Oral Delivery of Glypican 1 via Engineered Escherichia coli Nissle 1917: An Immunogenic Anticancer Therapy Approach.

Immunotherapy has gained significant traction as a novel approach to cancer treat- ment and prevention, driving innovation in vaccine development. Concurrently, emerging research indicates that the microbiome plays a critical role in modulating the immune system and the efficacy of immunotherapy. This dissertation bridges these two dynamic fields by investigating an innovative immunotherapeutic strat- egy: the utilization of genetically engineered Escherichia coli Nissle 1917 (EcN), a well characterized probiotic commercialized by CADIgroup as food supplement, as an oral vaccine delivery vehicle for cancer. Using modern molecular cloning tech- niques, EcN was transformed with a plasmid vector to produce both native GPC1 and a fusion protein of GPC1 coupled with Salmonella typhimurium flagellin gene FliC, which is recognized in the literature as a potent protein adjuvant. Biochem- ical assays substantiated the stable expression and solubility of these antigens in the engineered bacterial cells. Oral administration of the modified EcN in C57BL/6 murine models revealed remarkable humoral immunogenicity. This dissertation val- idates the promise of employing engineered EcN as a novel, orally-administered immunotherapeutic agent against cancer. By synergistically leveraging the microbiome’s immunomodulatory capabilities and innovative molecular techniques, this work lays a foundational framework for future research aimed at optimizing the immunogenicity and safety of this pioneering approach, with potential to redefine can- cer prevention and treatment paradigms.