INNATE IMMUNE SIGNAL TRANSDUCTION SPECIFICITY IN INFLAMMATORY DISEASE
W Derek, Assistant Professor Of Pathology
Case Western Reserve Universitycity: Cleveland country: United States (us)
Grant 3R01GM086550-02S1 from National Institute Of General Medical Sciences
Abstract: The innate immune system recognizes and responds to pathogenic organisms. In doing so, this system is responsible for initiating a cytokine response designed to tailor the adaptive immune system to eradicate the offending organism. This process must be tightly regulated as too much activity can lead to inflammatory disease. Because inflammatory diseases are characterized by prolonged innate immune activation and cytokine release, the mechanisms controlling downregulation of the innate immune response are paramount in limiting inflammatory pathology. This grant application aims to study the mechanisms of this downregulation by focusing on the signal transduction mechanisms of NOD2 protein (CARD15 gene) and on NOD2´s role in initiating and maintaining the cytokine response. The NOD2 protein is responsible for a number of inflammatory disorders including Blau Syndrome (a familial granulomatosis disease), a subset of Early Onset Sarcoidosis and for 15-20% of genetic Crohn´s Disease. NOD2 is activated in response to intracellular exposure to both gram-positive and gram-negative bacteria after which it helps to coordinate NF-?B activation and cytokine release through the lysine-63 (K63)-linked polyubiquitination of a novel site (K285) on the IKK scaffolding protein NEMO. We have recently extended this finding to show that the major extracellular innate immune signaling receptors, the Toll-like Receptors (TLRs), also require K285 NEMO ubiquitination to properly signal through NF-?B. This work suggests that regulation of the post-translational modifications on the IKK scaffolding protein, NEMO, helps to coordinate cross-talk between intracellular and extracellular innate immune pathways and also helps to regulate the identity, the amount and the duration of cytokines that are released. These findings also suggest that for NF-?B signaling, multiple innate immune signaling pathways converge on NEMO and that the post-translational modifications on NEMO serve as a rheostat to control NF-?B activity. As such, these post-translational modifications may also be targets for molecules aimed at downregulating the NF-?B response activated by NOD2 and other innate immune signaling pathways. The central hypothesis of this grant is that downregulation of NOD2 and TLR-stimulated NF-?B activation is paramount in avoiding inflammatory pathology. Failure to properly downregulate the NF-?B response and coordinate between alternative (MAP kinase) signaling pathways may underlie the pathophysiology of inflammatory disorders. Study of these pathways of downregulation could lead both to novel insight regarding the pathophysiology of these diseases and to novel druggable target to help treat these diseases. To begin to tackle this important problem, we have generated significant preliminary data. We have identified a novel innate immune-induced phosphorylation site on NEMO that controls NEMO ubiquitination and therefore, controls ultimate NF-?B activation. We have also identified a signaling pathway operating through an unexpected MAP3K which inhibits NEMO ubiquitination and shifts innate immune signaling from NF-?B activity toward p38 activity. The Specific Aims of this grant application aim to determine the biochemical mechanisms by which innate immune-induced NF-?B activity can be downregulated, to determine the function of MEKK4 in dictating signal specificity downstream of innate immune system activation and to determine the role of these signaling pathways in the pathophysiology of inflammatory disease. As humans, we are constantly exposed to bacteria, fungi and viruses, and we must respond to these pathogens so that we do not become infected. After responding to these pathogens, if our immune systems do not deactivate, we develop inflammatory disorders such as asthma, inflammatory bowel disease, multiple sclerosis and atherosclerosis (heart and vascular disease). Inflammatory diseases such as these are a significant cause of morbidity and mortality across a wide range of populations (infants to elderly). Due to the importance of downregulating the inflammatory response, our bodies have developed sophisticated mechanisms to dampen the inflammatory response. This grant application aims to study the mechanisms that dampen this inflammatory response and the mechanisms by which this dampening is faulty in inflammatory disease. This work aims to help determine the causes of inflammatory disease and aims to identify novel targets for pharmaceutical intervention in these debilitating disorders
Keywords: Applications Grants; Asthma; Atherosclerosis; Bacteria; Biochemical; Cardiovascular system; Crohn`s disease; cytokine; Cytokine Activation; Data; design; Disease; Down-Regulation; early onset; Elderly; Exposure to; extracellular; Failure (biologic function); Functional disorder; fungus; Genes; Genetic; Gram-Negative Bacteria; Grant; Human; Immune; immune activation; Immune response; Immune system; Infant; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; insight; Intervention; Lead; Link; Lysine; MAP Kinase Signaling Pathways; MAPK14 gene; Morbidity - disease rate; Mortality Vital Statistics; Multiple Sclerosis; novel; Organism; pathogen; Pathology; Pathway interactions; Pharmacologic Substance; Phosphorylation; Phosphorylation Site; Polyubiquitination; Population; Post-Translational Protein Processing; Process; Proteins; public health relevance; Receptor Signaling; Regulation; response; Role; Sarcoidosis; Scaffolding Protein; Serine; Signal Pathway; Signal Transduction; Site; Specificity; Syndrome; System; Toll-like receptors; Ubiquitination; Vascular Diseases; Virus; Work
Project start date: 2010-09-01
Project end date: 2011-08-31
Budget start date: 1-SEP-2010
Budget end date: 31-AUG-2011
PFA/PA: PA-07-070
3R01GM086550-02S1 (2010): $71396
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to W Derek
IRAK4 KINASE ACTIVITY´S ROLE IN IMMUNODEFICIENCY
W Derek, Assistant Professor Of Pathology
Case Western Reserve Universitycity: Cleveland country: United States (us)
Grant 5R03AI079766-02 from National Institute Of Allergy And Infectious Diseases
Abstract: Upon pathogen exposure, the innate immune system initiates a cytokine response such that the adaptive immune system is tailored to eradicate that pathogen (4, 11, 24). Defects in the innate immune signaling pathways result in patient susceptibility to infectious disease (4, 11, 24, 26). IRAK4 (IL-1 Receptor Associated Kinase 4) is a key signaling molecule that links extracellular pathogen exposure to cytokine transcription and release, and recently, a series of unrelated children who develop recurrent pyogenic infections have been found to have mutations in the IRAK4 gene (6, 15, 16, 22, 25). The mutations in IRAK4 cause C-terminal truncations and result in either the absence of the kinase domain of the molecule or the absence of the total IRAK4 protein (6, 15, 16, 22, 25). IRAK4 is part of a signaling pathway linking the Toll-like Receptors to the NF?B pathway and the MAP Kinase pathways. Mice genetically deleted for IRAK4 show an inability to respond to a variety of pathogen-associated molecules including LPS, peptidoglycan, viral RNA and bacterial DNA. In addition, while showing a normal TNF response, these mice cannot respond to IL-1 (30-33). Surprisingly, patients with mutated IRAK4 show a subtly different phenotype than that found in the mouse as these patients are predominantly susceptible to recurrent gram-positive pyogenic bacterial infections (6, 15, 16, 22, 25, 26). While IRAK4´s kinase activity plays a clear role in these children´s immunodefiency, the role of IRAK4´s kinase activity in TLR signaling is unclear (13, 14, 18, 19, 27). Conflicting data has been published on the requirement of IRAK4 kinase activity for TLR responses and IRAK4´s in vivo substrates and kinetics of activation are unknown. Given the importance of IRAK4 in mediating innate immunity, and given the fact that children with immunodeficiency caused by an IRAK4 mutation all show a deletion in the kinase domain, understanding the kinetics, spatial localization, and specificity of IRAK4´s kinase activity will be important. It will also be important to determine the features that cause differences in IRAK4´s role in gram-positive and gram-negative infections. The central hypothesis of this grant application is that IRAK4´s kinase activity is responsible for effective signaling responses to gram-positive organisms and that differences in this kinase activity (in regards to activity and spatial localization) may underlie the infectious pathology in children with IRAK4 deficiencies. This grant aims to develop a novel in vivo signaling reporter such that IRAK4´s kinase activity can be studied in vivo. If successful, this pilot grant will lead to insights regarding IRAK4´s role in immunodeficiencies and will generate reagents that will help carry the work forward in animal models. People with immunodeficiency syndromes are highly susceptible to infection with bacteria, fungi and viruses. They do not respond normally to these agents, and their immune systems cannot defend them against these pathogens. A mutation in a gene called IRAK4 gives rise to a newly discovered immunodeficiency syndrome. Patients with mutations in IRAK4 develop numerous recurrent infections to fever-causing bacteria. 43% of these patients die in childhood. It is important to understand the function of IRAK4 so that we can better understand the cause of this immunodeficiency syndrome and ultimately, better treat this immunodeficiency syndrome. This grant aims to develop novel reagents with which to study IRAK4 so that this immunodeficiency syndrome can be better understood
Keywords: Agonist; Animal Model; Applications Grants; Bacteria; Bacterial DNA; Bacterial Infections; C-terminal; Child; Childhood; Communicable Diseases; Conflict (Psychology); cytokine; Data; Defect; Dendritic Cells; Epithelial Cells; Exposure to; extracellular; Fever; Fibroblasts; fungus; Genes; Genetic Transcription; Grant; Immune; Immune system; Immunologic Deficiency Syndromes; in vivo; Infection; insight; Interleukin-1; interleukin-1 receptor-associated kinase; Kinetics; Lead; Link; macrophage; Mediating; Mitogen-Activated Protein Kinases; Mus; Mutate; Mutation; Natural Immunity; novel; Organism; pathogen; pathogen exposure; Pathology; Pathway interactions; Patients; Peptidoglycan; Phenotype; Phosphotransferases; Play; Predisposition; Proteins; public health relevance; Publishing; Reagent; Recurrence; Reporter; Research; response; Role; Series; Signal Pathway; Signal Transduction; Signaling Molecule; Specificity; Time; TNF gene; Toll-like receptors; viral RNA; Virus; Work
Project start date: 2008-07-15
Project end date: 2011-06-30
Budget start date: 1-JUL-2009
Budget end date: 30-JUN-2011
PFA/PA: PAR-07-447
5R03AI079766-02 (2009): $78500
INNATE IMMUNE SIGNAL TRANSDUCTION SPECIFICITY IN INFLAMMATORY DISEASE
W Derek, Assistant Professor Of Pathology
Case Western Reserve Universitycity: Cleveland country: United States (us)
Grant 5R01GM086550-03 from National Institute Of General Medical Sciences
Abstract: The innate immune system recognizes and responds to pathogenic organisms. In doing so, this system is responsible for initiating a cytokine response designed to tailor the adaptive immune system to eradicate the offending organism. This process must be tightly regulated as too much activity can lead to inflammatory disease. Because inflammatory diseases are characterized by prolonged innate immune activation and cytokine release, the mechanisms controlling downregulation of the innate immune response are paramount in limiting inflammatory pathology. This grant application aims to study the mechanisms of this downregulation by focusing on the signal transduction mechanisms of NOD2 protein (CARD15 gene) and on NOD2´s role in initiating and maintaining the cytokine response. The NOD2 protein is responsible for a number of inflammatory disorders including Blau Syndrome (a familial granulomatosis disease), a subset of Early Onset Sarcoidosis and for 15-20% of genetic Crohn´s Disease. NOD2 is activated in response to intracellular exposure to both gram-positive and gram-negative bacteria after which it helps to coordinate NF-?B activation and cytokine release through the lysine-63 (K63)-linked polyubiquitination of a novel site (K285) on the IKK scaffolding protein NEMO. We have recently extended this finding to show that the major extracellular innate immune signaling receptors, the Toll-like Receptors (TLRs), also require K285 NEMO ubiquitination to properly signal through NF-?B. This work suggests that regulation of the post-translational modifications on the IKK scaffolding protein, NEMO, helps to coordinate cross-talk between intracellular and extracellular innate immune pathways and also helps to regulate the identity, the amount and the duration of cytokines that are released. These findings also suggest that for NF-?B signaling, multiple innate immune signaling pathways converge on NEMO and that the post-translational modifications on NEMO serve as a rheostat to control NF-?B activity. As such, these post-translational modifications may also be targets for molecules aimed at downregulating the NF-?B response activated by NOD2 and other innate immune signaling pathways. The central hypothesis of this grant is that downregulation of NOD2 and TLR-stimulated NF-?B activation is paramount in avoiding inflammatory pathology. Failure to properly downregulate the NF-?B response and coordinate between alternative (MAP kinase) signaling pathways may underlie the pathophysiology of inflammatory disorders. Study of these pathways of downregulation could lead both to novel insight regarding the pathophysiology of these diseases and to novel druggable target to help treat these diseases. To begin to tackle this important problem, we have generated significant preliminary data. We have identified a novel innate immune-induced phosphorylation site on NEMO that controls NEMO ubiquitination and therefore, controls ultimate NF-?B activation. We have also identified a signaling pathway operating through an unexpected MAP3K which inhibits NEMO ubiquitination and shifts innate immune signaling from NF-?B activity toward p38 activity. The Specific Aims of this grant application aim to determine the biochemical mechanisms by which innate immune-induced NF-?B activity can be downregulated, to determine the function of MEKK4 in dictating signal specificity downstream of innate immune system activation and to determine the role of these signaling pathways in the pathophysiology of inflammatory disease. As humans, we are constantly exposed to bacteria, fungi and viruses, and we must respond to these pathogens so that we do not become infected. After responding to these pathogens, if our immune systems do not deactivate, we develop inflammatory disorders such as asthma, inflammatory bowel disease, multiple sclerosis and atherosclerosis (heart and vascular disease). Inflammatory diseases such as these are a significant cause of morbidity and mortality across a wide range of populations (infants to elderly). Due to the importance of downregulating the inflammatory response, our bodies have developed sophisticated mechanisms to dampen the inflammatory response. This grant application aims to study the mechanisms that dampen this inflammatory response and the mechanisms by which this dampening is faulty in inflammatory disease. This work aims to help determine the causes of inflammatory disease and aims to identify novel targets for pharmaceutical intervention in these debilitating disorders
Keywords: Applications Grants; Asthma; Atherosclerosis; Bacteria; Biochemical; Crohn`s disease; cytokine; Cytokine Activation; Data; design; Disease; Down-Regulation; early onset; Elderly; Exposure to; extracellular; Failure (biologic function); Functional disorder; fungus; Genes; Genetic; Gram-Negative Bacteria; Grant; Heart Diseases; Human; Immune; immune activation; Immune response; Immune system; Infant; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; insight; Intervention; Lead; Link; Lysine; MAP Kinase Signaling Pathways; MAPK14 gene; Morbidity - disease rate; Mortality Vital Statistics; Multiple Sclerosis; novel; Organism; pathogen; Pathology; Pathway interactions; Pharmacologic Substance; Phosphorylation; Phosphorylation Site; Polyubiquitination; Population; Post-Translational Protein Processing; Process; Proteins; public health relevance; Receptor Signaling; Regulation; response; RIPK2 gene; Role; Sarcoidosis; Scaffolding Protein; Serine; Signal Pathway; Signal Transduction; Site; Specificity; Syndrome; System; Toll-like receptors; Ubiquitination; Vascular Diseases; Virus; Work
Project start date: 2008-12-09
Project end date: 2013-11-30
Budget start date: 1-DEC-2010
Budget end date: 30-NOV-2011
PFA/PA: PA-07-070
5R01GM086550-03 (2011): $315446
5R01GM086550-02 (2010): $318632
UBIQUITINATION PATHWAYS MEDIATING CHRONIC INTESTINAL INFLAMMATION
W Derek, Assistant Professor Of Pathology
Case Western Reserve Universitycity: Cleveland country: United States (us)
Abstract: Project 2, headed by Dr. Derek Abbott, will will test the alternative hypothesis that exaggerated N0D2 signaling leads to chronic intestinal inflammation. This project will investigate the dysregulation of the Nod2 gene at the molecular level. Lack of coordination between inflammatory signaling pathways influences the development of CD. We recently published that the E3 ubiquifin ligase ITCH, causes K63-linked polyubiquitinafion of RIP2, and this event downregulates active NOD2RIP2 complexes. Mice in which Itch is genetically lost (itchy mice) develop inflammatory disease at mucosal surfaces (including intestinal inflammation). We have data showing that ITCH-/- mice develop gastritis, ileitis and colitis and that drugs that inhibit RIP2 tyrosine phosphorylation, such as tarceva and iressa, inhibit the exaggerated N0D2 responses. The central hypothesis of this project is that ITCH downregulates NOD2;RIP2-induced NFDB signaling, and that CD results when this downregulation is lost. Aim 1 will study this ITCH-induced ubiquitination event to determine the biochemistry and physiologic function of ITCH-induced RIP2 ubiquitination. In Aim 2, we will determine the role of tyrosine phosphorylation of R1P2 and the role that pharmacological inhibition of this phosphorylation plays in ITCH-induced R1P2 ubiquitination and N0D2- induced cytokine responses. In Aim 3, we will characterize the Gl inflammation of the Itchy mouse and will determine whether tarceva or iressa can alleviate chronic intestinal inflammation in these mice. Our preliminary data shows that Itchy mice have increased gastrointestinal permeability. This increased permeability allows MDP leakage into the lamina propria and causes prolonged NFkappaB activation to occur. We hypothesize that tarceva and iressa will inhibit exaggerated lamina propria N0D2 activation in the itchy mice and alleviate the chronic inflammation. The overall objective of this project is to determine the biochemistry of the ITCHRIP2 interaction, the physiologic significance of this interaction, and most importantly, whether this interaction can be inhibited pharmacologically to ameliorate chronic intestinal inflammation. RELEVANCE (See instructions) CD affects more than 500,000 individuals in the US and incurs significant costs to society. Understanding the precise mechanisms and immune defects that cause the disease will allow us to develop better therapies and begin to develop a cure for this devastating disease
Keywords: Abnormal coordination; Acetylmuramyl-Alanyl-Isoglutamine; Affect; Binding (Molecular Function); Biochemistry; Chronic; Colitis; Complex; cost; Crohn`s disease; cytokine; Data; Defect; Development; Disease; Disease susceptibility; Down-Regulation; Erlotinib; Event; experience; Exposure to; Extravasation; Gastritis; gastrointestinal; Gefitinib; Genes; Genetic; Head; Homeostasis; Ileitis; Immune; Immunology; Individual; Inflammation; Inflammatory; Inflammatory disease of the intestine; Instruction; Lamina Propria; Ligase; Link; Lung; macrophage; Manuscripts; Mediating; Modeling; Molecular; Mus; Natural Immunity; NF-kappa B; Pathogenesis; Pathway interactions; Patients; Peptidoglycan; Permeability; Pharmaceutical Preparations; Phenotype; Phosphorylation; Phosphorylation Inhibition; Phosphotransferases; Physiological; Play; Pneumonia; Polyubiquitination; Principal Investigator; Production; programs; Protein Kinase; Publishing; Reagent; response; RIPK2 gene; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Site; Societies; Surface; Susceptibility Gene; Testing; Toll-like receptors; Tyrosine Kinase Inhibitor; Tyrosine Phosphorylation; Tyrosine Phosphorylation Site; Ubiquitination; Work
Budget start date: 1-AUG-2011
Budget end date: 31-MAR-2012
1P01DK091222-01_6652 (2011): $242554
THE ROLE OF NEMO UBIQUITINATION IN EDA-ID
W Derek, Assistant Professor Of Pathology
Case Western Reserve Universitycity: Cleveland country: United States (us)
Grant 1R21AI091637-01A1 from National Institute Of Allergy And Infectious Diseases
Abstract: NF-kB signaling lies at the center of Immunodeficiency and Inflammatory diseases. A key regulator of NF-kB signal transduction, NEMO, has recently been found to be mutated in an Immunodeficiency Disorder called called Anhidrotic (hypohydrotic) Ectodermal Dysplasia with Immunodeficiency (EDA-ID). Patients with EDA-ID are susceptible to infection with gram-positive organisms, and molecularly, a dysfunctional NF-kB signaling pathway, owing to hypomorphic mutations in nemo is to blame. While the NF-kB pathway is so well-studied that it has become a paradigm for inflammatory signal transduction, this paradigm has shifted in recent years with the recognition that this pathways signal transduction strength and coordination is critically dependent on Lysine-63 (K63)-linked polyubiquitination. NEMO was very recently shown to contain a ubiquitin binding domain that is essential for NFB signaling, and NEMO, itself, is K63-polyubiquitinated on two sites in response to innate immune stimulation (NOD2 (Crohn´s Disease-susceptibility protein) and Toll-like Receptor (TLR) activation). This NEMO ubiquitination is necessary for optimal NFB signaling (1, 2, 6, 13, 26). The spectrum and location of point mutations of nemo in EDA-ID suggest that biochemically, they may be interfering with ubiquitin binding by NEMO and/or K63-linked polyubiquitination of NEMO in response to innate immune stimuli. In addition, the varied immunologic phenotypes and immunodeficiencies in EDA-ID suggest cell-type specificity in regards to the particular mutations. Lastly, it has been difficult for the field to uncouple ubiquitin binding by NEMO from K63-linked polyubiquitination of NEMO as it relates to function and ultimately, NFB-induced gene expression. All these difficulties point to the need to systematically evaluate EDA-ID- associated NEMO mutations in regards to ubiquitin binding, K63-linked polyubiquitination of NEMO and NF-kB-associated gene expression. These difficulties also point to a need for an in vivo model of defective NEMO ubiquitination to decipher its role in in vivo NFB-dependent gene expression and inflammatory and immunodeficiency disorders. The grant application aims to answer these key questions. The ability to determine the genetics of susceptibility to infectious disease has led to the identification of novel forms of immunodeficiency, and the challenge is to translate these genetic findings into biochemical mechanisms of disease to both better understand the disease and allow better treatment for that disease. NEMO, a protein that is central to the major inflammatory signaling pathway is mutated in a disease called EDA-ID, a disease that is characterized by susceptibility to bacterial infections. This grant aims to determine how NEMO is faulty in EDA-ID and to generate a mouse model that might mimic many of the features of EDA-ID in hopes that this might lead to a better understanding of and better treatments for this disease
Keywords: Acetylation; Amides; Applications Grants; Area; B-Lymphocytes; Bacterial Infections; Binding (Molecular Function); Binding Proteins; Biochemical; Biochemistry; Bloch Sulzberger syndrome; CD4 Positive T Lymphocytes; cell type; Cells; Characteristics; Circular Dichroism; Clinical Pathways; Co-Immunoprecipitations; Coiled-Coil Domain; Communicable Diseases; Crohn`s disease; Disease; Disease susceptibility; Dissociation; Distant; Ectodermal Dysplasia; Event; Female; Gene Activation; Gene Expression; Genes; Genetic; Genetic Predisposition to Disease; Gram-Positive Bacterial Infections; Grant; Helper-Inducer T-Lymphocyte; Heterozygote; Immune; Immunologic Deficiency Syndromes; Immunologics; in vivo; in vivo Model; Infection; Inflammatory; Lead; Link; Location; Lysine; macrophage; male; Manuscripts; Missense Mutation; mouse model; Mus; mutant; Mutate; Mutation; NF-kappa B; NFKB Signaling Pathway; novel; Organism; Pathology; Pathway interactions; Patients; Peptides; Phenocopy; Phenotype; Play; Point Mutation; Polyubiquitin; Polyubiquitination; Predisposition; Process; Proteins; Receptor Activation; reconstitution; response; Role; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Site; skeletal abnormality; Skin Abnormalities; Specificity; Stimulus; Structure; Surface; System; T-Lymphocyte; Testing; Toll-like receptors; Transduction Gene; Translating; Ubiquitin; Ubiquitination; Work; X Chromosome; X Inactivation
Relevance: The ability to determine the genetics of susceptibility to infectious disease has led to the identification of novel forms of immunodeficiency, and the challenge is to translate these genetic findings into biochemical mechanisms of disease to both better understand the disease and allow better treatment for that disease. NEMO, a protein that is central to the major inflammatory signaling pathway is mutated in a disease called EDA-ID, a disease that is characterized by susceptibility to bacterial infections. This grant aims to determine how NEMO is faulty in EDA-ID and to generate a mouse model that might mimic many of the features of EDA-ID in hopes that this might lead to a better understanding of and better treatments for this disease
Project start date: 2011-02-11
Project end date: 2013-01-31
Budget start date: 11-FEB-2011
Budget end date: 31-JAN-2012
PFA/PA: PAS-10-148
1R21AI091637-01A1 (2011): $235500
FEEDBACK REGULATION OF INNATE IMMUNE SIGNALING AT MUCOSAL SURFACES
W Derek, Assistant Professor Of Pathology
Case Western Reserve Universitycity: Cleveland country: United States (us)
Grant 5R21AI076886-02 from National Institute Of Allergy And Infectious Diseases
Abstract: As humans, we are continuously exposed to pathogens. Our innate immune system must be able to differentiate pathogenic from nonpathogenic organisms, and it must be able to tailor an immune response to respond to that pathogenic organism. This problem is particularly acute at mucosal surfaces, an area of the body in which the surface cells are in direct contact with bacteria, fungi and viruses. A number of inflammatory disorders, including Crohn´s Disease, are initiated at these mucosal surfaces when the initial innate immune response is not adequately down-regulated after the pathogen is eradicated. In this grant, we study the mechanisms that control this down-regulation at mucosal surfaces. We have found that a key anti-inflammatory protein, A20, is phosphorylated and activated by the central kinase in the NF-?B signaling pathway (IKK2). We mapped the site of phosphorylation and have shown that it is required for full A20 inhibitory activity. We generated a phospho-specific antibody against this site, and we have shown that this phosphorylation occurs in vivo in response to a number of inflammatory stimuli. Our central hypothesis is that the IKK-dependent phosphorylation of A20 leads to a novel feedback mechanism to inhibit the NF-?B response such that too much inflammation does not occur at mucosal surfaces. Failure of IKK to phosphorylate A20 may lead to inflammatory pathology such as that seen in Crohn´s Disease. This grant is designed to test this hypothesis. Mucosal immunity regulates the initial immune response to a variety of viral, bacterial and fungal pathogens. Dysregulation of mucosal immunity is an initiating event in a variety of inflammatory disorders including Inflammatory Bowel Disease, Asthma, Pyelonephritis and a number of primary immunodeficiencies. Understanding how this dysregulation occurs will have relevance both for understanding the pathophysiology of chronic inflammatory diseases and for preventing this dysregulation from occurring after exposure to pathogens. PUBLIC HEALTH RELEVANCE Mucosal immunity regulates the initial immune response to a variety of viral, bacterial and fungal pathogens. Dysregulation of mucosal immunity is an initiating event in a variety of inflammatory disorders including Inflammatory Bowel Disease, Asthma, Pyelonephritis, and a number of primary immunodeficiencies. Understanding how this dysregulation occurs will have relevance both for understanding the pathophysiology of chronic inflammatory diseases and for preventing this dysregulation from occurring after exposure to pathogens
Keywords: A20 protein; Acute; Affinity Chromatography; Anti-inflammatory; Anti-Inflammatory Agents; Applications Grants; Asthma; Bacteria; Binding (Molecular Function); Binding Proteins; Biochemical; Body Surface Area; Cell surface; Cells; Chronic; Colitis; Crohn`s disease; cytokine; design; Disease; Disease susceptibility; Down-Regulation; Event; Exposure to; extracellular; Failure (biologic function); Feedback; Functional disorder; fungus; Genotype; Grant; Human; Immune; Immune response; Immune system; Immunologic Deficiency Syndromes; in vivo; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; Inflammatory Response Pathway; Intestines; Invaded; Knockout Mice; Lead; Link; Maps; Mass Spectrum Analysis; Mucosal Immunity; novel; Organism; pathogen; Pathogenesis; Pathology; Patients; Phenotype; Phospho-Specific Antibodies; Phosphorylation; Phosphorylation Site; Phosphotransferases; prevent; Proteins; public health relevance; Pyelonephritis; receptor; Regulation; Research; response; Scaffolding Protein; Signal Pathway; Signal Transduction; Site; Stimulus; Surface; Testing; Tissues; Toll-like receptors; Transcriptional Regulation; ubiquitin-protein ligase; Ubiquitination; Up-Regulation (Physiology); Viral; Virus; Work
Project start date: 2008-06-01
Project end date: 2011-05-31
Budget start date: 1-JUN-2009
Budget end date: 31-MAY-2011
PFA/PA: PA-06-181
5R21AI076886-02 (2009): $274750