Signaling intermediates required for NF-κB activation and IL-8 expression in CF bronchial epithelial cells

J Li, XD Johnson, S Iazvovskaia… - … of Physiology-Lung …, 2003 - journals.physiology.org
J Li, XD Johnson, S Iazvovskaia, A Tan, A Lin, MB Hershenson
American Journal of Physiology-Lung Cellular and Molecular …, 2003journals.physiology.org
Ligation of the asialoGM1 Pseudomonas aeruginosa pilin receptor has been demonstrated
to induce IL-8 expression in airway epithelial cells via an NF-κB-dependent pathway. We
examined the signaling pathways required for asialoGM1-mediated NF-κB activation in IB3
cells, a human bronchial epithelial cell line derived from a cystic fibrosis (CF) patient, and C-
38 cells, the rescued cell line that expresses a functional CF transmembrane regulator.
Ligation of the asialoGM1 receptor with specific antibody induced greater IL-8 expression in …
Ligation of the asialoGM1 Pseudomonas aeruginosa pilin receptor has been demonstrated to induce IL-8 expression in airway epithelial cells via an NF-κB-dependent pathway. We examined the signaling pathways required for asialoGM1-mediated NF-κB activation in IB3 cells, a human bronchial epithelial cell line derived from a cystic fibrosis (CF) patient, and C-38 cells, the rescued cell line that expresses a functional CF transmembrane regulator. Ligation of the asialoGM1 receptor with specific antibody induced greater IL-8 expression in IB3 cells than C-38 cells, consistent with the greater density of asialoGM1 receptors in CF phenotype cells. AsialoGM1-mediated activation of NF-κB, IκB kinase (IKK), and ERK was also greater in IB3 cells. With the use of genetic inhibitors, we found that IKK-β and NF-κB-inducing kinase are required for maximal NF-κB transactivation and transcription from the IL-8 promoter. Finally, although ERK activation was required for maximal asialoGM1-mediated IL-8 expression, inhibition of ERK signaling had no effect on IKK or NF-κB activation, suggesting that ERK regulates IL-8 expression in an NF-κB-independent manner.
American Physiological Society