Biphasic Lipid Vesicles (Biphasix™) Enhance the Adjuvanticity of CpG Oligonucleotides Following Systemic and Mucosal Administration

CpG oligonucleotides (ODNs) are potent mucosal and systemic adjuvants. For practical applications however, improvements in delivery need to be developed. A mouse model was used to determine if the biological activity of CpG ODNs could be enhanced using a novel delivery system of biphasic lipid vesicles (BiphasixTM Vaccine-Targeting Adjuvant; VTA). Immunization studies were performed to evaluate the potential of VTA formulations to enhance the immunoadjuvant activity of CpG ODNs following systemic or mucosal administration with gD. Immune responses following immunization were assessed by protection from HSV-1 viral challenge and characterization of serum gD-specific antibody responses using ELISA. VTA formulations in combination with CpG and glycoprotein D (gD) were able to increase gD-specific IgG in serum compared to gD alone, and protect from a lethal HSV-1 challenge following subcutaneous immunization. Following mucosal immunization, VTA formulations in combination with CpG and antigen enhanced mucosal IgA responses compared to CpG and antigen administered in PBS.