Figure 4
HO53 and HO56 enhance antimicrobial response in BCi cells but are not directly bactericidal. (a) Effect of APDs treatment on Pseudomonas aeruginosa PAO1 invasion of BCi cells. Cells were stimulated with HO53 and HO56 (both at 75 µM) for 24 h, then infected with PAO1 for 1 h and the remaining extracellular bacteria were eliminated with gentamicin (100 µg/ml) treatment for 20 min. Intracellular bacteria are presented as a percentage of colony forming units (CFU) from untreated cells (Ctrl) showed as relative PAO1 number [%]. Gentamicin at low concentration (0.5 µg/ml) was used as a positive control. (b) The direct effect of the two APDs on PAO1 in the cell culture medium (BEGM) in absence of BCi cells, presented as CFU after 1 h direct exposure. Gentamicin at low concentration (1 µg/ml) and synthetic LL-37 peptide (1 µg/ml) were used as positive controls. (c) Pseudomonas aeruginosa PAO1 growth and d) viability after 2 h co-incubation with the two APDs in Luria Bertani (LB) medium. Independent experiments of 3 ± SEM, for (a,b and d) statistical significance was calculated using one-way ANOVA with Dunnett’s multiple comparisons test while comparing to untreated group (Ctrl) or with Sidak’s multiple comparisons test while comparing to solvent control group. For (c) statistical significance was calculated using two-way ANOVA with Dunnett’s multiple comparisons test, *p < 0.05, **p < 0.01, ****p < 0.0001. Significant changes are highlighted.
