LOW-DOSE RECOMBINANT VACCINE ANTIGEN DELIVERY BY ENGINEERED OUTER MEMBRANE VESICLES

The use of engineered antigen carriers to optimize the immune response to recombinant subunit vaccines has seen great advances in recent years. Optimization can take several forms, such as facilitating stimulation of certain immune cells or amplifying the adjuvancy effect of the vaccine formulation. In this paper, we applied dose/response analysis to demonstrate the ability of outer membrane vesicle (OMV) antigen carriers derived from engineered Escherichia coli to produce strong antigen-specific immune responses to a model antigen at a significantly decreased antigen load compared to an industry standard alum-based control. Inflammopathology and histological analysis of extended studies further supported a capacity to enhance immune cell recruitment locally at the injection site while decreasing inflammation and eliminating injection site scaring. The results indicate a strong potential for OMV-based vaccines as recombinant antigen delivery vehicles, affording strong immunogenicity at low doses with a broadly applicable platform for recombinant subunit antigen inclusion.