皮质类固醇拮抗剂损害单纯疱疹病毒1(HSV-1)生产性感染和外植体诱导的潜伏期再激活,提示皮质类固醇和糖皮质激素受体(GR)介导这些复杂的病毒-宿主相互作用的某些方面。GR-激素复合物正向和负向调节转录,在某种程度上,通过结合GR响应元件(GREs)。最近的研究显示感染的细胞蛋白0(ICP0),ICP4和ICP27启动子/顺式调节模块(CRM)被GR和Krüppel样因子15(KLF15)协同激活,形成前馈转录环。我们假设ICP0启动子含有被GR反式激活的独立CRMs,KLF15和合成皮质类固醇地塞米松(DEX)。这一假设是基于ICP0启动子含有多个转录因子结合位点的发现,GR和KLF15共同反式激活全长ICP0启动子。跨越-800至-635(片段A)的ICP0启动子序列被GR有效地反式激活,猴肾细胞(Vero)中的KLF15和DEX,而GR和DEX显著增强小鼠神经母细胞瘤细胞(Neuro-2A)中的启动子活性。此外,ICP0片段B(-458至-635)被GR有效地反式激活,KLF15和DEX在Vero细胞中,但不是Neuro-2A细胞.最后,片段D(-232至-24)在Vero细胞中被GR显著激活,KLF15和DEX,而KLF15和DEX足以在Neuro-2A细胞中进行反式激活。总的来说,这些研究揭示了GR对ICP0启动子内三个独立的CRM的有效反式激活,KLF15和/或DEX。最后,含有特异性蛋白1(Sp1)结合位点的富含GC的序列对于反式激活至关重要。
A corticosteroid antagonist impairs Herpes Simplex Virus 1 (HSV-1) productive infection and explant-induced reactivation from latency, suggesting corticosteroids and the glucocorticoid receptor (GR) mediate certain aspects of these complex virus-host interactions. GR-hormone complexes regulate transcription positively and negatively, in part, by binding GR response elements (GREs). Recent studies revealed infected cell protein 0 (ICP0), ICP4, and ICP27 promoter/cis-regulatory modules (CRMs) are cooperatively transactivated by GR and Krüppel-like factor 15 (KLF15), which forms a feed-forward transcription loop. We hypothesized the ICP0 promoter contains independent CRMs that are transactivated by GR, KLF15, and the synthetic corticosteroid dexamethasone (DEX). This hypothesis is based on the finding that the ICP0 promoter contains multiple transcription factor binding sites, and GR and KLF15 cooperatively transactivate the full-length ICP0 promoter. ICP0 promoter sequences spanning -800 to -635 (fragment A) were efficiently transactivated by GR, KLF15, and DEX in monkey kidney cells (Vero), whereas GR and DEX significantly enhanced promoter activity in mouse neuroblastoma cells (Neuro-2A). Furthermore, ICP0 fragment B (-458 to -635) was efficiently transactivated by GR, KLF15, and DEX in Vero cells, but not Neuro-2A cells. Finally, fragment D (-232 to -24) was transactivated significantly in Vero cells by GR, KLF15, and DEX, whereas KLF15 and DEX were sufficient for transactivation in Neuro-2A cells. Collectively, these studies revealed efficient transactivation of three independent CRMs within the ICP0 promoter by GR, KLF15, and/or DEX. Finally, GC-rich sequences containing specificity protein 1 (Sp1) binding sites were essential for transactivation.