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 BacRafts
Project Architecture of bacterial lipid rafts; inhibition of virulence and antibiotic resistance using raft-disassembling small molecules
Researcher (PI) Daniel López Serrano
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Call Details Starting Grant (StG), LS6, ERC-2013-StG
Summary Membranes of eukaryotic cells organize signal transduction proteins into microdomains or lipid rafts whose integrity is essential for numerous cellular processes. Lipid rafts has been considered a fundamental step to define the cellular complexity of eukaryotes, assuming that bacteria do not require such a sophisticated organization of their signaling networks. However, I have discovered that bacteria organize many signaling pathways in membrane microdomains similar to the eukaryotic lipid rafts. Perturbation of bacterial lipid rafts leads to a potent and simultaneous impairment of all raft-harbored signaling pathways. Consequently, the disassembly of lipid rafts in pathogens like Staphylococcus aureus generates a simultaneous inhibition of numerous infection-related processes that can be further explored to control bacterial infections. This unexpected sophistication in membrane organization is unprecedented in bacteria and hence, this proposal will explore the molecular basis of the assembly of bacterial lipid rafts and their role in the infection-related processes. These questions will be addressed in three main goals: First, I will elucidate the molecular components and the mechanism of assembly of bacterial lipid rafts using S. aureus as model organism. Second, I will dissect the molecular basis that links the functionality of the infection-related processes to the integrity of bacterial lipid rafts. Third, my collection of anti-raft small molecules that are able to disrupt lipid rafts will be tested as antimicrobial agents to prevent hospital-acquired infections, abrogate pre-existing infections and develop bacteria-free materials that can be used in clinical settings. I will use a number of molecular approaches in combination with cutting-edge techniques in flow cytometry, cell-imaging and transcriptomics to clarify the architecture and functionality of lipid rafts and demonstrate the feasibility of targeting lipid a new strategy for anti-microbial therapy.
Summary
Membranes of eukaryotic cells organize signal transduction proteins into microdomains or lipid rafts whose integrity is essential for numerous cellular processes. Lipid rafts has been considered a fundamental step to define the cellular complexity of eukaryotes, assuming that bacteria do not require such a sophisticated organization of their signaling networks. However, I have discovered that bacteria organize many signaling pathways in membrane microdomains similar to the eukaryotic lipid rafts. Perturbation of bacterial lipid rafts leads to a potent and simultaneous impairment of all raft-harbored signaling pathways. Consequently, the disassembly of lipid rafts in pathogens like Staphylococcus aureus generates a simultaneous inhibition of numerous infection-related processes that can be further explored to control bacterial infections. This unexpected sophistication in membrane organization is unprecedented in bacteria and hence, this proposal will explore the molecular basis of the assembly of bacterial lipid rafts and their role in the infection-related processes. These questions will be addressed in three main goals: First, I will elucidate the molecular components and the mechanism of assembly of bacterial lipid rafts using S. aureus as model organism. Second, I will dissect the molecular basis that links the functionality of the infection-related processes to the integrity of bacterial lipid rafts. Third, my collection of anti-raft small molecules that are able to disrupt lipid rafts will be tested as antimicrobial agents to prevent hospital-acquired infections, abrogate pre-existing infections and develop bacteria-free materials that can be used in clinical settings. I will use a number of molecular approaches in combination with cutting-edge techniques in flow cytometry, cell-imaging and transcriptomics to clarify the architecture and functionality of lipid rafts and demonstrate the feasibility of targeting lipid a new strategy for anti-microbial therapy.
Max ERC Funding
1 493 126 €
Duration
Start date: 2014-03-01, End date: 2019-02-28
Project acronym BACTERIAL RESPONSE
Project New Concepts in Bacterial Response to their Surroundings
Researcher (PI) Sigal Ben-Yehuda
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary Bacteria in nature exhibit remarkable capacity to sense their surroundings and rapidly adapt to diverse conditions by gaining new beneficial traits. This extraordinary feature facilitates their survival when facing extreme environments. Utilizing Bacillus subtilis as our primary model organism, we propose to study two facets of this vital bacterial attribute: communication via extracellular nanotubes, and persistence as resilient spores while maintaining the potential to revive. Exploring these fascinating aspects of bacterial physiology is likely to change our view as to how bacteria sense, respond, endure and communicate with their extracellular environment.
We have recently discovered a previously uncharacterized mode of bacterial communication, mediated by tubular extensions (nanotubes) that bridge neighboring cells, providing a route for exchange of intracellular molecules. Nanotube-mediated molecular sharing may represent a key form of bacterial communication in nature, allowing for the emergence of new phenotypes and increasing survival in fluctuating environments. Here we propose to develop strategies for observing nanotube formation and molecular exchange in living bacterial cells, and to characterize the molecular composition of nanotubes. We will explore the premise that nanotubes serve as a strategy to expand the cell surface, and will determine whether nanotubes provide a conduit for phage infection and spreading. Furthermore, the formation and functionality of interspecies nanotubes will be explored. An additional mode employed by bacteria to achieve extreme robustness is the ability to reside as long lasting spores. Previously held views considered the spore to be dormant and metabolically inert. However, we have recently shown that at least one week following spore formation, during an adaptive period, the spore senses and responds to environmental cues and undergoes corresponding molecular changes, influencing subsequent emergence from quiescence.
Summary
Bacteria in nature exhibit remarkable capacity to sense their surroundings and rapidly adapt to diverse conditions by gaining new beneficial traits. This extraordinary feature facilitates their survival when facing extreme environments. Utilizing Bacillus subtilis as our primary model organism, we propose to study two facets of this vital bacterial attribute: communication via extracellular nanotubes, and persistence as resilient spores while maintaining the potential to revive. Exploring these fascinating aspects of bacterial physiology is likely to change our view as to how bacteria sense, respond, endure and communicate with their extracellular environment.
We have recently discovered a previously uncharacterized mode of bacterial communication, mediated by tubular extensions (nanotubes) that bridge neighboring cells, providing a route for exchange of intracellular molecules. Nanotube-mediated molecular sharing may represent a key form of bacterial communication in nature, allowing for the emergence of new phenotypes and increasing survival in fluctuating environments. Here we propose to develop strategies for observing nanotube formation and molecular exchange in living bacterial cells, and to characterize the molecular composition of nanotubes. We will explore the premise that nanotubes serve as a strategy to expand the cell surface, and will determine whether nanotubes provide a conduit for phage infection and spreading. Furthermore, the formation and functionality of interspecies nanotubes will be explored. An additional mode employed by bacteria to achieve extreme robustness is the ability to reside as long lasting spores. Previously held views considered the spore to be dormant and metabolically inert. However, we have recently shown that at least one week following spore formation, during an adaptive period, the spore senses and responds to environmental cues and undergoes corresponding molecular changes, influencing subsequent emergence from quiescence.
Max ERC Funding
1 497 800 €
Duration
Start date: 2014-04-01, End date: 2019-03-31
Project acronym Danger ATP
Project Regulation of inflammatory response by extracellular ATP and P2X7 receptor signalling: through and beyond the inflammasome
Researcher (PI) Pablo Pelegrin Vivancos
Host Institution (HI) FUNDACION PARA LA FORMACION E INVESTIGACION SANITARIAS DE LA REGION DE MURCIA
Call Details Consolidator Grant (CoG), LS6, ERC-2013-CoG
Summary Inflammatory diseases affect over 80 million people worldwide and accompany many diseases of industrialized countries, being the majority of them infection-free conditions. There are few efficient anti-inflammatory drugs to treat chronic inflammation and thus, there is an urgent need to validate novel targets. We now know that innate immunity is the main coordinator and driver of inflammation. Recently, we and others have shown that the activation of purinergic P2X7 receptors (P2X7R) in immune cells is a novel and increasingly validated pathway to initiate inflammation through the activation of the NLRP3 inflammasome and the release of IL-1β and IL-18 cytokines. However, how NLRP3 sense P2X7R activation is not fully understood. Furthermore, extracellular ATP, the physiological P2X7R agonist, is a crucial danger signal released by injured cells, and one of the most important mediators of infection-free inflammation. We have also identified novel signalling roles for P2X7R independent on the NLRP3 inflammasome, including the release of proteases or inflammatory lipids. Therefore, P2X7R has generated increasing interest as a therapeutic target in inflammatory diseases, being drug like P2X7R antagonist in clinical trials to treat inflammatory diseases. However, it is often questioned the functionality of P2X7R in vivo, where it is thought that extracellular ATP levels are below the threshold to activate P2X7R. The overall significance of this proposal relays to elucidate how extracellular ATP controls host-defence in vivo, ultimately depicting P2X7R signalling through and beyond inflammasome activation. We foresee that our results will generate a leading innovative knowledge about in vivo extracellular ATP signalling during the host response to infection and sterile danger.
Summary
Inflammatory diseases affect over 80 million people worldwide and accompany many diseases of industrialized countries, being the majority of them infection-free conditions. There are few efficient anti-inflammatory drugs to treat chronic inflammation and thus, there is an urgent need to validate novel targets. We now know that innate immunity is the main coordinator and driver of inflammation. Recently, we and others have shown that the activation of purinergic P2X7 receptors (P2X7R) in immune cells is a novel and increasingly validated pathway to initiate inflammation through the activation of the NLRP3 inflammasome and the release of IL-1β and IL-18 cytokines. However, how NLRP3 sense P2X7R activation is not fully understood. Furthermore, extracellular ATP, the physiological P2X7R agonist, is a crucial danger signal released by injured cells, and one of the most important mediators of infection-free inflammation. We have also identified novel signalling roles for P2X7R independent on the NLRP3 inflammasome, including the release of proteases or inflammatory lipids. Therefore, P2X7R has generated increasing interest as a therapeutic target in inflammatory diseases, being drug like P2X7R antagonist in clinical trials to treat inflammatory diseases. However, it is often questioned the functionality of P2X7R in vivo, where it is thought that extracellular ATP levels are below the threshold to activate P2X7R. The overall significance of this proposal relays to elucidate how extracellular ATP controls host-defence in vivo, ultimately depicting P2X7R signalling through and beyond inflammasome activation. We foresee that our results will generate a leading innovative knowledge about in vivo extracellular ATP signalling during the host response to infection and sterile danger.
Max ERC Funding
1 794 948 €
Duration
Start date: 2014-09-01, End date: 2019-08-31
Project acronym DCBIOX
Project Phagosome functions and antigen cross presentation in primary dendritic cells
Researcher (PI) Sebastian Amigorena
Host Institution (HI) INSTITUT CURIE
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary T cell cross priming (the initiation of CD8+ T cell responses to antigen that are not expressed by dendritic cells, DCs) requires the phagocytosis of antigens by DCs and their presentation on MHC class I molecules, a process referred to as “cross presentation”. Here, we propose a series of integrated approaches to address the most fundamental mechanisms of cross presentation and explore the use of this process for translational purposes in human cancer.
This proposal will pursue three main objectives:
1) To analyze the mechanisms of control of antigen cross presentation and phagocytic functions in DCs. We will use genome wide screens and conditional KO mice, associated to quantitative assays for phagosomal functions and cross presentation, to investigate the molecular mechanisms of cross presentation in vitro and in vivo.
2) To study the epigenetic programing of cross presentation during the ontogeny of mouse DC subpopulations. We will define a “cross presentation gene signature” that will be validated by systematic gene silencing in vitro and we will analyze the epigenetic basis of control of cross presentation-related genes developing DCs.
3) To investigate the regulation of cross presentation in human primary DCs and to develop translational approaches in cancer. We will study cross presentation and phagosome functions in primary human DC subpopulations and its regulation by innate receptors for the development of original immunomodulation and vaccination strategies. We will explore the use of DCs cross presentation abilities in solid tumor infiltrating DCs and their use for prognosis in cancer.
The results of this project will unravel fundamental mechanisms of phagocytosis and its control by innate signals in mice and humans. The proposal also aims at defining new possible strategies for cancer treatment and prognosis.
Summary
T cell cross priming (the initiation of CD8+ T cell responses to antigen that are not expressed by dendritic cells, DCs) requires the phagocytosis of antigens by DCs and their presentation on MHC class I molecules, a process referred to as “cross presentation”. Here, we propose a series of integrated approaches to address the most fundamental mechanisms of cross presentation and explore the use of this process for translational purposes in human cancer.
This proposal will pursue three main objectives:
1) To analyze the mechanisms of control of antigen cross presentation and phagocytic functions in DCs. We will use genome wide screens and conditional KO mice, associated to quantitative assays for phagosomal functions and cross presentation, to investigate the molecular mechanisms of cross presentation in vitro and in vivo.
2) To study the epigenetic programing of cross presentation during the ontogeny of mouse DC subpopulations. We will define a “cross presentation gene signature” that will be validated by systematic gene silencing in vitro and we will analyze the epigenetic basis of control of cross presentation-related genes developing DCs.
3) To investigate the regulation of cross presentation in human primary DCs and to develop translational approaches in cancer. We will study cross presentation and phagosome functions in primary human DC subpopulations and its regulation by innate receptors for the development of original immunomodulation and vaccination strategies. We will explore the use of DCs cross presentation abilities in solid tumor infiltrating DCs and their use for prognosis in cancer.
The results of this project will unravel fundamental mechanisms of phagocytosis and its control by innate signals in mice and humans. The proposal also aims at defining new possible strategies for cancer treatment and prognosis.
Max ERC Funding
2 500 000 €
Duration
Start date: 2014-09-01, End date: 2019-08-31
Project acronym DECRYPT
Project Decrypting signals in the crypt
Researcher (PI) Philippe, Joseph Sansonetti
Host Institution (HI) INSTITUT PASTEUR
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary Pathogens and symbionts: War and Peace at mucosal surface in intestinal crypts.
In the proposed program called DECRYPT, I wish to strengthen novel orientations of our laboratory aimed at decrypting the dialogue between the microbiota and the host, while keeping a balance with the study of pathogens, both being analyzed at their interface with the gut mucosa to further our knowledge of the homeostatic and pathogenic mechanisms that respectively characterize a healthy and a diseased gut. The intestinal crypt is a key location to study this dialogue because it contains the stem cells, the differentiation and transit amplifying/proliferative compartments that are essential for epithelial regeneration at homeostasis, and restitution following an aggression. It is also embedded in a niche of immune cells that participate in homeostatic and pathological processes under microbial stimuli. Thus the breaking nature of my project will bear on the demonstration that crypt homeostasis depends on signals “emitted” by the microbiota, thereby stressing the depth of our symbiosis with the microbial world, and on the demonstration that the crypt is also the target of enteric pathogens like Shigella, thus introducing the novel paradigm that pathogenesis is not only matter of inflammatory destruction of infected tissues, but also of altered epithelial restitution. An extension of this paradigm is that loss or subversion of the microbiota-crypt homeostasis may account not only for inflammatory bowel diseases (IBD), but also for colon cancer. This fundamental knowledge will also be the basis for translational research, particularly the search for molecules that boost antimicrobial defenses and comfort homeostasis. In summary, I propose a balanced combination between the “cellular microbiology of pathogens” and the “cellular microbiology of symbionts”.
Summary
Pathogens and symbionts: War and Peace at mucosal surface in intestinal crypts.
In the proposed program called DECRYPT, I wish to strengthen novel orientations of our laboratory aimed at decrypting the dialogue between the microbiota and the host, while keeping a balance with the study of pathogens, both being analyzed at their interface with the gut mucosa to further our knowledge of the homeostatic and pathogenic mechanisms that respectively characterize a healthy and a diseased gut. The intestinal crypt is a key location to study this dialogue because it contains the stem cells, the differentiation and transit amplifying/proliferative compartments that are essential for epithelial regeneration at homeostasis, and restitution following an aggression. It is also embedded in a niche of immune cells that participate in homeostatic and pathological processes under microbial stimuli. Thus the breaking nature of my project will bear on the demonstration that crypt homeostasis depends on signals “emitted” by the microbiota, thereby stressing the depth of our symbiosis with the microbial world, and on the demonstration that the crypt is also the target of enteric pathogens like Shigella, thus introducing the novel paradigm that pathogenesis is not only matter of inflammatory destruction of infected tissues, but also of altered epithelial restitution. An extension of this paradigm is that loss or subversion of the microbiota-crypt homeostasis may account not only for inflammatory bowel diseases (IBD), but also for colon cancer. This fundamental knowledge will also be the basis for translational research, particularly the search for molecules that boost antimicrobial defenses and comfort homeostasis. In summary, I propose a balanced combination between the “cellular microbiology of pathogens” and the “cellular microbiology of symbionts”.
Max ERC Funding
2 499 992 €
Duration
Start date: 2014-04-01, End date: 2019-03-31
Project acronym FICModFun
Project FIC-Mediated Post-Translational Modifications at the
Pathogen-Host Interface: Elucidating Structure, Function and Role in Infection
Researcher (PI) Christoph Georg Fritz Dehio
Host Institution (HI) UNIVERSITAT BASEL
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary The ubiquitous FIC domain catalyzes post-translational modifications (PTMs) of target proteins; i.e.
adenylylation (=AMPylation) and, more rarely, uridylylation and phosphocholination. Fic proteins are
thought to play critical roles in intrinsic signaling processes of prokaryotes and eukaryotes; however, a
subset encoded by bacterial pathogens is translocated via dedicated secretion systems into the cytoplasm of
mammalian host cells. Some of these host-targeted Fic proteins modify small GTPases leading to collapse of
the actin cytoskeleton and other drastic cellular changes. Recently, we described a large set of functionally
diverse homologues in pathogens of the genus Bartonella that are required for their “stealth attack” strategy
and persistent course of infection [1, 2]. Our preliminary functional analysis of some of these host-targeted
Fic proteins of Bartonella demonstrated adenylylation activity towards novel host targets (e.g. tubulin and
vimentin). Moreover, in addition to the canonical adenylylation activity they may also display a competing
kinase activity resulting from altered ATP binding to the FIC active site. Finally, we described a conserved
mechanism of FIC active site auto- inhibition that is relieved by a single amino acid exchange [1], thus
facilitating functional analysis of any Fic protein of interest. Despite this recent progress only a few Fic
proteins have been functionally characterized to date; our understanding of the functional plasticity of the
FIC domain in mediating diverse target PTMs and their specific roles in infection thus remains limited.
In this project, we aim to study the vast repertoire of host-targeted Fic proteins of Bartonella to: 1)
identify novel target proteins and types of PTMs; 2) study their physiological consequences and molecular
mechanisms of action; and 3) analyze structure-function relationships critical for FIC-mediated PTMs and infer from these data determinants of target specificity, type of PTM and mode of regulation. At the forefront of infection biology research, this project is ground-breaking as (i) we will identify a
plethora of novel host target PTMs that are critical for a “stealth attack” infection strategy and thus will open
new avenues for investigating fundamental mechanisms of persistent infection; and (ii), we will unveil the
molecular basis of the remarkable functional versatility of the structurally conserved FIC domain.
Summary
The ubiquitous FIC domain catalyzes post-translational modifications (PTMs) of target proteins; i.e.
adenylylation (=AMPylation) and, more rarely, uridylylation and phosphocholination. Fic proteins are
thought to play critical roles in intrinsic signaling processes of prokaryotes and eukaryotes; however, a
subset encoded by bacterial pathogens is translocated via dedicated secretion systems into the cytoplasm of
mammalian host cells. Some of these host-targeted Fic proteins modify small GTPases leading to collapse of
the actin cytoskeleton and other drastic cellular changes. Recently, we described a large set of functionally
diverse homologues in pathogens of the genus Bartonella that are required for their “stealth attack” strategy
and persistent course of infection [1, 2]. Our preliminary functional analysis of some of these host-targeted
Fic proteins of Bartonella demonstrated adenylylation activity towards novel host targets (e.g. tubulin and
vimentin). Moreover, in addition to the canonical adenylylation activity they may also display a competing
kinase activity resulting from altered ATP binding to the FIC active site. Finally, we described a conserved
mechanism of FIC active site auto- inhibition that is relieved by a single amino acid exchange [1], thus
facilitating functional analysis of any Fic protein of interest. Despite this recent progress only a few Fic
proteins have been functionally characterized to date; our understanding of the functional plasticity of the
FIC domain in mediating diverse target PTMs and their specific roles in infection thus remains limited.
In this project, we aim to study the vast repertoire of host-targeted Fic proteins of Bartonella to: 1)
identify novel target proteins and types of PTMs; 2) study their physiological consequences and molecular
mechanisms of action; and 3) analyze structure-function relationships critical for FIC-mediated PTMs and infer from these data determinants of target specificity, type of PTM and mode of regulation. At the forefront of infection biology research, this project is ground-breaking as (i) we will identify a
plethora of novel host target PTMs that are critical for a “stealth attack” infection strategy and thus will open
new avenues for investigating fundamental mechanisms of persistent infection; and (ii), we will unveil the
molecular basis of the remarkable functional versatility of the structurally conserved FIC domain.
Max ERC Funding
1 699 858 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym FLAMMASEC
Project "Inflammasome-induced IL-1 Secretion: Route, Mechanism, and Cell Fate"
Researcher (PI) Olaf Groß
Host Institution (HI) UNIVERSITAETSKLINIKUM FREIBURG
Call Details Starting Grant (StG), LS6, ERC-2013-StG
Summary "Inflammasomes are intracellular danger-sensing protein complexes that are important for host protection. They initiate inflammation by controlling the activity of the proinflammatory cytokine interleukin-1β (IL-1β). Unlike most other cytokines, IL-1β is produced and retained in the cytoplasm in an inactive pro-form. Inflammasome-dependent maturation of proIL-1β is mediated by the common component of all inflammasomes, the protease caspase-1. Caspase-1 also controls the secretion of IL-1β, but the mechanism and route of secretion are unknown. We have recently demonstrated that the ability of caspase-1 to control IL-1β secretion is not dependent on its protease activity, but rather on a scaffold or adapter function of caspase-1. Furthermore, we and others could show that caspase-1 can control the secretion of non-substrates like IL-1α. These insights provide us with new and potentially revealing means to investigate the downstream effector functions of caspase-1, including the route and mechanism of IL-1 secretion. We will develop new tools to study the process of IL-1 secretion by microscopy and the novel mode-of-action of caspase-1 through the generation of transgenic models.
Despite the important role of IL-1 in host defence against infection, dysregulated inflammasome activation and IL-1 production has a causal role in a number of acquired and hereditary auto-inflammatory conditions. These include particle-induced sterile inflammation (as is seen in gout and asbestosis), hereditary periodic fever syndromes, and metabolic diseases like diabetes and atherosclerosis. Currently, recombinant proteins that block the IL-1 receptor or deplete secreted IL-1 are used to treat IL-1-dependent diseases. These are costly treatments, and are also therapeutically cumbersome since they are not orally available. We hope that a better understanding of caspase-1-mediated secretion of IL-1 will unveil mechanisms that may serve as targets for future therapies for these diseases."
Summary
"Inflammasomes are intracellular danger-sensing protein complexes that are important for host protection. They initiate inflammation by controlling the activity of the proinflammatory cytokine interleukin-1β (IL-1β). Unlike most other cytokines, IL-1β is produced and retained in the cytoplasm in an inactive pro-form. Inflammasome-dependent maturation of proIL-1β is mediated by the common component of all inflammasomes, the protease caspase-1. Caspase-1 also controls the secretion of IL-1β, but the mechanism and route of secretion are unknown. We have recently demonstrated that the ability of caspase-1 to control IL-1β secretion is not dependent on its protease activity, but rather on a scaffold or adapter function of caspase-1. Furthermore, we and others could show that caspase-1 can control the secretion of non-substrates like IL-1α. These insights provide us with new and potentially revealing means to investigate the downstream effector functions of caspase-1, including the route and mechanism of IL-1 secretion. We will develop new tools to study the process of IL-1 secretion by microscopy and the novel mode-of-action of caspase-1 through the generation of transgenic models.
Despite the important role of IL-1 in host defence against infection, dysregulated inflammasome activation and IL-1 production has a causal role in a number of acquired and hereditary auto-inflammatory conditions. These include particle-induced sterile inflammation (as is seen in gout and asbestosis), hereditary periodic fever syndromes, and metabolic diseases like diabetes and atherosclerosis. Currently, recombinant proteins that block the IL-1 receptor or deplete secreted IL-1 are used to treat IL-1-dependent diseases. These are costly treatments, and are also therapeutically cumbersome since they are not orally available. We hope that a better understanding of caspase-1-mediated secretion of IL-1 will unveil mechanisms that may serve as targets for future therapies for these diseases."
Max ERC Funding
1 495 533 €
Duration
Start date: 2014-03-01, End date: 2019-02-28
Project acronym HIVINNATE
Project Characterisation and Manipulation of Primate Lentiviral Interactions with Innate Immunity
Researcher (PI) Gregory John Towers
Host Institution (HI) UNIVERSITY COLLEGE LONDON
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary Our aim is to seek detailed molecular level understanding of the interactions between HIV-1 and innate immune sensors expressed in myeloid cells. We have demonstrated that HIV-1 replicates in primary human macrophages without triggering interferon production. However, by specific mutation of HIV-1 proteins or by manipulating interaction with host cofactors we can reveal the virus to innate immune receptors and activate an antiviral response leading to secretion of soluble type 1 interferon and cessation of replication. We propose to define the sensors and the details of the antiviral pathways that are activated in macrophages using proven RNA interference techniques reading out activation of innate immune responses by measurement of secreted interferon and induction of gene expression. We have also characterised small molecules that potently inhibit HIV-1 by revealing HIV-1 to innate immune sensors. In collaboration with crystallographers and medicinal chemists we aim to improve the potency and specificity of these drugs and to use them to study the anti-HIV-1 innate immune response. DC are sentinels of innate immunity and their infection induced maturation leads to interferon production and DC dependent T cell maturation that defines the nature and potency of the immune response. We will examine the effect of triggering innate responses in DC using HIV-1 mutants/drug treated wild type virus on allogeneic responses, by measurement of T cell proliferation and function and in an ex vivo CD8 T cell killing assays using peripheral blood CD8 cells from HIV‑1 infected patients. In this way we will uncover the molecular details of HIV-1’s interaction with innate immunity and discover how the virus replicates in primary immune cells without detection. This work will make a significant technical and intellectual contribution to an important emerging scientific field focusing on understanding and manipulating the complex relationship between HIV-1 and innate immunity.
Summary
Our aim is to seek detailed molecular level understanding of the interactions between HIV-1 and innate immune sensors expressed in myeloid cells. We have demonstrated that HIV-1 replicates in primary human macrophages without triggering interferon production. However, by specific mutation of HIV-1 proteins or by manipulating interaction with host cofactors we can reveal the virus to innate immune receptors and activate an antiviral response leading to secretion of soluble type 1 interferon and cessation of replication. We propose to define the sensors and the details of the antiviral pathways that are activated in macrophages using proven RNA interference techniques reading out activation of innate immune responses by measurement of secreted interferon and induction of gene expression. We have also characterised small molecules that potently inhibit HIV-1 by revealing HIV-1 to innate immune sensors. In collaboration with crystallographers and medicinal chemists we aim to improve the potency and specificity of these drugs and to use them to study the anti-HIV-1 innate immune response. DC are sentinels of innate immunity and their infection induced maturation leads to interferon production and DC dependent T cell maturation that defines the nature and potency of the immune response. We will examine the effect of triggering innate responses in DC using HIV-1 mutants/drug treated wild type virus on allogeneic responses, by measurement of T cell proliferation and function and in an ex vivo CD8 T cell killing assays using peripheral blood CD8 cells from HIV‑1 infected patients. In this way we will uncover the molecular details of HIV-1’s interaction with innate immunity and discover how the virus replicates in primary immune cells without detection. This work will make a significant technical and intellectual contribution to an important emerging scientific field focusing on understanding and manipulating the complex relationship between HIV-1 and innate immunity.
Max ERC Funding
2 499 643 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym HLA-DR15 in MS
Project Functional Role of the HLA-DR15 Haplotype in Multiple Sclerosis
Researcher (PI) Roland Michael Gunnar Martin
Host Institution (HI) UNIVERSITAT ZURICH
Call Details Advanced Grant (AdG), LS6, ERC-2013-ADG
Summary Multiple sclerosis (MS) is a prototypic CD4+ T cell-mediated autoimmune disease that damages the central nervous system. MS affects young adults and women twice as often as men. Neurological deficits cause substantial disability at an early age with high socioeconomic impact.
Both a complex genetic trait and environmental factors are involved in MS etiology. Similar to other autoimmune diseases it has been known for almost 40 years that certain HLA-class II genes, in MS the two DR15 alleles DRB1*15:01 and DRB5*01:01, confer by far most of the genetic risk. Despite this clear role remarkably little is known about the functional contribution of these genes to MS pathogenesis, and this holds also true for all other T cell-mediated autoimmune diseases. It is assumed that the DR15 alleles present peptides from organ-specific self-proteins to T cells and select an autoreactive CD4+ T cell repertoire that can be activated by certain environmental triggers. Interestingly, the effects of the three known environmental risk factors in MS, Epstein Barr virus (EBV), low vitamin D3 and smoking, are all amplified by DR15.
This core issue of research on autoimmune diseases and also MS, how disease-associated HLA-class II molecules contribute to disease development at the functional level, will be studied with state-of-the-art methodologies and a series of novel approaches. These will include in silico modeling approaches, studies of self-peptides, T cell receptor (TCR) repertoire and HLA-DR/peptide complexes, clonally expanded T cells from MS brain tissue and hypothesis-open methods such as combinatorial chemistry and tissue-derived cDNA libraries to identify target antigens. Finally, translational studies will investigate the relationship between the above aspects and MS disease heterogeneity and explore antigen-specific tolerization in proof-of concept clinical trials in MS.
Summary
Multiple sclerosis (MS) is a prototypic CD4+ T cell-mediated autoimmune disease that damages the central nervous system. MS affects young adults and women twice as often as men. Neurological deficits cause substantial disability at an early age with high socioeconomic impact.
Both a complex genetic trait and environmental factors are involved in MS etiology. Similar to other autoimmune diseases it has been known for almost 40 years that certain HLA-class II genes, in MS the two DR15 alleles DRB1*15:01 and DRB5*01:01, confer by far most of the genetic risk. Despite this clear role remarkably little is known about the functional contribution of these genes to MS pathogenesis, and this holds also true for all other T cell-mediated autoimmune diseases. It is assumed that the DR15 alleles present peptides from organ-specific self-proteins to T cells and select an autoreactive CD4+ T cell repertoire that can be activated by certain environmental triggers. Interestingly, the effects of the three known environmental risk factors in MS, Epstein Barr virus (EBV), low vitamin D3 and smoking, are all amplified by DR15.
This core issue of research on autoimmune diseases and also MS, how disease-associated HLA-class II molecules contribute to disease development at the functional level, will be studied with state-of-the-art methodologies and a series of novel approaches. These will include in silico modeling approaches, studies of self-peptides, T cell receptor (TCR) repertoire and HLA-DR/peptide complexes, clonally expanded T cells from MS brain tissue and hypothesis-open methods such as combinatorial chemistry and tissue-derived cDNA libraries to identify target antigens. Finally, translational studies will investigate the relationship between the above aspects and MS disease heterogeneity and explore antigen-specific tolerization in proof-of concept clinical trials in MS.
Max ERC Funding
2 368 068 €
Duration
Start date: 2015-01-01, End date: 2019-12-31
