Enhanced cell immune responses to hepatitis C virus core by novel heterologous DNA prime/lambda nanoparticles boost in mice.

Hepatitis C virus (HCV) is a worldwide problem which does not have an effective vaccine and more than 170 million people worldwide are chronically infected by HCV. T cell responses are associated with spontaneous clearance of HCV infection. We report here the development of recombinant Lambda bacteriophage nanoparticles encoding HCV Core antigen. The aim of this study was to investigate the antigen-specific immune responses triggered in mice by different prime-boost combinations of DNA and Lambda phage nanoparticles encoding the HCV Core. The homologous prime/boost with recombinant Lambda nanoparticles induced higher levels of cellular and humoral immune response than the DNA vaccines. However, a heterologous prime/boost of HCV Core protein, using DNA vaccine priming followed by Lambda boost, induced highest level of lymphocyte proliferation, CD8 lymphocytes with cytotoxic function, and shifting the immune response toward a T helper (Th1) pattern and in overall improved immunity. Our study provides a new, safe, and effective vaccine for the prime-boost regimen which augments robust immunity and highlights novel promising strategies in HCV vaccine development.