Developing efficient and safe adjuvants for use in human vaccines remains both a challenge and a necessity. CIA07 is a immunostimulatory agent composed of E.coli DNA fragments and modified lipopolysaccharide (LPS) lacking the lipid A moiety. In this s...
Developing efficient and safe adjuvants for use in human vaccines remains both a challenge and a necessity. CIA07 is a immunostimulatory agent composed of E.coli DNA fragments and modified lipopolysaccharide (LPS) lacking the lipid A moiety. In this study, we investigated adjuvant activity of CIA07 using HPV L1 VLPs as the immunogen. Mice were immunized intramuscularly two times at 3-week intervals with HPV 6/11/16/18 L1 VLP vaccine alone or in combination with bacterial DNA fragments, modified LPS or CIA07, and immune responses were assessed. Modified LPS and CIA07 adjuvanted formulation showed significantly higher titers of HPV 16/18 L1 VLPs specific antibodies than aluminium salt. HPV 16/18 L1 VLPs specific IgG isotype titers were measured. Modified LPS adjuvanted formulation stimulated the IgG1 antibody response effectively, but did not induce a significant increase in the IgG2a antibody response. On the other hand, CIA07 adjuvanted formulation induced significantly higher titers of HPV 16/18 L1 VLPs specific IgG1 as well as IgG2a antibodies at 28-day post-immunization II. Furthermore, the ratio of IgG2a to IgG1 antibody titers in mice administered with CIA07 adjuvanted formulation was higher compared to aluminium salt at 28-day post-immunization II, indicating that CIA07 could stimulate higher Th1-type immune responses to HPV 16/18 L1 VLPs.These data demonstrated that CIA07 adjuvanted formulation has the ability to induce higher humoral and cellular immune responses in mice when compared with the aluminium salt, and support the role of the CIA07 as an effective adjuvant to the HPV quadrivalent recombinant vaccine.