Engineered Therapeutic Bacteria with High-Yield Membrane Vesicle Production Inspired by Eukaryotic Membrane Curvature for Treating Inflammatory Bowel Disease.

Abstract

Bacterial membrane vesicles (BMVs) are emerging as powerful natural nanoparticles with transformative potential in medicine and industry. Despite their promise, scaling up BMV production and ensuring stable isolation and storage remain formidable challenges that limit their broader application. Inspired by eukaryotic mechanisms of membrane curvature, we engineered <i>Escherichia coli</i> DH5α to serve as a high-efficiency BMV factory. By fusing the ethanolamine utilization microcompartment shell protein EutS with the outer membrane via the ompA signal peptide, we induced dramatic membrane curvatures that drove enhanced vesiculation. Simultaneously, overexpression of fatty acyl reductase led to the production of amphiphilic fatty alcohols, further amplifying the BMV yield. Dynamic modulation of peptidoglycan hydrolase (PGase) expression facilitated efficient BMV release, resulting in a striking 149.11-fold increase in vesicle production. Notably, the high-yield BMVs from our engineered strain, without the need for purification, significantly bolstered innate immune responses and demonstrated therapeutic efficacy in treating inflammatory bowel disease (IBD). This study presents a strategy to overcome BMV production barriers, showcasing the therapeutic potential of engineered bacteria and BMVs for IBD treatment, while highlighting their potential applications in diverse biomedical fields.