Role of the human cytomegalovirus major immediate-early promoter's 19-base-pair-repeat cyclic AMP-response element in acutely infected cells
Role of the human cytomegalovirus major immediate-early promoter's 19-base-pair-repeat cyclic AMP-response element in acutely infected cells
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DOI：
10.1128/jvi.77.12.6666-6675.2003
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发表时间：
2003-06-01
影响因子：
5.4
通讯作者：
Meier, JL
中科院分区：
文献类型：
--
作者：
Keller, MJ;Wheeler, DG;Meier, JL
先前的研究表明，5个拷贝的19-碱基重复的环磷酸腺苷(CAMP)反应元件(CRE)在主要的即刻早期(MIE)启动子激活中起作用，这是人类巨细胞病毒(HCMV)复制的限速步骤。我们使用了两种不同的HCMV基因组修改策略，在急性感染的细胞中验证了这一假设。我们的研究结果如下：(I)在高或低感染复数(MOI)的人包皮成纤维细胞(HIFF)或NTera2来源的神经细胞中，CRES不控制MIE启动子活性的基础水平；(Ii)血清和病毒组分在低感染复数(MOI)时显著增加MIE启动子依赖的转录，但这种增加不是由CRES介导的；(Iii)Forsklin刺激cAMP信号通路在低MOI时以CRE特异性的方式诱导HFF和NTera2来源的神经细胞MIE RNA水平增加两到三倍；(4)CRES不调节HFF中高MOI或低MOI时HCMV DNA复制的基础水平。它们的存在确实在低MOI下给予Forsklin诱导的病毒DNA复制增加，但只有在实验上降低MIE启动子活性的基础水平时才能实现。总而言之，19个碱基重复的Cres增加了在急性感染的刺激细胞中发生的强大的MIE启动子活性，尽管Cres的更大作用可能是在其他环境中。
Prior studies have suggested a role of the five copies of the 19-bp-repeat cyclic AMP (cAMP)-response element (CRE) in major immediate-early (MIE) promoter activation, the rate-limiting step in human cytomegalovirus (HCMV) replication. We used two different HCMV genome modification strategies to test this hypothesis in acutely infected cells. We report the following: (i) the CREs do not govern basal levels of MIE promoter activity at a high or low multiplicity of infection (MOI) in human foreskin fibroblast (HIFF)- or NTera2-derived neuronal cells; (ii) serum and virion components markedly increase MIE promoter-dependent transcription at a low multiplicity of infection (MOI), but this increase is not mediated by the CREs; (iii) forskolin stimulation of the cAMP signaling pathway induces a two- to threefold increase in MIE RNA levels in a CRE-specific manner at a low MOI in both HFF- and NTera2-derived neuronal cells; and (iv) the CREs do not regulate basal levels of HCMV DNA replication at a high or low MOI in HFF. Their presence does impart a forskolin-induced increase in viral DNA replication at a low MOI but only when basal levels of MIE promoter activity are experimentally diminished. In conclusion, the 19-bp-repeat CREs add to the robust MIE promoter activity that occurs in the acutely infected stimulated cells, although the CREs' greater role may be in other settings.