Rational design of a multiepitope vaccine encoding T-Lymphocyte epitopes for treatment of chronic hepatitis B virus infections
Rational design of a multiepitope vaccine encoding T-Lymphocyte epitopes for treatment of chronic hepatitis B virus infections
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DOI：
10.1128/jvi.01505-07
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发表时间：
2008-01-01
影响因子：
5.4
通讯作者：
Meheus, Lydie
中科院分区：
文献类型：
--
作者：
Depla, Erik;Van der Aa, Annegret;Meheus, Lydie
分析了来自多个B肝炎病毒（HBV）分离株的蛋白质序列中细胞毒性T淋巴细胞（CTL）和辅助性T淋巴细胞（HTL）表位特征性氨基酸基序的存在，目的是鉴定适用于治疗性疫苗的保守表位。具体地，鉴定带有HLA-A1、-A2、-A3、424、-B7和-DR超型结合基序的序列，合成为肽，并测试与可溶性HLA的结合。随后使用HLA转基因小鼠（CTL）和HLA交叉反应H-2（bxd）（BALB/c x C57 BL/6 J）小鼠（HTL）评估以中等至高亲和力结合的肽的免疫原性。通过这个过程，选择30个CTL和16个HTL表位作为一组，这将是最有用的疫苗设计，基于HBV序列之间的表位保守性和基于HLA的预测的人口覆盖率在不同的种族群体。设计了一种基于质粒DNA的疫苗，该疫苗将表位编码为单个基因产物，每个表位由间隔残基分开以增强适当的表位加工。在小鼠中的免疫原性测试证明了多种CTL和HTL应答的诱导。此外，作为一种补充方法，质谱法允许从用DNA质粒转染的人细胞中鉴定正确加工的和主要组织相容性复合物呈递的表位。用质粒DNA和重组MVA的异源初免-加强免疫进一步增强了免疫应答。因此，成功地设计并在体外和HLA转基因小鼠中评价了能够刺激那些被认为对控制和清除HBV感染至关重要的细胞免疫应答的多表位治疗性疫苗候选物。
Protein sequences from multiple hepatitis B virus (HBV) isolates were analyzed for the presence of amino acid motifs characteristic of cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes with the goal of identifying conserved epitopes suitable for use in a therapeutic vaccine. Specifically, sequences bearing HLA-A1, -A2, -A3, 424, -B7, and -DR supertype binding motifs were identified, synthesized as peptides, and tested for binding to soluble HLA. The immunogenicity of peptides that bound with moderate to high affinity subsequently was assessed using HLA transgenic mice (CTL) and HLA cross-reacting H-2(bxd) (BALB/c x C57BL/6J) mice (HTL). Through this process, 30 CTL and 16 HTL epitopes were selected as a set that would be the most useful for vaccine design, based on epitope conservation among HBV sequences and HLA-based predicted population coverage in diverse ethnic groups. A plasmid DNA-based vaccine encoding the epitopes as a single gene product, with each epitope separated by spacer residues to enhance appropriate epitope processing, was designed. Immunogenicity testing in mice demonstrated the induction of multiple CTL and HTL responses. Furthermore, as a complementary approach, mass spectrometry allowed the identification of correctly processed and major histocompatibility complex-presented epitopes from human cells transfected with the DNA plasmid. A heterologous prime-boost immunization with the plasmid DNA and a recombinant MVA gave further enhancement of the immune responses. Thus, a multiepitope therapeutic vaccine candidate capable of stimulating those cellular immune responses thought to be essential for controlling and clearing HBV infection was successfully designed and evaluated in vitro and in HLA transgenic mice.