Project acronym BACTERIAL SPORES
Project Investigating the Nature of Bacterial Spores
Researcher (PI) Sigal Ben-Yehuda
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary When triggered by nutrient limitation, the Gram-positive bacterium Bacillus subtilis and its relatives enter a pathway of cellular differentiation culminating in the formation of a dormant cell type called a spore, the most resilient cell type known. Bacterial spores can survive for long periods of time and are able to endure extremes of heat, radiation and chemical assault. Remarkably, dormant spores can rapidly convert back to actively growing cells by a process called germination. Consequently, spore forming bacteria, including dangerous pathogens, (such as C. botulinum and B. anthracis) are highly resistant to antibacterial treatments and difficult to eradicate. Despite significant advances in our understanding of the process of spore formation, little is known about the nature of the mature spore. It is unrevealed how dormancy is maintained within the spore and how it is ceased, as the organization and the dynamics of the spore macromolecules remain obscure. The unusual biochemical and biophysical characteristics of the dormant spore make it a challenging biological system to investigate using conventional methods, and thus set the need to develop innovative approaches to study spore biology. We propose to explore the nature of spores by using B. subtilis as a primary experimental system. We intend to: (1) define the architecture of the spore chromosome, (2) track the complexity and fate of mRNA and protein molecules during sporulation, dormancy and germination, (3) revisit the basic notion of the spore dormancy (is it metabolically inert?), (4) compare the characteristics of bacilli spores from diverse ecophysiological groups, (5) investigate the features of spores belonging to distant bacterial genera, (6) generate an integrative database that categorizes the molecular features of spores. Our study will provide original insights and introduce novel concepts to the field of spore biology and may help devise innovative ways to combat spore forming pathogens.
Summary
When triggered by nutrient limitation, the Gram-positive bacterium Bacillus subtilis and its relatives enter a pathway of cellular differentiation culminating in the formation of a dormant cell type called a spore, the most resilient cell type known. Bacterial spores can survive for long periods of time and are able to endure extremes of heat, radiation and chemical assault. Remarkably, dormant spores can rapidly convert back to actively growing cells by a process called germination. Consequently, spore forming bacteria, including dangerous pathogens, (such as C. botulinum and B. anthracis) are highly resistant to antibacterial treatments and difficult to eradicate. Despite significant advances in our understanding of the process of spore formation, little is known about the nature of the mature spore. It is unrevealed how dormancy is maintained within the spore and how it is ceased, as the organization and the dynamics of the spore macromolecules remain obscure. The unusual biochemical and biophysical characteristics of the dormant spore make it a challenging biological system to investigate using conventional methods, and thus set the need to develop innovative approaches to study spore biology. We propose to explore the nature of spores by using B. subtilis as a primary experimental system. We intend to: (1) define the architecture of the spore chromosome, (2) track the complexity and fate of mRNA and protein molecules during sporulation, dormancy and germination, (3) revisit the basic notion of the spore dormancy (is it metabolically inert?), (4) compare the characteristics of bacilli spores from diverse ecophysiological groups, (5) investigate the features of spores belonging to distant bacterial genera, (6) generate an integrative database that categorizes the molecular features of spores. Our study will provide original insights and introduce novel concepts to the field of spore biology and may help devise innovative ways to combat spore forming pathogens.
Max ERC Funding
1 630 000 €
Duration
Start date: 2008-10-01, End date: 2013-09-30
Project acronym BCLYM
Project Molecular mechanisms of mature B cell lymphomagenesis
Researcher (PI) Almudena Ramiro
Host Institution (HI) CENTRO NACIONAL DE INVESTIGACIONESCARDIOVASCULARES CARLOS III (F.S.P.)
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Most of the lymphomas diagnosed in the western world are originated from mature B cells. The hallmark of these malignancies is the presence of recurrent chromosome translocations that usually involve the immunoglobulin loci and a proto-oncogene. As a result of the translocation event the proto-oncogene becomes deregulated under the influence of immunoglobulin cis sequences thus playing an important role in the etiology of the disease. Upon antigen encounter mature B cells engage in the germinal center reaction, a complex differentiation program of critical importance to the development of the secondary immune response. The germinal center reaction entails the somatic remodelling of immunoglobulin genes by the somatic hypermutation and class switch recombination reactions, both of which are triggered by Activation Induced Deaminase (AID). We have previously shown that AID also initiates lymphoma-associated c-myc/IgH chromosome translocations. In addition, the germinal center reaction involves a fine-tuned balance between intense B cell proliferation and program cell death. This environment seems to render B cells particularly vulnerable to malignant transformation. We aim at studying the molecular events responsible for B cell susceptibility to lymphomagenesis from two perspectives. First, we will address the role of AID in the generation of lymphomagenic lesions in the context of AID specificity and transcriptional activation. Second, we will approach the regulatory function of microRNAs of AID-dependent, germinal center events. The proposal aims at the molecular understanding of a process that lies in the interface of immune regulation and oncogenic transformation and therefore the results will have profound implications both to basic and clinical understanding of lymphomagenesis.
Summary
Most of the lymphomas diagnosed in the western world are originated from mature B cells. The hallmark of these malignancies is the presence of recurrent chromosome translocations that usually involve the immunoglobulin loci and a proto-oncogene. As a result of the translocation event the proto-oncogene becomes deregulated under the influence of immunoglobulin cis sequences thus playing an important role in the etiology of the disease. Upon antigen encounter mature B cells engage in the germinal center reaction, a complex differentiation program of critical importance to the development of the secondary immune response. The germinal center reaction entails the somatic remodelling of immunoglobulin genes by the somatic hypermutation and class switch recombination reactions, both of which are triggered by Activation Induced Deaminase (AID). We have previously shown that AID also initiates lymphoma-associated c-myc/IgH chromosome translocations. In addition, the germinal center reaction involves a fine-tuned balance between intense B cell proliferation and program cell death. This environment seems to render B cells particularly vulnerable to malignant transformation. We aim at studying the molecular events responsible for B cell susceptibility to lymphomagenesis from two perspectives. First, we will address the role of AID in the generation of lymphomagenic lesions in the context of AID specificity and transcriptional activation. Second, we will approach the regulatory function of microRNAs of AID-dependent, germinal center events. The proposal aims at the molecular understanding of a process that lies in the interface of immune regulation and oncogenic transformation and therefore the results will have profound implications both to basic and clinical understanding of lymphomagenesis.
Max ERC Funding
1 596 000 €
Duration
Start date: 2008-12-01, End date: 2014-11-30
Project acronym DC-LYMPH
Project The Role of Lymphatic Vessels in Dendritic Cell Homing and Maturation
Researcher (PI) Melody A. Swartz
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Dendritic cell (DC) activation and homing from the periphery to lymph nodes is a critical first event in the immune response. It involves upregulation of the chemokine receptor CCR7 and chemoinvasion towards lymphatic vessels. Despite its critical importance in adaptive immunity, the mechanisms of DC migration towards and entry into lymphatics are still poorly understood; this severely limits new therapeutic strategies for immunomodulation and even strategies for treating lymphedema, which is exacerbated by poor immune functioning. We propose a battery of physiological, cell-biological, molecular, and computational studies to determine both the mechanisms of DC homing to lymphatic vessels and how DCs modulate lymphatic function. We approach this from the perspectives of both the DC and the lymphatic vessel. Regarding the DC, we will examine computationally and experimentally how draining flows toward the lymphatic alter their migration tactics and test our hypothesis that DCs possess a biomolecular flow-detector network (which we refer to as autologous chemotaxis) and are thus able to sense the direction of the subtle flow of fluid toward the lymphatics. Regarding the lymphatic vessel, we will elucidate how biochemical and biophysical inflammatory signals regulate their drainage function, alter cell-cell adhesions and overall permeability, and alter adhesion receptors to facilitate DC homing and entry. Finally, we will examine DC migration in mice with dysfunctional lymphatics and explore strategies to improve immune response. These will be carried out in 4 main projects, and will complement our recent work in lymphatic functional biology as well as our more therapeutic investigations in DC targeting and activation (Reddy et al., Nature Biotechnol., 2007). This deeper knowledge of mechanisms of DC-lymphatic cross-talk in a relevant biophysical context will enable our long-term goal of rational design for therapeutic immunomodulation and lymphedema.
Summary
Dendritic cell (DC) activation and homing from the periphery to lymph nodes is a critical first event in the immune response. It involves upregulation of the chemokine receptor CCR7 and chemoinvasion towards lymphatic vessels. Despite its critical importance in adaptive immunity, the mechanisms of DC migration towards and entry into lymphatics are still poorly understood; this severely limits new therapeutic strategies for immunomodulation and even strategies for treating lymphedema, which is exacerbated by poor immune functioning. We propose a battery of physiological, cell-biological, molecular, and computational studies to determine both the mechanisms of DC homing to lymphatic vessels and how DCs modulate lymphatic function. We approach this from the perspectives of both the DC and the lymphatic vessel. Regarding the DC, we will examine computationally and experimentally how draining flows toward the lymphatic alter their migration tactics and test our hypothesis that DCs possess a biomolecular flow-detector network (which we refer to as autologous chemotaxis) and are thus able to sense the direction of the subtle flow of fluid toward the lymphatics. Regarding the lymphatic vessel, we will elucidate how biochemical and biophysical inflammatory signals regulate their drainage function, alter cell-cell adhesions and overall permeability, and alter adhesion receptors to facilitate DC homing and entry. Finally, we will examine DC migration in mice with dysfunctional lymphatics and explore strategies to improve immune response. These will be carried out in 4 main projects, and will complement our recent work in lymphatic functional biology as well as our more therapeutic investigations in DC targeting and activation (Reddy et al., Nature Biotechnol., 2007). This deeper knowledge of mechanisms of DC-lymphatic cross-talk in a relevant biophysical context will enable our long-term goal of rational design for therapeutic immunomodulation and lymphedema.
Max ERC Funding
1 730 966 €
Duration
Start date: 2008-05-01, End date: 2013-04-30
Project acronym DENDROWORLD
Project Mucosal dendritic cells in intestinal homeostasis and bacteria-related diseases
Researcher (PI) Maria Rescigno
Host Institution (HI) ISTITUTO EUROPEO DI ONCOLOGIA SRL
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary The bacterial microflora has always been regarded as beneficial for the host but recent studies have shown that this symbiosis has risks as well as benefits. Although active mechanisms allow tolerating the commensal flora, the physiological stress that is associated with the symbionts’ metabolism can exhaust the intestinal barrier resulting in serious effects on the health of the host. Protracted immune deregulations can lead to severe disorders including diabetes, cancer and inflammatory bowel disease (IBD). Several mechanisms and players are involved in the maintenance of intestinal immune homeostasis, including T regulatory cells and Immunoglobulin (Ig)-A. In this proposal we focus our attention on dendritic cells (DCs) for their ability to induce both tolerance and immunity by regulating B and T cell responses. We have recently shown that DC function is controlled by intestinal epithelial cell (EC) derived factors and in particular by Thymic stromal lymphopoietin (TSLP). EC-conditioned DCs acquire a ‘mucosal’ phenotype as they are prone to activate T regulatory cells and IgA responses. Three major issues related to the maintenance and disruption of intestinal immune homeostasis will be explored in this project: 1) What are the mediators and mechanisms that regulate the interaction between intestinal epithelial cells and dendritic cells? What is the function of TSLP? 2) Which are the sites and players for the activation of an IgA response to pathogenic and commensal bacteria? Can we visualize them in vivo? 3) Can prolonged infections or bacterial products promote intestinal tumour development? Are there different bacterial constituents acting as inducers or protectors of carcinogenesis? What is the role of Toll-like receptors?
Summary
The bacterial microflora has always been regarded as beneficial for the host but recent studies have shown that this symbiosis has risks as well as benefits. Although active mechanisms allow tolerating the commensal flora, the physiological stress that is associated with the symbionts’ metabolism can exhaust the intestinal barrier resulting in serious effects on the health of the host. Protracted immune deregulations can lead to severe disorders including diabetes, cancer and inflammatory bowel disease (IBD). Several mechanisms and players are involved in the maintenance of intestinal immune homeostasis, including T regulatory cells and Immunoglobulin (Ig)-A. In this proposal we focus our attention on dendritic cells (DCs) for their ability to induce both tolerance and immunity by regulating B and T cell responses. We have recently shown that DC function is controlled by intestinal epithelial cell (EC) derived factors and in particular by Thymic stromal lymphopoietin (TSLP). EC-conditioned DCs acquire a ‘mucosal’ phenotype as they are prone to activate T regulatory cells and IgA responses. Three major issues related to the maintenance and disruption of intestinal immune homeostasis will be explored in this project: 1) What are the mediators and mechanisms that regulate the interaction between intestinal epithelial cells and dendritic cells? What is the function of TSLP? 2) Which are the sites and players for the activation of an IgA response to pathogenic and commensal bacteria? Can we visualize them in vivo? 3) Can prolonged infections or bacterial products promote intestinal tumour development? Are there different bacterial constituents acting as inducers or protectors of carcinogenesis? What is the role of Toll-like receptors?
Max ERC Funding
1 195 680 €
Duration
Start date: 2008-07-01, End date: 2013-06-30
Project acronym GADD45&P38SIGNALING
Project Role of the Gadd45 family and p38 MAPK in tumor suppression and autoimmunity
Researcher (PI) Jesús Salvador
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Gadd45 family proteins play a critical role in genomic stability, cell cycle regulation proliferation and apoptosis. Gadd45a is activated by the tumor suppressor gene p53, which is mutated in >50% of human tumors. The lack of GADD45a in mice leads to spontaneous development of an autoimmune disease similar to systemic lupus erythematosus. The molecular mechanisms that cause autoimmunity are poorly understood. Recent evidence suggests that p38 activation is involved in autoimmune development and tumor suppression. We found that Gadd45a negatively regulates p38 activity in T cells by preventing phosphorylation on Tyr323. Inhibition of Tyr323p38 phosphorylation is a potential therapeutic target in several types of leukemia and autoimmune diseases, including lupus and rheumatoid arthritis. The main goals of this project are a) to study the in vivo function of the Gadd45 family and p38 in tumor suppression and autoimmunity, and b) to analyze their molecular mechanisms to identify targets for disease treatment. We will dissect the signaling pathways involved in development of autoimmunity and cancer using a multidisciplinary approach that combines mouse genetic, human epigenetic, biochemical, molecular biological and immunological techniques. Our project involves the characterization of murine models deficient in each member of the Gadd45 family (Gadd45a, Gadd45b, Gadd45g), as well as double- and triple-knockout mice, development of a knock-in model for p38a, in vivo and in vitro analysis of T cell activation, proliferation, apoptosis and differentiation, epigenetic studies of potential targets, and finally, validation of these results in autoimmune disease and cancer patients. The results of this project will help identify new therapeutic targets for autoimmune diseases and/or cancer.
Summary
Gadd45 family proteins play a critical role in genomic stability, cell cycle regulation proliferation and apoptosis. Gadd45a is activated by the tumor suppressor gene p53, which is mutated in >50% of human tumors. The lack of GADD45a in mice leads to spontaneous development of an autoimmune disease similar to systemic lupus erythematosus. The molecular mechanisms that cause autoimmunity are poorly understood. Recent evidence suggests that p38 activation is involved in autoimmune development and tumor suppression. We found that Gadd45a negatively regulates p38 activity in T cells by preventing phosphorylation on Tyr323. Inhibition of Tyr323p38 phosphorylation is a potential therapeutic target in several types of leukemia and autoimmune diseases, including lupus and rheumatoid arthritis. The main goals of this project are a) to study the in vivo function of the Gadd45 family and p38 in tumor suppression and autoimmunity, and b) to analyze their molecular mechanisms to identify targets for disease treatment. We will dissect the signaling pathways involved in development of autoimmunity and cancer using a multidisciplinary approach that combines mouse genetic, human epigenetic, biochemical, molecular biological and immunological techniques. Our project involves the characterization of murine models deficient in each member of the Gadd45 family (Gadd45a, Gadd45b, Gadd45g), as well as double- and triple-knockout mice, development of a knock-in model for p38a, in vivo and in vitro analysis of T cell activation, proliferation, apoptosis and differentiation, epigenetic studies of potential targets, and finally, validation of these results in autoimmune disease and cancer patients. The results of this project will help identify new therapeutic targets for autoimmune diseases and/or cancer.
Max ERC Funding
1 755 805 €
Duration
Start date: 2008-09-01, End date: 2014-08-31
Project acronym HCV_IMMUNOLOGY
Project The paradoxical role of type I interferons in Hepatitis C disease pathogenesis and treatment
Researcher (PI) Matthew Albert
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Hepatitis C virus (HCV) presents a significant public health problem with nearly 200 million infected people worldwide. Over the past three years, we have developed partnerships with clinicians and epidemiologists so that we can achieve better insight into immune pathogenesis of both acute and chronic HCV infection. My newly created research unit is committed to defining the complex interplay between virus and host from the perspective of type I interferons (IFNs) and IFN induced gene products. Furthermore, we aim to identify biomarkers predictive of viral clearance that could help identify, pre-treatment, which individuals will respond to their IFNα / ribavirin therapy. Specifically, we aim to: I. To define the role of IFN and IFN-induced genes in HCV clearance. This aim will utilize patient samples to define the role of endogenously produced IFNs in the clearance of HCV during acute infection and the paradoxical role they play in making chronically infected patients resistant to their exogenous IFN therapy. II. To characterize the effect of IFN and INF-induced gene products in the cross-priming of CD8+ T cells. This aim is based on our evidence that HCV-reactive CD8+ T cells are activated by an indirect pathway called cross-presentation and our recent data, which illustrates the complex ways in which type I IFNs can regulate this antigen presentation pathway. III. To determine the in vivo pro- and counter-inflammatory effect of IFN and INF-induced gene products in the cross-priming of CD8+ T cells. This aspect of the project will utilize mouse models to test our hypotheses regarding HCV disease pathogenesis. Our work and the studies outlined in this proposal will help push forward our understanding of the HCV disease pathogenesis and lead to the development of new diagnostic tools as well as strategies for improving upon existing therapeutic strategies.
Summary
Hepatitis C virus (HCV) presents a significant public health problem with nearly 200 million infected people worldwide. Over the past three years, we have developed partnerships with clinicians and epidemiologists so that we can achieve better insight into immune pathogenesis of both acute and chronic HCV infection. My newly created research unit is committed to defining the complex interplay between virus and host from the perspective of type I interferons (IFNs) and IFN induced gene products. Furthermore, we aim to identify biomarkers predictive of viral clearance that could help identify, pre-treatment, which individuals will respond to their IFNα / ribavirin therapy. Specifically, we aim to: I. To define the role of IFN and IFN-induced genes in HCV clearance. This aim will utilize patient samples to define the role of endogenously produced IFNs in the clearance of HCV during acute infection and the paradoxical role they play in making chronically infected patients resistant to their exogenous IFN therapy. II. To characterize the effect of IFN and INF-induced gene products in the cross-priming of CD8+ T cells. This aim is based on our evidence that HCV-reactive CD8+ T cells are activated by an indirect pathway called cross-presentation and our recent data, which illustrates the complex ways in which type I IFNs can regulate this antigen presentation pathway. III. To determine the in vivo pro- and counter-inflammatory effect of IFN and INF-induced gene products in the cross-priming of CD8+ T cells. This aspect of the project will utilize mouse models to test our hypotheses regarding HCV disease pathogenesis. Our work and the studies outlined in this proposal will help push forward our understanding of the HCV disease pathogenesis and lead to the development of new diagnostic tools as well as strategies for improving upon existing therapeutic strategies.
Max ERC Funding
1 098 000 €
Duration
Start date: 2009-01-01, End date: 2014-06-30
Project acronym LEPTINMS
Project Leptin, metabolic state and natural regulatory T cells: cellular and molecular basis for a novel immune intervention in autoimmunity
Researcher (PI) Giuseppe Matarese
Host Institution (HI) CONSIGLIO NAZIONALE DELLE RICERCHE
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Our Group has been investigating the cellular and molecular mechanisms involving leptin, the adipocyte-derived hormone, in the pathogenesis of autoimmunity such as experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS).We analyzed the serum and cerebro-spinal fluid (CSF) leptin secretion and the interaction between serum leptin and naturally occurring Foxp3+CD4+CD25+ regulatory T cells (Tregs) in naïve-to-therapy multiple sclerosis (MS) patients. Leptin production was significantly increased in serum and CSF of MS patients and correlated with interferon-gamma (IFN-g) secretion in the CSF.T cell lines against human myelin basic protein (hMBP) produced leptin and upregulated the expression of the leptin receptor (ObR) after activation with hMBP; treatment with either anti-leptin or anti-leptin receptor neutralizing antibodies inhibited in vitro proliferation to hMBP.Interestingly, in the MS patients an inverse correlation between serum leptin and percentage of circulating Tregs was also observed. Moreover, treatment of EAE-susceptible mice with a leptin antagonist increased the percentage of Tregs and ameliorated disease clinical course and progression in proteolipid protein peptide (PLP139-151)-induced EAE.These findings show for the first time an inverse relationship between leptin secretion and the frequency of Tregs in EAE and MS.In the present project, we intend to analyze in vitro and in vivo, the relationship between leptin and Tregs in human and in animal models, studying at molecular and cellular level the effect of leptin and its neutralization on the survival, proliferation and cytokine secretion of Tregs.Despite recent advances, the precise requirements for the physiological development of Tregs such as the necessary milieu and their molecular/biochemical requirements, remain enigmatic.Understanding these events will be important for the generation of Tregs which could have potential implications for treatment of autoimmunity.
Summary
Our Group has been investigating the cellular and molecular mechanisms involving leptin, the adipocyte-derived hormone, in the pathogenesis of autoimmunity such as experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS).We analyzed the serum and cerebro-spinal fluid (CSF) leptin secretion and the interaction between serum leptin and naturally occurring Foxp3+CD4+CD25+ regulatory T cells (Tregs) in naïve-to-therapy multiple sclerosis (MS) patients. Leptin production was significantly increased in serum and CSF of MS patients and correlated with interferon-gamma (IFN-g) secretion in the CSF.T cell lines against human myelin basic protein (hMBP) produced leptin and upregulated the expression of the leptin receptor (ObR) after activation with hMBP; treatment with either anti-leptin or anti-leptin receptor neutralizing antibodies inhibited in vitro proliferation to hMBP.Interestingly, in the MS patients an inverse correlation between serum leptin and percentage of circulating Tregs was also observed. Moreover, treatment of EAE-susceptible mice with a leptin antagonist increased the percentage of Tregs and ameliorated disease clinical course and progression in proteolipid protein peptide (PLP139-151)-induced EAE.These findings show for the first time an inverse relationship between leptin secretion and the frequency of Tregs in EAE and MS.In the present project, we intend to analyze in vitro and in vivo, the relationship between leptin and Tregs in human and in animal models, studying at molecular and cellular level the effect of leptin and its neutralization on the survival, proliferation and cytokine secretion of Tregs.Despite recent advances, the precise requirements for the physiological development of Tregs such as the necessary milieu and their molecular/biochemical requirements, remain enigmatic.Understanding these events will be important for the generation of Tregs which could have potential implications for treatment of autoimmunity.
Max ERC Funding
880 000 €
Duration
Start date: 2008-07-01, End date: 2011-10-31
Project acronym MICROFLEX
Project Microbiology of Dehalococcoides-like Chloroflexi
Researcher (PI) Lorenz Adrian
Host Institution (HI) HELMHOLTZ-ZENTRUM FUR UMWELTFORSCHUNG GMBH - UFZ
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary I propose to initiate research on a specific group of bacteria, here denominated as the “Dehalococcoides-like Chloroflexi”. This group of bacteria is formed by several cultivated strains of the genus Dehalococcoides and many sequences of uncultivated organisms mostly from marine sediment or subsurface locations. All together form one subphylum of the Chloroflexi. Bacteria of the Dehalococcoides-like Chloroflexi are of particular importance for two independent reasons: first, the subphylum contains all bacteria known to transform under anaerobic conditions toxic and persistent halogenated compounds such as chlorinated dioxins, benzenes, biphenyls, vinyl chloride or brominated biphenylethers; secondly, massive amounts of Dehalococcoides-like Chloroflexi have recently been detected in marine organic-rich deep sediments dominating the populations with up to 80% of the total cell counts. However, many aspects of the physiology of Dehalococcoides species are unclear and almost nothing is known about Chloroflexi in deep sediments. I have worked for many years on the microbiology, biochemistry and genomics of Dehalococcoides species. With the proposed group I plan to focus on the physiological links between Chloroflexi in contaminated aquifers and those in marine sediments. Initially, cultures of marine sediment-Chloroflexi will be established in our lab and compared with pure Dehalococcoides strains. Objectives of our research towards marine Chloroflexi will be the description of the physiology, of the biochemistry of energy conservation and of key genes encoded in the genomes. It is anticipated that the research leads to a substantiated hypothesis on the mode of energy fixation in marine deep-sediments and an initial description of the role of Dehalococcoides-like Chloroflexi in biogeochemical cycles. We also expect to find insights into Chloroflexi evolution and their role in earth history by comparing genomes between Dehalococcoides species and marine Chloroflexi.
Summary
I propose to initiate research on a specific group of bacteria, here denominated as the “Dehalococcoides-like Chloroflexi”. This group of bacteria is formed by several cultivated strains of the genus Dehalococcoides and many sequences of uncultivated organisms mostly from marine sediment or subsurface locations. All together form one subphylum of the Chloroflexi. Bacteria of the Dehalococcoides-like Chloroflexi are of particular importance for two independent reasons: first, the subphylum contains all bacteria known to transform under anaerobic conditions toxic and persistent halogenated compounds such as chlorinated dioxins, benzenes, biphenyls, vinyl chloride or brominated biphenylethers; secondly, massive amounts of Dehalococcoides-like Chloroflexi have recently been detected in marine organic-rich deep sediments dominating the populations with up to 80% of the total cell counts. However, many aspects of the physiology of Dehalococcoides species are unclear and almost nothing is known about Chloroflexi in deep sediments. I have worked for many years on the microbiology, biochemistry and genomics of Dehalococcoides species. With the proposed group I plan to focus on the physiological links between Chloroflexi in contaminated aquifers and those in marine sediments. Initially, cultures of marine sediment-Chloroflexi will be established in our lab and compared with pure Dehalococcoides strains. Objectives of our research towards marine Chloroflexi will be the description of the physiology, of the biochemistry of energy conservation and of key genes encoded in the genomes. It is anticipated that the research leads to a substantiated hypothesis on the mode of energy fixation in marine deep-sediments and an initial description of the role of Dehalococcoides-like Chloroflexi in biogeochemical cycles. We also expect to find insights into Chloroflexi evolution and their role in earth history by comparing genomes between Dehalococcoides species and marine Chloroflexi.
Max ERC Funding
1 287 258 €
Duration
Start date: 2008-06-01, End date: 2013-12-31
Project acronym MOLINFLAM
Project Molecular dissection of inflammatory pathways
Researcher (PI) Attila Mocsai
Host Institution (HI) SEMMELWEIS EGYETEM
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Inflammatory diseases are highly prevalent, often chronic diseases that cause diminished quality of life and are connected with major causes of death in Western societies. Despite their societal impact, their pathomechanism is incompletely understood, hindering development of novel therapeutic strategies. In particular, little is known about the intracellular signal transduction processes involved in the tissue destruction phase of aggressive autoimmune diseases such as rheumatoid arthritis. The present proposal aims to clarify this issue using in vivo and in vitro studies on genetically manipulated mice. During the proposed studies, mice deficient in various signal transduction molecules such as Syk, PLCg2, Gab2 and p190 RhoGAPs will be used to test their contribution to inflammatory responses. In vitro studies will test the activation of major effector cells of inflammation (neutrophils, macrophages and osteoclasts) while in vivo studies will utilize mouse models such as autoantibody- and cytokine-induced inflammatory arthritis or autoantibody-induced glomerulonephritis. Further studies will be performed to test the contribution of the above signaling molecules to disease pathogenesis in a lineage-restricted manner, using the Cre-lox approach. Finally, wild type and mutant versions of the signaling molecules tested will be retrovirally re-expressed into the relevant knockout hematopoietic stem cells in vivo to allow structure-function studies during in vivo inflammation. Two novel transgenic strains and a knock-in (floxed) mutant will also be generated during the course of the project. Using state-of-the-art approaches and techniques, this project will provide information at unprecedented molecular detail on signal transduction mechanisms involved in inflammatory diseases, and is expected to point to possible future targets of novel anti-inflammatory therapies.
Summary
Inflammatory diseases are highly prevalent, often chronic diseases that cause diminished quality of life and are connected with major causes of death in Western societies. Despite their societal impact, their pathomechanism is incompletely understood, hindering development of novel therapeutic strategies. In particular, little is known about the intracellular signal transduction processes involved in the tissue destruction phase of aggressive autoimmune diseases such as rheumatoid arthritis. The present proposal aims to clarify this issue using in vivo and in vitro studies on genetically manipulated mice. During the proposed studies, mice deficient in various signal transduction molecules such as Syk, PLCg2, Gab2 and p190 RhoGAPs will be used to test their contribution to inflammatory responses. In vitro studies will test the activation of major effector cells of inflammation (neutrophils, macrophages and osteoclasts) while in vivo studies will utilize mouse models such as autoantibody- and cytokine-induced inflammatory arthritis or autoantibody-induced glomerulonephritis. Further studies will be performed to test the contribution of the above signaling molecules to disease pathogenesis in a lineage-restricted manner, using the Cre-lox approach. Finally, wild type and mutant versions of the signaling molecules tested will be retrovirally re-expressed into the relevant knockout hematopoietic stem cells in vivo to allow structure-function studies during in vivo inflammation. Two novel transgenic strains and a knock-in (floxed) mutant will also be generated during the course of the project. Using state-of-the-art approaches and techniques, this project will provide information at unprecedented molecular detail on signal transduction mechanisms involved in inflammatory diseases, and is expected to point to possible future targets of novel anti-inflammatory therapies.
Max ERC Funding
1 200 000 €
Duration
Start date: 2008-10-01, End date: 2014-03-31
Project acronym PAGE
Project The role of mRNA-processing bodies in ageing
Researcher (PI) Popi Syntichaki
Host Institution (HI) IDRYMA IATROVIOLOGIKON EREUNON AKADEMIAS ATHINON
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary Recently, we and others have revealed that, in the nematode Caenorhabditis elegans, reduction of protein synthesis rates in somatic cells extends lifespan. Based on this, we postulate that the molecular factors and mechanisms that control the mRNA metabolism in post-mitotic cells are critical determinants of ageing. This project will validate this hypothesis using C. elegans as main model system, but parallel studies in Saccharomyces cerevisiae and Drosophila melanogaster will prove the conservation of our observations. The cellular factors involved in mRNA metabolism (degradation/storage) are localized at specific particles in the cytoplasm of all eukaryotic cells, termed mRNA processing (P) bodies. Additionally, stress granules are cytoplasmic sites of mRNA-metabolism that are formed under stress conditions in mammalian cells. The objectives of this project include: -Monitoring of both P bodies and stress granules in adult worms and characterization of the age-related alterations in their profile, by immunostaining and real-time fluorescence imaging -Direct alterations in the expression of genes encoding factors of each particle in wild-type worms and analysis of the effects on lifespan and stress resistance -Comparison of the age-related changes in the profile of P bodies and stress granules between wild-type and long- or short-lived mutant worms -Direct alterations in the expression of genes encoding factors of each particle in worms with altered lifespan and investigation of the effects on lifespan and stress resistance -Observation of the age-related alterations in the profile of P bodies in yeast and flies, both in wild-type and long-lived strains. The rationale for this project is to provide insight into the modulation of ageing and stress resistance at the level of mRNA metabolism, which is a yet unexplored field of the biology of ageing and global stress response.
Summary
Recently, we and others have revealed that, in the nematode Caenorhabditis elegans, reduction of protein synthesis rates in somatic cells extends lifespan. Based on this, we postulate that the molecular factors and mechanisms that control the mRNA metabolism in post-mitotic cells are critical determinants of ageing. This project will validate this hypothesis using C. elegans as main model system, but parallel studies in Saccharomyces cerevisiae and Drosophila melanogaster will prove the conservation of our observations. The cellular factors involved in mRNA metabolism (degradation/storage) are localized at specific particles in the cytoplasm of all eukaryotic cells, termed mRNA processing (P) bodies. Additionally, stress granules are cytoplasmic sites of mRNA-metabolism that are formed under stress conditions in mammalian cells. The objectives of this project include: -Monitoring of both P bodies and stress granules in adult worms and characterization of the age-related alterations in their profile, by immunostaining and real-time fluorescence imaging -Direct alterations in the expression of genes encoding factors of each particle in wild-type worms and analysis of the effects on lifespan and stress resistance -Comparison of the age-related changes in the profile of P bodies and stress granules between wild-type and long- or short-lived mutant worms -Direct alterations in the expression of genes encoding factors of each particle in worms with altered lifespan and investigation of the effects on lifespan and stress resistance -Observation of the age-related alterations in the profile of P bodies in yeast and flies, both in wild-type and long-lived strains. The rationale for this project is to provide insight into the modulation of ageing and stress resistance at the level of mRNA metabolism, which is a yet unexplored field of the biology of ageing and global stress response.
Max ERC Funding
1 080 000 €
Duration
Start date: 2008-09-01, End date: 2014-08-31
