Submitted on February 2, 2009
Revised on March 30, 2009
Accepted on April 7, 2009
Listeriolysin O affects barrier function and induces chloride secretion in HT-29/B6 colon epithelial cells
Jan F Richter1, Alfred H Gitter2, Dorothee Günzel1, Siegfried Weiss3, Walid Mohamed4, Trinad Chakraborty4, Michael Fromm5, and Jörg D. Schulzke6*
1 Charité Berlin
2 University of Applied Sciences Jena
3 HZI Braunschweig
4 Justus Liebig University Giessen
5 Charite, Campus Benjamin Franklin
6 Charité
* To whom correspondence should be addressed. E-mail: joerg.schulzke{at}charite.de.
Listeria monocytogenes is a foodborne pathogen, which is able to induce diarrhea when residing in the intestine. We studied the effect of listeriolysin O (LLO), an extracellular virulence factor of L. monocytogenes, on intestinal transport and barrier function in HT-29/B6 cell monolayers using the Ussing technique, in order to understand the pathomechanisms involved. Mucosal addition of LLO, but not a LLO-mutant, induced a dose- and pH-dependent increase in short circuit-current (Isc). Sodium and chloride tracer flux and DIDS-sensitivity studies revealed that the ISC is mainly due to electrogenic chloride secretion. Barrier function was impaired by LLO as assessed by transepithelial resistance (Rt) and mannitol flux measurements. Intracellular signal transduction occurred through Ca2+ release from intracellular stores and PKC activation. In conclusion, listeriolysin induces chloride secretion and perturbs epithelial barrier function, thus potentially contributing to Listeria-induced diarrhea.
