Engineered E. coli for the targeted deposition of therapeutic payloads to sites of disease

Abstract New drug platforms are needed which enable the directed delivery of therapeutics to sites of disease to maximize efficacy and limit off-target effects. Here, we report the development of PROT3EcT, commensal Escherichia coli engineered for the direct secretion of proteins into their surroundings. PROT3EcT are composed of four modular components: an E. coli chassis, a modified bacterial protein secretion system, a regulatable transcriptional activator, and a secretable therapeutic payload. PROT3EcT that secrete functional single-domain antibodies, nanobodies (Nb), stably colonize and maintain a functional secretion system within the intestines of mice. A single prophylactic dose of PROT3EcT that secretes a tumor necrosis factor alpha (TNFα) neutralizing Nb is sufficient to ablate TNF levels and prevent the development of injury and inflammation in a chemically-induced model of inflammatory bowel disease. This work lays the foundation for the development of PROT3EcT as a therapeutic platform for the treatment of at least gastrointestinal-based diseases.