Previous Article | Next Article ![]()
Infect Immun, June 1998, p. 2660-2665, Vol. 66, No. 6
Department of Ultrastructures, Istituto
Superiore di Sanità, 00161 Rome, Italy
Received 19 December 1997/Returned for modification 13 February
1998/Accepted 30 March 1998
Toxigenic strains of the anaerobic bacterium Clostridium
difficile produce at least two large, single-chain protein
exotoxins involved in the pathogenesis of antibiotic-associated
diarrhea and colitis. Toxin A (CdA) is a cytotoxic enterotoxin, while
toxin B (CdB) is a more potent cytotoxin lacking enterotoxic activity. This study dealt with CdB, providing the first evidence that intestinal cells exposed to this toxin exhibit typical features of apoptosis in
that a significant proportion of the treated cells displayed nuclear
fragmentation and chromatin condensation. In keeping with ultrastructural data, CdB-treated cells showed the typical flow cytometric hallmark of apoptosis consisting of a distinct
sub-G1 peak. The CdB-induced apoptotic response was dose
and time dependent and not simply due to the actin-disrupting effect of
the toxin or to the subsequent impairment of cell anchorage. Rather,
the inhibition of proteins belonging to the Rho family due to CdB seems
to play a role in the induction of apoptosis in intestinal cells. The
origin of cells and the growth rate may also be cofactors relevant to such a response.
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Clostridium difficile Toxin B Induces
Apoptosis in Intestinal Cultured Cells
*
Corresponding author. Mailing address: Department of
Ultrastructures, Istituto Superiore di Sanità, Viale Regina
Elena 299, 00161 Rome, Italy. Phone: 39-6-49903006. Fax:
39-6-49387140. E-mail: fiorentini{at}ul.net.iss.it.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|