Evaluation of the Effect of CD70 Co-Expression on CD8 T Cell Response in Protein-Prime MVA-Boost Vaccination in Mice.

Here, we investigate the potential of CD70 co-expression during viral vector boost vaccination to improve an antigen-specific T cell response. To determine the chance of activating antigen-specific T cells by CD70, we used the HBV core antigen as a model antigen in a heterologous protein-prime, Modified Vaccinia virus Ankara (MVA) boost vaccination scheme. Both the HBV core and a CD70 expression cassette were co-expressed upon delivery by an MVA vector under the same promoter linked by a P2A site.

Protein-prime/modified vaccinia virus Ankara vector-boost vaccination overcomes tolerance in high-antigenemic HBV-transgenic mice.

Background: Therapeutic vaccination is a novel treatment approach for chronic hepatitis B, but only had limited success so far. We hypothesized that optimized vaccination schemes have increased immunogenicity, and aimed at increasing therapeutic hepatitis B vaccine efficacy.

Methods: Modified Vaccinia virus Ankara (MVA) expressing hepatitis B virus (HBV) antigens was used to boost protein-prime vaccinations in wildtype and HBV-transgenic (HBVtg) mice.