MPLA-coated hepatitis B virus surface antigen (HBsAg) nanocapsules induce vigorous T cell responses in cord blood derived human T cells.

Chronic hepatitis B virus (HBV) infection is the most prevalent serious liver infection in the world. A frequent route of infection represents mother-to-child transmission. Efficient control of HBV replication depends on antigen-specific cellular immune response mediated by dendritic cells (DCs). Aim of the present study was to evaluate optimized adjuvant combinations, efficiently maturing monocyte-derived neonatal and adult dendritic cells (moDCs). In addition, the potential of polymeric HBsAg-nanocapsules (HBsAg-NCs) was investigated regarding up-take by moDCs and the subsequent induction of specific T cell responses in a human co-culture model. Simultaneous stimulation of moDCs with MPLA and IFNγ induced up-regulation of CD80 and HLA-DR along with vigorous secretion of IL-12p70. MPLA-coating of HBsAg-NCs promoted NCs-uptake by moDCs. Finally, MPLA-HBsAg-NCs-pulsed moDCs with IFNγ increased T cell proliferation and induced antigen-specific IFNγ release by T cells. The herein presented vaccine approach provides a rational for neonatal and therapeutic immunization strategies against HBV.