Clostridium difficile toxin CDT hijacks microtubule organization and reroutes vesicle traffic to increase pathogen adherence

Proc Natl Acad Sci U S A. 2014 Feb 11;111(6):2313-8. doi: 10.1073/pnas.1311589111. Epub 2014 Jan 27.

Abstract

Clostridium difficile causes antibiotic-associated diarrhea and pseudomembranous colitis by the actions of Rho-glucosylating toxins A and B. Recently identified hypervirulent strains, which are associated with increased morbidity and mortality, additionally produce the actin-ADP-ribosylating toxin C. difficile transferase (CDT). CDT depolymerizes actin, causes formation of microtubule-based protrusions, and increases pathogen adherence. Here we show that CDT-induced protrusions allow vesicle traffic and contain endoplasmic reticulum tubules, connected to microtubules via the calcium sensor Stim1. The toxin reroutes Rab11-positive vesicles containing fibronectin, which is involved in bacterial adherence, from basolateral to the apical membrane sides in a microtubule- and Stim1-dependent manner. The data yield a model of C. difficile adherence regulated by actin depolymerization, microtubule restructuring, subsequent Stim1-dependent Ca(2+) signaling, vesicle rerouting, and secretion of ECM proteins to increase bacterial adherence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Adhesion*
  • Bacterial Toxins / toxicity*
  • Biological Transport
  • Caco-2 Cells
  • Calcium Signaling
  • Clostridioides difficile / metabolism
  • Clostridioides difficile / pathogenicity*
  • Endoplasmic Reticulum / drug effects
  • Enterotoxins / toxicity*
  • Fibronectins / metabolism
  • Humans
  • Microtubules / drug effects*

Substances

  • Bacterial Toxins
  • Enterotoxins
  • Fibronectins
  • tcdA protein, Clostridium difficile