Functional Consequences of Calcium Influx Promoted by Bacterial Pore-Forming Toxins

Bacterial pore-forming toxins induce a rapid and massive increase in cytosolic Ca(2+) concentration due to the formation of pores in the plasma membrane and/or activation of Ca(2+)-channels. As Ca(2+) is an essential messenger in cellular signaling, a sustained increase in Ca(2+) concentration has dramatic consequences on cellular behavior, eventually leading to cell death. However, host cells have adapted mechanisms to protect against Ca(2+) intoxication, such as Ca(2+) efflux and membrane repair. The final outcome depends upon the nature and concentration of the toxin and on the cell type. This review highlights the repercussions of Ca(2+) overload on the induction of cell death, repair mechanisms, cellular adhesive properties, and the inflammatory response.