FIG 1.

(A to D) Morphology of human bronchial epithelial cells (5-week polarized cultures grown on 0.4-μm-pore inserts) subjected to P. aeruginosa Xen5 infection and treatment with the ceragenin CSA-13. The scale bar represents 15 μm. (A) Control epithelial cells. (B) Infected epithelial cells. (C and D) Infected epithelial cells treated with 10 μM CSA-13 (C) or 30 μM CSA-13 (D) 18 h after the addition of bacteria. Green staining, F-actin; red staining, α-tubulin (cilia). (E and F) P. aeruginosa Xen5 outgrowth (E) and chemiluminescence (F) from the apical interface of human bronchial epithelial cells at different times. ▲, 2 μM LL-37; ▼, 10 μM LL-37; ♢, 30 μM LL-37; ○, 2 μM CSA-13; □, 10 μM CSA-13; ●, 30 μM CSA-13. (G to K) Chemiluminescence of Pseudomonas aeruginosa Xen5 after the addition of bacteria to the apical interface of polarized A549 cells grown for 1 week on 3-μm-pore inserts, with (right) or without (left) the presence of butyric acid (BA). One hour after inoculation of bacteria, cells were treated with CSA-13 or LL-37 peptide. After the addition of antibacterial molecules, chemiluminescence was evaluated at different time points, i.e., 1 h (G), 2 h (H), or 8 h (I), using a Fuji Film LAS-300 system. Quantitative (densitometric) analysis of chemiluminescence intensity at the epithelial surface of cells growing without (J) or with (K) butyric acid also was performed. A.U., arbitrary units. (L) Decreasing release of IL-8 from A549 lung epithelial cell monolayers growing without or with butyric acid (4 mM) and subjected to LPS (25 ng/ml) activation in the presence of CSA-13 or LL-37 peptide. Error bars, standard deviations (n = 3 to 6). *, statistically significant (P < 0.05), compared to control group/time zero.