Archaeal lipid mucosal vaccine adjuvant and delivery system

Abstract

Archaeal polar lipids are being evaluated as adjuvants/vaccine delivery systems for mucosal vaccines that can provide protection against pathogens that enter the human host via the mucosal surfaces. Archaeosomes, liposomes made from polar lipids extracted from Archaea, with encapsulated antigens elicit strong antigen-specific systemic immune responses upon systemic or intranasal immunization, but fail to generate mucosal immune responses. However, intranasal immunization of mice with the archaeal lipid mucosal vaccine adjuvant and delivery (AMVAD) system, obtained by the interaction of archaeosomes/antigens with multivalent cations, induces robust, antigen-specific IgA responses in nasal and vaginal mucosa, feces, bile, and serum. In addition, strong antigen-specific systemic antibody (serum IgG, IgG1 and IgG2a) and cell-mediated responses, including CD8+ cytotoxic T lymphocyte, are generated. The responses are sustained over time and are subject to good memory-boost responses. The AMVAD formulations are stable during storage, have a good safety profile and show protective efficacy in a murine model of infection/challenge.