Exposure of bronchial airway epithelial cells to elexacaftor/tezacaftor/ivacaftor, Pseudomonas aeruginosa strain PA14 and outer membrane vesicles

Elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) is highly effective treatment for many cystic fibrosis patients, at least partly because it increases CFTR mediated Cl- and HCO3- secretion by airway epithelial cells leading to improved lung function and less frequent exacerbations and hospitalizations. However, little is known about how ETI affects airway epithelial cells in ways not related to CFTR mediated Cl- and HCO3- secretion, for example how ETI affects the expression of genes other than CFTR or how ETI might affect airway cells' response to infection. It is established that CF airway cells bearing the delta F 508 mutation the CFTR gene respond characteristically differently from wild type CFTR cells, and we hypothesized that, as a highly effective CFTR modulator, ETI might make airway cells from CF donors respond to pathogen stimulation (Pseudomonas aeruginosa PA14 or outer membrane vesicles isolated from these bacteria) in more the same way that cells from wild type, healthy control cells do. We tested this hypothesis by measuring gene expression responses in polarized primary CF airway cells exposed to ETI alone or ETI in the presence of a pathogen challenge (PA14 or outer membrane vesicles). Responses of CFTR wild type primary CF airway cells to PA14 or outer membrane vesicles was also measured for comparison Overall design: Polarized primary airway epithelial cells from donors with wild type CFTR were conditionally exposed to either Pseudomonas aeruginosa strain PA14 at a multiplicity of infection of 20:1 or 2e10 outer membrane vesicles (OMV) isolated from Pseudomonas aeruginosa strain PA14 for 6 hours, or media only as a control. Polarized primary airway epithelial cells from donors homozygous for the delta F 508 CFTR mutation were conditionally exposed to elexacaftor (3 micromolar) tezacaftor (3 micromolar) ivacaftor (10 nanomolar) dissolved in DMSO or DMSO as a control for 48 hours and then conditionally exposed to either Pseudomonas aeruginosa strain PA14 at a multiplicity of infection of 20:1 or 2e10 outer membrane vesicles (OMV) isolated from Pseudomonas aeruginosa strain PA14 for 6 hours, or media only as a control.