Pathological Conditioning of Neutrophils in Airway Inflammation Öffentlichkeit

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

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School	Laney Graduate School
Department	Biological and Biomedical Sciences
Subfield / Discipline	Immunology and Molecular Pathogenesis
Degree	Ph.D.
Submission	Dissertation
Language	English
Research Field	Health Sciences, Immunology
Stichwort	Neutrophil Cystic Fibrosis Inflammation
Committee Chair / Thesis Advisor	Tirouvanziam, Rabindra, Emory University
Committee Members	Kohlmeier, Jacob, Emory University Selvaraj, Periasamy, Emory University Brown, Lou Ann, Emory University Kalman, Daniel, Emory University

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