Spatiotemporal control of human cytomegalovirus transcriptional silencing during lytic and latent infection

裂解和潜伏感染期间人巨细胞病毒转录沉默的时空控制

• 批准号: 470699784
• 负责人: Professor Dr. Thomas Stamminger
• 金额: --
• 依托单位: Institut für Virologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/470699784?language=en
• 关键词: Spatiotemporal; control; human; cytomegalovirus; transcriptional

Human cytomegalovirus (HCMV), a species-specific herpesviruses, persists as a subclinical, lifelong infection in the normal human host. However, under conditions of immature or compromised immune control reactivation from latency frequently causes severe disease. Previous studies demonstrated that the HCMV genome undergoes transcriptional silencing during both lytic and latent infection, which is mediated by cellular heterochromatin building factors. So far, the molecular mechanisms governing the silencing of HCMV gene expression are still incompletely defined. We have shown that a group of cellular restriction factors (PML, Sp100, DAXX, ATRX, SPOC1) associating with parental viral genomes in a spatially and/or temporally regulated manner contribute to transcriptional silencing. In particular, we recently observed that the chromatin-remodeling factor SPOC1 interacts with the HCMV major immediate early promoter correlating with a shutdown of viral gene expression. Since SPOC1 recruits KAP1 and could be detected in association with the Human Silencing Hub (HUSH) complex one major aim of this proposal will be to investigate the contribution of these factors to the control of HCMV transcriptional silencing during both permissive infection and latency. The second objective will be to analyze viral chromatin accessibility and repressor occupancy in a genome-wide manner using novel methods allowing for efficient epigenomic profiling of small samples. The obtained results should help to understand how repressor occupancy dictates viral chromatin states and, consequently, determines the switch between silencing and activation of viral gene expression. This will be complemented by single cell RNA-Seq investigating whether a specific host transcriptional signature is associated with HCMV transcriptional silencing as well as live cell imaging experiments to visualize the silencing of individual HCMV genomes. In collaboration with other projects of the RU we aim at a comparative view of how repressor occupancy dictates distinct viral chromatin states and, consequently, determines the gene expression profile in various DNA viruses.

人巨细胞病毒（HCMV）是一种具有种属特异性的疱疹病毒，在正常人类宿主中以亚临床、终身感染的形式持续存在。然而，在免疫控制不成熟或受损的情况下，潜伏期的再激活经常导致严重的疾病。先前的研究表明，HCMV基因组在裂解和潜伏感染期间经历转录沉默，这是由细胞异染色质构建因子介导的。到目前为止，控制HCMV基因表达沉默的分子机制仍不完全清楚。我们已经表明，一组细胞限制因子（PML，Sp100，DAXX，ATRX，SPOC 1）与亲本病毒基因组在空间和/或时间调节的方式有助于转录沉默。特别是，我们最近观察到染色质重塑因子SPOC 1与HCMV主要立即早期启动子相互作用，与病毒基因表达的关闭相关。由于SPOC 1招募KAP 1，并可以检测到与人类沉默枢纽（HUSH）复合物的一个主要目的是调查这些因素的贡献，以控制HCMV转录沉默在允许感染和潜伏期。第二个目标将是分析病毒染色质的可及性和阻遏物占用在全基因组范围内的方式使用新的方法，允许有效的小样本的表观基因组分析。所获得的结果应有助于了解如何阻遏物占用决定病毒染色质状态，因此，决定沉默和激活病毒基因表达之间的切换。这将通过单细胞RNA-Seq研究特定宿主转录特征是否与HCMV转录沉默相关以及活细胞成像实验来补充，以可视化单个HCMV基因组的沉默。在与RU的其他项目合作，我们的目标是如何阻遏物占据支配不同的病毒染色质状态的比较视图，因此，决定在各种DNA病毒的基因表达谱。