TLR-induced inflammation in cystic fibrosis and non-cystic fibrosis airway epithelial cells.
Cystic fibrosis (CF) is a genetic disease characterized by severe neutrophil-dominated airway inflammation. An important cause of inflammation in CF is Pseudomonas aeruginosa infection. We have evaluated the importance of a number of P. aeruginosa components, namely lipopeptides, LPS, and unmethylated CpG DNA, as proinflammatory stimuli in CF by characterizing the expression and functional activity of their cognate receptors, TLR2/6 or TLR2/1, TLR4, and TLR9, respectively, in a human tracheal epithelial line, CFTE29o(-), which is homozygous for the DeltaF508 CF transmembrane conductance regulator mutation. We also characterized TLR expression and function in a non-CF airway epithelial cell line 16HBE14o(-). Using RT-PCR, we demonstrated TLR mRNA expression. TLR cell surface expression was assessed by fluorescence microscopy. Lipopeptides, LPS, and unmethylated CpG DNA induced IL-8 and IL-6 protein production in a time- and dose-dependent manner. The CF and non-CF cell lines were largely similar in their TLR expression and relative TLR responses. ICAM-1 expression was also up-regulated in CFTE29o(-) cells following stimulation with each agonist. CF bronchoalveolar lavage fluid, which contains LPS, bacterial DNA, and neutrophil elastase (a neutrophil-derived protease that can activate TLR4), up-regulated an NF-kappaB-linked reporter gene and increased IL-8 protein production in CFTE29o(-) cells. This effect was abrogated by expression of dominant-negative versions of MyD88 or Mal, key signal transducers for TLRs, thereby implicating them as potential anti-inflammatory agents for CF.
Greene
Catherine M
CM
Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland. cmgreene@rcsi.ie
Carroll
Tomás P
TP
Smith
Stephen G J
SG
Taggart
Clifford C
CC
Devaney
James
J
Griffin
Siobhan
S
O'neill
Shane J
SJ
McElvaney
Noel G
NG
D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D002460:Cell Line; D018899:CpG Islands / Q000502:physiology; D003550:Cystic Fibrosis / Q000276:immunology* / Q000382:microbiology / Q000473:pathology*; D006801:Humans; D018836:Inflammation Mediators / Q000819:agonists / Q000502:physiology*; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D055666:Lipopeptides; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008074:Lipoproteins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000819:agonists / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D009842:Oligopeptides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011552:Pseudomonas Infections / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D011956:Receptors, Cell Surface / Q000819:agonists / Q000096:biosynthesis / Q000502:physiology*; D011971:Receptors, Immunologic / Q000235:genetics / Q000502:physiology; D017472:Receptors, Interleukin-1; D020545:Respiratory Mucosa / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D020298:U937 Cells; D015854:Up-Regulation
D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; D001426:Bacterial Proteins; C408982:CPG-oligonucleotide; D018836:Inflammation Mediators; D015850:Interleukin-6; D016209:Interleukin-8; D055666:Lipopeptides; D008070:Lipopolysaccharides; D008074:Lipoproteins; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D009838:Oligodeoxyribonucleotides; D009842:Oligopeptides; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; C434984:TIRAP protein, human; C495342:TLR2 protein, human; C495345:TLR4 protein, human; C495371:TLR9 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D018799:Intercellular Adhesion Molecule-1; C106335:macrophage stimulatory lipopeptide 2