Eradication of Epstein-Barr virus episome and associated inhibition of infected tumor cell growth by adenovirus vector-mediated transduction of dominant-negative EBNA1
Eradication of Epstein-Barr virus episome and associated inhibition of infected tumor cell growth by adenovirus vector-mediated transduction of dominant-negative EBNA1
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DOI：
10.1016/j.ymthe.2004.12.017
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发表时间：
2005-04-01
影响因子：
12.4
通讯作者：
Imai, S
中科院分区：
文献类型：
--
作者：
Nasimuzzaman, M;Kuroda, M;Imai, S
EB 病毒 (EBV) 核抗原 1 (EBNA1) 是一种在受感染的增殖细胞中持续表达的潜伏病毒蛋白，是反式维持细胞中 EBV 附加体所必需的。我们构建了突变体 (mt) EBNA1，并检查它是否对病毒附加体的维持产生显性负效应，从而导致 EBV 感染的肿瘤细胞生长终止。使用用新霉素抗性重组 EBV (rEBV) 转化的淋巴细胞和上皮细胞系作为模型，腺病毒载体介导的 mtEBNA1（而非 LacZ）转导，使 rEBV 衍生的野生型 EBNA1 水平和三种主要病毒潜伏期的转化细胞系中的病毒基因组载量迅速而显着降低。通过 G418 抗性的细胞丧失和原位病毒信号，这一结果在单细胞水平上得到了进一步验证。 mtEBNA1 转导在体外和体内显着损害了天然携带 EBV 的伯基特淋巴瘤细胞的生长，这很大程度上与病毒附加体的根除有关。 mtEBNA1 的表达本身在未感染 EBV 的细胞中没有引起可检测到的细胞毒性。这些结果表明，mtEBNA1 可以作为显性失活效应子，有效阻止细胞中 EBV 依赖性恶性表型，无论病毒潜伏期或组织来源如何。该突变体将提供一种专门针对 EBV 相关恶性肿瘤的额外治疗策略。
Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1), a latent viral protein consistently expressed in infected proliferating cells, is essentially required in trans to maintain EBV episomes in cells. We constructed a mutant (mt) EBNA1 and examined whether it exerted dominant-negative effects on maintenance of the viral episome thereby leading to abrogation of EBV-infected tumor cell growth. Using lymphocyte and epithelial cell lines converted with neomycin-resistant recombinant EBV (rEBV) as models, adenovirus vector-mediated transduction of mtEBNA1, but not LacZ, brought about rapid and striking reductions in rEBV-derived wild-type EBNA1 levels and viral genomic loads in converted lines of three major viral latencies. This outcome was further validated at the single-cell level by cellular loss of G418 resistance and viral signals in situ. The mtEBNA1 transduction significantly impaired growth of naturally EBV-harboring Burkitt lymphoma cells in vitro and in vivo, largely in association with the eradication of viral episomes. Expression of mtEBNA1 per se caused no detectable cytotoxicity in EBV-uninfected cells. These results indicate that mtEBNA1 can act as a dominant-negative effector that efficiently impedes the EBV-dependent malignant phenotypes in cells regardless of viral latency or tissue origin. The mutant will afford an additional therapeutic strategy specifically targeting EBV-associated malignancies.