Joel D Ernst
New York University School Of Medicine
Project start date: 2010-01-15
Project end date: 2014-12-31
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Joel D Ernst
Initiation Of The Immune Response To M. Tuberculosis
Joel D Ernst, Professor
New York University School Of Medicine New York, Ny 10016
Grant 5R01AI051242-06 from National Institute Of Allergy And Infectious Diseases IRG: AARR
Abstract: Tuberculosis(TB) remains a common cause of death, and is the most common copathogen in HIV-associated deaths worldwide. The limitations of drug therapy have increased the interest in developing new vaccines for TB, and improved understanding of immunity to TB is essential for development of improved vaccines. While a role for T lymphocytes in immunity to TB is well established, the mechanisms of initiation of adaptive immunity to M. tuberculosis(Mtb) are not well understood. In particular, the specific contributions of macrophages and dendritic cells to initiation of immunity to Mtb are not known. We have found that immunity to Mtb in mice depends on recruitment of macrophages and dendritic cells to the lungs and to the mediastinal lymph node, which drains the lungs. We have also found that mice with a dendritic cell-selective defect in MHC class II antigen presentation exhibit defective CD4+ T cell responses to Mtb. We hypothesize that macrophages and dendritic cells play distinct roles in initiation of immunity to Mtb, that dendritic cells transport intact Mtb from the lung to the mediastinal lymph node, and that the mediastinal lymph node plays a dominant role in the immune response to Mtb. We will use novel procedures and mutant mice to test these hypotheses. We will characterize the immune response to Mtb in mice with a dendritic cell-selective defect in class II antigen presentation, to determine whether dendritic cells are essential for initiation of immunity to Mtb. We will use immunohisto chemistry and flow cytometry, with Mtb expressing heterologous markers, to determine the rates of infection of macrophages and dendritic cells in the lung, mediastinal lymph node, and spleen, and will test the hypothesis that dendritic cells transport Mtb from the lung to the mediastinal lymph node, by a mechanism that depends on the chemokines CCL19 and CCL21, and their receptor, CCR7. We will also quantitate the CD4+T cell response in the mediastinal lymph node and spleen, to determine the relative contributions of these organs to TB immunity. We will perform in vitro studies to determine whether dendritic cells are uniquely able to prime naive T lymphocytes to respond to antigens expressed by Mtb, and we will test the hypothesis that macrophages modify dendritic cell-dependent initiation of immunity to Mtb. These studies will provide a foundation for studies to target candidate vaccines to specific antigen-presenting cells, and will provide a basis for studies of variable immune responses to natural infection with M. tuberculosis.
Keywords: Mycobacterium tuberculosis, bacteria infection mechanism, dendritic cell, host organism interaction, macrophage, microorganism immunology, MHC class II antigen, antigen presentation, bacterial antigen, cell migration, chemokine, helper T lymphocyte, lymph node, spleen, tuberculosis, flow cytometry, immunocytochemistry, laboratory mouse
Project start date: 2002-09-01
Project end date: 2008-08-31
5R01AI051242-06 (2006): $458915
5R01AI051242-05 (2005): $468481
5R01AI051242-04 (2004): $467046
5R01AI051242-03 (2003): $461514
1R01AI051242-01A1 (2002): $354884
MYCOBACTERIUM TUBERCULOSIS EVASION OF CD4+ T CELLS IN VIVO
Joel D Ernst, Professor
New York University School Of Medicine, 550 1st Ave, New York, Ny 10016
Grant 1R01AI084041-01A1 from National Institute Of Allergy And Infectious Diseases
Abstract: The greatest barrier to development of efficacious vaccines against tuberculosis is the ability of Mycobacterium tuberculosis to persist and to cause progressive infection despite development of an adaptive immune response. While partially-efficacious vaccines may result from optimal selection of antigens, adjuvants, and delivery systems, major progress against tuberculosis will require novel approaches to enhancing resistance, based on overcoming or bypassing the mechanisms used by M. tuberculosis to evade adaptive immune responses. To identify and characterize those mechanisms, we have developed novel tools for use in a mouse model of immunity to M. tuberculosis to discover and characterize mechanisms that limit the efficacy of the adaptive immune response to M. tuberculosis. We have developed a system using a monoclonal antibody that recognizes a specific peptideMHC II complex and several recombinant strains of M. tuberculosis, to test the hypothesis that M. tuberculosis inhibits MHC II antigen presentation in vivo, and to test the hypothesis that M. tuberculosis transfers antigens to uninfected cells as an immune evasion strategy. We have also developed a system using CD4+ T cells from a unique line of mice with a transgenic T cell antigen receptor specific for M. tuberculosis Ag85B, and have discovered that downregulation of the gene encoding Ag85B during the chronic stage of M. tuberculosis infection is accompanied by diminished in vivo CD4+ T cell responses to Ag85B. Taken together, these results suggest that M. tuberculosis may modulate expression of antigen genes as a means of avoiding recognition and elimination by CD4+ effector T cells. We also developed a method for visualization and localization of M. tuberculosis-infected cells and CD4+ T cells in the lungs, and have found that a minority of M. tuberculosis-infected cells in the lungs are in direct contact with CD4+ T cells, which supports the hypothesis that CD4+ T cells recognize M. tuberculosis-infected cells poorly at the site of infection. In this application, we propose experiments to test the general hypothesis that interactions between M. tuberculosis-infected cells and antigen-specific CD4+ T cells in the lungs are defective, and that this contributes to persistence of the infection. We will test the specific hypothesis that defective interactions between M. tuberculosis-infected cells and CD4+ T cells during chronic infection are due to a combination of 1) M. tuberculosis inhibition of antigen presentation by infected cells; 2) decreased expression of M. tuberculosis antigens during the chronic stage of infection; and 3) transfer of M. tuberculosis antigens from infected cells to neighboring uninfected cells in granulomas, allowing uninfected cells to act as decoys to activate T cells at a distance from infected cells. Our proposed studies will provide unprecedented insight into the mechanisms used by M. tuberculosis to evade elimination by the mammalian adaptive immune response, and will guide future efforts to develop the means to increase human resistance to tuberculosis. One of the major problems that has prevented development of a successful TB vaccine is that the bacteria that cause TB are not eliminated by normal immune responses. In this project, we will identify and characterize the mechanisms that TB bacteria use to avoid recognition and elimination by immune cells. We expect that understanding these mechanisms will allow us and others to develop novel ways to increase resistance of people to tuberculosis
Keywords: AIDS Virus; APC; ATGN; Acquired Immune Deficiency Syndrome Virus; Acquired Immunodeficiency Syndrome Virus; Acute; Adjuvant; Antigen Presentation; Antigen-Presenting Cells; Antigens; Bacteria; Bone Marrow; Bypass; CD4 Positive T Lymphocytes; CD4 T cells; CD4 lymphocyte; CD4+ T cell; CD4+ T-Lymphocyte; CD4-Positive Lymphocytes; Cells; Cells, CD4; Chronic; Class II Antigens; Class II Major Histocompatibility Antigens; Communicable Diseases; Complex; Data; Dendritic Cells; Detection; Development; Disease; Disorder; Down-Regulation; Down-Regulation (Physiology); Downregulation; Drug Resistant Tuberculosis; Drug resistance; Drugs; Exhibits; Extreme drug resistant tuberculosis; Extremely drug resistant tuberculosis; Frequencies (time pattern); Frequency; Future; Genes; Genes, Class II; Genes, HLA Class II; Genes, MHC Class II; Granuloma; Granulomatous Lesion; HIV; HTLV-III; Histocompatibility Antigens Class II; History; Human; Human Immunodeficiency Viruses; Human T-Cell Leukemia Virus Type III; Human T-Cell Lymphotropic Virus Type III; Human T-Lymphotropic Virus Type III; Human, General; I-A Antigen; Ia Antigens; Ia-Like Antigens; Imagery; Immune; Immune Response Antigens; Immune response; Immune-Response-Associated Antigens; Immunity; Immunologic Accessory Cells; In Vitro; Individual; Infection; Infection Control; Infectious Disease Pathway; Infectious Diseases; Infectious Diseases and Manifestations; Infectious Disorder; LAV-HTLV-III; Lung; Lymphadenopathy-Associated Virus; M. tb; M. tuberculosis; M. tuberculosis antigen 85B; M.tb; M.tuberculosis; MHC Class II; MHC Class II Genes; MHC Class II Molecule; MHC Class II Protein; MHC Receptor; MHC class II antigen; MT 85B antigen complex; Major Histocompatibility Complex Class II; Major Histocompatibility Complex Receptor; Mammals, Mice; Man (Taxonomy); Man, Modern; Medication; Methods; Mice; Minority; Moab, Clinical Treatment; Monoclonal Antibodies; Monocytes / Macrophages / APC; Multidrug-Resistant Tuberculosis; Murine; Mus; Mycobacterium tuberculosis; Mycobacterium tuberculosis antigen 85B; Myelogenous; Myeloid; Peptide-MHC; Peptide-Major Histocompatibility Protein Complex; Peptide/MHC Complex; Pharmaceutic Preparations; Pharmaceutical Preparations; Phase; Population; Public Health; Publications; Reaction Time; Reagent; Receptors, Antigen, T-Cell; Recombinants; Recording of previous events; Reporting; Resistance; Respiratory System, Lung; Response RT; Response Time; Reticuloendothelial System, Bone Marrow; Scientific Publication; Site; Staging; System; System, LOINC Axis 4; T-Cell Receptor; T-Cells; T-Lymphocyte; T4 Cells; T4 Lymphocytes; TB vaccine; Testing; Thymus-Dependent Lymphocytes; Transgenic Organisms; Tuberculosis; Tuberculosis Vaccines; Tuberculosis, Drug Resistance; Tuberculosis, Drug Resistant; Tuberculosis, MDR; Tuberculosis, Multi-Drug Resistant; Tuberculosis, MultiDrug Resistance; Tuberculosis, Multidrug-Resistant; Vaccines; Veiled Cells; Virus-HIV; Visualization; XDR-Tuberculosis; accessory cell; anti-TB vaccine; antigen 85B, Mycobacterium tuberculosis; attenuation; base; disease/disorder; disseminated TB; disseminated tuberculosis; drug resistant; drug/agent; experiment; experimental research; experimental study; fbpB protein, Mycobacterium tuberculosis; helper T cell; host response; immune clearance; immunogen; immunoresponse; improved; in vivo; insight; macrophage; mouse model; mycolyl transferase 30; new approaches; novel; novel approaches; novel strategies; novel strategy; pMHC; pandemic; pandemic disease; prevent; preventing; psychomotor reaction time; public health medicine (field); public health relevance; pulmonary; research study; resistance to Drug; resistant; resistant to Drug; response; success; thymus derived lymphocyte; tool; transgenic; tuberculous spondyloarthropathy
Relevance: One of the major problems that has prevented development of a successful TB vaccine is that the bacteria that cause TB are not eliminated by normal immune responses. In this project, we will identify and characterize the mechanisms that TB bacteria use to avoid recognition and elimination by immune cells. We expect that understanding these mechanisms will allow us and others to develop novel ways to increase resistance of people to tuberculosis
Project start date: 2010-01-15
Project end date: 2014-12-31
Budget start date: 15-JAN-2010
Budget end date: 31-DEC-2010
PFA/PA: PA-07-070
1R01AI084041-01A1 (2010): $413507
MYCOBACTERIUM TUBERCULOSIS ANTIGEN DIVERSITY
Joel D Ernst, Professor
New York University School Of Medicine, New York, Ny 10016
Grant 1R01AI090928-01 from National Institute Of Allergy And Infectious Diseases
Abstract: Mycobacterium tuberculosis resists elimination by human immune responses through incompletely- characterized mechanisms. To determine whether M. tuberculosis uses antigenic variation to evade elimination by T cell responses, we tested the hypothesis that M. tuberculosis generates escape mutants of the epitopes recognized by human T cells. We compared the sequences of 491 experimentally-verified human T cell epitopes in 21 strains of M. tuberculosis from the six global lineages of the M. tuberculosis complex, and made the surprising discovery that 468 (95%) of the known epitopes exhibit no sequence variation across these lineages, which represent strains of M. tuberculosis whose ancestors diverged >30,000 years ago. To determine whether the observed hyperconservation of T cell epitopes was simply the effect of low sequence diversity in the M. tuberculosis genome, we compared the ratio of the rates of nonsynonymous and synonymous single- nucleotide polymorphisms (dN/dS) in the epitopes compared with that in the experimentally-determined essential and ssential genes, and found that the dN/dS of the known epitopes is the lowest in the M. tuberculosis genome. The observation that the known human T cell epitopes are hyperconserved suggests that the bacteria actually benefit from T cell recognition, but it is also consistent with the possibility that prior efforts at epitope discovery were skewed toward discovery of conserved epitopes. To test the hypothesis that there are variable T cell epitopes of M. tuberculosis, we will sequence 180 phylogenetically-diverse strains of M. tuberculosis, and identify the most diverse regions of the M. tuberculosis genome. We will then use extensive in silico analyses to identify those variable sequences that are predicted to encode human T cell epitopes. With that set of predicted epitopes, we will assay T cell responses to synthetic peptides having sequences matching those in the subject´s infecting isolate, to identify which of the predicted epitopes are true targets of human T cell recognition. Since we anticipate that these efforts will lead to the discovery of a large set of variable epitopes, we describe further efforts to test the hypothesis that sequence variations in the newly-discovered variable epitopes are due to selection by human T cell responses. In studies beyond the scope of this application, we will use selected newly-discovered variable epitopes to test the hypothesis that human T cell recognition of variable epitopes is more closely associated with protective immunity than is recognition of the previously-discovered hyperconserved epitopes. Our studies are likely to have a large overall impact on the field of human immunity to tuberculosis, as they will markedly expand our knowledge of targets of human T cells in M. tuberculosis, they will enable novel studies and discoveries that are not currently possible, and they are likely to provide a pathway to more efficacious TB vaccines. Tuberculosis afflicts nearly 1/3 of all humans, and kills nearly 2 million people every year. The work proposed in this project will reveal crucial new information on how the bacteria that cause tuberculosis interact with the human immune system. The findings will have an important impact on development of new vaccines against tuberculosis
Keywords: AIDS Seroconversion; AIDS Seropositivity; AIDS Virus; ATGN; Acquired Immune Deficiency Syndrome Virus; Acquired Immunodeficiency Syndrome Virus; Amino Acid Sequence; Animals; Anti-HIV Positivity; Antigen Variation; Antigenic Determinants; Antigenic Variability; Antigenic Variation; Antigens; Assay; Bacteria; Binding Determinants; Bioassay; Biologic Assays; Biological Assay; CD4 Positive T Lymphocytes; CD4 T cells; CD4 lymphocyte; CD4+ T cell; CD4+ T-Lymphocyte; CD4-Positive Lymphocytes; CD8; CD8 Cell; CD8 lymphocyte; CD8+ T-Lymphocyte; CD8-Positive Lymphocytes; CD8-Positive T-Lymphocytes; CD8B; CD8B1; CD8B1 gene; Cells; Cells, CD4; Clinical; Collection; Communicable Diseases; Complex; Computer Simulation; Computerized Models; Data Banks; Data Bases; Databank, Electronic; Databanks; Database, Electronic; Databases; Development; Drug resistance; Epidemiology; Epitopes; Epitopes, T-Lymphocyte; Escape Mutant; Evolution; Exhibits; Frequencies (time pattern); Frequency; Genes; Genome; Genomics; HCV; HIV; HIV Antibody Positivity; HIV Positive; HIV Positivity; HIV Seroconversion; HIV Seropositivity; HTLV-III; HTLV-III Seroconversion; HTLV-III Seropositivity; Hepatitis C virus; Hepatitus C; Human; Human Immunodeficiency Viruses; Human T-Cell Leukemia Virus Type III; Human T-Cell Lymphotropic Virus Type III; Human T-Lymphotropic Virus Type III; Human, General; Immune; Immune response; Immune system; Immunity; Immunocompetent; Infection; Infectious Disease Pathway; Infectious Diseases; Infectious Diseases and Manifestations; Infectious Disorder; Influenza Virus; Killings; Knowledge; LAV-HTLV-III; LYT3; Lead; Lymphadenopathy-Associated Virus; M. tb; M. tuberculosis; M.tb; M.tuberculosis; Mammals, Mice; Man (Taxonomy); Man, Modern; Mathematical Model Simulation; Mathematical Models and Simulations; Meningococcus; Mice; Models, Computer; Murine; Mus; Mycobacterium tuberculosis; Mycobacterium tuberculosis antigens; Neisseria meningitidis; Pathway interactions; Pb element; Peptides; Phylogeny; Plasmodium falciparum; Polymorphism, Single Base; Population; Pressure; Pressure- physical agent; Protein Structure, Primary; SEQ-AN; SNP; SNPs; Sequence Analyses; Sequence Analysis; Shapes; Simulation, Computer based; Single Nucleotide Polymorphism; T cell response; T-Cell Epitopes; T-Cells; T-Lymphocyte; T-Lymphocyte Epitopes; T4 Cells; T4 Lymphocytes; T8 Cells; T8 Lymphocytes; TB vaccine; Testing; Thymus-Dependent Lymphocytes; Transmission; Tuberculosis; Tuberculosis Vaccines; Variant; Variation; Virus-HIV; Work; anti-TB vaccine; antibody positive AIDS test; antigen positive AIDS test; base; body system, allergic/immunologic; clinical data repository; clinical data warehouse; computational modeling; computational models; computational simulation; computer based models; computerized modeling; computerized simulation; data repository; ddNT; ddNT (dideoxynucleotide); dideoxynucleotide; disseminated TB; disseminated tuberculosis; drug resistant; genome sequencing; heavy metal Pb; heavy metal lead; helper T cell; host response; human subject; immunogen; immunoresponse; in silico; influenzavirus; influenzavirus (unspecified); mutant; new approaches; new vaccines; next generation vaccines; novel; novel approaches; novel strategies; novel strategy; novel vaccines; organ system, allergic/immunologic; pathogen; pathway; pressure; protein sequence; public health relevance; relational database; resistance to Drug; resistant to Drug; seropositive (AIDS test); synthetic peptide; thymus derived lymphocyte; transmission process; tuberculosis immunity; tuberculous spondyloarthropathy; virtual simulation
Relevance: Tuberculosis afflicts nearly 1/3 of all humans, and kills nearly 2 million people every year. The work proposed in this project will reveal crucial new information on how the bacteria that cause tuberculosis interact with the human immune system. The findings will have an important impact on development of new vaccines against tuberculosis
Project start date: 2010-06-15
Project end date: 2015-05-31
Budget start date: 15-JUN-2010
Budget end date: 31-MAY-2011
PFA/PA: PA-07-070
1R01AI090928-01 (2010): $805513
Type I Interferons In Immunity To Tuberculosis
Joel D Ernst, Professor
Medicinenew York University School Of Medicine
550 1st Ave
new York, Ny 10016
Grant 5R01AI059667-05 from National Institute Of Allergy And Infectious Diseases IRG: ZRG1
Abstract: Mycobacterium tuberculosis (Mtb) causes more adult deaths worldwide than any other bacterium, and many strains are resistant to all first-line drugs. These properties contribute to the potential of Mtb as a major public health problem, as well as a potential agent of bioterrorism. In order to develop more effective means of prevention and control of tuberculosis, it is essential to better understand the mechanisms of protective immunity to Mtb. We have used a murine model to discover an essential role for type I interferons (IFNalphabeta) in control of virulent Mtb in vivo. We found that IFNlphabeta contributes to control of Mtb infection, revealed in mice that cannot respond to IFNalphabeta or to IFNgamma STAT1-/- and IFNalphabetagammaR-/- mice exhibit a more rapid progression of infection and higher bacterial loads than IFNgammaR-/- mice. Moreover, we found that IFNalphabeta and IFNalphabeta-responsive genes are induced by infection with Mtb in vivo. We propose to test three (nonmutually exclusive) hypotheses of the roles of IFNalphabeta in control of Mtb. First, we will characterize the microbiologic and pathologic course of Mtb infection in mice that lack the ability to respond to IFNalphabeta, IFNgamma, or both, compared to wild-type mice. We will then test the hypothesis that IFNaa contributes to control of Mtb by regulating the same genes, or a subset of genes, regulated by IFNgamma, using microarray and real-time RT-PCR of RNA from lungs of specific mutant mice. Next, we will test the hypothesis that IFNaa regulates priming, differentiation, and trafficking ofCD4+and CD8+ T lymphocytes during Mtb infection. If this indicates that IFNaa promotes the development of the adaptive immune response to Mtb, we will determine whether IFNalphabeta acts indirectly by promoting the maturation and/or trafficking of dendritic cells. Finally, we will test the hypothesis that IFNalphabeta contributes to control of Mtb through natural killer (NK) cells, by characterizing the rate and extent of development, differentiation, and trafficking of NK cells in Mtb-infected mutant mice. If this implies that IFNalphabeta regulates NK cells during Mtb infection, we will determine whether Mtb infection of macrophages induces expression of ligands for stimulatory NK cell receptors. The proposed experiments will provide improved understanding of innate and adaptive immunity to Mtb, and may guide development of new means of prevention and treatment of tuberculosis, including drug-resistant tuberculosis
Keywords: Mycobacterium tuberculosis, antibacterial antibody, bacteria infection mechanism, bactericidal immunity, immunogenetics, interferon alpha, interferon beta, interferon gamma, tuberculosis cytotoxic T lymphocyte, dendritic cell, drug resistance, helper T lymphocyte, leukocyte activation /transformation, natural killer cell, pathologic process, suppressor T lymphocyte, virulence genetically modified animal, laboratory mouse, microarray technology, nucleic acid chemical synthesis, polymerase chain reaction, wild animal
Project start date: 2004-02-15
Project end date: 2010-01-31
5R01AI059667-05 (2008): $392994
5R01AI059667-04 (2007): $400606
Sponsored Links Excellgen http://Excellgen.com
5R01AI059667-03 (2006): $412571
5R01AI059667-02 (2005): $422500
1R01AI059667-01 (2004): $401110
M. TUBERCULOSIS EVASION OF IMMUNE EFFECTOR MECHANISMS
Joel D Ernst, Professor
New York University School Of Medicine, 550 1st Ave, New York, Ny 10016
Grant 5R01AI046097-10 from National Institute Of Allergy And Infectious Diseases
Abstract: Mycobacterium tuberculosis (Mtb) causes more adult deaths worldwide than any other bacterium, and many strains are resistant to all first-line drugs. Although HIV infection is associated with a high rate of active tuberculosis (TB), Mtb can cause disease in people with normal immune systems, implying that Mtb can evade the immune response. We tested the hypothesis that Mtb inhibits effector mechanisms of the immune response, and found that Mtb inhibits macrophage (MO) transcriptional responses to IFNgamma. Studies during the present funding period revealed that Mtb utilizes 3 distinct mechanisms to inhibit MO responses to IFNg an Mtb lipoprotein (LP) activates a TLR2-dependent mechanism for inhibition; Mtb peptidoglycan (PG) activates a TLR2- and MyD88-independent mechanism, and Mtb induces secretion of interleukin-6, which also inhibits MO responses to IFNg. We also found that Mtb-LP and Mtb-PG block IFNg priming of MO to kill Mtb, implying that inhibition of MO responses to IFNg contributes to persistence and progression of TB. The overall goal of the experiments proposed in this application is to define the mechanisms of inhibition of MO responses to IFNg, in order to develop the means to overcome the inhibition and enhance the efficacy of the immune response to Mtb. Specific Aim 1 is to define the structural features of Mtb PG that account for its 40-fold greater potency compared to E. coli PG for inhibition of MO responses to IFNg; Specific Aim 2 is to determine the contributions of Mtb lipoproteins, peptidoglycan, and IL-6 to modulating gene expression and Mtb killing in MO, and Specific Aim 3 is to define the early, intermediate, and late steps in Mtb PG-induced inhibition of MO responses to IFNg, and compare them to the steps required for Mtb LP- and interleukin 6-initiated inhibition. The proposed experiments will provide high-resolution understanding of the mechanisms used by Mtb to block MO responses to IFNg, and will provide a basis for interventions to overcome the block and enhance immunity to Mtb
Keywords: 21+ years old; Accounting; Adult; B cell differentiation factor; B cell stimulating factor 2; B-Cell Differentiation Factor-2; B-Cell Stimulatory Factor-2; BCDF; BSF-2; BSF2; BSF2 (B cell stimulating factor 2); Bacteria; Cell Communication and Signaling; Cell Signaling; Cessation of life; Characteristics; Death; Differentiation Factor, B-Cell; Disease; Disorder; Drugs; E coli; Escherichia coli; Funding; Gamma interferon; Gene Expression; Gene Transcription; Genes; Genetic Transcription; Goals; HIV Infections; HPGF; HTLV-III Infections; HTLV-III-LAV Infections; Hepatocyte-Stimulating Factor; Human; Human, Adult; Human, General; Hybridoma Growth Factor; IFN; IFN-Gamma; IFN-beta 2; IFN-g; IFNB2; IFNG; IL-6; IL6 Protein; ISGF-3; Immune; Immune response; Immune system; Immunity; Interferon Gamma; Interferon Type II; Interferon gamma (human lymphocyte protein moiety reduced); Interferon, Immune; Interferon-gamma; Interferons; Interleukin 6 (Interferon, Beta 2); Interleukin-6; Intervention; Intervention Strategies; Intracellular Communication and Signaling; Investigation; Killings; Life; Lipoproteins; M. tb; M. tuberculosis; M.tb; M.tuberculosis; MGI-2; Mammals, Mice; Man (Taxonomy); Man, Modern; Medication; Methods; Mice; Molecular; Morbidity; Morbidity - disease rate; Mortality; Mortality Vital Statistics; Murein; Murine; Mus; Mycobacterium tuberculosis; Myeloid Differentiation-Inducing Protein; Peptidoglycan; Pharmaceutic Preparations; Pharmaceutical Preparations; Plasmacytoma Growth Factor; Public Health; RNA Expression; Rate; Resistance; Resolution; STAT1; STAT1 gene; STAT91; Signal Pathway; Signal Transduction; Signal Transduction Systems; Signaling; T-Lymphotropic Virus Type III Infections, Human; TIL4; TLR2; TLR2 receptor; Testing; Toll-Like Receptor 2; Toll/Interleukin 1 Receptor-Like 4; Toll/Interleukin 1 Receptor-Like Protein 4; Transcription; Transcription, Genetic; Tuberculosis; Work; adult human (21+); base; biological signal transduction; body system, allergic/immunologic; chemotherapy; cytokine; disease/disorder; disseminated TB; disseminated tuberculosis; drug/agent; experiment; experimental research; experimental study; host response; immunoresponse; insight; interferon beta 2; interventional strategy; lFN-Gamma; macrophage; novel; organ system, allergic/immunologic; pathogen; public health medicine (field); research study; resistant; response; success; transcription factor; tuberculous spondyloarthropathy
Project start date: 2000-06-01
Project end date: 2010-05-31
Budget start date: 1-JUN-2008
Budget end date: 31-MAY-2010
5R01AI046097-10 (2008): $0
5R01AI046097-09 (2007): $517655
5R01AI046097-08 (2006): $520436
3R01AI046097-07S1 (2005): $58893
5R01AI046097-07 (2005): $458497
2R01AI046097-06 (2004): $470842
MYCOBACTERIUM TUBERCULOSIS-INDUCED MACROPHAGE SIGNALING
Joel D Ernst, Professor
Medicineuniversity Of California San Francisco
3333 California St., Ste 315
san Francisco, Ca 941430962
Grant 5R01HL051992-02 from National Heart, Lung, And Blood Institute IRG: ZHL1
Abstract: Macrophages are the first line of defense against Mycobacterium tuberculosis and other microorganisms that circumvent the mechanical defenses of the airways. When macrophages encounter particles, they ingest them in a portion of the plasma membrane and form an intracellular vesicle termed a phagosome. Simultaneous with ingestion, signal transduction pathways are triggered that activate the microbicidal systems of the macrophage. Most bacteria are killed when phagosome membranes fuse with lysosome membranes and lysosome contents gain access to the ingested bacteria. In contrast, M. tuberculosis survives in macrophages within phagosomes that do not fuse with lysosomes, and thereby avoid being killed. The overall goal of the proposed research is to determine the molecular mechanism whereby M tuberculosis avoids phagosome-lysosome fusion. We will test the hypothesis that M. tuberculosis specifically blocks a step in the signal transduction pathway that culminates in Ca2+-dependent phagosome-lysosome fusion. As increases in intracellular ionized calcium concentrations ([Ca2+]i) are proven to be essential for phagosome-lysosome fusion in human neutrophils, we will determine whether increases in [Ca2+]i occur when macrophages ingest M. tuberculosis. If not increases in [Ca2+]i occur, we will identify the most proximal step in the signal transduction pathway that is defective and will characterize the mechanism of inhibition of this step in detail. If increases in [Ca2+]i do occur when macrophages ingest M. tuberculosis, we will determine whether Ca2+- dependent effectors (annexins and calmodulin-dependent protein kinase II) are functional. If we find signal transduction is not directly affected by Mr. tuberculosis, we will test the alternative hypothesis that M. tuberculosis enters macrophages by a receptor-mediated pathway that does not normally culminate in phagosome-lysosome fusion. If this proves to be the case, we will characterize the receptor(s) involved. We will also characterize the mechanism of ingestion, to determine whether it more closely resembles phagocytosis or receptor-mediated endocytosis. The information obtained from the proposed studies will guide efforts to prevent persistent infection with M. tuberculosis by significantly enhancing our understanding of the microbe-macrophage interaction
Keywords: Mycobacterium tuberculosis, alveolar macrophage, biological signal transduction, membrane fusion, phagocytosis attenuated microorganism, calcium, calmodulin dependent protein kinase, host organism interaction, lysosome, monocyte, receptor binding, receptor mediated pinocytosis, tuberculosis human tissue, immunoelectron microscopy, immunofluorescence technique, tissue /cell culture
Project start date: 1993-09-30
Project end date: 1996-08-31
5R01HL051992-02 (1994): $315085
Sponsored Links Excellgen http://Excellgen.com
1R01HL051992-01 (1993): $308404
INITIATION OF THE IMMUNE RESPONSE TO M. TUBERCULOSIS
Joel D Ernst, Professor
New York University School Of Medicine, New York, Ny 10016
Grant 5R01AI051242-09 from National Institute Of Allergy And Infectious Diseases
Abstract: Despite the availability of drugs and a partially-efficacious vaccine, tuberculosis remains an enormous health problem worldwide, due in part to the ability of M. tuberculosis to evade innate and adaptive immune responses. Development of economically-feasible improved methods of control of tuberculosis requires better understanding of the mechanisms underlying the development of immune responses to M. tuberculosis, and better understanding of the limitations of those responses. In the previous project period, we developed and used several novel tools and techniques in a mouse model to discover that M. tuberculosis-specific CD4+ T cell responses are initiated 10-11 days after infection of the lungs, occur earliest in the mediastinal lymph node, depend on transport of M. tuberculosis from the lungs to the lymph node by myeloid dendritic cells (DCs), and depend on production of antigen by bacteria in the lymph node, not the lungs. In addition, we determined that, while myeloid DCs transport M. tuberculosis to the lymph node, they are not the most efficacious antigen- presenting cells in the lymph node of M. tuberculosis-infected mice. These results indicate that better understanding of the immune response to M. tuberculosis and its limitations depends on better understanding of the events that precede and the events that follow acquisition of M. tuberculosis by DCs in the lungs. To better understand the mechanisms that precede acquisition of M. tuberculosis by DCs in the lungs, we will test the hypotheses that DCs do not acquire M. tuberculosis until 7-10 days after infection of the lungs, that interactions with lung epithelial cells and with neutrophils modulate acquisition of M. tuberculosis by DCs, and that bacterial inhibition of apoptosis contributes to delayed acquisition of M. tuberculosis by DCs in the lungs. To better understand the mechanisms of M. tuberculosis transport from the lungs to the mediastinal lymph node for initiation of the adaptive immune response, we will test the hypothesis that the chemokine receptors CCR7 and CCR8 mediate migration of mature DCs from the lungs to the mediastinal lymph node. We will also determine the respective roles of lymph node myeloid, lymphoid, and plasmacytoid DCs in initiating the adaptive immune response to M. tuberculosis. We will determine whether lymphoid and/or plasmacytoid DCs can present M. tuberculosis antigens after myeloid DCs transport the bacteria from the lungs to the lymph node, we will determine whether populations of lymphoid and plasmacytoid DCs acquire and present a secreted M. tuberculosis antigen in the lymph node during infection, and we will determine the respective contributions of individual infected and uninfected cells in presenting a mycobacterial peptide antigen in vivo. The proposed studies will yield unique new information on the events and mechanisms that contribute to initiation of adaptive immunity to M. tuberculosis, and will reveal specific targets for modulation to accelerate development of the adaptive immune response, to make it more efficacious. PUBLIC HEALTH RELEVANCE The immune response to Mycobacterium tuberculosis is only partially effective, as it allows survival of the bacteria and reactivation of disease in a large number of people. We have used a mouse model of tuberculosis to understand how the immune response is initiated during infection, and found that specific cells must carry the bacteria from the lungs to a local immune organ, called the mediastinal lymph node. In this project, we will determine how those specific cells acquire the bacteria, transport them from the lungs to the mediastinal lymph node, and stimulate lymphocytes to control the infection, to guide development of better ways to get the immune system to control tuberculosis
Keywords: AIDS Virus; APC; ATGN; Acquired Immune Deficiency Syndrome Virus; Acquired Immunodeficiency Syndrome Virus; Adherence; Adherence (attribute); Antigen-Presenting Cells; Antigens; Apoptosis; Apoptosis Pathway; Bacteria; Blood Neutrophil; Blood Polymorphonuclear Neutrophil; Blood Segmented Neutrophil; CCR8; CCR8 gene; CD4 Positive T Lymphocytes; CD4 T cells; CD4 lymphocyte; CD4+ T cell; CD4+ T-Lymphocyte; CD4-Positive Lymphocytes; CKR-L1; CKRL1; CMKBR8; CMKBRL2; CY6; Cell Death, Programmed; Cell Locomotion; Cell Migration; Cell Movement; Cells; Cells, CD4; Cellular Migration; Dendritic Cells; Development; Disease; Disorder; Drug Resistant Tuberculosis; Drug resistance; Drugs; Epithelial Cells; Epithelium, Respiratory; Evaluation; Event; Extreme drug resistant tuberculosis; Extremely drug resistant tuberculosis; GPR-CY6; Genes, Class II; Genes, HLA Class II; Genes, MHC Class II; HIV; HTLV-III; Health; Heterophil Granulocyte; History; Human Immunodeficiency Viruses; Human T-Cell Leukemia Virus Type III; Human T-Cell Lymphotropic Virus Type III; Human T-Lymphotropic Virus Type III; Immune; Immune response; Immune system; Immunologic Accessory Cells; Individual; Infection; Infection Control; Inhibition of Apoptosis; LAV-HTLV-III; Location; Lung; Lymph node proper; Lymphadenopathy-Associated Virus; Lymphocyte; Lymphocytic; Lymphoid; M. tb; M. tuberculosis; M.tb; M.tuberculosis; MHC Class II; MHC Class II Genes; Mammals, Mice; Marrow Neutrophil; Mediastinal Lymph Node; Mediastinal lymph node group; Mediating; Medication; Methods; Methods and Techniques; Methods, Other; Mice; Monocytes / Macrophages / APC; Motility; Motility, Cellular; Multidrug-Resistant Tuberculosis; Murine; Mus; Mycobacterium tuberculosis; Myelogenous; Myeloid; Neutrophilic Granulocyte; Neutrophilic Leukocyte; Organ; Peptides; Pharmaceutic Preparations; Pharmaceutical Preparations; Polymorph; Polymorphonuclear Cell; Polymorphonuclear Leukocytes; Polymorphonuclear Neutrophils; Population; Production; Public Health; Publications; Pulmonary Alveoli; Pulmonary alveolar structure; Recording of previous events; Reporting; Respiratory System, Lung; Reticuloendothelial System, Lymph Node; Role; Scientific Publication; Structure of respiratory epithelium; T cell response; T4 Cells; T4 Lymphocytes; TB vaccine; TER1; Techniques; Testing; Tuberculosis; Tuberculosis Vaccines; Tuberculosis, Drug Resistance; Tuberculosis, Drug Resistant; Tuberculosis, MDR; Tuberculosis, Multi-Drug Resistant; Tuberculosis, MultiDrug Resistance; Tuberculosis, Multidrug-Resistant; Vaccines; Veiled Cells; Virus-HIV; XDR-Tuberculosis; accessory cell; adaptive immunity; anti-TB vaccine; body system, allergic/immunologic; cell motility; chemokine receptor; disease/disorder; disseminated TB; disseminated tuberculosis; drug resistant; drug/agent; helper T cell; heparin-binding hemagglutinin; host response; immunogen; immunoresponse; improved; in vivo; lung alveolus; lymph cell; lymph gland; lymph nodes; migration; mouse model; mutant; mycobacteria HBHA; mycobacterial; neutrophil; new vaccines; next generation vaccines; novel; novel vaccines; organ system, allergic/immunologic; pandemic; pandemic disease; public health medicine (field); public health relevance; pulmonary; resistance to Drug; resistant to Drug; response; social role; tool; tuberculous spondyloarthropathy
Project start date: 2001-12-01
Project end date: 2013-06-30
Budget start date: 1-JUL-2010
Budget end date: 30-JUN-2011
PFA/PA: PA-07-070
5R01AI051242-09 (2010): $530161
5R01AI051242-08 (2009): $519922
2R01AI051242-07A1 (2008): $534000
Tuberculosis Immunity: Essential Host Genes
Joel D Ernst, Professor
New York University School Of Medicine New York, Ny 10016
Grant 5R03AI053074-03 from National Institute Of Allergy And Infectious Diseases IRG: BM
Abstract: Despite improved tuberculosis control measures in the United States, tuberculosis continues to be a disease of growing worldwide importance. The currently-available drugs and vaccine (BCG) are efficacious, but are insufficient to prevent tuberculosis from continuing to spread and cause morbidity and mortality. An improved vaccine, developed and evaluated with better understanding of the mechanisms of protective immunity required for control of tuberculosis, has the theoretical potential of markedly improving prevention of tuberculosis. While it is clearly established that the cytokine, interferon gamma, is essential for protective immunity to tuberculosis, the mechanisms of interferon gamma in protective immunity are incompletely understood. In particular, the host genes whose expression is regulated by interferon gamma and that mediate protection against tuberculosis remain to be identified. While nitric oxide synthetase is one of these genes, there is strong evidence that additional interferon gamma-regulated genes contribute to control of tuberculosis. In this project, we propose experiments whose long term goal is to identify interferon gamma-regulated genes that are essential for immune control of tuberculosis. We will first characterize the course of M. tuberculosis infection in mice lacking each of three transcription factors (STAT1, IRF1, and ICSBP) that mediate the effects of interferon gamma on gene expression, to determine whether the interferon gamma-regulated genes that control M. tuberculosis in the lung are downstream of one or more of these transcription factors. In addition, we will prepare bone marrow chimeric mice, to determine whether macrophages are the only cells whose response to interferon gamma contributes to control of M. tuberculosis in the lungs. Finally, we will use high-density DNA microarrays to analyze gene expression in the lungs of M. tuberculosis-infected mice lacking each of the interferon gamma-responsive transcription factors, to determine the feasibility of this approach in identifying the genes that mediate interferon gamma-dependent protective immunity to tuberculosis. The studies proposed in this application will contribute to the knowledge of the molecular and cellular mechanisms of immunity to tuberculosis. In addition, they will determine the feasibility of analysis of gene expression in the lungs of specific strains of mice to ultimately identify genes that confer protection against tuberculosis.
Keywords: Mycobacterium tuberculosis, bacteria infection mechanism, bactericidal immunity, host organism interaction, cell cell interaction, chimeric protein, gene expression, interferon gamma, transcription factor, flow cytometry, genetic transcription, laboratory mouse, microarray technology, transgenic animal
Project start date: 2002-09-15
Project end date: 2005-08-31
5R03AI053074-03 (2003): $75750
1R03AI053074-01 (2002): $75333
MYCOBACTERIUM TUBERCULOSIS;INDUCED MACROPHAGE SIGNALLING
Joel D Ernst, Professor
Medicineuniversity Of California San Francisco
3333 California St., Ste 315
san Francisco, Ca 941430962
Grant 5R01HL051992-05 from National Heart, Lung, And Blood Institute IRG: BM
Abstract: DESCRIPTION(Adapted from ´s ) Tuberculosis (TB) is the most common fatal infectious disease in the world, and remains a threat to health in the United States. While improved case finding and access to treatment have reduced the incidence of TB in the United States, further improvements in TB control and therapy depend on better understanding of the pathogenesis of TB. Macrophages are essential for defense against infections, and are central to the pathogenesis of TB. When macrophages encounter most bacteria, they phagocytose and kill them. In contrast, macrophages phagocytose, but do not kill M. tuberculosis, even when they are stimulated with IFN gamma. Recent experiments in the PI´s laboratory reveal that one means that M. tuberculosis uses to evade killing by macrophages is to block the signal transduction pathway initiated by interferon gamma. The PI has found that infection of macrophages with M. tuberculosis blocks several macrophage responses to IFN gamma, and has found that this disruption of signalling reduces transcriptional activation of IFN gamma-responsive genes at a distal step in the signalling pathway. M. tuberculosis infection of macrophages causes release of one or more soluble factors that inhibit IFN gamma signaling in uninfected macrophages. TGF-beta, IL-4, IL-6, IL-10, and prostaglandin E2 cannot account for this phenomenon. The PI proposes to identify the component of M. tuberculosis that initiates the inhibition of IFN gamma signaling. One hypothesis to be tested is that infection of macrophages by M. tuberculosis induces a repressor that binds specific DNA elements in the promoter region of interferon gamma-responsive genes. Finally, the PI will purify the soluble factor present in the conditioned medium from infected cells that inhibits interferon gamma signaling in uninfected macrophages. The proposed experiments will enhance the understanding of the pathogenesis of tuberculosis, and will provide insight essential for developing effective approaches to enhancing the protective immune response to M. tuberculosis
Keywords: Mycobacterium tuberculosis, bacteria infection mechanism, biological signal transduction, interferon gamma, macrophage, tuberculosis DNA binding protein, genetic promoter element, phagocytosis
Project start date: 1993-09-30
Project end date: 2002-08-31
5R01HL051992-05 (2000): $233035
MOLECULAR MECHANISMS OF NEUTROPHIL SECRETION
Joel D Ernst, Professor
University Of California San Francisco 3333 California St., Ste 315 San Francisco, Ca 941430962
Grant 5R01HL056001-04 from National Heart, Lung, And Blood Institute IRG: HEM
Abstract: Adapted from Applicant s ) Secretion of the granule contents of neutrophils contributes to acute inflammation and to the chronic tissue destruction characteristic of many human diseases. The ultimate regulators of granule membrane- plasma membrane fusion have not yet been characterized. The Investigator developed a highly efficient and reproducible method that introduces large pores into the plasma membrane of neutrophils, allowing free exchange of cytoplasmic proteins with the extracellular medium. The permeabilized neutrophils efficiently secrete lactoferrin in response to 1 Mm free calcium. Using this system, the Investigator will examine the role of annexin I, phospholipid metabolites and GTPases in regulating secretion.
Keywords: membrane permeability, neutrophil, secretion, annexin, blood protein, calcium, cell membrane, extracellular matrix, guanosinetriphosphatase, lactoferrin, lipid metabolism, membrane fusion, membrane protein, phospholipid, complementary DNA, human tissue, immunoaffinity chromatography, molecular cloning, monoclonal antibody, protein purification
Project start date: 1996-04-25
Project end date: 2001-03-31
5R01HL056001-04 (1999): $294233
5R01HL056001-03 (1998): $285620
5R01HL056001-02 (1997): $270896
Sponsored Links Excellgen http://Excellgen.com
M TUBERCULOSIS EVASION OF IMMUNE EFFECTOR MECHANISMS
Joel D Ernst, Professor
New York University School Of Medicine New York, Ny 10016
Grant 5R01AI046097-05 from National Institute Of Allergy And Infectious Diseases IRG: ZRG1
Abstract: Adapted from Applicant s ) Mycobacterium tuberculosis is one of the most successful human pathogens known. To achieve such success, M.tuberculosis must avoid destruction by the immune system. Nevertheless, its mechanisms of evading the immune system are not well understood. The PI tested the hypothesis that M.tuberculosis evades immune effector function by inhibiting the action of interferon gamma, a crucial mediator of innate immunity. The investigators found that M.tuberculosis infection of human macrophages blocks transcriptional activation of interferon gamma responsive genes, and that it does so by disrupting the interaction of the transcription factor, STAT 1, with the transcriptional coactivators CBP and p300. By blocking interferon gamma transcriptional responses, M.tuberculosis can inhibit activation of macrophages and can survive despite development of a cellular immune response. In this application experiments are proposed to identify the mechanism by which M.tuberculosis disrupts the STAT1-CBP interaction, and to determine whether overcoming those mechanisms allows human macrophages to respond to interferon gamma by killing M.tuberculosis. The effects of live M.tuberculosis can be replicated by gamma-irradiated bacteria, as well as a by a crude cell wall fraction, but not by LAM. We propose to identify the specific components of the M.tuberculosis cell wall that initiates inhibition of interferon gamma responses, and to characterize macrophage responses to that component. The investigators have also discovered that, in response to M.tuberculosis, macrophages synthesize and release a soluble protein (termed SINGR) that causes inhibition of interferon gamma responses in naive, uninfected cells. SINGR activity is not attributable to known cytokines, such as IL-4, Il-6, IL-10, or TGF-b. The investigators propose to identify SINGR by purification or expression cloning, prepare antibodies that neutralize its activity, and determine whether SINGR is an obligate intermediate molecule in the inhibition of interferon gamma responses by M.tuberculsois. It is hoped that the results of these studies will provide valuable insight into the interaction of M.tuberculosis with the human immune system, particularly the ability of this pathogen to persist in the face of a seemingly appropriate immune response.
Keywords: Mycobacterium tuberculosis, bacteria infection mechanism, cellular immunity, interferon gamma, alveolar macrophage, cell wall, cytokine, genetic transcription, inhibitor /antagonist, clinical research, diagnostic respiratory lavage, expression cloning, human subject, human tissue, laboratory mouse, laboratory rabbit, protein purification
Project start date: 2000-06-01
Project end date: 2004-05-31
5R01AI046097-05 (2003): $338728
5R01AI046097-03 (2002): $328863
5R01AI046097-02 (2001): $319286
1R01AI046097-01A1 (2000): $309986
MOLECULAR MECHANISMS OF NEUTROPHIL SECRETION
Joel D Ernst, Professor
University Of California San Francisco 3333 California St., Ste 315 San Francisco, Ca 941430962
Grant 1R01HL056001-01 from National Heart, Lung, And Blood Institute IRG: HEM
Project start date: 1996-04-25
Project end date: 2000-03-31
1R01HL056001-01 (1996): $260318