Krauer K G, Belzer D K, Liaskou D, Buck M, Cross S, Honjo T, Sculley T
The Joint Oncology Program, Queensland Institute of Medical Research, University of Queensland, 300 Herston Road, Herston, Brisbane, 4029, Australia.
Virology. 1998 Dec 20;252(2):418-30. doi: 10.1006/viro.1998.9441.
Epstein-Barr virus (EBV) infects B cells, resulting in the outgrowth of immortalised lymphoblastoid cell lines (LCLs). Here, we demonstrate through the use of intracellular staining that interleukin-1beta (IL-1beta) is expressed in LCLs and investigate the influence of the individual latent proteins on the expression of IL-1beta. Using RT-PCR, IL-1beta was shown to be up-regulated in EBV-transformed LCLs as well as in group III Burkitt's lymphoma (BL) cell lines, compared with group I BL cell lines. The up-regulation of IL-1beta message could be mediated by the latent membrane protein-1, EBV nuclear proteins 2, 3, 4, and 6 genes. Electrophoretic mobility shift assays (EMSAs) demonstrated that the -300 region of the IL-1beta promoter, which contains a nuclear factor-kappaB (NF-kappaB) binding site, contained a functional RBP binding site. Binding of RBP to this site could be inhibited by addition of EBV nuclear proteins 3 and 6, suggesting that these proteins displace RBP from its recognition sequence, removing transcriptional repression and allowing gene transcription to occur. In group I BL cells, containing low levels of NF-kappaB, only RBP binding was observed in EMSAs, whereas NF-kappaB binding could be demonstrated in EBV-transformed B cell lines containing high levels of activated NF-kappaB. In addition, the expression of latent membrane protein-1 led to activation of NF-kappaB that was capable of binding the IL-1beta promoter. The study demonstrates that EBV can up-regulate IL-1beta expression, possibly by using RBP, NF-kappaB, or both.
爱泼斯坦-巴尔病毒（EBV）感染B细胞，导致永生化淋巴母细胞系（LCLs）的增殖。在此，我们通过细胞内染色证明白细胞介素-1β（IL-1β）在LCLs中表达，并研究单个潜伏蛋白对IL-1β表达的影响。使用逆转录聚合酶链反应（RT-PCR）表明，与I组伯基特淋巴瘤（BL）细胞系相比，EBV转化的LCLs以及III组BL细胞系中IL-1β上调。IL-1β信息的上调可能由潜伏膜蛋白-1、EBV核蛋白2、3、4和6基因介导。电泳迁移率变动分析（EMSA）表明，IL-1β启动子的-300区域包含一个核因子κB（NF-κB）结合位点，其中含有一个功能性RBP结合位点。添加EBV核蛋白3和6可抑制RBP与该位点的结合，这表明这些蛋白将RBP从其识别序列上置换下来，消除转录抑制并允许基因转录发生。在含有低水平NF-κB的I组BL细胞中，EMSA仅观察到RBP结合，而在含有高水平活化NF-κB的EBV转化B细胞系中可证明NF-κB结合。此外，潜伏膜蛋白-1的表达导致能够结合IL-1β启动子的NF-κB活化。该研究表明，EBV可能通过使用RBP、NF-κB或两者来上调IL-1β表达。
