Description

Listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a host vacuolar compartment and grows rapidly in the cytosol. Listeriolysin O (LLO), one of its major virulence factors, is a secreted pore-forming protein essential for the escape of L. monocytogenes from the vacuole formed upon initial internalization.In addition, LLO influences the levels of intracellular calcium and stimulates phosphoinositide metabolism to favour bacterial entry. It is also a potent aggregator of lipid rafts and suppresses the host immune response. Phagosomal membrane disruption is enhanced by the bacterial phosphatidylinositol-specific and broad-range phospholipases C, PI-PLC (plcA) and PC-PLC (plcB), respectively. Enzymes cooperate with LLO in the lysis of primary and secondary vacuoles.