Characterization of the gammaherpes virus specific tegument protein, pORF52, in t

伽玛疱疹病毒特异性外皮蛋白 pORF52 的表征

• 批准号: 8061120
• 负责人: Melissa S Anderson
• 金额: $ 2.82万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-24 至 2013-09-23
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8061120
• 关键词: Characterization; gammaherpes; virus; specific; tegument

DESCRIPTION (provided by applicant): Rhesus monkey rhadinovirus (RRV), a gammaherpesvirus, is a close viral relative of Kaposi's sarcoma (KS)- associated herpesvirus (KSHV or HHV8), the causative agent of three human malignancies, Kaposi's Sarcoma (KS), primary effusion lymphoma, and multicentric Castleman's disease. RRV is an effective model to study the structure and assembly of gammaherpesviruses since it is able to produce high levels of progeny viruses in culture. The insights gained from studying mechanisms governing virally induced cancers can extend to a wide variety of malignancies, helping in the development of new treatments and therapies. Previous data from our laboratory have shown that RRV contains five gammaherpesvirus specific proteins in its tegument (middle) layer and of those, three have unknown functions, including the protein encoded by open reading frame 52, pORF52. Our hypothesis is that pORF52 plays a critical role in the structure of virions (viral particles) and their assembly as well as a potential role in cellular egress via a direct or indirect interaction with critical infrastructural components of the cell known as microtubules (MTs). Our methods of investigation include utilization of a wild-type (WT) RRV and an ORF52 deleted ( 52) RRV bacterial artificial chromosomes (BAC), each of which contains the remainder of the viral genome. Introducing these BACs into cells capable of supporting viral production will allow us to monitor the viral life cycle in the presence or absence of pORF52 production. The first goal will be to determine whether pORF52 is necessary for RRV DNA replication, a step preceding and required for progeny viral production. Quantitative analysis of the levels of individual viral proteins within the BAC containing cells will then help determine the requirement of pORF52 in the production of the various building block proteins necessary for viral assembly. In addition to these analyses, various imaging techniques will generate complementary data, helping us to examine the structure of the individual particles, the gross level of their production within the cells, as well as their intracellular localization and stage of maturation. In addition, media from cells containing either WT or 52 BAC will be assessed for a) infectious virus and b) production of structural viral proteins. Our preliminary results indicate that pORF52 is necessary for production of virus. To test this, 52 BAC containing cells will be complemented with the introduction of exogenous pORF52 and subsequently examined for the presence of infectious virions as described above. Additionally, RRV pORF52 expression by itself leads to its co-localization with, and stabilization of microtubules. Included in the second half of this proposal is a series of experiments that will investigate this potential interaction using microtubule binding assays, immunofluorescence and confocal microscopy, and assays that directly assess physical interactions between these two components. Combined with a series of mutations strategically introduced into pORF52, these approaches will allow the identification of the regions within the protein essential for not only its MT interactions but also its role in the viral life cycle. PUBLIC HEALTH RELEVANCE: The insights gained from studying mechanisms governing virally induced cancers can extend to a wide variety of malignancies, helping in the development of new treatments and therapies. In this application, we propose to characterize the actions of one specific protein in the life cycle of a subfamily of tumor forming viruses called gammaherpesviruses. We hypothesize that this particular protein may play an essential role in the formation of new viral particles and, thus, would be an attractive candidate for targeted anti-viral therapy.

描述（由申请方提供）：恒河猴鼻状病毒（RRV）是一种γ疱疹病毒，是卡波西肉瘤（KS）相关疱疹病毒（KSHV或HHV 8）的近亲，卡波西肉瘤（KS）相关疱疹病毒是三种人类恶性肿瘤卡波西肉瘤（KS）、原发性渗出性淋巴瘤和多中心Castleman病的病原体。RRV是研究γ疱疹病毒结构和组装的有效模型，因为它能够在培养物中产生高水平的子代病毒。从研究病毒诱导的癌症机制中获得的见解可以扩展到各种恶性肿瘤，有助于开发新的治疗方法和疗法。我们实验室以前的数据表明，RRV在其被膜（中间）层中含有五种γ疱疹病毒特异性蛋白，其中三种具有未知功能，包括由开放阅读框52编码的蛋白，pORF 52。我们的假设是pORF 52在病毒粒子（病毒颗粒）的结构及其组装中起关键作用，以及通过与细胞的关键基础结构组分（称为微管（MT））的直接或间接相互作用在细胞外出中起潜在作用。我们的研究方法包括利用野生型（WT）RRV和ORF 52缺失的（52）RRV细菌人工染色体（BAC），每一个都含有病毒基因组的剩余部分。将这些BAC引入能够支持病毒生产的细胞中将允许我们在存在或不存在pORF 52生产的情况下监测病毒生命周期。第一个目标是确定pORF 52是否是RRV DNA复制所必需的，这是子代病毒生产之前和所需的一个步骤。定量分析含有BAC的细胞内的单个病毒蛋白质的水平将有助于确定在病毒组装所需的各种结构单元蛋白质的生产中对pORF 52的需求。除了这些分析，各种成像技术将产生补充数据，帮助我们检查单个颗粒的结构，细胞内产生的总水平，以及它们的细胞内定位和成熟阶段。此外，将评估来自含有WT或52 BAC的细胞的培养基的a）感染性病毒和B）结构病毒蛋白的产生。我们的初步结果表明pORF 52是病毒生产所必需的。为了测试这一点，将通过引入外源pORF 52来补充52个含有BAC的细胞，随后如上所述检查感染性病毒体的存在。此外，RRV pORF 52表达本身导致其与微管共定位并稳定微管。包括在本提案的后半部分是一系列的实验，将调查这种潜在的相互作用，使用微管结合试验，免疫荧光和共聚焦显微镜，并测定，直接评估这两个组件之间的物理相互作用。结合一系列战略性引入pORF 52的突变，这些方法将允许鉴定蛋白质内不仅对其MT相互作用而且对其在病毒生命周期中的作用至关重要的区域。 公共卫生相关性：从研究病毒诱导的癌症机制中获得的见解可以扩展到各种恶性肿瘤，有助于开发新的治疗方法和疗法。在本申请中，我们建议表征一种特定蛋白质在称为γ疱疹病毒的肿瘤形成病毒亚科的生命周期中的作用。我们推测，这种特殊的蛋白质可能在新病毒颗粒的形成中发挥重要作用，因此，将是一个有吸引力的候选人靶向抗病毒治疗。