title: Role of the cystic fibrosis transmembrane conductance regulator in internalization of Pseudomonas aeruginosa by polarized respiratory epithelial cells.
abstract: Pseudomonas aeruginosa is an important human pathogen, producing lung infection in individuals with cystic fibrosis (CF), patients who are ventilated and those who are neutropenic. The respiratory epithelium provides the initial barrier to infection. Pseudomonas aeruginosa can enter epithelial cells, although the mechanism of entry and the role of intracellular organisms in its life cycle are unclear. We devised a model of infection of polarized human respiratory epithelial cells with P. aeruginosa and investigated the role of the cystic fibrosis transmembrane conductance regulator (CFTR) in adherence, uptake and IL-8 production by human respiratory epithelial cells. We found that a number of P. aeruginosa strains could invade and replicate within cells derived from a patient with CF. Intracellular bacteria did not produce host cell cytotoxicity over a period of 24 h. When these cells were transfected with wild-type CFTR, uptake of bacteria was significantly reduced and release of IL-8 following infection enhanced. We propose that internalized P. aeruginosa may play an important role in the pathogenesis of infection and that, by allowing greater internalization into epithelial cells, mutant CFTR results in an increased susceptibility of bronchial infection with this microbe.
authors.affiliation: Department of Infectious Diseases, Faculty of Medicine, Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
authors.forename: Katharine E A
authors.initials: KE
authors.lastname: Darling
authors.forename: Ann
authors.initials: A
authors.lastname: Dewar
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Evans
mesh_terms: D017209:Apoptosis; D001422:Bacterial Adhesion; D002460:Cell Line; D016764:Cell Polarity; D015169:Colony Count, Microbial; D003550:Cystic Fibrosis / Q000382:microbiology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics* / Q000378:metabolism*; D003593:Cytoplasm / Q000382:microbiology; D004847:Epithelial Cells / Q000382:microbiology* / Q000648:ultrastructure; D017353:Gene Deletion; D006801:Humans; D016209:Interleukin-8 / Q000032:analysis / Q000096:biosynthesis; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000502:physiology*; D020545:Respiratory Mucosa / Q000382:microbiology* / Q000648:ultrastructure
chemical_list: C505032:CFTR protein, human; D016209:Interleukin-8; D019005:Cystic Fibrosis Transmembrane Conductance Regulator