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Updated: Jun 10, 2026

Tractable Mammalian Cell Infections with Protozoan-primed Bacteria
Published on: April 2, 2013
Legionella effectors that promote nonlytic release from protozoa
John Chen1, Karim Suwwan de Felipe, Margaret Clarke
1Department of Microbiology, College of Physicians and Surgeons, Columbia University, 701 West 168th Street, New York, NY 10032, USA.
Abstract:
Legionella pneumophila, the bacterial agent of legionnaires' disease, replicates intracellularly within a specialized vacuole of mammalian and protozoan host cells. Little is known about the specialized vacuole except that the Icm/Dot type IV secretion system is essential for its formation and maintenance. The Legionella genome database contains two open reading frames encoding polypeptides (LepA and LepB) with predicted coiled-coil regions and weak homology to SNAREs; these are delivered to host cells by an Icm/Dot-dependent mechanism. Analysis of mutant strains suggests that the Lep proteins may enable the Legionella to commandeer a protozoan exocytic pathway for dissemination of the pathogen.
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