Sustained inhibition of IL-6 and IL-8 expression by decoy ODN to NF-κB delivered through respirable large porous particles in LPS-stimulated cystic fibrosis bronchial cells

Background Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Neutrophil-dominated inflammation and chronic bacterial infection are still considered the primary cause of bronchioectasis, respiratory failure and consequent death in CF patients. Activation of nuclear factor (NF)-kappa B is responsible for overproduction of cytokines, such as interleukin (IL)-6 and IL-8, in airways of CF patients. Thus, decoy oligodeoxynucleotides against NF-kappa B (dec-ODN) may limit lung inflammation in CF. In the present study, we studied the effects of dec-ODN delivered through biodegradable and respirable poly(D, L-lactide-co-glycolide) large porous particles (LPP) on IL-6 and IL-8 mRNA expression as well as NF-kappa B/DNA binding activity in cystic fibrosis cells stimulated with lipopolysaccharide (LPS) from Pseudomonas aeruginosa. Methods dec-ODN LPP were prepared by a modified double emulsion technique and characterized in terms of size, morphology, tapped density and dec-ODN loading. Human epithelial bronchial IB3-1 (CFTR-mutated) as well as S9 (CFTR-corrected) were stimulated with LPS from P. aeruginosa for 24 and 72 h in the absence or presence of naked dec-ODN or dec-ODN LPP. Results Stimulation of cells with LPS from P. aeruginosa caused an increase of IL-6 and IL-8 mRNA levels, which were significantly inhibited by dec-ODN LPP at 24 and 72 h, whereas naked dec-ODN inhibited those only at 24 h. Similar effects were exhibited by dec-ODN LPP or naked dec-ODN on NF-kappa B/DNA binding activity. Conclusions Our observations indicate that respirable biodegradable dec-ODN LPP may represent a promising strategy for inhibiting NF-kappa B transcriptional activity and related gene expression and, thus, reduce lung chronic inflammation in CF patients. Copyright (C) 2011 John Wiley & Sons, Ltd.