Kevin S Mciver
University Of Maryland College Pk Campus
Project start date: 2000-07-01
Project end date: 2017-01-31
Sponsored Links Excellgen http://Excellgen.com
Analysis Of Mga From The Group A Streptococcus
Kevin S Mciver, Associate Professor
University Of Texas Sw Med Ctr/dallas Dallas, Tx 753909105
Grant 2R01AI047928-05A1 from National Institute Of Allergy And Infectious Diseases IRG: BACP
Abstract: The group A streptococcus (Streptococcus pyogenes, GAS) is a bacterial pathogen of significant medical importance that has evolved specific mechanisms to express an appropriate set of virulence attributes upon encountering a particular host tissue. Mga is a DNA-binding protein of GAS that regulates the transcription of several key virulence genes encoding products essential for colonization and immune evasion of GAS in the host in response to the growth phase and other environmental conditions. Furthermore, orthologues of Mga involved in virulence gene regulation are being found in many other pathogenic streptococci. Thus, Mga provides an excellent system to study global regulatory networks involved in GAS pathogenesis as well as a paradigm for a new family of virulence regulators in Gram-positive pathogens. The overall objectives of this renewal application are (a) to continue a structure/function analysis of Mga and its promoter to better understand the mechanisms by which this key GAS virulence regulator contributes to streptococcal disease, and (b) improve our general understanding of global regulatory pathways that interact to broadly control virulence in these and other important pathogens. The specific aims of this project are (1) To characterize the predicted functional domains within Mga for their role in signal transduction and Mga-dependent transcriptional regulation (2) To examine the mechanisms of Mga-dependent auto-activation and Mga- independent regulation at the mga promoter (Pmga) (3) To establish the role for AmrA and potentially other upstream factors in the growth phase control of mga and the Mga regulon and (4) To investigate how growth phase regulation of the Mga regulon contributes to virulence during GAS infection in mice. A thorough understanding of Mga and its regulation described here will contribute valuable new insights into global virulence regulation not only in GAS, but in other Gram-positive pathogens as well.
Keywords: DNA binding protein, Streptococcus pyogenes, bacterial protein, biological signal transduction, genetic regulation, genetic transcription, protein structure function, virulence, bacteria infection mechanism, bacterial genetics, gene induction /repression, genetic promoter element, genetic regulatory element, host organism interaction, microorganism growth, hairless mouse, immunocytochemistry, laboratory mouse, microarray technology
Project start date: 2000-07-01
Project end date: 2006-08-24
2R01AI047928-05A1 (2006): $314000
Grants awarded to Kevin S Mciver
In Vivo Analysis Of Virulence Expression In Model Of Group A Streptococcal Diseas
Kevin S Mciver, Associate Professor
University Of Texas Sw Med Ctr/dallas Dallas, Tx 753909105
Grant 5P30AR041940-090034 from National Institute Of Arthritis And Musculoskeletal And Skin Diseases IRG: ZAR1
Abstract: The group A streptococcus (Streptococcus pyogenes, GAS) is unsurpassed among bacterial pathogens in its ability to cause a variety of skin infections ranging from the self-limiting impetigo to fulminant soft tissue destruction and necrotizing fasciitis. GAS pathogenesis is a multi-factorial process, involving numerous virulence components that are involved in the specific response of the bacteria to different environments encountered within the host. However, we know very little about when these different virulence products are produced during infection. The overall aim of this pilot proposal will be to establish an in vivo reporter system based on the Green Fluorescent Protein (GFP) to assay GAS virulence gene expression during skin disease in an animal model. The specific aims of the project will be as follows 1. To construct GAS vectors for transcriptional fusions to gfp and test their capabilities in vitro. 2. To establish in vivo conditions for assaying GFP expression in a mouse model of streptococcal invasive skin disease. 3. To assay in vivo expression of known virulence genes in a mouse model of streptococcal invasive skin disease. These studies will hopefully lead to the establishment of a useful model system for directly examining the host/pathogen interplay between GAS and the human host during invasive skin infections.
Keywords: Streptococcus pyogenes, bacteria infection mechanism, skin infection, virulence, bacterial genetics, green fluorescent protein, laboratory mouse, transfection /expression vector
Project start date: 1997-06-01
Project end date: 2001-05-31
ANALYSIS OF MGA FROM THE GROUP A STREPTOCOCCUS
Kevin S Mciver
University Of Maryland College Pk Campus, 3112 Lee Building, College Park, Md 20742-5141
Grant 5R01AI047928-10 from National Institute Of Allergy And Infectious Diseases
Abstract: The group A streptococcus (Streptococcus pyogenes, GAS) is a bacterial pathogen of significant medical importance that has evolved specific mechanisms to express an appropriate set of virulence attributes upon encountering a particular host tissue. Mga is a DNA-binding protein of GAS that regulates the transcription of several key virulence genes encoding products essential for colonization and immune evasion of GAS in the host in response to the growth phase and other environmental conditions. Furthermore, orthologues of Mga involved in virulence gene regulation are being found in many other pathogenic streptococci. Thus, Mga provides an excellent system to study global regulatory networks involved in GAS pathogenesis as well as a paradigm for a new family of virulence regulators in Gram-positive pathogens. The overall objectives of this renewal application are (a) to continue a structure/function analysis of Mga and its promoter to better understand the mechanisms by which this key GAS virulence regulator contributes to streptococcal disease, and (b) improve our general understanding of global regulatory pathways that interact to broadly control virulence in these and other important pathogens. The specific aims of this project are (1) To characterize the predicted functional domains within Mga for their role in signal transduction and Mga-dependent transcriptional regulation (2) To examine the mechanisms of Mga-dependent auto-activation and Mga- independent regulation at the mga promoter (Pmga) (3) To establish the role for AmrA and potentially other upstream factors in the growth phase control of mga and the Mga regulon and (4) To investigate how growth phase regulation of the Mga regulon contributes to virulence during GAS infection in mice. A thorough understanding of Mga and its regulation described here will contribute valuable new insights into global virulence regulation not only in GAS, but in other Gram-positive pathogens as well
Keywords: Body Tissues; C5a peptidase; Cell Communication and Signaling; Cell Signaling; Cells; Collagen; Complement Inactivators; Complement Inhibitors; DNA-Binding Proteins; Disease; Disorder; Family; Gene Action Regulation; Gene Expression Regulation; Gene Regulation; Gene Regulation Process; Gene Transcription; Generalized Growth; Genes; Genetic Transcription; Growth; Human; Human, General; Immune; Infection; Intracellular Communication and Signaling; Life; M Protein, multiple myeloma; M protein; Mammals, Mice; Man (Taxonomy); Man, Modern; Medical; Mice; Minor; Murine; Mus; Organism; Pathogenesis; Peptide Domain; Phase; Promoter; Promoters (Genetics); Promotor; Promotor (Genetics); Protein Domains; Proteins; RNA Expression; Regulation; Regulatory Pathway; Regulon; Role; S. pyogenes; S.pyogenes; Sensory; Severities; Signal Transduction; Signal Transduction Systems; Signaling; Sof protein, Streptococcus pyogenes; Streptococcus; Streptococcus Group A; Streptococcus pyogenes; Structure; Syndrome; System; System, LOINC Axis 4; Tertiary Protein Structure; Tissue Growth; Tissues; Transcription; Transcription Regulation; Transcription, Genetic; Transcriptional Control; Transcriptional Regulation; Virulence; biological signal transduction; disease/disorder; gene product; improved; insight; living system; multiple myeloma M Protein; ontogeny; opacity factor; pathogen; response; serum opacity factor; social role
Project start date: 2000-07-01
Project end date: 2010-11-30
Budget start date: 1-DEC-2009
Budget end date: 30-NOV-2010
5R01AI047928-10 (2010): $254617
5R01AI047928-07 (2007): $288387
Analysis Of MGA Protein From The Streptococcus Pyogenes
Kevin S Mciver, Associate Professor
Microbiologyuniversity Of Texas Sw Med Ctr/dallas
dallas, Tx 753909105
Grant 1R01AI047928-01A2 from National Institute Of Allergy And Infectious Diseases IRG: BM
Abstract: The group A streptococcus (Streptococcus pyogenes, GAS) is a bacterial pathogen of enormous medical importance to humans, causing a variety of disease syndromes that range in severity from minor to life-threatening. Mga is a DNA-binding protein of GAS that activates the transcription of several key virulence genes in response to changing environmental conditions, likely through interactions with other regulatory components in the cell. The Mga regulon encodes products essential for the survival of GAS in the host, including the antiphagocytic M protein, M-like immunoglobulin binding proteins, the secreted inhibitor of complement, a collagen-like protein, and a C5a peptidase. Thus, Mga provides an excellent model system to study global regulatory networks involved in GAS pathogenesis and how they may interact. However, we currently know very little about Mga, including what domains of the protein are critical for its function and how environmental signals control the Mga regulon. The specific aims of this project are (1) To identify domains of Mga involved in DNA-binding and characterize their role in targeting specific promoters; (2) To determine a consensus Mga binding element for each of the known promoter sites through identification of specific Mga/nucleotide interactions; (3) To investigate whether domains of Mga interact directly with other bacterial components to transduce environmental signals (i.e., is Mga a two-component response regulator?); (4) To identify additional factors required for the environmental regulation of the Mga regulon and assess their role in global virulence regulation. An attractive feature of this proposal is our ability to study Mga both as a purified protein in vitro and as a native molecule in its GAS background. As such, we will be able to thoroughly address key questions of GAS pathogenesis associated closely with the environmental regulation of the Mga regulon. The overall objectives of this proposal are (A) to undertake a structure/function analysis of Mga and determine the mechanisms by which this key GAS virulence regulator contributes to streptococcal disease, and (B) improve our general understanding of regulatory pathways that broadly control virulence in these gram-positive pathogens
Keywords: DNA binding protein, Streptococcus pyogenes, bacterial cytopathogenic effect, bacterial protein, biological signal transduction, genetic regulation, genetic transcription, protein structure function bacterial genetics, gene environment interaction, gene induction /repression, genetic promoter element, host organism interaction, intermolecular interaction, molecular site, nucleic acid sequence, virulence DNA footprinting, immunocytochemistry, laboratory mouse, laboratory rat, microarray technology, site directed mutagenesis
Project start date: 2001-09-30
Project end date: 2005-07-31
1R01AI047928-01A2 (2001): $235600
5R01AI047928-04 (2004): $283320
Francisella Tularensis Secreted Proteome In Tularemia
Kevin S Mciver, Associate Professor
University Of Texas Sw Med Ctr/dallas Dallas, Tx 753909105
Grant 1P01AI055637-010003 from National Institute Of Allergy And Infectious Diseases IRG: ZAI1
Abstract: Gram-negative bacterial pathogens, including those that grow intracellularly, are known to secrete a variety of virulence molecules into the surrounding environment at specific points during infection. Such secreted proteins are important tools for Gram-negative pathogens to manipulate their host environment to allow growth in vivo and elude the host immune response. To date, there have been no secreted proteins of Francisella tularensis implicated in the pathogenesis of this important biothreat, nor have any studies directly addressed this question. Thus, this proposal will combine proteomic and genomic approaches as well as in situ and in vivo infection models to characterize the role of exoproteins expressed during F. tularensis infection. A broad and thorough analysis of proteins secreted by the highly virulent F. tularensis Schu4 into the extracellular milieu of may lead to a significant advancement in our understanding the pathogenesis of this pathogen. The Specific Aims of the project are (1) To characterize the extracellular proteome of the virulent F. tularensis Schu4 strain grown under different conditions relevant to infection in vivo; (2) To identify the complete open reading frames (ORF s) encoding each secreted extracellular protein (Exp) characterized in Aim 1; (3) To determine the role of each F. tularensis Schu4 secreted extracellular protein (Exp) for in vitro growth in human macrophages and for virulence in murine models of tularemia; (4) To establish whether secreted extracellular proteins (Exp) of F. tularensis Schu4 represent targets for immunoprophylaxis or therapeutic treatment during early stages of tularemia. These aims will have strong relevance to the overall goals of the P01 application and close collaborations with the other five P01 investigators will markedly enhance the success of this project. These combined studies could lead to a better understand the pathogenesis of this organism, leading to the development of new diagnostic, vaccine, and intervention strategies.
Keywords: Francisella tularensis, bacterial protein, molecular pathology, tularemia, macrophage, open reading frame, proteomics, virulence, antiserum, bioterrorism /chemical warfare, laboratory mouse, laboratory rat
Project start date: 2003-07-01
Project end date: 2008-06-30
MGA TRANSCRIPTIONAL REGULATION IN STREPTOCOCCUS
Kevin S Mciver, Associate Professor
Microbiology And Immunologyemory University
1599 Clifton Road, 4th Floor
atlanta, Ga 30322
Grant 5F32AI009460-03 from National Institute Of Allergy And Infectious Diseases IRG: ZRG5
5F32AI009460-03 (1998): $31824
5F32AI009460-02 (1997): $29900
Sponsored Links Excellgen http://Excellgen.com
1F32AI009460-01 (1996): $28600