Amplification of antibody responses to antigen using small multilamellar vesicles for delivery system

New vaccines based on subunits, synthetic peptides, or DNA need innovative adjuvants or antigen delivery systems: Spherulites are multilamellar vesicles made of incompatible lipid bilayers without any aqueous core. In this study, we evaluated their ability to induce immune responses against human serum albumin (HSA). Mice were immunized by the intraperitoneal/intravenous route or subcutaneously with HSA without any adjuvant or in its encapsulated form. We showed that Spherulites strongly enhanced the seric antibody responses and led to a mixed isotypic distribution characterized by an IgG(2a) potentiation. This demonstrated that Spherulites can improve the presentation of weak antigens to the immune system.