Cytosolic delivery of siRNA by ultra-high affinity dsRNA binding proteins
Author(s)
Sun, Fangdi
Yang, Lucy F.
Traxlmayr, Michael W.
Yu, Yao
Xu, Yingda
Yang, Nicole Jie Yeon
Kauke, Monique Jacqueline
Maass, Katie F
Langer, Robert S
Anderson, Daniel Griffith
Date Issued
June 2017
Journal
Nucleic Acids Research
Publisher
Oxford University Press (OUP)
Citation
Yang, Nicole J. et al. “Cytosolic Delivery of siRNA by Ultra-High Affinity dsRNA Binding Proteins.” Nucleic Acids Research 45, 13 (June 2017): 7602–7614 © 2017 The Author(s)
Version
Final published version
Abstract
Protein-based methods of siRNA delivery are capable of uniquely specific targeting, but are limited by technical challenges such as low potency or poor biophysical properties. Here, we engineered a series of ultra-high affinity siRNA binders based on the viral protein p19 and developed them into siRNA carriers targeted to the epidermal growth factor receptor (EGFR). Combined in trans with a previously described endosome-disrupting agent composed of the pore-forming protein Perfringolysin O (PFO), potent silencing was achieved in vitro with no detectable cytotoxicity. Despite concerns that excessively strong siRNA binding could prevent the discharge of siRNA from its carrier, higher affinity continually led to stronger silencing. We found that this improvement was due to both increased uptake of siRNA into the cell and improved pharmacodynamics inside the cell. Mathematical modeling predicted the existence of an affinity optimum that maximizes silencing, after which siRNA sequestration decreases potency. Our study characterizing the affinity dependence of silencing suggests that siRNA-carrier affinity can significantly affect the intracellular fate of siRNA and may serve as a handle for improving the efficiency of delivery. The two-agent delivery system presented here possesses notable biophysical properties and potency, and provide a platform for the cytosolic delivery of nucleic acids.
MIT Department
Massachusetts Institute of Technology. Institute for Medical Engineering & Science
Massachusetts Institute of Technology. Department of Biological Engineering
Massachusetts Institute of Technology. Department of Chemical Engineering
Koch Institute for Integrative Cancer Research at MIT
Terms of Use
Attribution 4.0 International (CC BY 4.0)
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1093/NAR/GKX546
