Inflammasome-Mediated Interleukin-1β Drives Neutrophilic Airway Inflammation in Cystic Fibrosis Pubblico

Abstract

Cystic fibrosis (CF) patients experience progressive airway destruction due to opportunistic pathogen colonization and neutrophil-dominated chronic inflammation. In order to investigate the inflammatory response promoting disease progression, we assessed neutrophil inflammasomes and the resulting activation of the IL-1 (interleukin-1) pathway, consisting of pro-inflammatory IL-1β signaling and an endogenous inhibitor, interleukin-1 receptor antagonist (IL-1RA). Specifically, we performed ex vivo assays of CF human blood and airway samples with comparison to healthy control (HC) subjects and in vitro neutrophil inflammasome stimulations. Further, we assessed bioactivity of IL-1β to identify the potential role of IL-1RA in modulating the IL-1β activatory cascade, and to investigate potential correlations with disease severity. Results show that IL-1β production is significantly elevated in CF, compared to HC and chronic obstructive pulmonary disease (COPD) controls, confirming that CF disease is linked with IL-1 signaling. Furthermore, we observed a strong correlation between neutrophil numbers and IL-1β levels, consistent with a pro-inflammatory loop of neutrophil recruitment and IL-1β secretion that itself recruits more neutrophils. Results from inflammasome stimulation and follow-up in vitro assays together demonstrate that IL-1β secretion may not be concomitant with cell death, contrary to conventional belief. Finally, using a cell line genetically engineered to detect bioactive IL-1β, we found that IL-1β in CF airway samples is indeed bioactive and that this bioactivity is closely regulated by IL-1RA. Ultimately, results gathered strongly suggest that IL-1β is a clinically relevant modulator of CF, and a potential target for therapeutic intervention.

Table of Contents

I. Introduction. 1

i. Background. 1

ii. Genetic basis of CF. 1

iii. Pathophysiology of CF airway disease. 2

iv. PMN-mediated inflammation. 2

v. Inflammasome activation. 3

vi. Modulation of IL-1β pathway. 4

vii. Study rationale. 5

II. Materials and Methods. 5

i. Human subjects. 5

ii. Sample collection processing. 6

iii. ELISA. 6

iv. Human Embryonic Kidney (HEK)-Blue Cells. 8

v. in vitro inflammasome activation. 10

vi. LDH Assay. 11

vii. Statistical analysis. 12

III. Results. 12

IV. Discussion. 14

V. Tables and Figures. 18

i. T1. 18

ii. F1. 18

iii. F2. 19

iv. F3. 20

v. F4. 21

vi. F5. 22

vii. F6. 23

viii. F7. 24

ix. F8. 25

x. F9. 26

xi. F10. 27

xii. F11. 28

xiii. F12. 29

xiv. F13. 31

VI. References. 32

About this Honors Thesis

Rights statement

• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Emory College
Department	Biology
Degree	BS
Submission	Honors Thesis
Language	English
Research Field	Health Sciences, General Health Sciences, Immunology
Parola chiave	Lung Airway sputum Neutrophils Cytokines Immunology Cystic Fibrosis Inflammation Inflammasome Interleukin-1
Committee Chair / Thesis Advisor	Tirouvanziam, Rabindra M, Emory University
Committee Members	Gerardo, Nicole Marie, Emory University Brown, Lou Ann, Emory University

Ultima modifica

Primary PDF

Thumbnail	Title	Date Uploaded	Actions
	Inflammasome-Mediated Interleukin-1β Drives Neutrophilic Airway Inflammation in Cystic Fibrosis ()	2018-08-28 15:14:17 -0400	Press to Select an action Download

Supplemental Files

Thumbnail	Title	Date Uploaded	Actions