Regulation Of The Innate And Adaptive Immune Response Against Pathogens And Their Products

Lead Research Organisation: MRC National Inst for Medical Research

Abstract

White blood cells or leucocytes originating in the bone marrow when functionally mature are found in blood and lymphoid tissue and respond to infectious organisms by producing various effector molecules important for the eradication of the pathogen. Amongst these cells, dendritic cells are key initiators of such immune responses and play a key role in activating leucocytes, known as CD4+ T helper cells and CD8+ T killer cells, which produce substances key to protect the host from pathogens such as viruses, bacteria and parasites. In addition, the CD4+ T helper cells produce patterns of molecules called cytokines which play an important role in regulating other white blood cells involved in eradication of infectious organisms, but these need to be regulated so as to inflict minimum damage to the host. This is important since these cytokines can also activate cells which give rise to pathology, such as autoimmunity or allergy. Our research involves the study at a molecular level of how dendritic cells and T helper cells can be activated to elicit the right kind of immune response, and how this immune response is regulated in infection (e.g. tuberculosis and influenza) to eradicate infectious organisms with minimum damage to the individual.

Technical Summary

The type of immune response and effector cytokines elicited to pathogens can determine the outcome of infection. A major lab research focus is the regulation and function of cytokines in immune responses, defining molecular mechanisms of induction of the immunosuppressive cytokine IL-10 versus that of proinflammatory cytokines in immune cells. Although a major function of IL-10 is to regulate inflammation and damage to the host, a penalty is that IL-10 can also contribute to chronic infection. Recently my lab research has been expanded to study of the immune response in tuberculosis (TB), still a major global cause of morbidity and mortality. We have shown that IL-10 can contribute to chronic infection with Mycobacterium tuberculosis (MTb) by diminishing protective T helper (Th)1 responses and the production of IFN-? in the lung. The immune response to MTb is complex and incompletely characterized, hindering development of new diagnostics, treatments and vaccines. Although T cells and the cytokines TNF, IFN-?? and IL-12, are important for immune control of MTb infection, there is an incomplete understanding of the host factors determining protection or pathogenesis in TB. Using an unbiased whole genome array analysis of the transcriptome in blood of TB patients, we have identified potential factors leading to TB pathogenesis. Modular, pathway and gene analyses revealed a striking interferon (IFN)-inducible neutrophil-driven signature of active TB correlating with extent of radiographic disease, which was represented by Type I IFN as well as IFN-?? -inducible genes. This forms the basis of a patent, and the work is now accepted for publication in the journal Nature. We are now in an excellent position to apply the knowledge obtained from our study of human TB to further develop mouse models of TB and define mechanisms and potential determinants of pathogenesis. We will build on our past results to investigate further the molecular mechanisms for induction of IL-10 production and function. IL-10 is produced by multiple cells of the innate and adaptive immune response and thus is not controlled by a strict trajectory of cellular differentiation and is under the control of both cell intrinsic and extrinsic positive and negative regulatory loops in macrophages. Such control mechanisms, although likely, have not as yet been shown in other immune cells. Thus we will continue to characterize mechanisms of induction and regulation of IL-10 in macrophages, dendritic cells and T cells to uncover common and/or distinct mechanisms for its production. We will use basic molecular tools to delineate mechanisms of IL-10 expression both in vitro and in vivo and also extend this to in vivo models of infection with intracellular pathogens, with emphasis on TB. Leading on from our findings in human TB, we will dissect further potential factors in TB pathogenesis, using improved mouse models of TB. We will also use our findings to improve and define transcriptional biomarkers to enhance TB diagnosis and distinguish it from other lung diseases, and define prognostic markers predictive of outcome of latent TB to help develop targeted therapies needed to reduce the burden of TB globally. Technologies used include cell culture, flow cytometry immunoassay, in vivo whole animal immune responses, biochemical and molecular analysis of intracellular signalling pathways and gene regulation (protein and DNA-based technology), microarray technology of host mRNA.

Publications

10 25 50
 
Description Dana Foundation Research Grant-2007
Amount £25,352 (GBP)
Organisation Dana Foundation 
Sector Charity/Non Profit
Country United States
Start 01/2007 
End 01/2010
 
Description Dana Foundation-Research Grant-2007
Amount £162,356 (GBP)
Organisation Dana Foundation 
Sector Charity/Non Profit
Country United States
Start 01/2008 
End 01/2009
 
Description EU-Network of Excellence-FP6
Amount £116,953 (GBP)
Organisation Sixth Framework Programme (FP6) 
Sector Public
Country European Union (EU)
Start 03/2006 
End 03/2010
 
Description European Research Council ERC 2011 AdG
Amount € 1,550,000 (EUR)
Funding ID 294682 - TB-PATH 
Organisation European Research Council (ERC) 
Sector Public
Country European Union (EU)
Start 04/2012 
End 03/2017
 
Description MRC Clinical Training Fellowship (2009)
Amount £235,050 (GBP)
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 05/2009 
End 09/2012
 
Description Merieux-Research Grants
Amount £250,410 (GBP)
Organisation Merieux Institute 
Sector Private
Country France
Start 03/2010 
End 03/2013
 
Description IL-10 production in T helper cells 
Organisation Washington University in St Louis
Department Department of Pathology & Immunology
Country United States 
Sector Academic/University 
PI Contribution By providing mice provided by our collaborators at Washington Unversity, with particular genetic mutations we were able to show that all differentiated T helper cells produce the suppressive cytokine Interleukin-10 leading to feedback regulation of immune responses to stop host damage. We also further identified molecular pathways for IL-10 gene regulation. This led to a publication in the journal Immunity PMID: 19646904.
Collaborator Contribution By providing mice provided by our collaborators at Washington Unversity, with particular genetic mutations we were able to show that all differentiated T helper cells produce the suppressive cytokine Interleukin-10 leading to feedback regulation of immune responses to stop host damage. We also further identified molecular pathways for IL-10 gene regulation. This led to a publication in the journal Immunity PMID: 19646904.
Impact his led to a publication in the journal Immunity PMID: 19646904.
Start Year 2006
 
Description Induction of IL-10 in T cells from steroid-resistant patients using Vitamin D3 
Organisation King's College London
Department School of Medicine KCL
Country United Kingdom 
Sector Academic/University 
PI Contribution We defined the ability of vitamin D3 and dexamethasone to induce IL-10 production in mouse and human (with our collaborator C. Hawrylowicz) CD4+ T cells, and are using these findings to enahnce our knowledge of the mechanisms whereby IL-10 is induced in T cells. Professo Hawrylowicz has advanced this work by showing that vitamin D3 can overcome the inability of T cells from steroid-resistant asthma patients to respond to TCR signalling to produce IL-10. This furthers the mechanism of action of this drug and raises it's potential use in asthma treatment.
Collaborator Contribution We defined the ability of vitamin D3 and dexamethasone to induce IL-10 production in mouse and human (with our collaborator C. Hawrylowicz) CD4+ T cells, and are using these findings to enhance our knowledge of the mechanisms whereby IL-10 is induced in T cells. Professor Hawrylowicz has advanced this work by showing that vitamin D3 can overcome the inability of T cells from steroid-resistant asthma patients to respond to TCR signalling to produce IL-10. This furthers the mechanism of action of this drug and raises it's potential use in asthma treatment.
Impact We defined the ability of vitamin D3 and dexamethasone to induce IL-10 production in mouse and human (with our collaborator C. Hawrylowicz) CD4+ T cells, and are using these findings to enhance our knowledge of the mechanisms whereby IL-10 is induced in T cells. Professor Hawrylowicz has advanced this work by showing that vitamin D3 can overcome the inability of T cells from steroid-resistant asthma patients to respond to TCR signalling to produce IL-10. This furthers the mechanism of action of this drug and raises it's potential use in asthma treatment. This led to a collaobrative publication in 2006 in the Journal of Investigation Xystrakis et al., PMID: 16341266
 
Description Transcriptional Profiling in Latent and Active tuberculosis 
Organisation Baylor Scott & White Health
Department Baylor Institute for Immunology Research
Country United States 
Sector Academic/University 
PI Contribution We recruited the patients, performed the microarray data analysis and the immunological experiemtns on patient material, wrote the paper and the patent with the Balyor lawyers. Baylor Institute for Immunology Research contributed the microarray technology and the training for analysis of complex micorarray data by the MRC NIMR team.
Collaborator Contribution We have recruited and studies patients with active tuberculosis disease in London and South Africa. With technology provided by the Baylor Institute for Immunology Research for microarray analysis of transcriptional profiles in blood of tuberculosis patients we have described a signature which distinguishes latent asymptomatic tuberculosis patients from those with active disease and have also found a potentially predictive signature of active tuberculosis patients in 10% of latent individuals. A patent has been successfully filed on these findings as a potential diagnostic, and now updated for describing factors potentially involved in pathogenesis of active TB disease. A manuscript has now been submitted to the journal Nature with these findings and an abstract has now been published in Thorax, Berry et al. This study was published in the journal Nature in August 2010, and more recently McNab et al., 2011, EJI; and Bloom et al., 2012
Impact 2 patents has been successfully filed and published and a third submitted, on these findings as a potential diagnostic, and now updated for describing factors potentially involved in pathogenesis of active TB disease. A manuscript has now been submitted to the journal Nature with these findings and an abstract has now been published in Thorax, Berry et al. and in the journal Nature, and more recently McNab et al., 2011, EJI; and Bloom et al., 2012.
Start Year 2006
 
Description Transcriptional signatures of active versus latent tuberculosis 
Organisation Imperial College London
Department Faculty of Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution We recruited the patients, with the help of London and South Africa Hospitals in part with the help of Imperial College collaborators, performed the microarray data analysis and the immunological experiments on patient material, wrote the paper and the patent with the Balyor lawyers. Baylor Institute for Immunology Research contributed the microarray technology and the training for analysis of complex micorarray data by the MRC NIMR team.
Collaborator Contribution We have recruited and studies patients with active tuberculosis disease in London and South Africa in part with the help of Imperial College collaborators. With technology provided by the Baylor Institute for Immunology Research for microarray analysis of transcriptional profiles in blood of tuberculosis patients we have described a signature which distinguishes latent asymptomatic tuberculosis patients from those with active disease and have also found a potentially predictive signature of active tuberculosis patients in 10% of latent individuals. A patent has been successfully filed on these findings as a potential diagnostic, and now updated for describing factors potentially involved in pathogenesis of active TB disease. A manuscript has now been submitted to the journal Nature with these findings and an abstract has now been published in Thorax, Berry et al. This study was published in the journal Nature in August 2010, and more recently McNab et al., 2011, EJI; and Bloom et al., 2012
Impact 2 patents has been successfully filed and published and a third submitted, on these findings as a potential diagnostic, and now updated for describing factors potentially involved in pathogenesis of active TB disease. A manuscript has now been submitted to the journal Nature with these findings and an abstract has now been published in Thorax, Berry et al. and in the journal Nature, and more recently McNab et al., 2011, EJI; and Bloom et al., 2012.
Start Year 2006
 
Title BLOOD TRANSCRIPTIONAL SIGNATURE OF MYCOBACTERIUM TUBERCULOSIS INFECTION 
Description Transcriptional profiling of blood distinguishes patients with active tuberculsosis disease from those with latent tuberculosis (asymptomatic) and healthy controls 
IP Reference WO2009158521 
Protection Patent granted
Year Protection Granted 2009
Licensed No
Impact This discovery has potential for diagnosis tuberculosis during active disease and in latent patients who may be asymptomatic but will reactivate disease. The transcriptional profile is diminished upon drug treatment. This transcriptional profile may be effective in monitoring and directing treatment of patients.
 
Title Blood transcriptional signature of active versus latent tuberculosis infection 
Description Tuberculosis (TB), caused by infection with Mycobacterium tuberculosis (M. tuberculosis), is a major cause of morbidity and mortality worldwide and efforts to control TB are hampered by difficulties with diagnosis, prevention and treatment 1,2. Most people infected with M. tuberculosis remain asymptomatic, termed latent TB, with a 10% lifetime risk of developing active TB disease, but current tests cannot identify which individuals will develop disease 3. The immune response to M. tuberculosis is complex and incompletely characterized, hindering development of new diagnostics, therapies and vaccines 4,5. We identified a whole blood 393 transcript signature for active TB in intermediate and high burden settings, correlating with radiological extent of disease and reverting to that of healthy controls following treatment. A subset of latent TB patients had signatures similar to those in active TB patients. We also identified a specific 86-transcript signature that discriminated active TB from other inflammatory and infectious diseases. Modular and pathway analysis revealed that the TB signature was dominated by a neutrophil-driven interferon (IFN)-inducible gene profile, consisting of both IFN-? and Type I IFNaß signalling. Comparison with transcriptional signatures in purified cells and flow cytometric analysis, suggest that this TB signature reflects both changes in cellular composition and altered gene expression. Although an IFN signature was also observed in whole blood of patients with Systemic Lupus Erythematosus (SLE), their complete modular signature differed from TB with increased abundance of plasma cell transcripts. Our studies demonstrate a hitherto under-appreciated role of Type I IFNaß signalling in TB pathogenesis, which has implications for vaccine and therapeutic development. Our study also provides a broad range of transcriptional biomarkers with potential as diagnostic and prognostic tools to combat the TB epidemic. 
IP Reference WO2011066008 
Protection Patent application published
Year Protection Granted 2011
Licensed No
Impact Interest and funding from company Institut Merieux
 
Description Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach International
Primary Audience Participants in your research and patient groups
Results and Impact Cold Spring Harbor Symposium Conferecne, May-June 2013,
CSH, USA

Many applicants to my lab
Year(s) Of Engagement Activity 2013
 
Description School Visit 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Gave a talk on immunology and infection to biology class - A Level class - Henrietta Barnett School

Opened up knowledge gap for a number of pupils some of which were intending to follow medical/research career
Year(s) Of Engagement Activity 2007
 
Description School visit 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Talks sprked multiple questions and discussions during and afterwards

Talks led to multiple student placements at the NIMR in my laboratory and those of others
Year(s) Of Engagement Activity 2011,2013,2014
 
Description Scientific Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach International
Primary Audience Participants in your research and patient groups
Results and Impact 300 delegates attended
Keystone Conference on Innate Immunity
Brasil

Many applicants to my lab
Year(s) Of Engagement Activity 2013