Combinatorial Effects of the Glucocorticoid Receptor and Kruppel-Like Transcription Factor 15 on Bovine Herpesvirus 1 Transcription and Productive Infection
Combinatorial Effects of the Glucocorticoid Receptor and Kruppel-Like Transcription Factor 15 on Bovine Herpesvirus 1 Transcription and Productive Infection
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DOI：
10.1128/jvi.00904-17
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发表时间：
2017-11-01
影响因子：
5.4
通讯作者：
Jones, Clinton
中科院分区：
文献类型：
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作者：
El-Mayet, Fouad S.;Sawant, Laximan;Jones, Clinton
牛疱疹病毒1型（BoHV-1）是一种重要的牛病原体，在感觉神经元中建立终身潜伏期。潜伏感染的小牛在单次静脉注射合成皮质类固醇地塞米松后持续从潜伏期重新激活。驱动牛ICP 0（bICP 0）和bICP 4表达的立即早期转录单位1（IEtu 1）启动子受地塞米松刺激，因为它含有两个糖皮质激素受体（GR）反应元件（GRES）。几种Kruppel样转录因子（KLF），包括KLF 15，在潜伏期的再激活过程中被诱导，它们刺激某些病毒启动子和生产性感染。在这项研究中，我们表明，GR和KLF 15频繁表达在同一三叉神经节（TG）神经元在重新激活和协同刺激生产性感染和IEtu 1 GRES在小鼠神经母细胞瘤细胞（Neuro-2A）。我们进一步假设BoHV-1基因组中的其他区域被GR或应激诱导的转录因子反式激活。为了验证这一假设，BoHV-1 DNA片段（小于400 bp）含有潜在的GR和KLF结合位点进行了鉴定，并检查转录激活应激诱导的转录因子。独特的长52基因（UL 52; DNA引发酶/解旋酶复合物的一个组成部分），bICP 4，IEtu 2和独特的短区域内的基因间区域被KLF 15和GR刺激。染色质免疫沉淀研究表明，GR和KLF 15与IEtu 1 GRES和UL 52片段内的序列相互作用。免疫共沉淀研究表明，KLF 15和GR在转染细胞中相互关联。由于GR刺激KLF 15的表达，我们认为，这两个转录因子形成一个前馈回路，刺激病毒基因的表达和生产性感染后的压力stimulation.IMPORTANCE牛疱疹病毒1（BoHV-1）是一种重要的病毒病原体，导致呼吸道疾病，抑制免疫反应的牛，因此，危及生命的细菌性肺炎可能会发生。急性感染后，BoHV-1在感觉神经元中建立终身潜伏期。潜伏期的再激活由合成皮质类固醇地塞米松启动。地塞米松刺激潜伏感染BoHV-1的小牛感觉神经元中的裂解性周期病毒基因表达，最终导致病毒脱落和传播。两种应激诱导的细胞转录因子，Kruppel样转录因子15（KLF 15）和糖皮质激素受体（GR），合作刺激生产性感染和病毒转录。其他研究表明，KLF 15和GR形成稳定的复合物，这些应激诱导的转录因子与病毒DNA序列结合，这与转录激活相关。GR和KLF 15协同刺激病毒基因表达和生产性感染的能力可能对于BoHV-1在应激刺激后从潜伏期重新激活的能力至关重要。
Bovine herpesvirus 1 (BoHV-1), an important bovine pathogen, establishes lifelong latency in sensory neurons. Latently infected calves consistently reactivate from latency following a single intravenous injection of the synthetic corticosteroid dexamethasone. The immediate early transcription unit 1 (IEtu1) promoter, which drives bovine ICP0 (bICP0) and bICP4 expression, is stimulated by dexamethasone because it contains two glucocorticoid receptor (GR) response elements (GREs). Several Kruppel-like transcription factors (KLF), including KLF15, are induced during reactivation from latency, and they stimulate certain viral promoters and productive infection. In this study, we demonstrate that the GR and KLF15 were frequently expressed in the same trigeminal ganglion (TG) neuron during reactivation and cooperatively stimulated productive infection and IEtu1 GREs in mouse neuroblastoma cells (Neuro-2A). We further hypothesized that additional regions in the BoHV-1 genome are transactivated by the GR or stress-induced transcription factors. To test this hypothesis, BoHV-1 DNA fragments (less than 400 bp) containing potential GR and KLF binding sites were identified and examined for transcriptional activation by stress-induced transcription factors. Intergenic regions within the unique long 52 gene (UL52; a component of the DNA primase/helicase complex), bICP4, IEtu2, and the unique short region were stimulated by KLF15 and the GR. Chromatin immuno-precipitation studies revealed that the GR and KLF15 interacted with sequences within IEtu1 GREs and the UL52 fragment. Coimmunoprecipitation studies demonstrated that KLF15 and the GR were associated with each other in transfected cells. Since the GR stimulates KLF15 expression, we suggest that these two transcription factors form a feed-forward loop that stimulates viral gene expression and productive infection following stressful stimuli.IMPORTANCE Bovine herpesvirus 1 (BoHV-1) is an important viral pathogen that causes respiratory disease and suppresses immune responses in cattle; consequently, life-threatening bacterial pneumonia can occur. Following acute infection, BoHV-1 establishes lifelong latency in sensory neurons. Reactivation from latency is initiated by the synthetic corticosteroid dexamethasone. Dexamethasone stimulates lytic cycle viral gene expression in sensory neurons of calves latently infected with BoHV-1, culminating in virus shedding and transmission. Two stress-induced cellular transcription factors, Kruppel-like transcription factor 15 (KLF15) and the glucocorticoid receptor (GR), cooperate to stimulate productive infection and viral transcription. Additional studies demonstrated that KLF15 and the GR form a stable complex and that these stress-induced transcription factors bind to viral DNA sequences, which correlates with transcriptional activation. The ability of the GR and KLF15 to synergistically stimulate viral gene expression and productive infection may be critical for the ability of BoHV-1 to reactivate from latency following stressful stimuli.