Interactions between P. aeruginosa and autophagy in Airway epithelial cells


Principal Investigator: INDHIRA H DE LA ROSA
Abstract: DESCRIPTION (provided by applicant): The goal of our research proposal is to understand the interactions of Pseudomonas aeruginosa (P. aeruginosa) and its virulent type 3 secretion system (T3SS) with autophagy in airway epithelial cells (AECs). AECs provide initial protection against airborne pathogensby acting as a cellular barrier (1). P. aeruginosa is a gram-negative bacterium which can cause pneumonia in immunocompromised patients, and it is known to target AECs (2). T3SS of P. aeruginosa is a virulence mechanism associated with a high rate of mortality in humans, in which the bacterium inject toxins (effector proteins) into the host cells usually leading to cell death (3). Currently, it is not known whether P. aeruginosa is able to escape autophagy or if its T3SS interferes with autophagy. However, it has been demonstrated that P. aeruginosa T3SS can negatively alter other antimicrobial pathways, including phagocytosis (3). Our hypothesis is that P. aeruginosa T3SS inhibits autophagy thereby protecting P. aeruginosa from elimination in AECs. Recently, our lab has obtained a T3SS mutant P. aeruginosa, which cannot inject effector proteins into host cells as well as the WT strain (4). In addition, we have received plasmids encoding some of the P. aeruginosa T3SS effector proteins (5, 6), which are responsible for the T3SS toxicity (5). We will also obtain P. aeruginosa mutants for individual effectors proteins (3, 5). In the long term, we plan to study the potential mechanism of how P. aeruginosa T3SS is able to modulate autophagy and how this regulation affects P. aeruginosa survival in AECs. In order to reach our goal, the following research strategy has been designed: (a) Determine the interactions between P. aeruginosa and autophagy in AECs by analyzing WT and T3SS mutant P. aeruginosa survival during autophagy induction by colony forming unit assay, as well as by evaluating their colocalization with autophagy membranes using both fluorescence and electron microscopy. (b) Investigate whether P. aeruginosa T3SS effector proteins inhibit autophagy and the mechanism by which this occurs. This aim will be completed by infecting cells with P. aeruginosa mutants for individual T3SS effector proteins or by over-expressing plasmids containing the sequence of T3SS effector proteins and by evaluating autophagy induction or blockage via Western blotting, fluorescence microscopy and co-Immunoprecipitation. (c) Determine the role of autophagy in ciliated AECs during WT and T3SS mutant P. aeruginosa infection in vivo by infecting normal and autophagy deficient in ciliated AECs mice and evaluating bacteria clearance, inflammatory responses and mouse survival. Understanding whether P. aeruginosa T3SS negatively affect autophagy could provide insight into P. aeruginosa pathogenesis and new therapeutic targets to promote the clearance of these bacteria.
Funding Period: 2012-08-07 - 2014-08-06
more information: NIH RePORT

Research Grants

Detail Information

Research Grants31

  1. Negative regulation of virulence in Pseudomonas aeruginosa
    Albert Siryaporn; Fiscal Year: 2013
    ..The findings from this study will shed light on how bacterial cells detect surfaces and how virulence is regulated. Additionally, it may also provide further details about the initial stages of biofilm formation. ..
  2. Host-pathogen competition in IFN mediated antiviral defense
    Jae U Jung; Fiscal Year: 2013
  3. Genetically-engineered pig organ transplantation into nonhuman primates
    DAVID KC COOPER; Fiscal Year: 2013
    ..abstract_text> ..
  4. Molecular Targets Phase III CoBRE
    Donald M Miller; Fiscal Year: 2013
    ..The robust translational research infrastructure at the James Graham Brown Cancer Center and University of Louisville will ensure the success and sustainability of this unique program. ..
    William M Nauseef; Fiscal Year: 2013
  6. Transplant Tolerance in Non-Human Primates
    ..This goal will be accomplished via four interrelated projects and two supporting cores. ..
  7. Genomics for Transplantation: Discovery and Biomarkers
    Daniel R Salomon; Fiscal Year: 2013
    ..Ultimately, we hope to create the genomic tools that will allow physicians to optimize and personalize the safety and efficacy of immunosuppression. ..
  8. Pulmonary Innate Immune Modulation by Helical Carbon Nanotubes
    BRENT WALLING; Fiscal Year: 2013
    ..Finally, we will be using a chronic P. aeuruginosa infection model to examine the impact of HCNT exposure as it relates to pulmonary inflammation, fibrosis, and clearance. ..
  9. Epithelial Barrier Programs in Asthma and Allergic Disease
    Michael J Holtzman; Fiscal Year: 2013
    ..abstract_text> ..
    David H Sachs; Fiscal Year: 2013
    ..abstract_text> ..
  11. Phagocyte Intoxication by ExoU in Pseudomonas Pneumonia
    ANGELICA ZHANG; Fiscal Year: 2013
    ..Our goal is to understand how P. aeruginosa impairs immune defenses to cause these severe infections of the lungs. This knowledge will aid the development of improved strategies in prevention, management, and treatment of pneumonia. ..
  12. Oklahoma Center for Respiratory and Infectious Diseases
    Lin Liu; Fiscal Year: 2013
    ..The completion of the goals of the present COBRE will have a major impact on research programs on respiratory infectious diseases in the State of Oklahoma. ..
  13. Endothelial Injury and Repair: CardioPulmonary Vascular Biology COBRE
    SHARON IRENE SMITH ROUNDS; Fiscal Year: 2013
    ..abstract_text> ..
  14. Pacific NorthWest Regional Center of Excellence (PNWRCE)
    Jay A Nelson; Fiscal Year: 2013
    ..pseudomallei host pathogen response during both the septicemic as well as the intracellular phases of the disease. ..
  15. Southeast Regional Centers of Excellence for Biodefense &Emerging Infectious Di
    Philip Frederick Sparling; Fiscal Year: 2013
    ..SERCEB brings new investigators to the biodefense effort through a combination of educational programs, support of innovative new projects, and the synergistic interactions among its world-class investigators. ..
  16. New England Regional Center of Excellence in Biodefense and Emerging Infectious D
    Dennis L Kasper; Fiscal Year: 2013
    ..NERCE will also continue its Developmental Projects program and Career Development in Biodefense program in an effort to initiate new research efforts and to attract new investigators to this field. ..
  17. Molecular Analyses and Interventions for Biodefense and Emerging Pathogens
    Olaf Schneewind; Fiscal Year: 2013
    ..Research and training at the GLRCE is governed by a mechanism involving ongoing review of scientific excellence and translational goals, inter-institutional advisory boards and external scientific advisory bodies. ..
    Martyn T Smith; Fiscal Year: 2013
    ..The program will be overseen and coordinated by an Administration core (A). ..
  19. Linking the physical and chemical characteristics of Qdots to their toxicity
    TERRANCE JAMES KAVANAGH; Fiscal Year: 2013
    ..These advances can then be used in safe design and manufacturing of nanomaterials so as to maximize their utility for many applications. ..
  20. Integrating Structive Activity, Biokinetics and Response for ENP Risk Assessment
    Brian D Thrall; Fiscal Year: 2013
  21. Rocky Mountain Regional Center of Excellence or Biodefense and Emerging Infectiou
    John T Belisle; Fiscal Year: 2013
    ..abstract_text> ..
  22. Improving Cardiac Function After Myocardial Infarction
    Steven R Houser; Fiscal Year: 2013
    ..A gene vector core will generate AAV6 vectors with novel therapeutics for testing in the pig Ml model. An administrative core will ensure data sharing and effective use of all resources. ..