()-Epigallocatechin-3-Gallate Inhibits EBV Lytic Replication via Targeting LMP1-Mediated MAPK Signal Axes.
()-Epigallocatechin-3-Gallate Inhibits EBV Lytic Replication via Targeting LMP1-Mediated MAPK Signal Axes.
复制标题
(-)-表没食子儿茶素-3-没食子酸酯通过靶向 LMP1 介导的 MAPK 信号轴抑制 EBV 裂解复制
DOI：
10.3727/096504021x16135618512563
复制
发表时间：
2021-09-07
影响因子：
3.1
通讯作者：
Cao Y
中科院分区：
文献类型：
--
作者：
Li H;Li Y;Hu J;Liu S;Luo X;Tang M;Bode AM;Dong Z;Liu X;Liao W;Cao Y
爱泼斯坦-巴尔病毒（EBV）编码的潜伏膜蛋白1（LMP1）在病毒潜伏感染中发挥着重要的致癌作用。最近，越来越多的证据表明，LMP1 在 EBV 溶核周期中的高表达与病毒的溶核复制有关。然而，LMP1调控EBV裂解复制的机制仍不清楚。(-)-表没食子儿茶素-3-棓酸盐（EGCG）通过直接靶向多种膜蛋白防止癌变，并有效抑制 EBV 溶解级联。在这里，我们证明了 LMP1 通过下游信号分子 MAPKs（包括 ERKs、p38 和 JNKs）促进 EBV 溶解复制。LMP1通过MAPKs诱导p53磷酸化，从而增强野生型p53（wt-p53）激活BZLF1基因表达的能力，而JNKs/c-Jun信号轴似乎参与了p53突变体方式下LMP1诱导的EBV裂解复制。我们利用荧光淬灭法、等温滴定量热法和 CNBR 激活的 Sepharose 4B pull-down 亲和层析法首次证明了 EGCG 直接靶向病毒膜 LMP1（K d = 0.36 μM，n = 1）。此外，我们还发现，EGCG通过抑制LMP1从而阻断下游MAPKs/wt-p53信号轴（在AGS-EBV细胞中）和JNKs/c-Jun信号轴（在p53突变体B95.8细胞中）来抑制EB病毒的溶解复制。我们的研究首次报道了EGCG与EBV编码的关键肿瘤蛋白LMP1的结合和抑制作用。这些发现表明了LMP1在调控EB病毒溶解周期中的新功能，并揭示了EGCG通过抑制病毒再活化在EB病毒相关恶性肿瘤中的新作用。
Epstein–Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) plays an important oncogenic role in the viral latent infection. Recently, increasing evidence indicates that the high expression of LMP1 during EBV lytic cycle is related to the viral lytic replication. However, the mechanism by which LMP1 regulates EBV lytic replication remains unclear. (−)-Epigallocatechin-3-gallate (EGCG) prevents carcinogenesis by directly targeting numerous membrane proteins and effectively inhibits EBV lytic cascade. Here, we demonstrated that LMP1 promotes EBV lytic replication through the downstream signal molecules MAPKs, including ERKs, p38, and JNKs. LMP1 induces the phosphorylation of p53 through MAPKs to enhance the ability of wild-type p53 (wt-p53) to activate expression of BZLF1 gene, while the JNKs/c-Jun signal axis appears to be involved in EBV lytic replication induced by LMP1 in p53 mutant manner. We provided the first evidence that EGCG directly targets the viral membrane LMP1 (K d = 0.36 μM, n = 1) using fluorescence quenching, isothermal titration calorimetry (ITC) assay, and CNBR-activated Sepharose 4B pull-down affinity chromatography. Furthermore, we revealed that EGCG inhibits EBV lytic replication via suppressing LMP1 and thus blocking the downstream MAPKs/wt-p53 signal axis in AGS-EBV cells and JNKs/c-Jun signal axis in p53 mutant B95.8 cells. Our study, for the first time, reports the binding and inhibitory efficacy of EGCG to the LMP1, which is a key oncoprotein encoded by EBV. These findings suggest the novel function of LMP1 in the regulation of EBV lytic cycle and reveal the new role of EGCG in EBV-associated malignancies through suppressing viral reactivation.