Vibrio cholerae derived outer membrane vesicles modulate the inflammatory response of human intestinal epithelial cells by inducing microRNA-146a

Sci Rep. 2019 May 10;9(1):7212. doi: 10.1038/s41598-019-43691-9.

Abstract

The small intestinal epithelium of Vibrio cholerae infected patients expresses the immunomodulatory microRNAs miR-146a and miR-155 at acute stage of disease. V. cholerae release outer membrane vesicles (OMVs) that serve as vehicles for translocation of virulence factors including V. cholerae cytolysin (VCC). The aim was to investigate whether OMVs, with and/or without VCC-cargo could be responsible for induction of microRNAs in intestinal epithelial cells and thereby contribute to immunomodulation. Polarized tight monolayers of T84 cells were challenged with OMVs of wildtype and a VCC deletion mutant of the non-O1/non-O139 (NOVC) V. cholerae strain V:5/04 and with soluble VCC. OMVs, with and without VCC-cargo, caused significantly increased levels of miR-146a. Increase was seen already after 2 hours challenge with OMVs and persisted after 12 hours. Challenge with soluble VCC caused significant increases in interleukin-8 (IL-8), tumour necrosis factor-α (TNF-α), CCL20, IL-1β, and IRAK2 mRNA levels while challenge with OMVs did not cause increases in expression levels of any of these mRNAs. These results suggest that V. cholerae bacteria release OMVs that induce miR-146a in order to pave the way for colonization by reducing the strength of an epithelial innate immune defence reaction and also preventing inflammation in the mucosa that factors like VCC can evoke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Bacterial Proteins / pharmacology*
  • Chemokine CCL20 / genetics
  • Chemokine CCL20 / metabolism
  • Cholera / microbiology
  • Cholera / pathology
  • Epithelial Cells / cytology
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Humans
  • Immunomodulation / drug effects*
  • Interleukin-1 Receptor-Associated Kinases / genetics
  • Interleukin-1 Receptor-Associated Kinases / metabolism
  • Interleukin-8 / genetics
  • Interleukin-8 / metabolism
  • Intestines / cytology
  • MicroRNAs / metabolism*
  • Nanoparticles / chemistry
  • Perforin / metabolism
  • Perforin / pharmacology
  • Secretory Vesicles / metabolism*
  • Up-Regulation / drug effects*
  • Vibrio cholerae / metabolism*

Substances

  • Bacterial Proteins
  • Chemokine CCL20
  • Interleukin-8
  • MIRN146 microRNA, human
  • MicroRNAs
  • Perforin
  • IRAK3 protein, human
  • Interleukin-1 Receptor-Associated Kinases