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Principal Investigator: Joshua D Chandler
Organization: EMORY UNIVERSITY
Fiscal Year: 2024
Award: $385,205
Funding agency: National Heart Lung and Blood Institute
PROJECT SUMMARY / ABSTRACT
Current standard of care for cystic fibrosis (CF) does not include drugs unequivocally effective at curbing
airway inflammation, in contrast to crucial gains made in correcting defects in the CF transmembrane
conductance regulator (CFTR) via highly effective modulator therapy (HEMT) and an array of antimicrobial
drugs. Effectively treating exuberant neutrophil-dominated inflammation in CF, particularly in the earliest stages
of the disease, is a critical goal because doing so would increase patient lifespan and health span. This project
is designed to test the hypothesis that neutrophil hyperexocytosis, which occurs in CF from a very young age,
is a critical event that releases active myeloperoxidase (MPO) from neutrophil granules and enables the
generation of extracellular hypochlorous acid (HOCl), a strong and promiscuous oxidant that can damage cells.
We further hypothesize that the released MPO becomes associated with extracellular vesicles (EVs), providing
MPO with sustained metabolism to fuel its HOCl-generating activity and conferring resistance to inhibitors.
Ultimately, we hypothesize that increased airway HOCl injures airway epithelial cells (AECs) and promotes
maladaptive cellular responses that contribute to bronchiectasis. Research from our group has shown that
MPO is active in CF airways from the earliest stages of disease and is associated with initial manifestations of
bronchiectasis. Furthermore, we have identified molecular products of HOCl exposure, such as methionine
sulfoxide, that can be monitored by LC-MS across a broad range of biological specimens, including basic and
translational models and clinical samples. Using state-of-the-art LC-MS, rigorous cell-, protein-, and EV-
detection methods, highly translational models of neutrophils and EVs, and clinical sample validation, this
project sets out a series of parallel experiments designed to identify the sequence of events leading from
neutrophil transmigration into CF airways, to active MPO release and extracellular HOCl generation, to CF
AEC injury and maladaptation to the potent oxidative insult. These experiments are enumerated in the
following Specific Aims: (1) Determine the impact of hyperexocytosis on extracellular HOCl and innate
defense; (2) Determine mechanisms of granule-releasing, immunomodulatory, and metabolically active (GRIM)
neutrophil EV-based HOCl production; and (3) Determine mechanisms of CF airway epithelial cytotoxicity
mediated by MPO and HOCl. Furthermore, these experiments account for potential impacts of novel HEMT
therapy elexacaftor-tezacaftor-ivacaftor (ETI) in inflammatory pathways by comparing CF sputum samples with
HEMT to the same samples from donors not receiving ETI. The ultimate goal of the proposed studies is to
generate knowledge informing clinical and drug development research and forestall CF lung disease
progression at the earliest stages and before end organ damage. Furthermore, owing to the prevalence of
GRIM neutrophils in a number of lung diseases beyond CF, information pertinent to other lung diseases
including neutrophil inflammation will also be gained by the completion of this project.
Terms: <Active Oxygen><Acute><Address><Age><Anti-Inflammatories><Anti-Inflammatory Agents><Anti-inflammatory><Antioxidants><Binding><Biological><Birth><Blood Neutrophil><Blood Polymorphonuclear Neutrophil><Body Tissues><Bronchiectasis><CF airway><CF airway epithelia><CF lung disease><CF patients><CF sputum><CFTR><CFTR Protein><Caring><Cell Body><Cell Communication and Signaling><Cell Signaling><Cell Survival><Cell Viability><Cells><Cellular injury><Chemoattractants><Chemotactic Factors><Chemotaxins><Chlorides><Chlorine><Cl element><Clinical><Clinical Research><Clinical Study><Cystic Fibrosis><Cystic Fibrosis Transmembrane Conductance Regulator><Cystic Fibrosis sputum><Cytoplasmic Granules><D-Glucose><Data><Defect><Development and Research><Dextrose><Disease><Disease Progression><Disorder><Enzyme Gene><Enzymes><Epithelial Cells><Epithelium><Event><Exhibits><Exocytosis><Experimental Designs><Generations><Glucose><Glutathione><Goals><H2O2><Hemi-Myeloperoxidase><Human><Hydrogen Peroxide><Hydroperoxide><Hypochlorous Acid><Immunobiology><Immunomodulation><Immunophysiology><In Vitro><Incubated><Inflammation><Inflammatory><Intermediary Metabolism><Intervention><Intervention Strategies><Intracellular Communication and Signaling><Ivacaftor><Knowledge><LTB4><Label><Leukotriene B-4><Leukotriene B4><Lung><Lung Diseases><Lung Inflammation><Lung Respiratory System><Lung damage><Lytotoxicity><Marrow Neutrophil><Mediating><Membrane Protein Gene><Membrane Proteins><Membrane-Associated Proteins><Metabolic><Metabolic Processes><Metabolism><Mice><Mice Mammals><Modeling><Modern Man><Molecular><Molecular Interaction><Monitor><Mucoviscidosis><Murine><Mus><Myeloperoxidase><Neutrophilic Granulocyte><Neutrophilic Leukocyte><Nutrient><O element><O2 element><Organ><Oxidants><Oxidation-Reduction><Oxidizing Agents><Oxygen><Oxygen Radicals><P aeruginosa><P. aeruginosa><Parturition><Pathway interactions><Patients><Peroxidases><Phenotype><Physiologic><Physiological><Pneumonitis><Polymorphonuclear Cell><Polymorphonuclear Leukocytes><Polymorphonuclear Neutrophils><Prevalence><Pro-Oxidants><Production><Proteins><Proteomics><Pseudomonas aeruginosa><Pseudomonas pyocyanea><Pulmonary Cystic Fibrosis><Pulmonary Diseases><Pulmonary Disorder><Pulmonary Inflammation><Pulmonary Pathology><R & D><R&D><Reaction><Reactive Oxygen Species><Redox><Research><Research Specimen><Resistance><Respiratory Epithelium><Rhodanates><Role><S aureus><S. aureus><Sampling><Series><Signal Transduction><Signal Transduction Systems><Signaling><Specimen><Sputum><Staining method><Stains><Staph aureus><Staphylococcus aureus><Structure of respiratory epithelium><Surface Proteins><Testing><Therapeutic><Thiocyanates><Tissues><VX-770><Validation><Vesicle><ages><airway epithelium><airway epithelium inflammation><airway inflammation><analytical method><anti-microbial agent><anti-microbial drug><antioxidant therapy><autooxidation><biologic><biological signal transduction><cell damage><cell injury><cellular damage><chlorination><clinical development><complement chemotactic factor><cystic fibrosis airway><cystic fibrosis airway epithelia><cystic fibrosis lung><cystic fibrosis lung disease><cystic fibrosis patients><cystic fibrosis transmembrane regulator><cytotoxicity><damage to cells><design><designing><detection method><detection procedure><detection technique><disease of the lung><disorder of the lung><drug development><early CF><early cystic fibrosis><electron acceptor><experiment><experimental research><experimental study><experiments><extracellular><extracellular vesicles><gamma-L-Glu-L-Cys-Gly><gamma-L-Glutamyl-L-Cysteinylglycine><glucose RA><glucose production><glucose rate of appearance><granule><health-span><healthspan><healthy life span><immune modulation><immune regulation><immunologic reactivity control><immunomodulatory><immunoregulation><immunoregulatory><improved><individuals with CF><individuals with cystic fibrosis><inflammatory lung disease><inhibitor><injury to cells><interventional strategy><life span><lifespan><lung disorder><lung injury><lung pathology><metabolism measurement><metabolomics><metabonomics><methionine sulfoxide><migration><mortality><mutant><neutrophil><next generation><novel><oxidation><oxidation reduction reaction><pathogen><pathway><patients with CF><patients with cystic fibrosis><pharmacologic><pulmonary><pulmonary damage><pulmonary injury><pulmonary tissue damage><pulmonary tissue injury><rational design><research and development><resistant><respiratory inflammation><respiratory tract epithelium><respiratory tract inflammation><response><social role><standard of care><targeted biomarker><targeted drug therapy><targeted drug treatments><targeted therapeutic><targeted therapeutic agents><targeted therapy><targeted treatment><trafficking><translational model><validations>