Single Dose of Protein Vaccine with Peptide Nanofibers As Adjuvants Elicits Long-Lasting Antibody Titer

Self-assembling materials based on peptides have shown great potential as vaccine adjuvants. In our previous work, we have demonstrated that nanofibers based on D peptide Nap-G(D)F(D)F(D)Y are good candidates for vaccine adjuvants. Here we further found that supramolecular hydrogels based on positively charged D-peptide Nap-G(D)F(D)F(D)Y(D)K as vaccine adjuvants could induce stronger immune response. We designed and synthesized two D -peptide derivatives, one with a positive charge (Nap-G(D)F(D)F(D)Y(D)K) and the other with a negative charge (Nap-G(D)F(D)F(D)Y(D)E). Both of them could form the hydrogels constructed by nanofibers. The nanofibers formed by Nap_Gr) DDnic FFypromoted the more powerful immune response in mice against the antigen chicken egg albumin (OVA) than peptides Nap-G(D)F(D)F(D)Y and Nap-G(D)F(D)F(D)Y(D)E. Through cell experiments, we demonstrated that the main reason was that nanofibers formed by Nap-GDFDFDYDK could enhance the uptake of OVA by primary antigen presenting cells. Most importantly, it was intriguing that the nonofibres based on Nap-G(D)F(D)F(D)Y(D)K could evoke long-lasting antibody titers for 28 weeks at a single dose of protein vaccine. Our study demonstrated that supramolecular hydrogels based on positively charged D-peptide were promising vaccine adjuvants and might be very useful for antibody production and vaccine development.