Nature Cell Biology
5, 720 - 726 (2003)
Published online: 6 July 2003; | doi:10.1038/ncb1021
Connexin-dependent inter-cellular communication increases invasion and dissemination of Shigella in epithelial cellsGuy Tran Van Nhieu1, Caroline Clair1, Roberto Bruzzone2, Marc Mesnil3, Philippe Sansonetti1
& Laurent Combettes41
Unité de Pathogénie Microbienne Moléculaire, Inserm U389, Institut Pasteur, 75724, Paris, France. 2
Unité de Neurovirologie et Régénération du Système Nerveux, Institut Pasteur, 75724, Paris, France. 3
Laboratoire des Biomembranes et Signalisation Cellulaire, CNRS-UMR 6558 − LBSC, Université de Poitiers, Poitiers, France. 4
Unité de Signalisation Cellulaire et Calcium, Inserm U442, IBAIC, Université de Paris-Sud, Orsay, France.
Correspondence should be addressed to Guy Tran Van Nhieu gtranvan@pasteur.fr
Shigella flexneri, the causative agent of bacillar dystentery, invades the colonic mucosa where it elicits an intense inflammatory reaction responsible for destruction of the epithelium1,
2. During cell invasion, contact with host cells activates the type-III secretion of the Shigella IpaB and IpaC proteins3,
4. IpaB and IpaC are inserted into host cell plasma membranes and trigger initial signals that result in actin polymerization, while allowing cytosolic access of other bacterial effectors that further reorganize the cytoskeleton5,
6. After internalization, Shigella moves intracellularly and forms protrusions that infect neighbouring cells, promoting bacterial dissemination across the epithelium2,
6. Here, we show that during cell invasion, Shigella induces transient peaks in intracellular calcium concentration that are dependent on a functional type-III secretory apparatus. In addition, Shigella invasion induces the opening of Connexin 26 (Cx26) hemichannels in an actin- and phospholipase-C-dependent manner, allowing release of ATP into the medium. The released ATP, in turn, increases bacterial invasion and spreading, as well as calcium signalling induced by Shigella. These results provide evidence that pathogen-induced opening of connexin channels promotes signalling events that favour bacterial invasion and dissemination.
|
