scholarly journals Proteomic profile of cystic fibrosis sputum cells in adults chronically infected with Pseudomonas aeruginosa

2017 ◽  
Vol 50 (1) ◽  
pp. 1601569 ◽  
Author(s):  
Sally H. Pattison ◽  
David S. Gibson ◽  
Elinor Johnston ◽  
Samantha Peacock ◽  
Keith Rivera ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Cell Death ◽  
Lung Function ◽  
Lung Disease ◽  
Protein Identification ◽  
Immune Cell ◽  
Small Gtpase ◽  
Cellular Proteins ◽  
Extracellular Proteases

Lung disease is the main cause of morbidity and mortality in cystic fibrosis (CF), and involves chronic infection and perturbed immune responses. Tissue damage is mediated mostly by extracellular proteases, but other cellular proteins may also contribute to damage through their effect on cell activities and/or release into sputum fluid by means of active secretion or cell death.We employed MudPIT (multidimensional protein identification technology) to identify sputum cellular proteins with consistently altered abundance in adults with CF, chronically infected with Pseudomonas aeruginosa, compared with healthy controls. Ingenuity Pathway Analysis, Gene Ontology, protein abundance and correlation with lung function were used to infer their potential clinical significance.Differentially abundant proteins relate to Rho family small GTPase activity, immune cell movement/activation, generation of reactive oxygen species, and dysregulation of cell death and proliferation. Compositional breakdown identified high abundance of proteins previously associated with neutrophil extracellular traps. Furthermore, negative correlations with lung function were detected for 17 proteins, many of which have previously been associated with lung injury.These findings expand our current understanding of the mechanisms driving CF lung disease and identify sputum cellular proteins with potential for use as indicators of disease status/prognosis, stratification determinants for treatment prescription or therapeutic targets.

scholarly journals An 8 week open-label interventional multicenter study to evaluate the lung clearance index as endpoint for clinical trials in cystic fibrosis patients ≥8 years of age, chronically infected with Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Sivagurunathan Sutharsan ◽  
Susanne Naehrig ◽  
Uwe Mellies ◽  
Christian Sieder ◽  
joerg Zeigler
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Function ◽  
Lung Disease ◽  
Small Airways ◽  
Open Label ◽  
Lung Clearance ◽  
Efficacy Trials ◽  
Inhaled Antibiotics ◽  
Lung Clearance Index

Abstract Background Forced expiratory volume in 1 second (FEV 1 ) is the only parameter currently recognized as a surrogate endpoint in cystic fibrosis (CF) trials. However, FEV 1 is relatively insensitive to changes in the small airways of patients with milder lung disease. This pilot study aimed to evaluate the lung clearance index (LCI) as a marker for use in efficacy trials with inhaled antibiotics in CF. Methods This open-label, single-arm study enrolled CF patients with Pseudomonas aeruginosa infection, who were treated with tobramycin (28-day on/off regime). FEV 1 , LCI and bacterial load in sputum (CFU) were assessed at baseline, after 1, 4 and 8 weeks of treatment. Results All patients (n=17) showed elevated LCI of >11 despite 3 patients having normal FEV 1 (>90% predicted) at baseline. Overall, LCI improved in 8 (47%) patients and FEV 1 in 9 (53%) patients. At week 4, LCI improved by 0.88, FEV 1 increased by 0.52%, and P. aeruginosa reduced by 30481.3 CFU/mL. These changes were however statistically non-significant. Six adverse events occurred in 5/17 (29.4%) patients, most of which were mild-to-moderate in severity. Conclusions Due to the low evaluable sample size, no specific trend was observed related to the changes between LCI, FEV1 and CFU. Based on the individual data from this study and from recently published literature, LCI has been shown to be a more sensitive parameter than FEV1 for lung function. LCI can hypothesized to be an appropriate endpoint for efficacy trials in CF patients if the heterogeneity in lung function is limited by enrolling younger patients or patients with more milder lung disease and thus, limiting the ventilation inhomogeneities. Trial registration : The study is registered with ClinicalTrials.gov, identifier: NCT02248922

scholarly journals Impairment in inflammasome signaling by the chronic Pseudomonas aeruginosa isolates from cystic fibrosis patients results in an increase in inflammatory response

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Melissa S. Phuong ◽  
Rafael E. Hernandez ◽  
Daniel J. Wolter ◽  
Lucas R. Hoffman ◽  
Subash Sad
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Cell Death ◽  
Inflammatory Cytokines ◽  
Immune Cell ◽  
Host Cells ◽  
Respiratory Pathogen ◽  
Cell Death Pathways ◽  
The Relationship

AbstractPseudomonas aeruginosa is a common respiratory pathogen in cystic fibrosis (CF) patients which undergoes adaptations during chronic infection towards reduced virulence, which can facilitate bacterial evasion of killing by host cells. However, inflammatory cytokines are often found to be elevated in CF patients, and it is unknown how chronic P. aeruginosa infection can be paradoxically associated with both diminished virulence in vitro and increased inflammation and disease progression. Thus, we investigated the relationship between the stimulation of inflammatory cell death pathways by CF P. aeruginosa respiratory isolates and the expression of key inflammatory cytokines. We show that early respiratory isolates of P. aeruginosa from CF patients potently induce inflammasome signaling, cell death, and expression of IL-1β by macrophages, yet little expression of other inflammatory cytokines (TNF, IL-6 and IL-8). In contrast, chronic P. aeruginosa isolates induce relatively poor macrophage inflammasome signaling, cell death, and IL-1β expression but paradoxically excessive production of TNF, IL-6 and IL-8 compared to early P. aeruginosa isolates. Using various mutants of P. aeruginosa, we show that the premature cell death of macrophages caused by virulent bacteria compromises their ability to express cytokines. Contrary to the belief that chronic P. aeruginosa isolates are less pathogenic, we reveal that infections with chronic P. aeruginosa isolates result in increased cytokine induction due to their failure to induce immune cell death, which results in a relatively intense inflammation compared with early isolates.

scholarly journals Single nucleotide variants in Pseudomonas aeruginosa populations from sputum correlate with baseline lung function and predict disease progression in individuals with cystic fibrosis

2021 ◽  
Author(s):  
Morteza M Saber ◽  
Jannik Donner ◽  
Inès Levade ◽  
Nicole Acosta ◽  
Michael D Perkins ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Genetic Variation ◽  
Lung Function ◽  
Lung Disease ◽  
Disease Severity ◽  
Single Nucleotide Variants ◽  
Lung Function Decline ◽  
Single Nucleotide ◽  
Lung Disease Severity

Complex polymicrobial communities inhabit the lungs of individuals with cystic fibrosis (CF) and contribute to the decline in lung function. However, the severity of lung disease and its progression in CF patients are highly variable and imperfectly predicted by host clinical factors at baseline, CFTR mutations in the host genome, or sputum polymicrobial community variation. The opportunistic pathogen Pseudomonas aeruginosa (Pa) dominates airway infections in the majority of CF adults. Here we hypothesized that genetic variation within Pa populations would be predictive of lung disease severity. To quantify Pa genetic variation within whole CF sputum samples, we used deep amplicon sequencing on a newly developed custom Ion AmpliSeq panel of 209 Pa genes previously associated with the host pathoadaptation and pathogenesis of CF infection. We trained machine learning models using Pa single nucleotide variants (SNVs), clinical and microbiome diversity data to classify lung disease severity at the time of sputum sampling, and to predict future lung function decline over five years in a cohort of 54 adult CF patients with chronic Pa infection. The models using Pa SNVs alone classified baseline lung disease with good sensitivity and specificity, with an area under the receiver operating characteristic curve (AUROC) of 0.87. While the models were less predictive of future lung function decline, they still achieved an AUROC of 0.74. The addition of clinical data to the models, but not microbiome community data, yielded modest improvements (baseline lung function: AUROC=0.92; lung function decline: AUROC=0.79), highlighting the predictive value of the AmpliSeq data. Together, our work provides a proof-of-principle that Pa genetic variation in sputum is strongly associated with baseline lung disease, moderately predicts future lung function decline, and provides insight into the pathobiology of Pa's effect on CF.

scholarly journals Early Detection of Lung Disease in Children with Cystic Fibrosis Using Lung Function

2008 ◽  
Vol 9 (3) ◽  
pp. 160-167 ◽  
Author(s):  
Sarath Ranganathan ◽  
Barry Linnane ◽  
Gary Nolan ◽  
Catherine Gangell ◽  
Graham Hall
Keyword(s):  
Cystic Fibrosis ◽  
Lung Function ◽  
Early Detection ◽  
Lung Disease

scholarly journals Prevalence and impact of oprD mutations in Pseudomonas aeruginosa strains in cystic fibrosis

2019 ◽  
Author(s):  
Laura J. Sherrard ◽  
Bryan A. Wee ◽  
Christine Duplancic ◽  
Kay A. Ramsay ◽  
Keyur A. Dave ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Function ◽  
Hazard Rate ◽  
Carbapenem Resistance ◽  
Adverse Outcomes ◽  
Nonsense Mutations ◽  
Allelic Variants ◽  
Novel Variants

ABSTRACTDefective OprD porins contribute to carbapenem resistance and may be important in Pseudomonas aeruginosa adaptation to cystic fibrosis airways. It is unclear whether oprD mutations are fixed in populations of shared strains that are transmitted between patients or whether novel variants arise during infection. We investigated oprD sequences and antimicrobial resistance of two common Australian shared strains, constructed P. aeruginosa mutants with the most common oprD allelic variants and compared characteristics between patients with or without evidence of infection with strains harbouring these variants. Our data show that three independently acquired nonsense mutations arising from a 1-base pair substitution are fixed in strain sub-lineages. These nonsense mutations are likely to contribute to reduced carbapenem susceptibility in the sub-lineages without compromising in vitro fitness. Not only was lung function worse among patients infected with strains harbouring the nonsense mutations than those without, but they also had an increased hazard rate of lung transplantation/death. Our findings further highlight that understanding adaptive changes may help to distinguish patients with greater adverse outcomes despite infection with the same strain.

scholarly journals Type-4 Phosphodiesterase (PDE4) Blockade Reduces NETosis in Cystic Fibrosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Licia Totani ◽  
Concetta Amore ◽  
Antonio Piccoli ◽  
Giuseppe Dell’Elba ◽  
Angelo Di Santo ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Disease ◽  
Pde4 Inhibitor ◽  
Free Dna ◽  
Impaired Lung Function ◽  
Cellular Integrity ◽  
Net Release

Neutrophilic inflammation is a key determinant of cystic fibrosis (CF) lung disease. Neutrophil-derived free DNA, released in the form of extracellular traps (NETs), significantly correlates with impaired lung function in patients with CF, underlying their pathogenetic role in CF lung disease. Thus, specific approaches to control NETosis of neutrophils migrated into the lungs may be clinically relevant in CF. We investigated the efficacy of phosphodiesterase (PDE) type-4 inhibitors, in vitro, on NET release by neutrophils from healthy volunteers and individuals with CF, and in vivo, on NET accumulation and lung inflammation in mice infected with Pseudomonas aeruginosa. PDE4 blockade curbed endotoxin-induced NET production and preserved cellular integrity and apoptosis in neutrophils, from healthy subjects and patients with CF, challenged with endotoxin, in vitro. The pharmacological effects of PDE4 inhibitors were significantly more evident on CF neutrophils. In a mouse model of Pseudomonas aeruginosa chronic infection, aerosol treatment with roflumilast, a selective PDE4 inhibitor, gave a significant reduction in free DNA in the BALF. This was accompanied by reduced citrullination of histone H3 in neutrophils migrated into the airways. Roflumilast-treated mice showed a significant improvement in weight recovery. Our study provides the first evidence that PDE4 blockade controls NETosis in vitro and in vivo, in CF-relevant models. Since selective PDE4 inhibitors have been recently approved for the treatment of COPD and psoriasis, our present results encourage clinical trials to test the efficacy of this class of drugs in CF.

scholarly journals Pseudomonas aeruginosa Susceptibility Patterns and Associated Clinical Outcomes in People with Cystic Fibrosis following Approval of Aztreonam Lysine for Inhalation

2020 ◽  
pp. AAC.02327-20 ◽  
Author(s):  
Claire L Keating ◽  
Jonathan B Zuckerman ◽  
Pradeep K Singh ◽  
Matthew McKevitt ◽  
Oksana Gurtovaya ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Function ◽  
Clinical Outcomes ◽  
Primary Endpoint ◽  
The United States ◽  
Study Endpoint ◽  
Primary Study ◽  
Antibiotic Exposure ◽  
Pulmonary Exacerbations

Rationale: Approval of aztreonam lysine for inhalation solution (AZLI) raised concerns that additional antibiotic exposure would potentially affect susceptibility profiles of Pseudomonas aeruginosa (PA) isolates from cystic fibrosis (CF) patients.Objective: This 5-year, prospective, observational study tracked susceptibility changes and clinical outcomes in CF patients in the United States with chronic PA infection.Methods: Sputum cultures were collected annually (2011-2016). The primary study endpoint was the proportion of subjects whose least susceptible PA isolate had an aztreonam minimum inhibitory concentration (MIC) that was >8 μg/mL (parenteral breakpoint) and increased ≥4-fold compared with the least susceptible isolate from the previous year. Annualized data for pulmonary exacerbations, hospitalizations, and FEV1% predicted were obtained from the CF Foundation Patient Registry and compared between subjects meeting/not meeting the primary endpoint.Results: 510 subjects were enrolled; 334 (65%) completed the study. A consistent proportion of evaluable subjects (13-22%) met the primary endpoint each year; and AZLI use during the previous 12 months was not associated with meeting the primary endpoint. While the annual decline in lung function was comparable for subjects meeting/not meeting the primary endpoint, more pulmonary exacerbations and hospitalizations were experienced by those who met it.Conclusions: Aztreonam susceptibility of PA remained consistent during the 5-year study. The relationship between PA isolate susceptibilities and clinical outcomes is complex; reduced susceptibility was not associated with accelerated decline in lung function, but was associated with more exacerbations and hospitalizations, likely reflecting increased overall antibiotic exposure.

scholarly journals 413. Differences in Inflammatory Mechanisms in Pseudomonas aeruginosa and Staphyloccoccus auereus Infections in Cystic Fibrosis

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S209-S209
Author(s):  
Melissa S Phuong ◽  
Rafael E Hernandez ◽  
Subash Sad
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Cell Death ◽  
Cytokine Production ◽  
Neutral Red ◽  
Chronic Infections ◽  
Neutral Red Assay ◽  
The One ◽  
The University

Abstract Background Chronic bacterial lung infections are the primary cause of morbidity and mortality in cystic fibrosis (CF). The most common CF pathogens, Pseudomonas aeruginosa (P. aeruginosa) or Staphylococcus aureus (S. aureus), are common commensal or environmental organisms that adapt to the CF lung. We sought to investigate whether adaptation from early lung colonizer to chronic pathogen alters the bacterial effects on host inflammation. Methods P. aeruginosa (n = 25) and S. aureus (n = 25) isolates from CF patients with early and chronic infections were acquired from Seattle Children’s CF. Environmental (n = 8) and clinical, non-CF P. aeruginosa (n = 8) isolates were obtained from the University of Ottawa. P. aeruginosa reference strain PA14 and PA14 transposon mutants for T3SS and flagellin were used to observe the relationship between cell death and cytokine production. We infected THP-1-derived macrophages (PMA differentiated) in vitro for 3 hours with various MOIs. We subsequently measured cell death of THP-1-derived macrophages using neutral red assay and cytokine production using ELISAs. Results Infections with PA14 mutants and non-CF P. aeruginosa isolates demonstrated that rapid cell death of THP-1-derived macrophages caused a reduction in cytokine production relative to strains that did not cause as much cell death. At 10 MOI, early P. aeruginosa isolates from CF patients induced more THP-1-derived macrophage cell death compared with chronic isolates (P < 0.0001). Chronic P. aeruginosa isolates induced greater production of TNF, IL-8, and IL-6 (P < 0.01, P < 0.0001, and P < 0.0001, respectively) compared with early strains. No difference in IL-1β production was observed. When controlling for cell death between the two groups by using heat-killed bacteria, the only difference maintained was in TNF production (P < 0.01). Between early and chronic S. aureus isolates, the one difference observed was greater IL-8 production among early isolates (P < 0.01). Conclusion Chronic P. aeruginosa isolates from CF patients induce less cell death but more TNF, IL-8, and IL-6 production compared with early isolates. This suggests that P. aeruginosa producing chronic infections induce inflammatory signals that may contribute to increased morbidity among CF patients. Disclosures All authors: No reported disclosures.

Sign in / Sign up

Export Citation Format

Share Document