Dendritic Cells Express Tight Junction Proteins and Penetrate Gut Epithelial Monolayers to Sample Bacteria

Nat Immunol. 2001 Apr;2(4):361-7. doi: 10.1038/86373.

Abstract

Penetration of the gut mucosa by pathogens expressing invasion genes is believed to occur mainly through specialized epithelial cells, called M cells, that are located in Peyer's patches. However, Salmonella typhimurium that are deficient in invasion genes encoded by Salmonella pathogenicity island 1 (SPI1) are still able to reach the spleen after oral administration. This suggests the existence of an alternative route for bacterial invasion, one that is independent of M cells. We report here a new mechanism for bacterial uptake in the mucosa tissues that is mediated by dendritic cells (DCs). DCs open the tight junctions between epithelial cells, send dendrites outside the epithelium and directly sample bacteria. In addition, because DCs express tight-junction proteins such as occludin, claudin 1 and zonula occludens 1, the integrity of the epithelial barrier is preserved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caco-2 Cells
  • Cell Line
  • Coculture Techniques
  • Dendritic Cells / immunology*
  • Dendritic Cells / metabolism
  • Dendritic Cells / ultrastructure*
  • Digestive System / immunology*
  • Digestive System / microbiology*
  • Epithelial Cells / immunology
  • Epithelial Cells / microbiology
  • Epithelial Cells / ultrastructure
  • Humans
  • Intestinal Mucosa / immunology
  • Intestinal Mucosa / microbiology
  • Membrane Proteins / metabolism
  • Mice
  • Microscopy, Electron
  • Models, Biological
  • Salmonella typhimurium / immunology
  • Salmonella typhimurium / pathogenicity
  • Tight Junctions / immunology*
  • Tight Junctions / metabolism
  • Tight Junctions / ultrastructure

Substances

  • Membrane Proteins