Proceedings of the National Academy of Sciences of the United States of America
Geisel School of Medicine
Recurrent Pseudomonas aeruginosa infections coupled with robust, damaging neutrophilic inflammation characterize the chronic lung disease cystic fibrosis (CF). The proresolving lipid mediator, 15-epi lipoxin A4 (15-epi LXA4), plays a critical role in limiting neutrophil activation and tissue inflammation, thus promoting the return to tissue homeostasis. Here, we show that a secreted P. aeruginosa epoxide hydrolase, cystic fibrosis transmembrane conductance regulator inhibitory factor (Cif), can disrupt 15-epi LXA4 transcellular biosynthesis and function. In the airway, 15-epi LXA4 production is stimulated by the epithelial-derived eicosanoid 14,15-epoxyeicosatrienoic acid (14,15-EET). Cif sabotages the production of 15-epi LXA4 by rapidly hydrolyzing 14,15-EET into its cognate diol, eliminating a proresolving signal that potently suppresses IL-8-driven neutrophil transepithelial migration in vitro. Retrospective analyses of samples from patients with CF supported the translational relevance of these preclinical findings. Elevated levels of Cif in bronchoalveolar lavage fluid were correlated with lower levels of 15-epi LXA4, increased IL-8 concentrations, and impaired lung function. Together, these findings provide structural, biochemical, and immunological evidence that the bacterial epoxide hydrolase Cif disrupts resolution pathways during bacterial lung infections. The data also suggest that Cif contributes to sustained pulmonary inflammation and associated loss of lung function in patients with CF.
Flitter BA, Hvorecny KL, Ono E, Eddens T, Yang J, Kwak DH, Bahl CD, Hampton TH, Morisseau C, Hammock BD, Liu X, Lee JS, Kolls JK, Levy BD, Madden DR, Bomberger JM. Pseudomonas aeruginosa sabotages the generation of host proresolving lipid mediators. Proc Natl Acad Sci U S A. 2017 Jan 3;114(1):136-141. doi: 10.1073/pnas.1610242114. Epub 2016 Dec 15. PMID: 27980032; PMCID: PMC5224368.
Dartmouth Digital Commons Citation
Flitter, Becca A.; Hvorecny, Kelli L.; Ono, Emiko; and Eddens, Taylor, "Pseudomonas Aeruginosa Sabotages the Generation of Host Proresolving Lipid Mediators" (2017). Dartmouth Scholarship. 1705.