Chromosome 1 Damage in HCMV Infected Cells

HCMV 感染细胞中 1 号染色体损伤

• 批准号: 6463333
• 负责人: ELIZABETH A FORTUNATO
• 金额: $ 28.6万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6463333
• 关键词: DNA damage; DNA repair; cell cycle; cytomegalovirus; tissue /cell culture; virus replication

DESCRIPTION (provided by applicant): Human Cytomegalovirus (HCMV) is the major viral cause of birth defects, infecting 1-2 percent of all newborns annually. Approximately 5-10 percent of these congenitally infected infants will manifest signs of serious neurological damage at birth which can include deafness, blindness, mental retardation and microcephaly. Another 10-15 percent will develop sensori-neural hearing loss and/or learning disabilities within the first 10 years of life. Our long-term goal is to understand the mechanism behind the development of morbidity and mortality in infants congenitally infected with HCMV. To this end, we have studied the interaction of HCMV with the cell cycle and DNA repair machinery of the permissively infected cell over the last several years. What we have discerned is that HCMV sequesters many of the key players of maintenance and repair into its viral replication centers. However, it appears to partition the components of several complexes so that all the proteins are present within the replication centers, but not all are available to the cellular genome. We have also determined that HCMV can induce very specific genotoxic damage at positions 1q21 and 1q42 when cells are infected during S-phase. Coupled with reports of others regarding the nonspecific damage induced at late times post infection, it is becoming more clear that HCMV is indeed genotoxic to the host cell genome. We hypothesize that long-term detrimental consequences to the cellular genome may occur if 1) this initial specific damage is propagated or 2)damage incurred at late times post infection is not repaired due to sequestration of the repair machinery. To test our hypothesis, we propose three specific aims. First, we will thoroughly define the parameters of chromosome 1q breakage in HCMV-infected cells with regard to rapidity of induction and cell cycle phase at time of infection. We will also determine what virion components are required for break induction. We think it is imperative that our results be moved into more clinically relevant cell types, especially cells of neural lineage, as these are the cells most severely affected by the virus during congenital infection. Second, we also will determine the consequences of chromosome 1 damage in these clinically relevant cells, and whether in a semi-permissive environment we can observe propagation of the chromosome 1 damage instead of healing of the break or movement of the cell toward apoptosis. Lastly, we will characterize the ability of HCMV-infected cells to repair exogenously introduced damage at late times post infection, after viral replication centers are assembled. It is our belief that results we obtain in culture will aid in our understanding of the central nervous system problems observed in congenitally infected infants.

描述（由申请人提供）：人巨细胞病毒（HCMV）是主要的 病毒导致出生缺陷，每年感染1- 2%的新生儿。 大约5- 10%的先天性感染婴儿会表现出 出生时严重神经损伤的迹象，包括耳聋， 失明、智力迟钝和小头畸形。另外10%到15%的人 发展感觉神经听力损失和/或学习障碍， 人生的第一个十年我们的长期目标是了解 婴儿先天性发病率和死亡率的发展背后 感染了人巨细胞病毒。为此，我们研究了HCMV与 允许感染细胞的细胞周期和DNA修复机制 过去几年里。我们已经发现，HCMV隔离了许多 病毒复制中心的主要维护者和修复者。 然而，它似乎将几种复合物的组分分开， 所有的蛋白质都存在于复制中心，但不是所有的都是 可用于细胞基因组。我们还确定HCMV可以诱导 当细胞在1 q21和1 q42位置时， 在S期感染。 再加上其他人关于晚些时候引起的非特异性损害的报告， 感染后20倍，人们越来越清楚地发现HCMV确实具有遗传毒性 到宿主细胞基因组。我们假设长期的有害后果 如果1）这种最初的特异性损伤是 传播或2）感染后后期发生的损伤未修复 因为修理机器被封存了为了验证我们的假设，我们 提出三个具体目标。首先，我们将彻底定义 HCMV感染细胞中染色体1 q断裂的速度 诱导和细胞周期阶段。我们还将确定 断裂诱导需要哪些病毒体成分。我们认为这是 我们的结果必须转移到更临床相关的细胞类型， 特别是神经细胞，因为这些细胞是最严重的 在先天性感染期间受到病毒的影响。第二，我们也将 确定1号染色体损伤的后果，在这些临床相关的 细胞，以及是否在半许可的环境中，我们可以观察到传播 1号染色体的损伤，而不是愈合的断裂或运动的 细胞凋亡。最后，我们将描述 HCMV感染的细胞在术后晚期修复外源性损伤 感染，病毒复制中心组装后。我们相信 我们在文化中获得的结果将有助于我们理解 先天性感染婴儿的神经系统问题。