Malmassari Silvina, Lone Yu Chun, Zhang Menghua, Transy Catherine, Michel Marie-Louise
Institut National de la Santé et de la Recherche Médicale, Unité 370, Institut Pasteur, Unité carcinogenèse hépatique et virologie moléculaire, Département de médecine moléculaire, 28, rue du Dr. Roux, 75724 Paris cedex 15, France.
Microbes Infect. 2005 Apr;7(4):626-34. doi: 10.1016/j.micinf.2004.12.022. Epub 2005 Mar 16.
A polyepitopic CD8+ T-cell response is critical for the control of hepatitis B virus (HBV) infection. The HBV X protein (HBx) is a multifunctional protein that is important for the viral life cycle and for host-virus interactions. The aim of this study was to analyze the immunogenicity and dominance of various HLA-A0201-restricted HBx-derived epitopes. For this purpose, we immunized HLA-A0201-transgenic mice with HBx-derived peptides and DNA. This is a powerful model for studying the induction of HLA-A*0201-restricted immune responses in vivo, as these mice possess a cytotoxic T lymphocyte (CTL) repertoire representative of HLA-A2.1 individuals. We used cytotoxic tests and enzyme-linked immunosorbent spot (ELISPOT) assays to study the induction of specific cytotoxic and interferon (IFN)-gamma-secreting T cells. This allowed us to classify the HBx epitopes according to their T-cell activation capacity. After endogenous processing of the antigen synthesized in vivo after DNA-based immunization, we found that the HBx-specific T-cell response is targeted against one immunodominant epitope. Furthermore, following peptide immunization, we identified six additional novel subdominant T-cell epitopes. Inclusion of well-characterized epitopic sequences of HBx in a new vaccine for chronic HBV infections could help to broaden the T-cell response.
多表位CD8 + T细胞反应对于控制乙型肝炎病毒（HBV）感染至关重要。HBV X蛋白（HBx）是一种多功能蛋白，对病毒生命周期和宿主-病毒相互作用都很重要。本研究的目的是分析各种HLA-A0201限制性HBx衍生表位的免疫原性和优势性。为此，我们用HBx衍生肽和DNA免疫HLA-A0201转基因小鼠。这是一个用于研究体内HLA-A*0201限制性免疫反应诱导的强大模型，因为这些小鼠拥有代表HLA-A2.1个体的细胞毒性T淋巴细胞（CTL）库。我们使用细胞毒性试验和酶联免疫斑点（ELISPOT）分析来研究特异性细胞毒性和分泌干扰素（IFN）-γ的T细胞的诱导情况。这使我们能够根据其T细胞激活能力对HBx表位进行分类。在基于DNA免疫后体内合成的抗原进行内源性加工后，我们发现HBx特异性T细胞反应针对一个免疫显性表位。此外，在肽免疫后，我们鉴定出另外六个新的亚显性T细胞表位。在慢性HBV感染的新疫苗中纳入特征明确的HBx表位序列可能有助于拓宽T细胞反应。
