Listeriolysin O-mediated calcium influx potentiates entry of Listeria monocytogenes into the human Hep-2 epithelial cell line.
To investigate factors which modulate the entry of Listeria monocytogenes into mammalian cells, we have analyzed the role of Ca(2+). We show that L. monocytogenes induced Ca(2+) transients into the human Hep-2 epithelial cell line. The nonpathogenic species L. innocua or a L. monocytogenes mutant strain defective in listeriolysin O (LLO) production was unable to induce these calcium fluxes. Addition of plasma membrane calcium channel antagonists or chelation of extracellular calcium markedly reduced L. monocytogenes entry. In contrast, chelation of host cytosolic Ca(2+) or blockade of Ca(2+) release from intracellular stores did not affect invasion. These results indicate that L. monocytogenes-induced mobilization of extracellular Ca(2+) by LLO and activation of downstream Ca(2+)-dependent signaling are required for efficient cell invasion.
Dramsi
Shaynoor
S
Unité des Interactions Bactéries-Cellules, Institut Pasteur, 75724 Paris Cedex 15, France.
Cossart
Pascale
P
D001422:Bacterial Adhesion; D001427:Bacterial Toxins; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D004533:Egtazic Acid / Q000494:pharmacology; D004847:Epithelial Cells / Q000382:microbiology; D006360:Heat-Shock Proteins / Q000502:physiology*; D006460:Hemolysin Proteins; D006801:Humans; D008089:Listeria monocytogenes / Q000502:physiology*
D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D004533:Egtazic Acid; C038705:hlyA protein, Listeria monocytogenes; D002118:Calcium