Bioengineering bacterial outer membrane vesicles as vaccine platform

Outer membrane vesicles (OMVs) are naturally non-replicating, highly immunogenic spherical nanoparticles derived from Gram-negative bacteria. OMVs from pathogenic bacteria have been successfully used as vaccines against bacterial meningitis and sepsis among others and the composition of the vesicles can easily be engineered. OMVs can be used as a vaccine platform by engineering heterologous antigens to the vesicles. The major advantages of adding heterologous proteins to the OMV are that the antigens retain their native conformation, the ability of targeting specific immune responses, and a single production process suffices for many vaccines. Several promising vaccine platform concepts have been engineered based on decorating OMVs with heterologous antigens. This review discusses these vaccine concepts and reviews design considerations as the antigen location, the adjuvant function, physiochemical properties, and the immune response. [Display omitted] •Decorating OMVs with heterologous proteins makes them suited as vaccine platform.•Adding heterologous glycans to OMVs creates alternative glycoconjugate vaccines.•The complex immunogenicity of OMVs can be fine-tuned for desired immune response.•Adding multiple antigens from different pathogens can design multivalent vaccines.•The use of an OMV vaccine platform will decrease the time to market significantly.