Pseudomonas aeruginosa breaches respiratory epithelia through goblet cell invasion in a microtissue model

Nat Microbiol. 2024 Jul;9(7):1725-1737. doi: 10.1038/s41564-024-01718-6. Epub 2024 Jun 10.

Abstract

Pseudomonas aeruginosa, a leading cause of severe hospital-acquired pneumonia, causes infections with up to 50% mortality rates in mechanically ventilated patients. Despite some knowledge of virulence factors involved, it remains unclear how P. aeruginosa disseminates on mucosal surfaces and invades the tissue barrier. Using infection of human respiratory epithelium organoids, here we observed that P. aeruginosa colonization of apical surfaces is promoted by cyclic di-GMP-dependent asymmetric division. Infection with mutant strains revealed that Type 6 Secretion System activities promote preferential invasion of goblet cells. Type 3 Secretion System activity by intracellular bacteria induced goblet cell death and expulsion, leading to epithelial rupture which increased bacterial translocation and dissemination to the basolateral epithelium. These findings show that under physiological conditions, P. aeruginosa uses coordinated activity of a specific combination of virulence factors and behaviours to invade goblet cells and breach the epithelial barrier from within, revealing mechanistic insight into lung infection dynamics.

MeSH terms

  • Bacterial Translocation
  • Cyclic GMP / analogs & derivatives
  • Cyclic GMP / metabolism
  • Goblet Cells* / metabolism
  • Goblet Cells* / microbiology
  • Humans
  • Organoids / microbiology
  • Pseudomonas Infections* / microbiology
  • Pseudomonas aeruginosa* / genetics
  • Pseudomonas aeruginosa* / pathogenicity
  • Pseudomonas aeruginosa* / physiology
  • Respiratory Mucosa* / cytology
  • Respiratory Mucosa* / microbiology
  • Type III Secretion Systems / genetics
  • Type III Secretion Systems / metabolism
  • Type VI Secretion Systems / genetics
  • Type VI Secretion Systems / metabolism
  • Virulence Factors / genetics
  • Virulence Factors / metabolism

Substances

  • Type VI Secretion Systems
  • Virulence Factors
  • Type III Secretion Systems
  • Cyclic GMP
  • bis(3',5')-cyclic diguanylic acid