PELC is a novel emulsion-type adjuvant that contains the bioresorbable polymer poly (ethylene glycol)-block-poly (lactide-co-ε-caprolactone) (PEG-b-PLACL), Span?85 and squalene. To investigate whether PELC is able to enhance CTL responses of antigens for treating tumor, peptide or protein antigen derived from HPV16 E7 were formulated with PELC nanoparticles and CpG oligodeoxynucleotide. We identified that PELC formulation could delay release of antigens in vittro and in vivo. We assessed the immunogenicity of an H-2Db-restricted CTL epitope RAHYNIVTF (RAH) formulated with PELC or PELC/CpG and investigated the ability of these formulations to promote tumor regression. Following a single-dose subcutaneous injection in mice, we found that the RAH peptide formulated with PELC/CpG (RAH/PELC/CpG) resulted in increased numbers of IFN-γ-secreting cells and RAH-specific CD8+ T cells and an enhanced cytotoxic T cell response compared with RAH formulated with PELC or CpG alone. The tumor-bearing mice received a single-dose injection of RAH/PELC/CpG, which induced complete tumor regression. These results demonstrated that peptide antigen formulated with PELC/CpG nanoparticles is feasible for cancer immunotherapy.
Date:
2014-01
Relation:
Journal of Controlled Release. 2014 Jan;173(1):158-165.
