The use of host cell machinery in the pathogenesis of Listeria monocytogenes

The bacterial pathogen, Listeria monocytogenes, exploits the host cell's ma chinery, enabling the pathogen to enter into cells and spread from cell to cell. Three bacterial surface proteins are crucial for these processes: int ernalin and InIB, which mediate entry into cells, and ActA, which induces a ctin polymerisation at one pole of the bacterium and promotes intracellular and intercellular motility. Recent studies have identified several of the cellular factors involved in the entry process and major discoveries have u nravelled the mechanisms underlying the actin-based motility. Increasing ev idence shows that many cellular genes are up- or down-regulated during infe ction and probably play a role in the establishment of infection, inflammat ion and induction of the host immune response.