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Single Cell Measurements of Vacuolar Rupture Caused by Intracellular Pathogens
Published on: June 12, 2013
Galectin-3, a marker for vacuole lysis by invasive pathogens
Irit Paz1, Martin Sachse, Nicolas Dupont
1Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 75724 Paris, Cedex 15, France.
Cellular Microbiology
|December 3, 2009
Summary
Shigella infection causes galectin-3 to form structures near bacteria within host cells. These galectin-3 structures indicate phagosome lysis, offering a new way to detect bacterial invasion.
Area of Science:
- Microbiology
- Cell Biology
- Immunology
Background:
- Shigella invades host cells, lyses the phagosome, and escapes into the cytoplasm.
- Galectin-3, a beta-galactoside-binding protein, plays roles in immune responses and infection.
- Galectins are secreted and bind extracellular beta-galactosides.
Purpose of the Study:
- To investigate the localization of galectin-3 after Shigella invasion.
- To understand the role of galectin-3 in host-pathogen interactions.
- To identify potential biomarkers for phagosome lysis.
Main Methods:
- Immuno-electron microscopy to analyze galectin-3 localization.
- Studying galectin-3 binding to host N-acetyllactosamine-containing glycans.
- Investigating the dependence on Shigella's type three secretion system and phagosome lysis.
Main Results:
- Intracellular galectin-3 rapidly accumulated in structures near internalized Shigella.
- Galectin-3 was found in membranes of the phagosome, endocytic tubules, and vesicles.
- Formation of these structures required galectin-3 binding to host glycans and was dependent on the type three secretion system and phagosome lysis.
- Similar structures were observed with Listeria and Salmonella (sifA mutant).
Conclusions:
- Shigella invasion triggers the formation of galectin-3-containing membrane structures.
- These structures are linked to phagosome lysis and bacterial escape into the cytoplasm.
- Galectin-3 structures may serve as a novel indicator for detecting vacuole lysis during bacterial infections.
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