Engineered E. Coli Delivers Therapeutic Nanobodies to the Gut

Authors: Jason P Lynch, Coral González-Prieto, Analise Z Reeves, Sena Bae, Urmila Powale, Neha P Godbole, Jacqueline M Tremblay, Florian I Schmidt, Hidde L Ploegh, Vikram Kansra, Jonathan N Glickman, John M Leong, Charles B Shoemaker, Wendy S Garrett, Cammie F Lesser

Full Article: Engineered E. Coli Delivers Therapeutic Nanobodies to the Gut (

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Drug platforms that enable the directed delivery of therapeutics to sites of diseases to maximize efficacy and limit off-target effects are needed. Here, we report the development of PROT3EcT, a suite of commensal Escherichia coli engineered to secrete proteins directly into their surroundings. These bacteria consist of three modular components: a modified bacterial protein secretion system, the associated regulatable transcriptional activator, and a secreted therapeutic payload. PROT3EcT secrete functional single-domain antibodies, nanobodies (Nbs), and stably colonize and maintain an active secretion system within the intestines of mice. Furthermore, a single prophylactic dose of a variant of PROT3EcT that secretes a tumor necrosis factor-alpha (TNF-α)-neutralizing Nb is sufficient to ablate pro-inflammatory TNF levels and prevent the development of injury and inflammation in a chemically induced model of colitis. This work lays the foundation for developing PROT3EcT as a platform for the treatment of gastrointestinal-based diseases.