Chimerically fused antigen rich of overlapped epitopes from latent membrane protein 2 (LMP2) of Epstein-Barr virus as a potential vaccine and diagnostic agent
Chimerically fused antigen rich of overlapped epitopes from latent membrane protein 2 (LMP2) of Epstein-Barr virus as a potential vaccine and diagnostic agent
复制标题
富含 Epstein-Barr 病毒潜伏膜蛋白 2 (LMP2) 重叠表位的嵌合融合抗原，作为潜在的疫苗和诊断剂
DOI：
10.1038/cmi.2015.29
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发表时间：
2016-07-01
影响因子：
24.1
通讯作者：
Zhang，Lifang
中科院分区：
文献类型：
--
作者：
Lin，Xiaoyun;Chen，Shao;Zhang，Lifang
EB病毒（EBV）在全世界流行，并与人类的几种恶性疾病有关。EB病毒潜伏膜蛋白2（LMP 2）在EB病毒相关肿瘤的发病机制中起重要作用，因此LMP 2被认为是一个潜在的免疫诊断和免疫治疗靶点。基于多表位的抗原是用于治疗性疫苗和此类恶性肿瘤的诊断的有希望的选择。本研究利用生物信息学方法系统地筛选了EBV-LMP 2中的细胞毒性T淋巴细胞（CTL）、辅助性T细胞（Th）和B细胞表位。基于该筛选，选择两种富含T细胞和B细胞的重叠表位的肽来构建含有称为EBV-LMP 2 m的嵌合多表位蛋白的序列的质粒，所述嵌合多表位蛋白由LMP 2aa 195 - 232和LMP 2aa 419 - 436组成。在E.原核密码子优化后的大肠杆菌BL 21（DE 3）。将纯化的嵌合抗原接种BALB/c小鼠，不仅诱导血清中高水平的特异性IgG和阴道粘液中分泌的伊加，而且诱导特异性CTL应答。以纯化的EBV-LMP 2 m为抗原，检测202例鼻咽癌患者血清中特异性IgG，其敏感性为52.84%，特异性为95.40%，较传统的VCA-IgA检测方法（敏感性60.53%，特异性76.86%）有明显提高。上述结果表明，EBV-LMP 2 m不仅可以用作EBV相关肿瘤的潜在靶抗原，而且可以用作NPC患者的诊断剂。
Epstein–Barr virus (EBV) is prevalent throughout the world and is associated with several malignant diseases in humans. Latent membrane protein 2 (LMP2) of EBV plays a crucial role in the pathogenesis of EBV-associated tumors; therefore, LMP2 has been considered to be a potential immunodiagnostic and immunotherapeutic target. A multi-epitope-based antigen is a promising option for therapeutic vaccines and diagnoses of such malignancies. In this study, we systematically screened cytotoxic T lymphocyte (CTL), helper T cell (Th) and B-cell epitopes within EBV-LMP2 using bioinformatics. Based on the screen, two peptides rich in overlapping epitopes of both T cells and B cells were selected to construct a plasmid containing the sequence for a chimeric multi-epitope protein referred to as EBV-LMP2m, which is composed of LMP2aa195∼ 232 and LMP2aa419∼ 436. The EBV-LMP2m protein was expressed in E. coli BL21 (DE3) after prokaryotic codon optimization. Inoculation of the purified chimeric antigen in BALB/c mice induced not only high levels of specific IgG in the serum and secretory IgA in the vaginal mucus but also a specific CTL response. By using purified EBV-LMP2m as an antigen, the presence of specific IgG in the serum specimens of 202 nasopharyngeal carcinoma (NPC) patients was effectively detected with 52.84% sensitivity and 95.40% specificity, which represents an improvement over the traditional detection method based on VCA-IgA (60.53% sensitivity and 76.86% specificity). The above results indicate that EBV-LMP2m may be used not only as a potential target antigen for EBV-associated tumors but also a diagnostic agent for NPC patients.