Deletion of Kaposi's Sarcoma-Associated Herpesvirus FLICE Inhibitory Protein, vFLIP, from the Viral Genome Compromises the Activation of STAT1-Responsive Cellular Genes and Spindle Cell Formation in Endothelial Cells
Deletion of Kaposi's Sarcoma-Associated Herpesvirus FLICE Inhibitory Protein, vFLIP, from the Viral Genome Compromises the Activation of STAT1-Responsive Cellular Genes and Spindle Cell Formation in Endothelial Cells
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DOI：
10.1128/jvi.00226-11
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发表时间：
2011-10-01
影响因子：
5.4
通讯作者：
Schulz, Thomas F.
中科院分区：
文献类型：
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作者：
Alkharsah, Khaled R.;Singh, Vivek Vikram;Schulz, Thomas F.
卡波西肉瘤疱疹病毒 (KSHV) Fas 相关死亡结构域 (FADD) 样白介素 1 β 转换酶 (FLICE) 抑制蛋白 vFLIP 具有抗凋亡特性，是 NF-kappa B 通路的有效激活剂，当在原代内皮细胞中过表达时，可诱导内皮梭形细胞的形成，这是卡波西肉瘤的标志细胞。我们使用反向遗传学方法在整个病毒基因组背景下研究 KSHV vFLIP 的多种功能。从细菌人工染色体 (BAC) 中克隆的 KSHV 基因组中删除编码 vFLIP 的基因，会降低病毒在原代人脐静脉内皮细胞 (HUVEC) 中持续存在并诱导梭形细胞形成的能力。在野生型 KSHV (KSHV-wt) 感染的内皮细胞中，只有少数基因（主要是干扰素 (IFN) 反应性）的表达水平高于 KSHV-Delta FLIP 感染的内皮细胞中的表达水平，这与过表达 vFLIP 诱导的大量细胞基因形成鲜明对比。与这一观察结果一致，vFLIP 在内皮细胞中以 NF-κ B 依赖性方式诱导 STAT1 和 STAT2 磷酸化。在内皮细胞感染 KSHV-wt、KSHV-Delta FLIP 和 KSHV-vFLIP 回复病毒后，可以证明 STAT1 和 STAT2 的 vFLIP 依赖性磷酸化。这些发现记录了 KSHV vFLIP 在病毒持续存在期间对原代内皮细胞转录组的影响，并强调了 vFLIP 在 KSHV 激活 STAT1/STAT2 和 STAT 反应性细胞基因中的作用。
Kaposi's sarcoma herpesvirus (KSHV) Fas-associated death domain (FADD)-like interleukin-1 beta-converting enzyme (FLICE)-inhibitory protein, vFLIP, has antiapoptotic properties, is a potent activator of the NF-kappa B pathway, and induces the formation of endothelial spindle cells, the hallmark of Kaposi's sarcoma, when overexpressed in primary endothelial cells. We used a reverse genetics approach to study several functions of KSHV vFLIP in the context of the whole viral genome. Deletion of the gene encoding vFLIP from a KSHV genome cloned in a bacterial artificial chromosome (BAC) reduced the ability of the virus to persist and induce spindle cell formation in primary human umbilical vein endothelial cells (HUVECs). Only a few, mainly interferon (IFN)-responsive, genes were expressed in wild-type KSHV (KSHV-wt)-infected endothelial cells at levels higher than those in KSHV-Delta FLIP-infected endothelial cells, in contrast to the plethora of cellular genes induced by overexpressed vFLIP. In keeping with this observation, vFLIP induces the phosphorylation of STAT1 and STAT2 in an NF-kappa B-dependent manner in endothelial cells. vFLIP-dependent phosphorylation of STAT1 and STAT2 could be demonstrated after endothelial cells were infected with KSHV-wt, KSHV-Delta FLIP, and a KSHV-vFLIP revertant virus. These findings document the impact of KSHV vFLIP on the transcriptome of primary endothelial cells during viral persistence and highlight the role of vFLIP in the activation of STAT1/STAT2 and STAT-responsive cellular genes by KSHV.