Browsing by Subject "cystic fibrosis (CF)"

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    Development of a New in vitro System for Cystic Fibrosis Research
    (Office of the Vice Chancellor for Research, 2013-04-05) Coffey, Barbara M.; Anderson, Gregory G.
    Individuals with cystic fibrosis (CF) have a life expectancy of 40 years and require daily treatments to mitigate the effects of the disease. CF impacts organs throughout the body, especially the lungs, where thick mucus builds up, impairs breathing, and provides an environment for bacterial growth. Chronic lung infection is the leading cause of mortality in CF. The majority of CF lung infections are caused by Pseudomonas aeruginosa, a common bacterium which typically does not cause disease in healthy individuals. In the CF lung, however, P. aeruginosa burrows into the thick mucus layer, evades the immune system, and resists antibiotic therapy by encasing itself in a protective matrix called a biofilm. Laboratory methods for studying biofilm are not true replicas of the CF lung environment, leaving a knowledge gap between how bacteria grow in a test tube (in vitro) and how they grow in the lungs of a person with CF. The focus of this work is to develop an improved laboratory model which combines artificial sputum (as a surrogate for mucus in the CF lung) and cultured CF airway epithelial cells. To assess the potential of this model, we have performed experiments to compare P. aeruginosa in artificial sputum versus standard laboratory media. Results demonstrate that P. aeruginosa in artificial sputum exhibits differences in growth, biofilm formation, toxin production, cytotoxicity, and protein expression, compared to results in standard media. These data suggest that our model system can contribute new information to the understanding of CF airway infection. The aim of future studies is to use this system to identify sputum components and bacterial proteins which have not been recognized previously by standard methods. It is our ultimate goal to contribute knowledge leading to improved longevity and quality of life for people with CF.
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    Going After Lipotoxins to Reduce Inflammation in the Airway of Cystic Fibrosis Patients
    (Office of the Vice Chancellor for Research, 2013-04-05) Akhand, Saeed S.; Anderson, Gregory G.
    People with cystic fibrosis (CF) typically have chronic lung infections, predominantly with Pseudomonas aeruginosa. Lung inflammation, in connection with bacterial colonization, is one of the major factors contributing to the morbidity and mortality of CF patients. Recent studies suggest that a common mutation among CF P. aeruginosa isolates (in the gene mucA) results in high-level expression of lipoproteins which stimulates a pro-inflammatory reaction in cultured CF-derived airways cell (CFBE). Our previous work in this area has revealed that a strain containing a mutation in the putative lipotoxin gene PA4326 is dramatically less toxic to CFBE. We hypothesize that lipotoxins lead to airway structure damage by causing epithelial cell death and tissue destruction, possibly as a downstream effect of immune stimulation. Our results demonstrate that deletion of the PA4326 gene does not affect growth, motility, adhesion, or biofilm development. However, this mutant strain produces 59.1% less pyocyanin compared to the non-mutant strain. Pyocyanin is a bacterial toxin that triggers airway inflammation by stimulating the immune system to produce the signaling molecule IL-8. Thus, our data suggest a possible clue about the decreased toxicity of the PA4325 mutant. The aim of future work is to confirm the role of this lipotoxin gene in the inflammatory process and to elucidate the underlying mechanism of its function. Our long term goal is to characterize other lipotoxins and to develop a novel inhibitor of lspA (a bacterial gene required for lipotoxin production) as an anti-inflammatory strategy to slow down the airway damage and hence improve the longevity and quality of life for people with CF.