Hepatitis B virus (HBV)-derived DRB1*0101-restricted CD4 T-cell epitopes help in the development of HBV-specific CD8+ T cells in vivo.

We previously identified two HLA-DRB1*0101-restricted epitopes in hepatitis B virus (HBV) X protein (HBx) and in HBV envelope proteins (preS2). To evaluated their help in the development of CD8+ T-cell responses, mice transgenic for human class I and class II HLA molecules were immunized with HBV-T helper constructs. The preS2 epitope favored a well-balanced response with CD4+ and CD8+ T cells producing IFN-gamma, IL-2 and TNF-alpha. The response was focused on CD8+ T cells with the HBx epitope. Fine characterization of helper activities may meet clinical needs in terms of enhancing the potency of preventive or therapeutic polyepitope vaccines. Copyright 2010 Elsevier Ltd. All rights reserved.