Project acronym ADAM
Project The Adaptive Auditory Mind
Researcher (PI) Shihab Shamma
Host Institution (HI) ECOLE NORMALE SUPERIEURE
Call Details Advanced Grant (AdG), SH4, ERC-2011-ADG_20110406
Summary Listening in realistic situations is an active process that engages perceptual and cognitive faculties, endowing speech with meaning, music with joy, and environmental sounds with emotion. Through hearing, humans and other animals navigate complex acoustic scenes, separate sound mixtures, and assess their behavioral relevance. These remarkable feats are currently beyond our understanding and exceed the capabilities of the most sophisticated audio engineering systems. The goal of the proposed research is to investigate experimentally a novel view of hearing, where active hearing emerges from a deep interplay between adaptive sensory processes and goal-directed cognition. Specifically, we shall explore the postulate that versatile perception is mediated by rapid-plasticity at the neuronal level. At the conjunction of sensory and cognitive processing, rapid-plasticity pervades all levels of auditory system, from the cochlea up to the auditory and prefrontal cortices. Exploiting fundamental statistical regularities of acoustics, it is what allows humans and other animal to deal so successfully with natural acoustic scenes where artificial systems fail. The project builds on the internationally recognized leadership of the PI in the fields of physiology and computational modeling, combined with the expertise of the Co-Investigator in psychophysics. Building on these highly complementary fields and several technical innovations, we hope to promote a novel view of auditory perception and cognition. We aim also to contribute significantly to translational research in the domain of signal processing for clinical hearing aids, given that many current limitations are not technological but rather conceptual. The project will finally result in the creation of laboratory facilities and an intellectual network unique in France and rare in all of Europe, combining cognitive, neural, and computational approaches to auditory neuroscience.
Summary
Listening in realistic situations is an active process that engages perceptual and cognitive faculties, endowing speech with meaning, music with joy, and environmental sounds with emotion. Through hearing, humans and other animals navigate complex acoustic scenes, separate sound mixtures, and assess their behavioral relevance. These remarkable feats are currently beyond our understanding and exceed the capabilities of the most sophisticated audio engineering systems. The goal of the proposed research is to investigate experimentally a novel view of hearing, where active hearing emerges from a deep interplay between adaptive sensory processes and goal-directed cognition. Specifically, we shall explore the postulate that versatile perception is mediated by rapid-plasticity at the neuronal level. At the conjunction of sensory and cognitive processing, rapid-plasticity pervades all levels of auditory system, from the cochlea up to the auditory and prefrontal cortices. Exploiting fundamental statistical regularities of acoustics, it is what allows humans and other animal to deal so successfully with natural acoustic scenes where artificial systems fail. The project builds on the internationally recognized leadership of the PI in the fields of physiology and computational modeling, combined with the expertise of the Co-Investigator in psychophysics. Building on these highly complementary fields and several technical innovations, we hope to promote a novel view of auditory perception and cognition. We aim also to contribute significantly to translational research in the domain of signal processing for clinical hearing aids, given that many current limitations are not technological but rather conceptual. The project will finally result in the creation of laboratory facilities and an intellectual network unique in France and rare in all of Europe, combining cognitive, neural, and computational approaches to auditory neuroscience.
Max ERC Funding
3 199 078 €
Duration
Start date: 2012-10-01, End date: 2018-09-30
Project acronym AHRIMMUNITY
Project The influence of Aryl hydrocarbon receptor ligands on protective and pathological immune responses
Researcher (PI) Brigitta Stockinger
Host Institution (HI) MEDICAL RESEARCH COUNCIL
Call Details Advanced Grant (AdG), LS6, ERC-2008-AdG
Summary The Aryl hydrocarbon receptor is an evolutionary conserved widely expressed transcription factor that mediates the toxicity of a substantial variety of exogenous toxins, but is also stimulated by endogenous physiological ligands. While it is known that this receptor mediates the toxicity of dioxin, this is unlikely to be its physiological function. We have recently identified selective expression of AhR in the Th17 subset of effector CD4 T cells. Ligation of AhR by a candidate endogenous ligand (FICZ) which is a UV metabolite of tryptophan causes expansion of Th17 cells and the induction of IL-22 production. As a consequence, AhR ligation will exacerbate autoimmune diseases such as experimental autoimmune encephalomyelitis. Little is known so far about the impact of AhR ligands on IL-17/IL-22 mediated immune defense functions. IL-22 is considered a pro-inflammatory Th17 cytokine, which is involved in the etiology of psoriasis, but it has also been shown to be a survival factor for epithelial cells. AhR is polymorphic and defined as high or low affinity receptor for dioxin leading to the classification of high and low responder mouse strains based on defined mutations. In humans similar polymorphisms exist and although on the whole human AhR is thought to be of low affinity in humans, there are identified mutations that confer high responder status. No correlations have been made with Th17 mediated immune responses in mice and humans. This study aims to investigate the role of AhR ligands and polymorphisms in autoimmunity as well as protective immune responses using both mouse models and human samples from normal controls as well as psoriasis patients.
Summary
The Aryl hydrocarbon receptor is an evolutionary conserved widely expressed transcription factor that mediates the toxicity of a substantial variety of exogenous toxins, but is also stimulated by endogenous physiological ligands. While it is known that this receptor mediates the toxicity of dioxin, this is unlikely to be its physiological function. We have recently identified selective expression of AhR in the Th17 subset of effector CD4 T cells. Ligation of AhR by a candidate endogenous ligand (FICZ) which is a UV metabolite of tryptophan causes expansion of Th17 cells and the induction of IL-22 production. As a consequence, AhR ligation will exacerbate autoimmune diseases such as experimental autoimmune encephalomyelitis. Little is known so far about the impact of AhR ligands on IL-17/IL-22 mediated immune defense functions. IL-22 is considered a pro-inflammatory Th17 cytokine, which is involved in the etiology of psoriasis, but it has also been shown to be a survival factor for epithelial cells. AhR is polymorphic and defined as high or low affinity receptor for dioxin leading to the classification of high and low responder mouse strains based on defined mutations. In humans similar polymorphisms exist and although on the whole human AhR is thought to be of low affinity in humans, there are identified mutations that confer high responder status. No correlations have been made with Th17 mediated immune responses in mice and humans. This study aims to investigate the role of AhR ligands and polymorphisms in autoimmunity as well as protective immune responses using both mouse models and human samples from normal controls as well as psoriasis patients.
Max ERC Funding
1 242 352 €
Duration
Start date: 2009-02-01, End date: 2014-01-31
Project acronym ALBUGON
Project Genomics and effectoromics to understand defence suppression and disease resistance in Arabidopsis-Albugo candida interactions
Researcher (PI) Jonathan Jones
Host Institution (HI) THE SAINSBURY LABORATORY
Call Details Advanced Grant (AdG), LS6, ERC-2008-AdG
Summary This project focuses on two questions about host/parasite interactions: how do biotrophic plant pathogens suppress host defence? and, what is the basis for pathogen specialization on specific host species? A broadly accepted model explains resistance and susceptibility to plant pathogens. First, pathogens make conserved molecules ( PAMPS ) such as flagellin, that plants detect via cell surface receptors, leading to PAMP-Triggered Immunity (PTI). Second, pathogens make effectors that suppress PTI. Third, plants carry 100s of Resistance (R) genes that detect an effector, and activate Effector-Triggered Immunity (ETI). One effector is sufficient to trigger resistance. Albugo candida (Ac) (white rust) strongly suppresses host defence; Ac-infected Arabidopsis are susceptible to pathogen races to which they are otherwise resistant. Ac is an oomycete, not a fungus. Arabidopsis is resistant to races of Ac that infect brassicas. The proposed project involves three programs. First ( genomics, transcriptomics and bioinformatics ), we will use next-generation sequencing (NGS) methods (Solexa and GS-Flex), and novel transcriptomics methods to define the genome sequence and effector set of three Ac strains, as well as carrying out >40- deep resequencing of 7 additional Ac strains. Second, ( effectoromics ), we will carry out functional assays using Effector Detector Vectors (Sohn Plant Cell 19:4077 [2007]), with the set of Ac effectors, screening for enhanced virulence, for suppression of defence, for effectors that are recognized by R genes in disease resistant Arabidopsis and for host effector targets. Third, ( resistance diversity ), we will characterize Arabidopsis germplasm for R genes to Ac, both for recognition of Arabidopsis strains of Ac, and for recognition in Arabidopsis of effectors from Ac strains that infect brassica. This proposal focuses on Ac, but will establish methods that could discover new R genes in non-hosts against many plant diseases.
Summary
This project focuses on two questions about host/parasite interactions: how do biotrophic plant pathogens suppress host defence? and, what is the basis for pathogen specialization on specific host species? A broadly accepted model explains resistance and susceptibility to plant pathogens. First, pathogens make conserved molecules ( PAMPS ) such as flagellin, that plants detect via cell surface receptors, leading to PAMP-Triggered Immunity (PTI). Second, pathogens make effectors that suppress PTI. Third, plants carry 100s of Resistance (R) genes that detect an effector, and activate Effector-Triggered Immunity (ETI). One effector is sufficient to trigger resistance. Albugo candida (Ac) (white rust) strongly suppresses host defence; Ac-infected Arabidopsis are susceptible to pathogen races to which they are otherwise resistant. Ac is an oomycete, not a fungus. Arabidopsis is resistant to races of Ac that infect brassicas. The proposed project involves three programs. First ( genomics, transcriptomics and bioinformatics ), we will use next-generation sequencing (NGS) methods (Solexa and GS-Flex), and novel transcriptomics methods to define the genome sequence and effector set of three Ac strains, as well as carrying out >40- deep resequencing of 7 additional Ac strains. Second, ( effectoromics ), we will carry out functional assays using Effector Detector Vectors (Sohn Plant Cell 19:4077 [2007]), with the set of Ac effectors, screening for enhanced virulence, for suppression of defence, for effectors that are recognized by R genes in disease resistant Arabidopsis and for host effector targets. Third, ( resistance diversity ), we will characterize Arabidopsis germplasm for R genes to Ac, both for recognition of Arabidopsis strains of Ac, and for recognition in Arabidopsis of effectors from Ac strains that infect brassica. This proposal focuses on Ac, but will establish methods that could discover new R genes in non-hosts against many plant diseases.
Max ERC Funding
2 498 923 €
Duration
Start date: 2009-01-01, End date: 2014-06-30
Project acronym Anti-Virome
Project A combined evolutionary and proteomics approach to the discovery, induction and application of antiviral immunity factors
Researcher (PI) Frank Kirchhoff
Host Institution (HI) UNIVERSITAET ULM
Call Details Advanced Grant (AdG), LS6, ERC-2012-ADG_20120314
Summary "Humans are equipped with a variety of intrinsic immunity or host restriction factors. These evolved under positive selection pressure for diversification and represent a first line of defence against invading viruses. Unfortunately, however, many pathogens have evolved effective antagonists against our defences. For example, the capability of HIV-1 to counteract human restriction factors that interfere with reverse transcription, uncoating and virion release has been a prerequisite for the global spread of AIDS. We are just beginning to understand the diversity and induction of antiretroviral factors and how pandemic HIV-1 group M (major) strains evolved to counteract all of them. Here, I propose to use a genetics, proteomics and evolutionary approach to discover and define as-yet-unknown antiviral effectors and their inducers. To identify novel antiviral factors, we will examine the capability of all primate genes that are under strong positive selection pressure to inhibit HIV and its simian (SIV) precursors. This examination from the evolutionary perspective of the invading pathogen will also reveal which adaptations allowed HIV-1 to cause the AIDS pandemic. Furthermore, complex peptide-protein libraries representing essentially the entire human peptidome, will be utilized to identify novel specific inducers of antiviral restriction factors. My ultimate aim is to unravel the network of inducers and effectors of antiviral immunity - the ""Anti-Virome"" - and to use this knowledge to develop novel effective preventive and therapeutic approaches based on the induction of combinations of antiviral factors targeting different steps of the viral life cycle. The results of this innovative and interdisciplinary program will provide fundamental new insights into intrinsic immunity and may offer alternatives to conventional vaccine and therapeutic approaches because most restriction factors have broad antiviral activity and are thus effective against various pathogens."
Summary
"Humans are equipped with a variety of intrinsic immunity or host restriction factors. These evolved under positive selection pressure for diversification and represent a first line of defence against invading viruses. Unfortunately, however, many pathogens have evolved effective antagonists against our defences. For example, the capability of HIV-1 to counteract human restriction factors that interfere with reverse transcription, uncoating and virion release has been a prerequisite for the global spread of AIDS. We are just beginning to understand the diversity and induction of antiretroviral factors and how pandemic HIV-1 group M (major) strains evolved to counteract all of them. Here, I propose to use a genetics, proteomics and evolutionary approach to discover and define as-yet-unknown antiviral effectors and their inducers. To identify novel antiviral factors, we will examine the capability of all primate genes that are under strong positive selection pressure to inhibit HIV and its simian (SIV) precursors. This examination from the evolutionary perspective of the invading pathogen will also reveal which adaptations allowed HIV-1 to cause the AIDS pandemic. Furthermore, complex peptide-protein libraries representing essentially the entire human peptidome, will be utilized to identify novel specific inducers of antiviral restriction factors. My ultimate aim is to unravel the network of inducers and effectors of antiviral immunity - the ""Anti-Virome"" - and to use this knowledge to develop novel effective preventive and therapeutic approaches based on the induction of combinations of antiviral factors targeting different steps of the viral life cycle. The results of this innovative and interdisciplinary program will provide fundamental new insights into intrinsic immunity and may offer alternatives to conventional vaccine and therapeutic approaches because most restriction factors have broad antiviral activity and are thus effective against various pathogens."
Max ERC Funding
1 915 200 €
Duration
Start date: 2013-04-01, End date: 2018-03-31
Project acronym APOLs
Project Role of Apolipoproteins L in immunity and disease
Researcher (PI) Etienne Pays
Host Institution (HI) UNIVERSITE LIBRE DE BRUXELLES
Call Details Advanced Grant (AdG), LS6, ERC-2014-ADG
Summary Work conducted in my laboratory on the trypanosome killing factor of human serum led to the identification
of the primate-specific Apolipoprotein L1 (APOL1) as a novel pore-forming protein with striking similarities
with proteins of the apoptotic BCL2 family. APOL1 belongs to a family of proteins induced under
inflammatory conditions in myeloid and endothelial cells. APOL1 is efficiently neutralized by the SRA
protein of Trypanosoma rhodesiense, accounting for the ability of this trypanosome subspecies to infect
humans and cause sleeping sickness. We found that natural APOL1 variants escaping SRA neutralization and
therefore conferring human resistance to T. rhodesiense are associated with chronic kidney disease.
Moreover, transgenic mice expressing these APOL1 variants exhibit an obese phenotype. Our unpublished
results also indicate that APOLs control the lifespan of dendritic cells and podocytes activated by viral
stimuli. Therefore, we propose that the pathology of APOL variants is due to their deregulated activity on the
control of the cellular lifespan in myeloid/endothelial cells activated by pathogen detection.
This project aims at characterizing (i) the molecular mechanism by which APOLs control the lifespan of
activated dendritic cells and podocytes, which has direct impact on innate immunity and inflammation, and
(ii) the mechanism by which APOL1 variants cause pathology. In addition, we plan to detail the
physiological function of APOLs by studying the phenotype of transgenic mice either expressing human
APOL1 (wild-type and variants) or devoid of APOL genes, which we have recently generated. Finally, we
propose to exploit the extraordinary potential of trypanosomes for antigenic variation in order to produce
SRA variants able to neutralize the pathogenic APOL1 variants. Preliminary experiments suggest that in
podocytes SRA antagonizes APOL1 induction by viral stimulus and subsequent cell death, opening new
perspectives to treat kidney disease.
Summary
Work conducted in my laboratory on the trypanosome killing factor of human serum led to the identification
of the primate-specific Apolipoprotein L1 (APOL1) as a novel pore-forming protein with striking similarities
with proteins of the apoptotic BCL2 family. APOL1 belongs to a family of proteins induced under
inflammatory conditions in myeloid and endothelial cells. APOL1 is efficiently neutralized by the SRA
protein of Trypanosoma rhodesiense, accounting for the ability of this trypanosome subspecies to infect
humans and cause sleeping sickness. We found that natural APOL1 variants escaping SRA neutralization and
therefore conferring human resistance to T. rhodesiense are associated with chronic kidney disease.
Moreover, transgenic mice expressing these APOL1 variants exhibit an obese phenotype. Our unpublished
results also indicate that APOLs control the lifespan of dendritic cells and podocytes activated by viral
stimuli. Therefore, we propose that the pathology of APOL variants is due to their deregulated activity on the
control of the cellular lifespan in myeloid/endothelial cells activated by pathogen detection.
This project aims at characterizing (i) the molecular mechanism by which APOLs control the lifespan of
activated dendritic cells and podocytes, which has direct impact on innate immunity and inflammation, and
(ii) the mechanism by which APOL1 variants cause pathology. In addition, we plan to detail the
physiological function of APOLs by studying the phenotype of transgenic mice either expressing human
APOL1 (wild-type and variants) or devoid of APOL genes, which we have recently generated. Finally, we
propose to exploit the extraordinary potential of trypanosomes for antigenic variation in order to produce
SRA variants able to neutralize the pathogenic APOL1 variants. Preliminary experiments suggest that in
podocytes SRA antagonizes APOL1 induction by viral stimulus and subsequent cell death, opening new
perspectives to treat kidney disease.
Max ERC Funding
2 250 000 €
Duration
Start date: 2015-09-01, End date: 2020-08-31
Project acronym ASTHMACRYSTALCLEAR
Project Role of protein crystallization in type 2 immunity and asthma
Researcher (PI) Bart LAMBRECHT
Host Institution (HI) VIB
Call Details Advanced Grant (AdG), LS6, ERC-2017-ADG
Summary Spontaneous protein crystallization is a rare event in biology. Eosinophilic inflammation such as seen in the airways in asthma, chronic rhinosinusitis and helminth infection is however accompanied by accumulation of large amounts of extracellular Charcot-Leyden crystals. These are made of Galectin-10, a protein of unknown function produced by eosinophils, hallmark cells of type 2 immunity. In mice, eosinophilic inflammation is also accompanied by protein crystal build up, composed of the chitinase-like proteins Ym1 and Ym2, produced by alternatively activated macrophages. Here we challenge the current view that these crystals are just markers of eosinophil demise or macrophages activation. We hypothesize that protein crystallization serves an active role in immunoregulation of type 2 immunity. On the one hand, crystallization might turn a harmless protein into a danger signal. On the other hand, crystallization might sequester and eliminate the physiological function of soluble Galectin-10 and Ym1, or prolong it via slow release elution. For full understanding, we therefore need to understand the function of the proteins in a soluble and crystalline state. Our program at the frontline of immunology, molecular structural biology and clinical science combines innovative tool creation and integrative research to investigate the structure, function, and physiology of galectin-10 and related protein crystals. We chose to study asthma as the crystallizing proteins are abundantly present in human and murine disease. There is still a large medical need for novel therapies that could benefit patients with chronic steroid-resistant disease, and are alternatives to eosinophil-depleting antibodies whose long term effects are unknown.
Summary
Spontaneous protein crystallization is a rare event in biology. Eosinophilic inflammation such as seen in the airways in asthma, chronic rhinosinusitis and helminth infection is however accompanied by accumulation of large amounts of extracellular Charcot-Leyden crystals. These are made of Galectin-10, a protein of unknown function produced by eosinophils, hallmark cells of type 2 immunity. In mice, eosinophilic inflammation is also accompanied by protein crystal build up, composed of the chitinase-like proteins Ym1 and Ym2, produced by alternatively activated macrophages. Here we challenge the current view that these crystals are just markers of eosinophil demise or macrophages activation. We hypothesize that protein crystallization serves an active role in immunoregulation of type 2 immunity. On the one hand, crystallization might turn a harmless protein into a danger signal. On the other hand, crystallization might sequester and eliminate the physiological function of soluble Galectin-10 and Ym1, or prolong it via slow release elution. For full understanding, we therefore need to understand the function of the proteins in a soluble and crystalline state. Our program at the frontline of immunology, molecular structural biology and clinical science combines innovative tool creation and integrative research to investigate the structure, function, and physiology of galectin-10 and related protein crystals. We chose to study asthma as the crystallizing proteins are abundantly present in human and murine disease. There is still a large medical need for novel therapies that could benefit patients with chronic steroid-resistant disease, and are alternatives to eosinophil-depleting antibodies whose long term effects are unknown.
Max ERC Funding
2 499 846 €
Duration
Start date: 2018-08-01, End date: 2023-07-31
Project acronym AsthmaVir
Project The roles of innate lymphoid cells and rhinovirus in asthma exacerbations
Researcher (PI) Hergen Spits
Host Institution (HI) Academisch Medisch Centrum bij de Universiteit van Amsterdam
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary Asthma exacerbations represent a high unmet medical need in particular in young children. Human Rhinoviruses (HRV) are the main triggers of these exacerbations. Till now Th2 cells were considered the main initiating effector cell type in asthma in general and asthma exacerbations in particular. However, exaggerated Th2 cell activities alone do not explain all aspects of asthma and exacerbations. Building on our recent discovery of type 2 human innate lymphoid cells (ILC2) capable of promptly producing high amounts of IL-5, IL-9 and IL-13 upon activation and on mouse data pointing to an essential role of these cells in asthma and asthma exacerbations, ILC2 may be the main initiating cells in asthma exacerbations in humans. Thus we hypothesize that HRV directly or indirectly stimulate ILC2s to produce cytokines driving the effector functions leading to the end organ effects that characterize this debilitating disease. Targeting ILC2 and HRV in parallel will provide a highly attractive therapeutic option for the treatment of asthma exacerbations. In depth study of the mechanisms of ILC2 differentiation and function will lead to the design effective drugs targeting these cells; thus the first two objectives of this project are: 1) To unravel the lineage relationship of ILC populations and to decipher the signal transduction pathways that regulate the function of ILCs, 2) to test the functions of lung-residing human ILCs and the effects of compounds that affect these functions in mice which harbour a human immune system and human lung epithelium under homeostatic conditions and after infections with respiratory viruses. The third objective of this project is developing reagents that target HRV; to this end we will develop broadly reacting highly neutralizing human monoclonal antibodies that can be used for prophylaxis and therapy of patients at high risk for developing severe asthma exacerbations.
Summary
Asthma exacerbations represent a high unmet medical need in particular in young children. Human Rhinoviruses (HRV) are the main triggers of these exacerbations. Till now Th2 cells were considered the main initiating effector cell type in asthma in general and asthma exacerbations in particular. However, exaggerated Th2 cell activities alone do not explain all aspects of asthma and exacerbations. Building on our recent discovery of type 2 human innate lymphoid cells (ILC2) capable of promptly producing high amounts of IL-5, IL-9 and IL-13 upon activation and on mouse data pointing to an essential role of these cells in asthma and asthma exacerbations, ILC2 may be the main initiating cells in asthma exacerbations in humans. Thus we hypothesize that HRV directly or indirectly stimulate ILC2s to produce cytokines driving the effector functions leading to the end organ effects that characterize this debilitating disease. Targeting ILC2 and HRV in parallel will provide a highly attractive therapeutic option for the treatment of asthma exacerbations. In depth study of the mechanisms of ILC2 differentiation and function will lead to the design effective drugs targeting these cells; thus the first two objectives of this project are: 1) To unravel the lineage relationship of ILC populations and to decipher the signal transduction pathways that regulate the function of ILCs, 2) to test the functions of lung-residing human ILCs and the effects of compounds that affect these functions in mice which harbour a human immune system and human lung epithelium under homeostatic conditions and after infections with respiratory viruses. The third objective of this project is developing reagents that target HRV; to this end we will develop broadly reacting highly neutralizing human monoclonal antibodies that can be used for prophylaxis and therapy of patients at high risk for developing severe asthma exacerbations.
Max ERC Funding
2 499 593 €
Duration
Start date: 2014-03-01, End date: 2019-02-28
Project acronym AUTO-CD
Project COELIAC DISEASE: UNDERSTANDING HOW A FOREIGN PROTEIN DRIVES AUTOANTIBODY FORMATION
Researcher (PI) Ludvig Magne Sollid
Host Institution (HI) UNIVERSITETET I OSLO
Call Details Advanced Grant (AdG), LS6, ERC-2010-AdG_20100317
Summary The goal of this project is to understand the mechanism of how highly disease specific autoantibodies are generated in response to the exposure to a foreign antigen. IgA autoantibodies reactive with the enzyme transglutaminase 2 (TG2) are typical of coeliac disease (CD). These antibodies are only present in subjects who are HLA-DQ2 or -DQ8, and their production is dependent on dietary gluten exposure. This suggests that CD4+ gluten reactive T cells, which are found in CD patients and which recognise gluten peptides deamidated by TG2 in context of DQ2 or DQ8, are implicated in the generation of these autoantibodies. Many small intestinal IgA+ plasma cells express membrane Ig hence allowing isolation of antigen specific cells. Whereas control subjects lack anti-TG2 IgA+ plasma cells, on average 10% of the plasma cells of CD patients are specific for TG2. We have sorted single TG2 reactive IgA+ plasma cells, cloned their VH and VL genes and expressed recombinant mAbs. So far we have expressed 26 TG2 specific mAbs. There is a strong bias for VH5-51 usage, and surprisingly the antibodies are modestly mutated. TG2 acts on specific glutamine residues and can either crosslink these to other proteins (transamidation) or hydrolyse the glutamine to a glutamate (deamidation). None of the 18 mAbs tested affected either transamidation or deamidation leading us to hypothesise that retained crosslinking ability of TG2 when bound to membrane Ig of B cells is an integral part of the anti-TG2 response. Four models of how activation of TG2 specific B cells is facilitated by TG2 crosslinking and the help of gluten reactive CD4 T cells are proposed. These four models will be extensively tested including doing in vivo assays with a newly generated transgenic anti-TG2 immunoglobulin knock-in mouse model.
Summary
The goal of this project is to understand the mechanism of how highly disease specific autoantibodies are generated in response to the exposure to a foreign antigen. IgA autoantibodies reactive with the enzyme transglutaminase 2 (TG2) are typical of coeliac disease (CD). These antibodies are only present in subjects who are HLA-DQ2 or -DQ8, and their production is dependent on dietary gluten exposure. This suggests that CD4+ gluten reactive T cells, which are found in CD patients and which recognise gluten peptides deamidated by TG2 in context of DQ2 or DQ8, are implicated in the generation of these autoantibodies. Many small intestinal IgA+ plasma cells express membrane Ig hence allowing isolation of antigen specific cells. Whereas control subjects lack anti-TG2 IgA+ plasma cells, on average 10% of the plasma cells of CD patients are specific for TG2. We have sorted single TG2 reactive IgA+ plasma cells, cloned their VH and VL genes and expressed recombinant mAbs. So far we have expressed 26 TG2 specific mAbs. There is a strong bias for VH5-51 usage, and surprisingly the antibodies are modestly mutated. TG2 acts on specific glutamine residues and can either crosslink these to other proteins (transamidation) or hydrolyse the glutamine to a glutamate (deamidation). None of the 18 mAbs tested affected either transamidation or deamidation leading us to hypothesise that retained crosslinking ability of TG2 when bound to membrane Ig of B cells is an integral part of the anti-TG2 response. Four models of how activation of TG2 specific B cells is facilitated by TG2 crosslinking and the help of gluten reactive CD4 T cells are proposed. These four models will be extensively tested including doing in vivo assays with a newly generated transgenic anti-TG2 immunoglobulin knock-in mouse model.
Max ERC Funding
2 291 045 €
Duration
Start date: 2011-05-01, End date: 2017-04-30
Project acronym Autonomous CLL-BCRs
Project Role of autonomous B cell receptor signalling and external antigen in the pathogenesis of chronic lymphocytic leukaemia (CLL)
Researcher (PI) Hassan JUMAA-WEINACHT
Host Institution (HI) UNIVERSITAET ULM
Call Details Advanced Grant (AdG), LS6, ERC-2015-AdG
Summary The proposed project aims at investigating the molecular mechanisms that activate B cell antigen receptor (BCR) signalling in chronic lymphocytic leukaemia (CLL). While it is widely accepted that the unbroken BCR expression in CLL cells is indicative for a key role in disease development, the mechanisms that induce BCR activation and survival of malignant cells are still elusive. Using a unique reconstitution system, we have recently shown that CLL-derived BCRs possess the exceptional capacity for cell-autonomous signalling independent of external antigen. Crystallographic analyses confirmed our model that CLL-BCRs bind to intrinsic motifs in nearby BCRs on the very same cell. In addition to the BCR, several pathogenic factors influence the biological behaviour of CLL cells, but the functional hierarchy and the effect on BCR signalling are insufficiently understood. Here, we aim at investigating the structural cause of autonomous signalling as well as the characterization of important signalling pathways and their mechanistic action in CLL pathogenesis.
By combining crystallography with the measurement of autonomous signalling of wild type and mutated receptors in our unique reconstitution system, we will generate a structure-function relationship for CLL-BCRs. By generating new animal models and by employing classical as well as cutting-edge approaches of biochemistry and molecular/cellular immunology, we will comprehensively characterize the signalling pathways that are activated by autonomous signalling and might be important for CLL pathogenesis.
These systematic efforts are necessary to understand how various biological mechanisms operate and ultimately activate downstream pathways that result in a lymphoproliferative disease. In addition, a cohesive model of CLL pathogenesis, which elucidates the hierarchical order of pathogenic factors and their interaction with BCR signalling, may well lead to novel disease-specific preventive or therapeutic intervention.
Summary
The proposed project aims at investigating the molecular mechanisms that activate B cell antigen receptor (BCR) signalling in chronic lymphocytic leukaemia (CLL). While it is widely accepted that the unbroken BCR expression in CLL cells is indicative for a key role in disease development, the mechanisms that induce BCR activation and survival of malignant cells are still elusive. Using a unique reconstitution system, we have recently shown that CLL-derived BCRs possess the exceptional capacity for cell-autonomous signalling independent of external antigen. Crystallographic analyses confirmed our model that CLL-BCRs bind to intrinsic motifs in nearby BCRs on the very same cell. In addition to the BCR, several pathogenic factors influence the biological behaviour of CLL cells, but the functional hierarchy and the effect on BCR signalling are insufficiently understood. Here, we aim at investigating the structural cause of autonomous signalling as well as the characterization of important signalling pathways and their mechanistic action in CLL pathogenesis.
By combining crystallography with the measurement of autonomous signalling of wild type and mutated receptors in our unique reconstitution system, we will generate a structure-function relationship for CLL-BCRs. By generating new animal models and by employing classical as well as cutting-edge approaches of biochemistry and molecular/cellular immunology, we will comprehensively characterize the signalling pathways that are activated by autonomous signalling and might be important for CLL pathogenesis.
These systematic efforts are necessary to understand how various biological mechanisms operate and ultimately activate downstream pathways that result in a lymphoproliferative disease. In addition, a cohesive model of CLL pathogenesis, which elucidates the hierarchical order of pathogenic factors and their interaction with BCR signalling, may well lead to novel disease-specific preventive or therapeutic intervention.
Max ERC Funding
2 256 250 €
Duration
Start date: 2016-11-01, End date: 2021-10-31
Project acronym B-INNATE
Project Innate signaling networks in B cell antibody production: new targets for vaccine development
Researcher (PI) Andrea Cerutti
Host Institution (HI) FUNDACIO INSTITUT MAR D INVESTIGACIONS MEDIQUES IMIM
Call Details Advanced Grant (AdG), LS6, ERC-2011-ADG_20110310
Summary The long-term goal of this proposal is to explore a novel immune pathway that involves an unexpected interplay between marginal zone (MZ) B cells and neutrophils. MZ B cells are strategically positioned at the interface between the immune system and the circulation and rapidly produce protective antibodies to blood-borne pathogens through a T cell-independent pathway that remains poorly understood. We recently found that the human spleen contains a novel subset of B cell helper neutrophils (NBH cells) with a phenotype and gene expression profile distinct from those of conventional circulating neutrophils (NC cells). In this proposal, we hypothesize that NC cells undergo splenic reprogramming into NBH cells through an IL-10-dependent pathway involving perifollicular sinusoidal endothelial cells. We contend that these unique endothelial cells release NC cell-attracting chemokines and IL-10 upon sensing blood-borne bacteria through Toll-like receptors. We also argue that IL-10 from sinusoidal endothelial cells stimulates NC cells to differentiate into NBH cells equipped with powerful MZ B cell-stimulating activity. The following three aims will be pursued. Aim 1 is to determine the mechanisms by which splenic sinusoidal endothelial cells induce reprogramming of NC cells into NBH cells upon sensing bacteria through Toll-like receptors. Aim 2 is to elucidate the mechanisms by which NBH cells induce IgM production, IgG and IgA class switching, and plasma cell differentiation in MZ B cells. Aim 3 is to evaluate the mechanisms by which NBH cells induce V(D)J gene somatic hypermutation and high-affinity antibody production in MZ B cells. These studies will uncover previously unknown facets of the immunological function of neutrophils by taking advantage of unique cells and tissues from patients with rare primary immunodeficiencies and by making use of selected mouse models. Results from these studies may also lead to the identification of novel vaccine strategies.
Summary
The long-term goal of this proposal is to explore a novel immune pathway that involves an unexpected interplay between marginal zone (MZ) B cells and neutrophils. MZ B cells are strategically positioned at the interface between the immune system and the circulation and rapidly produce protective antibodies to blood-borne pathogens through a T cell-independent pathway that remains poorly understood. We recently found that the human spleen contains a novel subset of B cell helper neutrophils (NBH cells) with a phenotype and gene expression profile distinct from those of conventional circulating neutrophils (NC cells). In this proposal, we hypothesize that NC cells undergo splenic reprogramming into NBH cells through an IL-10-dependent pathway involving perifollicular sinusoidal endothelial cells. We contend that these unique endothelial cells release NC cell-attracting chemokines and IL-10 upon sensing blood-borne bacteria through Toll-like receptors. We also argue that IL-10 from sinusoidal endothelial cells stimulates NC cells to differentiate into NBH cells equipped with powerful MZ B cell-stimulating activity. The following three aims will be pursued. Aim 1 is to determine the mechanisms by which splenic sinusoidal endothelial cells induce reprogramming of NC cells into NBH cells upon sensing bacteria through Toll-like receptors. Aim 2 is to elucidate the mechanisms by which NBH cells induce IgM production, IgG and IgA class switching, and plasma cell differentiation in MZ B cells. Aim 3 is to evaluate the mechanisms by which NBH cells induce V(D)J gene somatic hypermutation and high-affinity antibody production in MZ B cells. These studies will uncover previously unknown facets of the immunological function of neutrophils by taking advantage of unique cells and tissues from patients with rare primary immunodeficiencies and by making use of selected mouse models. Results from these studies may also lead to the identification of novel vaccine strategies.
Max ERC Funding
2 214 035 €
Duration
Start date: 2012-04-01, End date: 2017-09-30