Pathological Conditioning of Neutrophils in Airway Inflammation Open Access
Forrest, Osric (Spring 2018)
Abstract
Airway inflammation in cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), and severe asthma is marked by massive recruitment of polymorphonuclear neutrophils (PMNs) from blood into the airway lumen. Therein, PMNs may assume a pathogenic role notably via the release of toxic granule mediators such as neutrophil elastase (NE). In CF, extracellular NE activity strongly correlates (negatively) with lung function. Despite this critical pathological importance, it remains unclear how and why NE and other granule mediators from PMNs are released into the lung lumen. In studies presented here, we describe for the first time the development of an in vitro model system that recapitulates the functional and metabolic changes that occur upon PMN recruitment to the CF lung. Using this model, we show that airway fluid from CF patients induces rapid transepithelial migration, primary granule release, increased glycolysis, and oxidant production by recruited PMNs. We also show that CF airway PMNs in vivo and in vitro increase intracellular caspase-1 activity, and surface expression of IL-1R1, both key elements of the inflammasome pathway. Moreover, we find that extracellular vesicles (EVs) from CF airway fluid are able to induce caspase-1 activation in naïve PMNs and airway epithelial cells. Conditioned PMNs also release resistin, an immunometabolic mediator which levels correlate strongly with lung disease in both children and adults with CF. Collectively, conditioning by CF airway fluid results in the development of the pathogenic “GRIM” PMN fate, featuring heightened primary granule release, immunoregulatory functions (arginase-1 and caspase-1 activation), and metabolic licensing. We identify GRIM PMNs in COPD and severe asthma (both in vivo and in our in vitro model) suggesting that this pathogenic fate is not restricted to CF. Finally, we show that the metabolic drug metformin modulates GRIM PMNs by decreasing their metabolic activity, granule release and oxidant production. Our work open new avenues for better understanding and targeting the process of pathogenic conditioning of PMNs as it occurs in chronic inflammatory airway diseases such as CF, COPD, and severe asthma.
Table of Contents
Chapter 1: An Introduction to Neutrophil Development, Function, and Regulation, with a Focus on Their Impact on Cystic Fibrosis Airway Inflammation
Introduction………………………………………………………………………1
Figures……………………………………………………………………………24
References………………………………………………………………………...29
Chapter 2: Pathological Conditioning of Human Neutrophils Recruited to the Airway Milieu in Cystic Fibrosis
Introduction……………………………………………………………………...53
Methods………………………………………………………………………….55
Results…………………………………………………………………………....62
Discussion………………………………………………………………………..67
Figures………………………………………………………………………........72
References………………………………………………………………………..94
Chapter 3: Extracellular Vesicles Activate Inflammasome Signaling in Cystic Fibrosis Airway Disease
Introduction……………………………………………………………………102
Methods………………………………………………………………………...105
Results………………………………………………………………………….110
Discussion…………………………………………………………………… ...113
Figures………………………………………………………………………… 116
References……………………………………………………………………....127
Chapter 4: Resistin, A Novel Biomarker of Neutrophil-Driven Inflammation in Cystic Fibrosis Airway Disease
Part 1: Resistin is Elevated in Cystic Fibrosis Plasma and Sputum and Correlates Negatively with Lung Function
Introduction……………………………………………………………………136
Methods………………………………………………………………………..138
Results………………………………………………………………………….141
Discussion…………………………………………………………………… ..145
Figures…………………………………………………………………………148
Part 2: Resistin is an Early Marker of Airway Disease in Children with Cystic Fibrosis
Introduction……………………………………………………………………163
Methods………………………………………………………………………..164
Results………………………………………………………………………….166
Discussion…………………………………………………………………… ..167
Figures………………………………………………………………………….170
References……………………………………………………………………...175
Chapter 5: Summary and Future Directions
Introduction……………………………………………………………………182
Figures……………………………………………………………………….....164
References……………………………………………………………………...198
About this Dissertation
School | |
---|---|
Department | |
Subfield / Discipline | |
Degree | |
Submission | |
Language |
|
Research Field | |
Keyword | |
Committee Chair / Thesis Advisor | |
Committee Members |
Primary PDF
Thumbnail | Title | Date Uploaded | Actions |
---|---|---|---|
Pathological Conditioning of Neutrophils in Airway Inflammation () | 2018-04-20 07:28:09 -0400 |
|
Supplemental Files
Thumbnail | Title | Date Uploaded | Actions |
---|