Long-term promoter activity during herpes simplex virus latency.
Long-term promoter activity during herpes simplex virus latency.
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单纯疱疹病毒潜伏期的长期启动子活性。
DOI：
10.1128/jvi.68.11.7148-7158.1994
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发表时间：
1994
影响因子：
5.4
通讯作者：
Feldman,LT
中科院分区：
文献类型：
--
作者：
Lokensgard,JR;Bloom,DC;Dobson,AT;Feldman,LT
单纯疱疹病毒1型(HSV-1)基因组在急性或潜伏感染时引导外源基因表达的能力是利用HSV载体进行基因治疗的一个日益重要的课题。关于神经元中存在的转录因子的类型，或者神经节中不同的神经元群体是否在这些因子的互补方面存在差异，人们知之甚少。关于HSV-1潜伏期，目前尚不清楚潜伏期相关转录子(LAT)启动子如何或为什么能够在潜伏期内持续发挥作用，而所有其他病毒启动子都是无效的。为了进一步研究这两种现象，我们构建了7种不同启动子结构的重组病毒来驱动LacZ报告基因的表达。将每个重组载体插入HSV-1病毒的糖蛋白C位点，检测重组病毒在小鼠背根神经节急性和潜伏感染过程中表达β-半乳糖苷酶的能力。在小鼠背根神经节急性感染过程中，启动子的活性变化很大。含有小鼠金属硫蛋白启动子(MT1)、磷酸甘油酸激酶启动子、Moloney小鼠白血病病毒长末端重复序列(LTR)或HSV LAT核心启动子(LAT)上游区域的重组载体在感染的急性期而不是潜伏期是活跃的。MT1和LTR启动子(分别为LAT-MT1和LAT-LTR)上游LAT区域的转录因子结合位点的增加显著增加了急性期的表达。尽管有这些高的初始转录速率，但在所有的启动子结构中，只有LAT-LTR能够在潜伏期建立后保持转录活性。因此，Moloney鼠白血病病毒LTR提供了一种DNA元件，其功能是防止潜伏期内启动子的失活。在上游的LAT启动子中显然不存在类似的HSV长期表达元件，这表明HSV的长期表达功能是由感染急性期提供高水平神经元表达的区域之外的区域提供的。
The ability to direct foreign gene expression from the herpes simplex virus type 1 (HSV-1) genome during an acute or latent infection is a subject of increasing importance in the utilization of HSV vectors for gene therapy. Little is known about the types of transcription factors present in neurons or about whether different neuronal populations within a ganglion vary in their complement of these factors. With respect to HSV-1 latency, it is not known how or why the latency-associated transcript (LAT) promoter is able to function continually during latency while all other viral promoters are inactive. To further studies of these two phenomena, we constructed seven recombinant viruses with various promoter constructs driving expression of the lacZ reporter gene. Each construct was inserted into HSV-1 at the glycoprotein C locus, and recombinant viruses were evaluated for the ability to express beta-galactosidase during acute and latent viral infections in murine dorsal root ganglia. During acute infection of murine dorsal root ganglia, the activities of the promoters varied over a wide range. Constructs containing the murine metallothionein promoter (MT1), the phosphoglycerate kinase promoter, the Moloney murine leukemia virus long terminal repeat (LTR), or the region upstream of and including the HSV LAT core promoter (LAT) were active during the acute but not the latent phase of infection. The addition of transcription factor binding sites present in the upstream LAT region to the MT1 and LTR promoters (LAT-MT1 and LAT-LTR, respectively) significantly increased acute-phase expression. Despite these high initial rates of transcription, of all the promoter constructs only LAT-LTR was able to remain transcriptionally active after the establishment of a latent state. Thus, the Moloney murine leukemia virus LTR provides a DNA element which functions to prevent promoter inactivation during latency. An analogous HSV long-term-expression element is evidently not present in the upstream LAT promoter, indicating that the HSV long-term-expression function is provided by a region outside of that which gives high-level neuronal expression during the acute phase of infection.