Development of a novel Vaccine Platform using Outer Membrane Vesicles

Outer membrane vesicles (OMV) are small vesicles (diameter ~ 100nm) which are released by gram-negative bacteria. As the surface of the vesicles is very similar to the surface of the bacteria the vesicle may trigger an immune response against the bacteria while being safe as they are non-replicative and non-infectious. The vesicles elicit an immune response and self-adjuvant effect as OMVs present several Pathogen-associated Molecular Patterns (PAMP) such as lipidA and bacterial cell wall constituents. OMVs containing multiple pathogen-specific protein antigens can be produced in E. coli by the use of plasmid-based expression systems and subsequently purified to high purity followed by careful analytics. In a cooperation with a Swiss industry partner E. coli derived OMVs are produced containing recombinant protein and carbohydrate antigens originated from an important antimicrobial resistant pathogen. Preclinical studies in mouse and rabbit demonstrate excellent safety and high immunogenicity towards all recombinant antigens. Taken together, this platform has great potential for developing new multivalent vaccines candidates composed of E. coli derived OMVs containing several pathogen-specific antigens.

Funded by Innosuisse.