Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms

The chronic infection of the cystic fibrosis (CF) lung with Pseudomonas aeruginosa strongly correlates with critical outcomes. Pseudomonas alkyl-quinolone signal (PQS) is a diffusible cell-density dependent signal controlling the production of virulence determinants. The PQS amount in the CF lung wa...

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Main Author: Liu, Yi-Chia
Format: Thesis (University of Nottingham only)
Language:English
Published: 2014
Online Access:http://eprints.nottingham.ac.uk/27807/
http://eprints.nottingham.ac.uk/27807/1/LiuYC_thesis_final.pdf
id nottingham-27807
recordtype eprints
spelling nottingham-278072017-12-15T19:51:56Z http://eprints.nottingham.ac.uk/27807/ Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms Liu, Yi-Chia The chronic infection of the cystic fibrosis (CF) lung with Pseudomonas aeruginosa strongly correlates with critical outcomes. Pseudomonas alkyl-quinolone signal (PQS) is a diffusible cell-density dependent signal controlling the production of virulence determinants. The PQS amount in the CF lung was proportionate to P. aeruginosa colonisation and PQS molecules have been demonstrated to inhibit pro-inflammatory signalling. However, how PQS influence the recognition of P. aeruginosa by the human lung is unknown. The contribution of PQS to the interaction of P. aeruginosa with human bronchial epithelial cells (HBECs) was characterised using a PQS-deficient mutant ΔpqsA in comparison with its isogenic wild type (WT). Although ΔpqsA appeared attenuated, the pathogenesis of WT and ΔpqsA upon infection of HBEC did not differ in bacterial growth, actin and junctional protein degradation, and pro-inflammatory activation. Despite PQS being highly secreted by a CF isolate LESB58, preliminary data showed that LESB58 was less cytotoxic than the laboratory WT. Our results suggest that PQS does not alter P. aeruginosa pathogenicity on HBECs. Idiopathic pulmonary fibrosis (IPF) is characterised with heterogeneous pathological patterns caused by scarring leading to irreversible destruction of lung architecture. Emerging evidence suggests that dysregulated immunological events could cause the failure of tissue-healing. Systemic immune responses of patients with IPF and age- and sex-matched healthy donors were determined by quantifying cytokines produced by peripheral blood mononuclear cells (PBMCs) upon an array of stimuli. The results showed that PBMCs in patients with IPF were less likely to produce IL-17A, IL-10 and IL-13 than healthy controls (OR 0.14-0.3, 95% CI 0.003-0.03). Patients with lower levels of cytokines had a four to six-fold increased risk of death (HR 4.31-6.13, 95% CI 0.0052-0.0176). This study contributes to a better understanding of the role of PQS in P. aeruginosa pathogenesis and identified cytokine production as a novel biomarker in IPF. 2014-12-09 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en http://eprints.nottingham.ac.uk/27807/1/LiuYC_thesis_final.pdf Liu, Yi-Chia (2014) Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms. PhD thesis, University of Nottingham.
repository_type Digital Repository
institution_category Local University
institution University of Nottingham Malaysia Campus
building Nottingham Research Data Repository
collection Online Access
language English
description The chronic infection of the cystic fibrosis (CF) lung with Pseudomonas aeruginosa strongly correlates with critical outcomes. Pseudomonas alkyl-quinolone signal (PQS) is a diffusible cell-density dependent signal controlling the production of virulence determinants. The PQS amount in the CF lung was proportionate to P. aeruginosa colonisation and PQS molecules have been demonstrated to inhibit pro-inflammatory signalling. However, how PQS influence the recognition of P. aeruginosa by the human lung is unknown. The contribution of PQS to the interaction of P. aeruginosa with human bronchial epithelial cells (HBECs) was characterised using a PQS-deficient mutant ΔpqsA in comparison with its isogenic wild type (WT). Although ΔpqsA appeared attenuated, the pathogenesis of WT and ΔpqsA upon infection of HBEC did not differ in bacterial growth, actin and junctional protein degradation, and pro-inflammatory activation. Despite PQS being highly secreted by a CF isolate LESB58, preliminary data showed that LESB58 was less cytotoxic than the laboratory WT. Our results suggest that PQS does not alter P. aeruginosa pathogenicity on HBECs. Idiopathic pulmonary fibrosis (IPF) is characterised with heterogeneous pathological patterns caused by scarring leading to irreversible destruction of lung architecture. Emerging evidence suggests that dysregulated immunological events could cause the failure of tissue-healing. Systemic immune responses of patients with IPF and age- and sex-matched healthy donors were determined by quantifying cytokines produced by peripheral blood mononuclear cells (PBMCs) upon an array of stimuli. The results showed that PBMCs in patients with IPF were less likely to produce IL-17A, IL-10 and IL-13 than healthy controls (OR 0.14-0.3, 95% CI 0.003-0.03). Patients with lower levels of cytokines had a four to six-fold increased risk of death (HR 4.31-6.13, 95% CI 0.0052-0.0176). This study contributes to a better understanding of the role of PQS in P. aeruginosa pathogenesis and identified cytokine production as a novel biomarker in IPF.
format Thesis (University of Nottingham only)
author Liu, Yi-Chia
spellingShingle Liu, Yi-Chia
Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
author_facet Liu, Yi-Chia
author_sort Liu, Yi-Chia
title Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
title_short Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
title_full Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
title_fullStr Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
title_full_unstemmed Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
title_sort understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
publishDate 2014
url http://eprints.nottingham.ac.uk/27807/
http://eprints.nottingham.ac.uk/27807/1/LiuYC_thesis_final.pdf
first_indexed 2018-09-06T11:45:57Z
last_indexed 2018-09-06T11:45:57Z
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