Neutrophil recruitment in Clostridium difficile toxin A enteritis in the rabbit

J Clin Invest. 1994 Mar;93(3):1257-65. doi: 10.1172/JCI117080.


Neutrophil infiltration is a prominent feature of Clostridium difficile-associated enteritis and colitis. The aim of this study was to examine the importance of neutrophil recruitment and neutrophil-mediated tissue damage in C. difficile toxin A-induced enteritis. Competitive binding experiments using purified 3H-toxin A demonstrated the presence of a single class of medium affinity receptors on rabbit neutrophils (Kd 7 x 10(-8) M). Pertussis toxin and the nonhydrolyzable GTP analog GTPgamma S both inhibited 3H-toxin A binding (by 56 and 65%, respectively), indicating that the rabbit neutrophil toxin A receptor is G protein linked. Toxin A elicited a dose-dependent (25-200 micrograms/ml) stimulation of neutrophil migration in vitro, and this functional effect was also pertussis toxin sensitive (69% inhibition). Treatment of neutrophils with R15.7, a blocking monoclonal antibody to the leuocyte adhesion molecule CD18, inhibited toxin A-stimulated neutrophil migration by 85% in vitro. Pretreatment of rabbits with R15.7 also prevented neutrophil infiltration of toxin A-exposed ileal loops in vivo as determined by histologic examination and by ileal tissue myeloperoxidase levels. Furthermore, R15.7 effected a substantial inhibition of fluid secretion (by 65%), mannitol permeability (by 66%), and histologic damage in toxin A-exposed ileal loops. Anti-CD18 (R15.7) had no inhibitory effect on cholera toxin enterotoxicity. These data demonstrate that C. difficile toxin A is a proinflammatory toxin whose enterotoxic effects are substantially dependent upon neutrophil recruitment.

Publication types

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

MeSH terms

  • Animals
  • Antigens, CD / physiology
  • Bacterial Toxins / toxicity*
  • CD18 Antigens
  • Clostridioides difficile / pathogenicity*
  • Enteritis / blood
  • Enteritis / etiology*
  • Enterotoxins / metabolism
  • Enterotoxins / toxicity*
  • GTP-Binding Proteins / physiology
  • Male
  • Neutrophils / drug effects*
  • Neutrophils / metabolism
  • Rabbits


  • Antigens, CD
  • Bacterial Toxins
  • CD18 Antigens
  • Enterotoxins
  • tcdA protein, Clostridium difficile
  • GTP-Binding Proteins