Fig. 4: PAO1 ∆mexEFoprN is hypervirulent in CF infection models.
a Schematic representation of CF airway barrier dysfunction assay created using Biorender. b Transepithelial electrical resistance (TEER) of air liquid interface (ALI) cultures derived from human cystic fibrosis (CF) airways (∆F508/∆F508 CFTR) measured using STX2 chopstick electrodes. TEER < 330 Ω.cm2 (dotted line) indicates a loss in epithelial barrier function. TEER was recorded before (0 h) and at 6 h after exposure to PAO1, PAO1 ∆mexEFoprN, or PAO1 ∆mexEFoprN∆lasB∆rhlA supernatants. Data show mean ± SEM, n = 3 independent experiments. Statistical significance analyzed by ANOVA Fisher’s LSD test. c Permeability of the CF airway epithelial barrier determined using 4 kDa fluorescein isothiocyanate (FITC) labeled dextran at 6 h post exposure to PAO1, PAO1 ∆mexEFoprN, or PAO1 ∆mexEFoprN∆lasB∆rhlA supernatants. Data show mean ± SEM, n = 3 independent experiments. Statistical significance analyzed by ANOVA Fisher’s LSD test. d Schematic representation of chronic lung infections in Scnn1b-Tg mice created using Biorender. e Bacterial CFU enumerated on day 7 from the lung homogenates of Scnn1b-Tg mice infected with PAO1 (n = 10) or PAO1 ∆mexEFoprN (n = 13) embedded in agar beads. Data show mean ± SEM. Statistical significance analyzed by two-sided unpaired t-test. f Survival curves of Scnn1b-Tg mice infected with PAO1 (n = 10) or PAO1 ∆mexEFoprN (n = 13) embedded in agar beads. Statistical significance analyzed by Mantel-Cox test. n indicates the number of mice/group. g, h Flow cytometry for total immune cells, monocyte, macrophages, and neutrophils in the lungs of PAO1 (n = 4) or PAO1 ∆mexEFoprN (n = 3) infected mice at day 7 post infection. Data show mean ± SEM. Statistical significance analyzed by two-sided unpaired t-test.
