A CaP-Mineralized PLGA Formulation Carrying Dual Agonists Promotes the Formation of Germinal Centers to Combat HPV.

Although HPV vaccines currently in use with aluminum adjuvants demonstrate significant stimulation of humoral immunity, the weak cellular immune response that they elicit indicates a need for further improvement. On the other hand, not only the poor immune promotion effect inducted by a single adjuvant but also finding an efficient antigen and adjuvant codelivery carriers need to be addressed. Here, a double Toll like receptor agonist (R848, Poly(I:C)) and antigen of HPV16 L1 pentamer were codelivered by using calcium phosphate (CaP) mineralized PLGA microparticles. The results of in vivo experiments indicate that the secretion of specific antibodies and neutralizing antibodies was significantly increased, and T/B cells in lymph nodes were effectively activated. Of particular note is the formation of more germinal centers in vivo stimulated by the formulation. In addition, the cellar immunity is also promoted with a higher level of cytokines secretion as IFN-γ, TNF-α, and IL-12p70. Therefore, the as-prepared formulations are a potential platform for preventing the HPV virus infection.