Regulation of Epstein-Barr Virus Life Cycle and Cell Proliferation by Histone H3K27 Methyltransferase EZH2 in Akata Cells.
Regulation of Epstein-Barr Virus Life Cycle and Cell Proliferation by Histone H3K27 Methyltransferase EZH2 in Akata Cells.
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DOI：
10.1128/msphere.00478-18
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发表时间：
2018-11-28
期刊：
影响因子：
4.8
通讯作者：
Murata T
中科院分区：
文献类型：
--
作者：
Ichikawa T;Okuno Y;Sato Y;Goshima F;Yoshiyama H;Kanda T;Kimura H;Murata T
EBV的生命周期受表观遗传修饰（如CpG甲基化和组蛋白修饰）调节。在此，我们发现编码组蛋白H3 K27甲基转移酶的EZH 2的表达由EBV感染诱导;因此，我们产生EZH 2-KO细胞以研究EZH 2在EBV感染的Akata B细胞中的作用。EZH 2的破坏导致在裂解期EBV基因的表达增加，因此，有效的病毒复制和后代生产。我们的研究结果从表观遗传学的角度阐明了重新激活的机制，并进一步表明EZH 2作为一种先天免疫形式的作用，限制了病毒在感染细胞中的复制。表观遗传修饰在Epstein-Barr病毒（EBV）基因的表达中起着关键作用。我们发现，原发性B细胞的从头EBV感染引起zeste同源物2（EZH 2）的增强子的适度诱导，EZH 2是主要的组蛋白H3赖氨酸27（K27）甲基转移酶。为了研究EZH 2的作用，我们通过CRISPR/Cas9系统敲除EBV阴性Akata细胞中的EZH 2基因，并用EBV感染细胞，然后选择EBV阳性细胞。在潜伏状态期间，与野生型对照相比，感染后EZH 2敲除（KO）细胞的生长显著较慢，尽管细胞系之间的病毒基因表达水平相似。在通过抗IgG诱导裂解周期后，EZH 2的KO引起潜伏和裂解病毒基因的表达的显著诱导，以及病毒DNA复制和子代产生的增加。这些结果表明，EZH 2是至关重要的复杂的表观遗传调控不仅溶解，而且在Akata细胞中的潜伏基因表达。EBV的生命周期受表观遗传修饰的调节，如CpG甲基化和组蛋白修饰。在此，我们发现编码组蛋白H3 K27甲基转移酶的EZH 2的表达由EBV感染诱导;因此，我们产生EZH 2-KO细胞以研究EZH 2在EBV感染的Akata B细胞中的作用。EZH 2的破坏导致在裂解期EBV基因的表达增加，因此，有效的病毒复制和后代生产。我们的研究结果从表观遗传学的角度阐明了重新激活的机制，并进一步表明EZH 2作为一种先天免疫形式的作用，限制了病毒在感染细胞中的复制。
The life cycle of EBV is regulated by epigenetic modifications, such as CpG methylation and histone modifications. Here, we found that the expression of EZH2, which encodes a histone H3K27 methyltransferase, was induced by EBV infection; therefore, we generated EZH2-KO cells to investigate the role of EZH2 in EBV-infected Akata B cells. Disruption of EZH2 resulted in increased expression of EBV genes during the lytic phase and, therefore, efficient viral replication and progeny production. Our results shed light on the mechanisms underlying reactivation from an epigenetic point of view and further suggest a role for EZH2 as a form of innate immunity that restricts viral replication in infected cells. Epigenetic modifications play a pivotal role in the expression of the genes of Epstein-Barr virus (EBV). We found that de novo EBV infection of primary B cells caused moderate induction of enhancer of zeste homolog 2 (EZH2), the major histone H3 lysine 27 (K27) methyltransferase. To investigate the role of EZH2, we knocked out the EZH2 gene in EBV-negative Akata cells by the CRISPR/Cas9 system and infected the cells with EBV, followed by selection of EBV-positive cells. During the latent state, growth of EZH2-knockout (KO) cells was significantly slower after infection compared to wild-type controls, despite similar levels of viral gene expression between cell lines. After induction of the lytic cycle by anti-IgG, KO of EZH2 caused notable induction of expression of both latent and lytic viral genes, as well as increases in both viral DNA replication and progeny production. These results demonstrate that EZH2 is crucial for the intricate epigenetic regulation of not only lytic but also latent gene expression in Akata cells. IMPORTANCE The life cycle of EBV is regulated by epigenetic modifications, such as CpG methylation and histone modifications. Here, we found that the expression of EZH2, which encodes a histone H3K27 methyltransferase, was induced by EBV infection; therefore, we generated EZH2-KO cells to investigate the role of EZH2 in EBV-infected Akata B cells. Disruption of EZH2 resulted in increased expression of EBV genes during the lytic phase and, therefore, efficient viral replication and progeny production. Our results shed light on the mechanisms underlying reactivation from an epigenetic point of view and further suggest a role for EZH2 as a form of innate immunity that restricts viral replication in infected cells.