A self-adjuvanting lipopeptide-based vaccine candidate for the treatment of hepatitis C virus infection

SummaryEffective CD8+ T cell responses have been induced using totally synthetic self-adjuvanting lipopeptides containing the dipalmitoyl-S-glyceryl cysteine lipid moiety, which is a ligand for Toll-like receptor 2 (TLR2) on dendritic cells (DC). In this study, we evaluated the use of lipopeptide vaccine candidates containing HLA-A2-restricted epitopes for DC-based immunotherapy of HCV infection. Lipopeptides were able to induce specific CD8+ T cell responses in HLA-A2 transgenic mice and consistently activated human monocyte-derived DC from both healthy individuals and HCV infected patients. Lipopeptide-pulsed human DC were also found to secrete the pro-inflammatory cytokine IL-12p70 and were able to activate antigen-specific IFN-γ production by autologous CD8+ T cells obtained from a hepatitis C patient. These results show that DC from HCV patients can be matured and antigen loaded with TLR2-targeting lipopeptides for effective presentation of CD8+ T cell epitopes; the use of autologous lipopeptide-pulsed DC or direct lipopeptide vaccination may be successful approaches for the priming or boosting of anti-HCV CD8+ T cell responses to aid in the clearance of the virus in chronically infected individuals.