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Engineered Synthetic STxB for Enhanced Cytosolic Delivery
Justine Hadjerci1, Anne Billet1,2, Pascal Kessler3
1Cellular and Chemical Biology Unit, Institut Curie, Université PSL, U1143 INSERM, UMR3666 CNRS, 26 Rue d'Ulm, CEDEX 05, 75248 Paris, France.
Cells
|May 13, 2023
Summary
Researchers enhanced Shiga toxin B-subunit (STxB) delivery into cells by chemically modifying it with hydrophobic entities. This modification significantly increased STxB’s translocation into the cytosol, opening new avenues for targeted cancer therapies.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Many cancer therapy targets reside in the cytosol, but therapeutic macromolecules struggle to cross cell membranes.
- Shiga toxin B-subunit (STxB) naturally delivers molecules to the cytosol of Gb3-receptor-expressing cells, inducing CD8+ T cell responses.
Purpose of the Study:
- To enhance the membrane translocation capacity of STxB for broader therapeutic applications.
- To explore chemical modifications of STxB to improve cytosolic delivery.
Main Methods:
- Chemically synthesized STxB with unnatural amino acids at specific positions.
- Functionalized STxB with hydrophobic entities to destabilize endosomal membranes.
- Quantified intracellular trafficking and cytosolic arrival using confocal microscopy and a novel translocation assay.
Main Results:
- Identified the most effective hydrophobic moiety for enhancing STxB translocation.
- Achieved a 2.5-fold increase in STxB translocation efficiency.
- Demonstrated improved cytosolic delivery of functionalized STxB.
Conclusions:
- Chemical modification of STxB with hydrophobic entities significantly enhances its cytosolic delivery.
- This improved translocation opens new possibilities for developing targeted cancer therapies and other biomedical applications.
- The developed methods provide a robust platform for engineering protein-based drug delivery systems.
