Neutralizing antibodies and broad, functional T cell immune response following immunization with hepatitis C virus proteins-based vaccine formulation

• MixprotHC, comprising Core, E1, E2 and NS3 in non-equivalent ratio is described.
• IgG from MixprotHC immunized mice and monkeys neutralized the infectivity of HCVcc.
• MixprotHC vaccinated mice developed broad T cell response functional in vivo.
• MixprotHC elicited broad specific proliferative and IFNγ response in mice and monkeys.

HCV is a worldwide health problem despite the recent advances in the development of more effective therapies. No preventive vaccine is available against this pathogen. However, non-sterilizing immunity has been demonstrated and supports the potential success of HCV vaccines. Induction of cross-neutralizing antibodies and T cell responses targeting several conserved epitopes, have been related to hepatitis C virus (HCV) clearance. Therefore, in this work, the immunogenicity of a preparation (MixprotHC) based on protein variants of HCV Core, E1, E2 and NS3 was evaluated in mice and monkeys. IgG from MixprotHC immunized mice and monkeys neutralized the infectivity of heterologous HCVcc. Moreover, strong CD4+ and CD8+ T cells proliferative and IFN-γ secretion responses were elicited against HCV proteins. Remarkably, immunization with MixprotHC induced control of viremia in a surrogate challenge model in mice. These results suggest that MixprotHC might constitute an effective immunogen against HCV in humans with potential for reducing the likelihood of immune escape and viral persistence.