Fig. 1: Schematic of the oral delivery of therapeutic protein by synthetic commensal bacteria outfitted with modified T0SS to detoxify circulating metabolites.
From: Oral delivery of therapeutic proteins by engineered bacterial type zero secretion system
EcN was engineered to increase OMV biosynthesis by genomic deletion of an outer membrane lipoprotein encoding gene nlpI, heterologously overexpress protein of interest (POI) on a stable plasmid in the absence of antibiotic selection (through deleting an essential gene thyA in the genome and compensate it on the plasmid), and endogenously load POI into OMVs guided by a periplasm-targeted secretion signal peptide. After oral administration of our synthetic EcN outfitted with modified T0SS, the protein-loaded OMVs produced in situ by engineered EcN could resist proteolysis, penetrate the intact gut epithelial barrier and enter the circulation. Pinocytosis and dynamin-dependent pathways are involved in this transcellular transport. Synthetic EcN outfitted with modified T0SS can deliver therapeutic proteins to the circulation and detoxify circulating metabolites, presenting an oral protein delivery strategy. Created in BioRender. Gong, X. (2025) https://BioRender.com/o53n846.
