The aim of the present study was to improve the immunogenicity of
peptide epitope vaccines using novel nanocarriers based on self-assembling materials. Several studies demonstrated that
peptide antigens in nanoparticulate form induce stronger immune responses than their soluble forms. However, several issues such as poor loading and risk of inducing T cell anergy due to premature release of antigenic
epitopes have challenged the clinical success of such systems. In the present study, we developed two
vaccine delivery systems by appending a self-assembling
peptide (Ac-AAVVLLLW-COOH) or a thermosensitive
polymer poly(N-isopropylacrylamide (
pNIPAm) to the N-terminus of different
peptide antigens (OVA250-264, HPV-E743-57) to generate self-assembling
peptide epitopes (SAPEs). The obtained results showed that the SAPEs were able to form nanostructures with a diameter from 20 to 200 nm. The SAPEs adjuvanted with CpG induced and expanded
antigen-specific CD8+ T cells in mice. Furthermore,
tumor-bearing mice vaccinated with SAPEs harboring the HPV E743-57
peptide showed a delayed
tumor growth and an increased survival compared to
sham-treated mice. In conclusion, self-assembling
peptide based systems increase the immunogenicity of
peptide epitope vaccines and therefore warrants further development toward clinical use.