ACTIVATION OF NF-KAPPA-B BY ADHERENT PSEUDOMONAS-AERUGINOSA IN NORMALAND CYSTIC-FIBROSIS RESPIRATORY EPITHELIAL-CELLS

PMN-dominated airway inflammation is a major component of cystic fibro sis (CF) lung disease. Epithelial cells respond to organisms such as P seudomonas aeruginosa, the major pathogen in CF, by expressing the leu kocyte chemokine IL-8, Experiments were performed using several differ ent types of respiratory epithelial cells that demonstrate that ligati on of ceramide-associated receptors on epithelial surfaces by P. aerug inosa pill is a major stimulus for the translocation of transcription factor nuclear factor (NF)-kappa B and initiation of IL-8 expression b y epithelial cells. Using electrophoretic mobility shift assays and We stern hybridizations, nuclear NF-kappa B was found shortly after epith elial cells were stimulated by either whole organisms, isolated pill, or antibody to the pilin receptor asialoGM1. IB3 cells, which express mutations in cystic fibrosis transmembrane conductance regulator (CFTR ) (Delta F508/W1282X), were noted to have significantly greater amount s of endogenous nuclear NF-kappa B, but not the transcription factor C /EBP, than CF cells corrected by episomal copies of normal CFTR (C-38) or IB3 cells grown at a permissive temperature (25 degrees C). activa tion of NF-KB and subsequent IL-8 expression in epithelial cells can r esult from activation of at least two pathways: an exogenous signaling cascade that is activated by ligation of ceramide-associated adhesins such as P. aeruginosa pilin, or endogenous stimulation, suggested to be a consequence of cell stress caused by the accumulation of mutant C FTR in the endoplasmic reticulum.