The Combinations Chitosan-Pam 3 CSK 4 and Chitosan-Monophosphoryl Lipid A: Promising Immune-Enhancing Adjuvants for Anticaries Vaccine PAc

We previously demonstrated that recombinant protein PAc could be administered as an anticaries vaccine. However, the relatively weak immunogenicity of PAc limits its application. In the present study, we investigated the effect of two adjuvant combinations of chitosan plus Pam CSK (chitosan-Pam CSK ) and of chitosan plus monophosphoryl lipid A (chitosan-MPL) in the immune responses to the PAc protein and PAc-chitosan-Pam CSK or PAc-chitosan-MPL promoted significantly higher PAc-specific antibody titers in serum and saliva, inhibited colonization onto the tooth surfaces, and endowed better protection effect with significantly less caries activities than PAc alone. Chitosan-Pam CSK and chitosan-MPL showed no statistically significant differences. In conclusion, our study demonstrated that the chitosan-Pam CSK and chitosan-MPL combinations are promising for anticaries vaccine development.