

With recently achieved understanding of the molecular mechanisms behind the set up of sustained inflammation, opportunities are now emerging to embark on a systematic and comprehensive analysis of this biological process and to develop new therapeutic strategies designed to control its magnitude and duration. As such, the proposed research could be advantageous for a wide range of beneficiaries, including industry and private sector; UK and EU policy-makers; patients with autoimmune conditions and charities supporting the research in inflammatory diseases; students and wider public interested in immune conditions.

1. Industry/private sector: The identification of amino acid groups involved in RelA-IRF5 interactions and the proof-of-principle modulation of specific gene expression by competing peptides provides a rational for a large-scale chemical library screen of compounds and/or drug design. This will benefit players in the industry and private sector, that are focused on chemical drug design and production, as they will be able to capitalise on our discovery and its implications furthered during the course of this project, by bringing about new drugs for chronic inflammatory and autoimmune diseases. We are currently engaged in exploring the possibilities of setting up a collaborative research programme with Novartis. Considering that the initial discovery and the research into ways of modulating IRF5 activity have been patented by the Imperial Innovations on our behalf, industry and private sector involvement will ultimately lead to fostering economic performance and competitiveness of the UK.

2. Policy-makers: The proposed research fully aligns with the MRC strategic priorities to train post-doctoral researchers in next-generation sequencing analyses while at the same time providing analytical capacity to UK-based experimental groups. The computational part of the proposal will be undertaking in close collaboration with CGAT, and thus it will contribute to training of computational biologists capable of analysing and interpreting next-generation sequencing data sets and will help to address the UK-wide shortage in this area. Our engagement in the EU scientific framework will ensure that the results of this project will be fully disseminated via the EU FP7 Model-In consortium web-site as well as communicated to the project officer, as the research which extends beyond the Model-In objective and together may shape the new FP7 funding calls.

3. Patients: IRF5, a molecule that determines whether key cells of the immune system promote inflammation or inhibit it, could hold the key to new treatments for autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. The proposed research together with already ongoing investigations in the physiological role of IRF5 in mouse models of inflammatory diseases, such as house dust mite induced asthma (grant application to the American Asthma Foundation), collagen induced inflammatory arthritis (grant application to the Arthritis Research UK), inflammatory bowel disease (fellowship application to the Wellcome Trust), obesity related inflammation has the potential to bring about new drugs and therapeutic interventions and thus to contribute to the nation's health and wealth.

4. Students and wider public: Our communication plan presents the opportunity for a wider dissemination of the results via taught under-graduate and post-graduate courses, such as Advanced Topics in Molecular and Cellular Immunobiology, co-designed by the principal applicant for the 3rd year Imperial College under-graduates in Biology/Biochemistry/Immunology. We have an excellent working relationship with the press offices of Imperial College and Oxford University, as well as the number of immunology review journals and news agencies and which widely publicised our discovery of the role of IRF5 in macrophage polarization. These will be used to publicised the results of this study.

Publications

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DeLaney AA (2019) Caspase-8 promotes c-Rel-dependent inflammatory cytokine expression and resistance against . in Proceedings of the National Academy of Sciences of the United States of America

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Ryzhakov G (2015) Activation and function of interferon regulatory factor 5. in Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research

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Weiss M (2013) IRF5 is a specific marker of inflammatory macrophages in vivo. in Mediators of inflammation

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Weiss M (2015) IRF5 controls both acute and chronic inflammation. in Proceedings of the National Academy of Sciences of the United States of America

 
Title Photo exhibition 
Description "Scientists at work" photo exhibition in the local gallery 
Type Of Art Artwork 
Year Produced 2012 
Impact Members of the group organising a photo club and taking monthly photos of interest. The topic "Scientists at work" was presented at the local gallery in London 
 
Description Investigator Award
Amount £1,550,000 (GBP)
Funding ID 209422/Z/17/Z 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 06/2018 
End 06/2023
 
Description Kennedy Institute Trustees Research Fund
Amount £120,000 (GBP)
Funding ID KIR06-2013 
Organisation University of Oxford 
Department Kennedy Institute of Rheumatology
Sector Academic/University
Country United Kingdom
Start 10/2013 
End 09/2017
 
Description Kennedy Institute Trustees Research Fund
Amount £100,000 (GBP)
Organisation University of Oxford 
Department Kennedy Institute of Rheumatology
Sector Academic/University
Country United Kingdom
Start 10/2013 
End 09/2015
 
Description NovoNordisk2
Amount kr 2,293,957 (DKK)
Organisation Novo Nordisk Foundation 
Sector Charity/Non Profit
Country Denmark
Start 01/2016 
End 01/2019
 
Description NovoNordisk_1
Amount £100,000 (GBP)
Funding ID Metabolites 
Organisation Novo Nordisk 
Sector Public
Country Denmark
Start 01/2016 
End 01/2018
 
Title ChIP-Seq 
Description ChIP-Seq data for a number of transcription factors and polymerase II in M1 macrophages 
Type Of Material Database/Collection of Data/Biological Samples 
Provided To Others? No  
Impact map of binding sites for transcription factors essential for interpretation of gene expression data 
 
Title expression arrays 
Description gene expression datasets for wild type bone marrow derived macrophages and those deficient in specific transcription factors 
Type Of Material Database/Collection of Data/Biological Samples 
Provided To Others? No  
Impact critical for understanding the gene target of important transcription factors 
 
Description AH 
Organisation Medical Research Council (MRC)
Department MRC Functional Genomics Unit
Country United Kingdom 
Sector Public 
PI Contribution ChIP-Seq datasets for transcription factors
Collaborator Contribution bioinformatic support for the genome-wide analysis
Impact MRC project grant MR/J0018991/1 IRF5:RelA interaction targets inflammatory genes in macrophages. Saliba DG, Heger A, Eames HL, Oikonomopoulos S, Teixeira A, Blazek K, Androulidaki A, Wong D, Goh FG, Weiss M, Byrne A, Pasparakis M, Ragoussis J, Udalova IA. Cell Rep. 2014 Sep 11;8(5):1308-17
Start Year 2011
 
Description CL 
Organisation Imperial College London
Department National Heart & Lung Institute (NHLI)
Country United Kingdom 
Sector Academic/University 
PI Contribution question and plan of the reseacrh, expertise in molecular technologies
Collaborator Contribution expertise in animal models of asthma
Impact AAF funding; manusript in revision by Nature Communications;
Start Year 2011
 
Description FP 
Organisation University College Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution expertise in IRF5 and macrophage biology
Collaborator Contribution expertise in IBD and colitis animal models
Impact joint DPhil studentship 2013-2016
Start Year 2013
 
Description GN 
Organisation European Institute of Oncology (IEO)
Country Italy 
Sector Charity/Non Profit 
PI Contribution Intellectual contribution to DNA-protein interactions and genome analysis
Collaborator Contribution Intellectual contribution to the aspects of gene regulation; transferring chromatin immunoprecipitation and 3C techniques
Impact Grants: 1. FP7-EU grant 222008 "Genomic determinants of inflammation" 2. Royal Society joint grant "Examining DNA sequence selectivity by alternative NF-kappaB proteins" 3. Horizon 2020 PCH03 proposal "Unifying basis of Chronic Inflammatory Diseases" submitted
Start Year 2006
 
Description JR 
Organisation University of Oxford
Department Wellcome Trust Centre for Human Genetics
Country United Kingdom 
Sector Academic/University 
PI Contribution I have initially set up and developed high throughput analysis of transcription factor - DNA interactions in vitro, further optimised and developed by the collaborator's team.
Collaborator Contribution Using the genomic platform developed in this collaboration, Ragoussis team has produced our analysis of their functional properties and conservation.
Impact Publications: 1. PMID: 17785540 2. PMID: 17785540 3. PMID: 16888364 4. Linnell J, Mott R, Field S, Kwiatkowski DP, Ragoussis J, Udalova IA. Quantitative high-throughput analysis of transcription factor binding specificities. Nucleic Acids Res. 2004 Feb 27;32(4):e44. PMID: 14990752 Grants: 1. FP7-EU grant 222008 "Genomic determinants of inflammation" 2. MRC collaborative grant G0700818
 
Description NP 
Organisation University of Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution expertise in IRF5 biology
Collaborator Contribution expertise in transcriptional termination
Impact joint DPhil studentship 2013-2016
Start Year 2013
 
Description RR 
Organisation Merck
Country Germany 
Sector Private 
PI Contribution IRF5 interactome
Collaborator Contribution ALIS screen for IRF5 binding sites for small molecules
Impact pending
Start Year 2012
 
Description SS 
Organisation University of California, Los Angeles (UCLA)
Country United States 
Sector Academic/University 
PI Contribution reseacrh question and expertise in IRF5 biology and gene regulation
Collaborator Contribution chromatin remodelling
Impact joint experiments
Start Year 2012
 
Title IRF5 in macrophage differentiation 
Description This invention relates to modulating the immune system, and in particular to methods for modulating the immune system to treat disease. The invention further relates to methods for identifying agents that modulate the immune system to treat disease 
IP Reference WO2012093258 
Protection Patent application published
Year Protection Granted 2011
Licensed No
Impact potential industrial collaborations
 
Title FACS 
Description Use antibodies to IRF5 as a marker of inflammatory macrophages (FACS staining) 
Type Diagnostic Tool - Imaging
Current Stage Of Development Initial development
Year Development Stage Completed 2013
Development Status Under active development/distribution
Impact May facilitate profiling of very heterogeneous immune cells in norm and during disease progression 
 
Title Peptide 
Description Identification of a peptide potentially capable of inhibiting specific IRF5 activities 
Type Therapeutic Intervention - Cellular and gene therapies
Current Stage Of Development Initial development
Year Development Stage Completed 2013
Development Status Actively seeking support
Impact novel modulatory agent capable of targetting IRF5 intercations with co-factor, is efficacy in cellular assays is confirmed can be used to block inflammatory response 
 
Description Photo exhibition 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Local people attended a photo exhibition designed to demonstrate Scientists at work

summer placements at the Institute for school children
Year(s) Of Engagement Activity 2012