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Visualization of Bacterial Toxin Induced Responses Using Live Cell Fluorescence Microscopy
Published on: October 1, 2012
Bacillus sphaericus binary toxin elicits host cell autophagy as a response to intoxication
Onya Opota1, Nils C Gauthier, Anne Doye
1Institut National de la Recherche Agronomique, UMR Interactions Biotiques et Santé Végétale, INRA 1301-CNRS 6243-Université de Nice Sophia Antipolis, Sophia Antipolis, France. onya.opota@epfl.ch
Plos One
|February 23, 2011
Summary
Bacillus sphaericus binary toxin (Bin) causes mosquito cell vacuolation by affecting autolysosomes and inducing autophagy. The toxin traffics to recycling endosomes, avoiding degradation.
Area of Science:
- Molecular Biology
- Cell Biology
- Biotechnology
Background:
- Bacillus sphaericus binary toxin (Bin) is a biopesticide targeting mosquito larvae.
- Bin toxin disrupts mosquito midgut epithelial cells by binding to Culex pipiens maltase 1 (Cpm1).
- Mammalian cells expressing Cpm1 mimic Bin-induced cytopathology.
Purpose of the Study:
- Investigate the mechanism of Bin-induced vacuolation in intoxicated cells.
- Determine the role of autophagy in the cellular response to Bin toxin.
- Elucidate the intracellular trafficking pathway of the internalized Bin toxin.
Main Methods:
- Utilized mammalian epithelial MDCK cells engineered to express Cpm1.
- Observed Bin intoxication effects including cytoplasmic vacuolation.
- Analyzed autolysosome involvement and autophagy induction.
- Tracked the intracellular localization of internalized Bin toxin.
Main Results:
- Bin-induced vacuolation is a transient event affecting autolysosomes.
- Intoxicated cells exhibit induced autophagy.
- Internalized Bin toxin localizes to recycling endosomes.
- Bin toxin is not found within vacuolating autolysosomes or degradative compartments.
Conclusions:
- Bin toxin triggers autophagy as a cellular defense mechanism.
- The cell protects Bin toxin from degradation via recycling pathways.
- Understanding Bin toxin's cellular interactions can inform biopesticide development.
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