Send to

Choose Destination
See comment in PubMed Commons below
EMBO J. 1992 May;11(5):1991-9.

IpaB of Shigella flexneri causes entry into epithelial cells and escape from the phagocytic vacuole.

Author information

Unité de Pathogénie Microbienne Moléculaire, Unité INSERM 199, Institut Pasteur, Paris, France.


By creating mutations within the Shigella flexneri ipaB gene, we have demonstrated that the invasion of epithelial cells is a three-step process encompassing adhesion on the cell surface, entry and lysis of the phagocytic vacuole allowing subsequent access to the cytoplasm. SC403, an insertion mutant which lacks expression of IpaB but still expresses downstream genes, has been particularly studied. It is non-invasive, does not elicit actin polymerization, but binds to HeLa cells indicating that an adhesion step occurs immediately prior to the entry process. The consequence of the inactivation of ipaB on the intracellular behaviour of S.flexneri was investigated using the macrophage cell line J774. SC403 was unable to lyse the phagocytic vacuole; moreover, this strain did not display the contact mediated haemolytic activity characteristics of Shigella. In addition to being a major component of the invasion complex, IpaB acts as a membrane-lysing toxin enabling escape to the cytoplasmic compartment.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for PubMed Central
    Loading ...
    Support Center