Type IV B pili are required for invasion but not for adhesion of Salmonella enterica serovar Typhi into BHK epithelial cells in a cystic fibrosis transmembrane conductance regulator-independent manner

Denisse Bravo, Carlos J. Blondel, Anilei Hoare, Lisette Leyton, Miguel A. Valvano, Inés Contreras

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

The cystic fibrosis transmembrane conductance regulator (CFTR) has been proposed as an epithelial cell receptor for the entry of Salmonella Typhi but not Salmonella Typhimurium. The bacterial ligand recognized by CFTR is thought to reside either in the S. Typhi lipopolysaccharide core region or in the type IV pili. Here, we assessed the ability of virulent strains of S. Typhi and S. Typhimurium to adhere to and invade BHK epithelial cells expressing either the wild-type CFTR protein or the ΔF508 CFTR mutant. Both S. Typhi and S. Typhimurium invaded the epithelial cells in a CFTR-independent fashion. Furthermore and also in a CFTR-independent manner, a S. Typhi pilS mutant adhered normally to BHK cells but displayed a 50% reduction in invasion as compared to wild-type bacteria. Immunofluorescence microscopy revealed that bacteria and CFTR do not colocalize at the epithelial cell surface. Together, our results strongly argue against the established dogma that CFTR is a receptor for entry of Salmonella to epithelial cells.

Original languageEnglish
Pages (from-to)373-377
Number of pages5
JournalMicrobial Pathogenesis
Volume51
Issue number5
DOIs
Publication statusPublished - 1 Nov 2011

Keywords

  • Cystic fibrosis transmembrane conductance regulator
  • Epithelial cell invasion
  • Lipopolysaccharide
  • Salmonella
  • Type IV pili

ASJC Scopus subject areas

  • Microbiology
  • Infectious Diseases

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