Abstract
Methods
Primary epithelial cells from one healthy and one CF donor were cultured under Air-Liquid Interface (ALI) conditions and colonized either with the laboratory strain PAO1, or with a less virulent isogenic Type III ΔpscC strain. Co-infections with the BCi-NS1.1 cell line were used as controls. Morphological and functional changes of the differentiated ALI cultureswere monitored byepithelial integrity, and cytokine secretion over 14 hs of infection. Bacterial and host tissue responses were further characterized through dual-species transcriptomics.
Results
Epithelial integrity measurements showed a virulent phenotype of PAO1, which in the ΔpscC strain was significantly dampened. In contrast, levels of cytokine IL-8 were increased upon colonization of the ALI cultures with both strains. Notably, the global gene expression profile as determined in uninfected ALI cultures from primary cells was highly different from that determined in control cultures. Upon colonization with PAO1, CF cells showed a significantly reduced expression of pathogen-associated factors in comparison to healthy cells and control cells. Regarding bacterial gene expression, no differences were found comparing the co-cultures infections with healthy primary cells or the control. Strikingly, upon colonization of the CF epithelium, both PAO1 and ΔpscC showed downregulation of different quorum sensing signaling pathways.
Conclusions
During the initial co-culture period, PA can sense the CF environment and shut down its virulent repertoire. This led to less hyperactivation of the immune response in the CF cells. Our infection model thus captures a snapshot of the interplay between PA and lung cells and recapitulates some of the features from in vivo CF lung infections.
Primary epithelial cells from one healthy and one CF donor were cultured under Air-Liquid Interface (ALI) conditions and colonized either with the laboratory strain PAO1, or with a less virulent isogenic Type III ΔpscC strain. Co-infections with the BCi-NS1.1 cell line were used as controls. Morphological and functional changes of the differentiated ALI cultureswere monitored byepithelial integrity, and cytokine secretion over 14 hs of infection. Bacterial and host tissue responses were further characterized through dual-species transcriptomics.
Results
Epithelial integrity measurements showed a virulent phenotype of PAO1, which in the ΔpscC strain was significantly dampened. In contrast, levels of cytokine IL-8 were increased upon colonization of the ALI cultures with both strains. Notably, the global gene expression profile as determined in uninfected ALI cultures from primary cells was highly different from that determined in control cultures. Upon colonization with PAO1, CF cells showed a significantly reduced expression of pathogen-associated factors in comparison to healthy cells and control cells. Regarding bacterial gene expression, no differences were found comparing the co-cultures infections with healthy primary cells or the control. Strikingly, upon colonization of the CF epithelium, both PAO1 and ΔpscC showed downregulation of different quorum sensing signaling pathways.
Conclusions
During the initial co-culture period, PA can sense the CF environment and shut down its virulent repertoire. This led to less hyperactivation of the immune response in the CF cells. Our infection model thus captures a snapshot of the interplay between PA and lung cells and recapitulates some of the features from in vivo CF lung infections.
| Original language | English |
|---|---|
| Journal | Journal of Cystic Fibrosis |
| Volume | 23 |
| Pages (from-to) | S41 |
| ISSN | 1569-1993 |
| DOIs | |
| Publication status | Published - 2024 |