lumacaftor and Pseudomonas-Infections

Cystic fibrosis (CF), the most common lethal genetic disease in Caucasians, is characterized by chronic bacterial lung infection and excessive inflammation, which lead to progressive loss of lung function and premature death. Although ivacaftor (VX-770) alone and ivacaftor in combination with lumacaftor (VX-809) improve lung function in CF patients with the Gly551Asp and del508Phe mutations, respectively, the effects of these drugs on the function of human CF macrophages are unknown. Thus studies were conducted to examine the effects of lumacaftor alone and lumacaftor in combination with ivacaftor (i.e., ORKAMBI) on the ability of human CF ( del508Phe/ del508Phe) monocyte-derived macrophages (MDMs) to phagocytose and kill Pseudomonas aeruginosa. Lumacaftor alone restored the ability of CF MDMs to phagocytose and kill P. aeruginosa to levels observed in MDMs obtained from non-CF (WT-CFTR) donors. This effect contrasts with the partial (~15%) correction of del508Phe Cl

Topics: Aminophenols; Aminopyridines; Benzodioxoles; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Drug Combinations; Forced Expiratory Volume; Humans; Macrophages; Mutation; Phagocytosis; Pseudomonas aeruginosa; Pseudomonas Infections; Quinolones

Cystic fibrosis patients exhibit chronic Pseudomonas aeruginosa respiratory infections and sustained proinflammatory state favoring lung tissue damage and remodeling, ultimately leading to respiratory failure. Loss of cystic fibrosis transmembrane conductance regulator (CFTR) function is associated with MAPK hyperactivation and increased cytokines expression, such as interleukin-8 [chemoattractant chemokine (C-X-C motif) ligand 8 (CXCL8)]. Recently, new therapeutic strategies directly targeting the basic CFTR defect have been developed, and ORKAMBI (Vx-809/Vx-770 combination) is the only Food and Drug Administration-approved treatment for CF patients homozygous for the F508del mutation. Here we aimed to determine the effect of the Vx-809/Vx-770 combination on the induction of the inflammatory response by fully differentiated primary bronchial epithelial cell cultures from CF patients carrying F508del mutations, following exposure to P. aeruginosa exoproducts. Our data unveiled that CFTR functional rescue with Vx-809/Vx-770 drastically reduces CXCL8 (as well as CXCL1 and CXCL2) transcripts and p38 MAPK phosphorylation in response to P. aeruginosa exposure through a CFTR-dependent mechanism. These results suggest that ORKAMBI has anti-inflammatory properties that could decrease lung inflammation and contribute to the observed beneficial impact of this treatment in CF patients.

Topics: Aminophenols; Aminopyridines; Benzodioxoles; Bronchi; Cells, Cultured; Chloride Channel Agonists; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Epithelial Cells; Humans; Interleukin-8; Mutation; Pseudomonas aeruginosa; Pseudomonas Infections; Quinolones

The function of cystic fibrosis transmembrane conductance regulator (CFTR) channels is crucial in human airways. However unfortunately, chronic

Topics: Aminopyridines; Bacterial Proteins; Benzodioxoles; Cell Line; Cells, Cultured; Child; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Down-Regulation; Epithelial Cells; Gene Expression Regulation, Bacterial; Humans; Infant; Mutation; Piperazines; Pseudomonas aeruginosa; Pseudomonas Infections; Quinazolines; Quorum Sensing; Respiratory System; Trans-Activators

The tumor suppressor PTEN controls cell proliferation by regulating phosphatidylinositol-3-kinase (PI3K) activity, but the participation of PTEN in host defense against bacterial infection is less well understood. Anti-inflammatory PI3K-Akt signaling is suppressed in patients with cystic fibrosis (CF), a disease characterized by hyper-inflammatory responses to airway infection. We found that Ptenl

Topics: Aminophenols; Aminopyridines; Animals; Benzodioxoles; Cell Membrane; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Gene Expression Regulation; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; Models, Molecular; Monocytes; Phosphatidylinositol 3-Kinases; Protein Binding; Protein Conformation; Protein Transport; Proto-Oncogene Proteins c-akt; Pseudomonas aeruginosa; Pseudomonas Infections; PTEN Phosphohydrolase; Quinolones; Signal Transduction

P. aeruginosa is an opportunistic pathogen that chronically infects the lungs of 85% of adult patients with Cystic Fibrosis (CF). Previously, we demonstrated that P. aeruginosa reduced wt-CFTR Cl secretion by airway epithelial cells. Recently, a new investigational drug VX-809 has been shown to increase F508del-CFTR Cl secretion in human bronchial epithelial (HBE) cells, and, in combination with VX-770, to increase FEV1 (forced expiratory volume in 1 second) by an average of 3-5% in CF patients homozygous for the F508del-CFTR mutation. We propose that P. aeruginosa infection of CF lungs reduces VX-809 + VX-770- stimulated F508del-CFTR Cl secretion, and thereby reduces the clinical efficacy of VX-809 + VX-770.. F508del-CFBE cells and primary cultures of CF-HBE cells (F508del/F508del) were exposed to VX-809 alone or a combination of VX-809 + VX-770 for 48 hours and the effect of P. aeruginosa on F508del-CFTR Cl secretion was measured in Ussing chambers. The effect of VX-809 on F508del-CFTR abundance was measured by cell surface biotinylation and western blot analysis. PAO1, PA14, PAK and 6 clinical isolates of P. aeruginosa (3 mucoid and 3 non-mucoid) significantly reduced drug stimulated F508del-CFTR Cl secretion, and plasma membrane F508del-CFTR.. The observation that P. aeruginosa reduces VX-809 and VX-809 + VX-770 stimulated F508del CFTR Cl secretion may explain, in part, why VX-809 + VX-770 has modest efficacy in clinical trials.

Topics: Aminopyridines; Benzodioxoles; Bronchi; Cell Line; Cell Membrane; Chlorides; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; DNA-Binding Proteins; Epithelial Cells; Humans; Mutation; Nuclear Proteins; Pseudomonas aeruginosa; Pseudomonas Infections; Transcription Factors