There is an unmet need for delivery platforms that realize the full potential of next‐generation nucleic acid therapeutics. The in vivo usefulness of current delivery systems is limited by numerous weaknesses, including poor targeting specificity, inefficient access to target cell cytoplasm, immune activation, off‐target effects, small therapeutic windows, limited genetic encoding and cargo capacity, and manufacturing challenges. Here we characterize the safety and efficacy of a delivery platform comprising engineered live, tissue‐targeting, non‐pathogenic bacteria (Escherichia coli SVC1) for intracellular cargo delivery. SVC1 bacteria are engineered to specifically bind to epithelial cells via a surface‐expressed targeting ligand, to allow escape of their cargo from the phagosome, and to have minimal immunogenicity. We describe SVC1's ability to deliver short hairpin RNA (shRNA), localized SVC1 administration to various tissues, and its minimal immunogenicity. To validate the therapeutic potential of SVC1, we used it to deliver influenza‐targeting antiviral shRNAs to respiratory tissues in vivo. These data are the first to establish the safety and efficacy of this bacteria‐based delivery platform for use in multiple tissue types and as an antiviral in the mammalian respiratory tract. We expect that this optimized delivery platform will enable a variety of advanced therapeutic approaches.
There is an unmet need for delivery platforms that realize the full potential of next-generation therapeutic and vaccine technologies, especially those that require intracellular delivery of nucleic acids. The in vivo usefulness of the current state-of-the-art delivery systems is limited by numerous intrinsic weaknesses, including lack of targeting specificity, inefficient entry and endosomal escape into target cells, undesirable immune activation, off-target effects, a small therapeutic window, limited genetic encoding and cargo capacity, and manufacturing challenges. Here we present our characterization of a delivery platform based on the use of engineered live, tissue-targeting, non-pathogenic bacteria (Escherichia coli strain SVC1) for intracellular cargo delivery. The SVC1 bacteria are engineered to specifically bind to epithelial cells via a surface-expressed targeting ligand, to escape the endosome upon intracellularization, and to have minimal immunogenicity. Here we report findings on key features of this system. First, we demonstrated that bacterial delivery of a short hairpin RNA (shRNA) can target and silence a gene in an in vitro mammalian respiratory cell model. Next, we used an in vivo mouse model to demonstrate that SVC1 bacteria are invasive to epithelial cells of various tissues and organs (eye, nose, mouth, stomach, vagina, skeletal muscle, and lungs) via local administration. We also showed that repeat dosing of SVC1 bacteria to the lungs is minimally immunogenic and that it does not have adverse effects on tissue homeostasis. Finally, to validate the potential of SVC1 bacteria in therapeutic applications, we demonstrated that bacterial delivery of influenza- targeting shRNAs to the respiratory tissues can mitigate viral replication in a mouse model of influenza infection. Our ongoing work is focused on further refining this platform for efficient delivery of nucleic acids, gene editing machinery, and therapeutic proteins, and we expect that this platform technology will enable a wide range of advanced therapeutic approaches.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.