Clostridioides difficile infection damages colonic stem cells via TcdB, impairing epithelial repair and recovery from disease

Proc Natl Acad Sci U S A. 2020 Apr 7;117(14):8064-8073. doi: 10.1073/pnas.1915255117. Epub 2020 Mar 20.

Abstract

Gastrointestinal infections often induce epithelial damage that must be repaired for optimal gut function. While intestinal stem cells are critical for this regeneration process [R. C. van der Wath, B. S. Gardiner, A. W. Burgess, D. W. Smith, PLoS One 8, e73204 (2013); S. Kozar et al., Cell Stem Cell 13, 626-633 (2013)], how they are impacted by enteric infections remains poorly defined. Here, we investigate infection-mediated damage to the colonic stem cell compartment and how this affects epithelial repair and recovery from infection. Using the pathogen Clostridioides difficile, we show that infection disrupts murine intestinal cellular organization and integrity deep into the epithelium, to expose the otherwise protected stem cell compartment, in a TcdB-mediated process. Exposure and susceptibility of colonic stem cells to intoxication compromises their function during infection, which diminishes their ability to repair the injured epithelium, shown by altered stem cell signaling and a reduction in the growth of colonic organoids from stem cells isolated from infected mice. We also show, using both mouse and human colonic organoids, that TcdB from epidemic ribotype 027 strains does not require Frizzled 1/2/7 binding to elicit this dysfunctional stem cell state. This stem cell dysfunction induces a significant delay in recovery and repair of the intestinal epithelium of up to 2 wk post the infection peak. Our results uncover a mechanism by which an enteric pathogen subverts repair processes by targeting stem cells during infection and preventing epithelial regeneration, which prolongs epithelial barrier impairment and creates an environment in which disease recurrence is likely.

Keywords: Clostridium difficile; gut infection; infection; stem cell damage; toxins.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bacterial Proteins / metabolism*
  • Bacterial Proteins / toxicity
  • Bacterial Toxins / metabolism*
  • Bacterial Toxins / toxicity
  • Cells, Cultured
  • Clostridioides difficile / metabolism
  • Clostridioides difficile / pathogenicity*
  • Clostridium Infections / microbiology
  • Clostridium Infections / pathology*
  • Colon / cytology
  • Colon / microbiology
  • Colon / pathology*
  • Disease Models, Animal
  • Female
  • Frizzled Receptors / genetics
  • Frizzled Receptors / metabolism
  • Humans
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / microbiology
  • Intestinal Mucosa / pathology*
  • Mice
  • Organoids
  • Primary Cell Culture
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Stem Cells / microbiology
  • Stem Cells / pathology*

Substances

  • Bacterial Proteins
  • Bacterial Toxins
  • Frizzled Receptors
  • Recombinant Proteins
  • toxB protein, Clostridium difficile