Functional Analysis of STAT3 in Gammaherpesvirus Infection

 描述(申请人提供)：疱疹病毒病原体在其宿主中建立终身感染，而人类伽玛疱疹病毒是病毒相关癌症的主要病原体。了解伽马疱疹病毒用来促进潜伏期的分子机制是有效干预的关键。这项建议的广泛目标是确定对建立和维持潜伏感染至关重要的病毒-宿主相互作用。小鼠伽玛疱疹病毒(MHV68)是一个有价值的致病模型，可用于识别和研究病毒与宿主之间的相互作用，这些相互作用对慢性伽马至关重要 体内的疱疹病毒感染。令人兴奋的小鼠感染初步结果揭示了宿主 信号转导和转录激活因子3，STAT3，是促进MHV68潜伏期所必需的。有条件缺失STAT3基因的动物存在缺陷，无法在原代B细胞中建立潜伏感染。STAT3支持细胞的生存和增殖，并与许多癌症有关。然而，关于STAT3如何在宿主环境中对B细胞中的病毒感染的初始事件起作用，人们知之甚少。我们的中心假设是，伽马疱疹病毒需要STAT3来促进B细胞潜伏期，而病毒反式激活因子RTA拮抗STAT3的功能来促进生产性复制的启动。这项建议描述了创新的、高影响的实验方法，以阐明STAT3对伽马疱疹病毒潜伏期的贡献，以及病毒如何调节STAT3以促进感染。在目标1中，将通过检测MHV68在存在或不存在STAT3的情况下建立和维持潜伏期的能力来确定STAT3在伽马疱疹病毒感染的致病模型系统中的作用。调节潜伏期的依赖于STAT3的细胞基因网络将被确定。在目标2中，我们将定义RTA调节STAT3的机制。将确定STAT3作用所需的功能基序，以及影响培养和培养中感染的潜伏或裂解结果的STAT3的病毒基因靶点。 被感染的动物将被确定。在自然宿主中伽马疱疹病毒感染的背景下，这些对宿主：病毒界面的机械性研究将为伽马疱疹病毒如何在潜伏期和生产性感染期间差异地使用和颠覆宿主信号传递过程提供重要的洞察。

 DESCRIPTION (provided by applicant): Herpesvirus pathogens establish life-long infections in their host, and the human gammaherpesviruses are leading agents of viral-associated cancers. An understanding of the molecular mechanisms used by gammaherpesviruses to promote latency is key to effective intervention. The broad objective of this proposal is to identiy virus-host interactions that are critical for the establishment and maintenance of latent infections. The murine gammaherpesvirus (MHV68) is a valuable model for pathogenesis that can be used to identify and investigate virus-host interactions that are critical for chronic gamma herpesvirus infection in vivo. Exciting preliminary results with infection of mice reveals the host signal transducer and activator of transcription 3, STAT3, is needed to promote MHV68 latency. Animals that have a conditional deletion of the STAT3 gene are defective for establishment of a latent infection in primary B cells. STAT3 supports cell survival and proliferation, and is causall linked to many cancers. However, little is known regarding how STAT3 contributes to the initial events of viral infection in B cells in the context of the host. Our central hypothesis is that gammaherpesviruses need STAT3 to promote B cell latency, and the viral transactivator RTA antagonizes STAT3 function to promote the initiation of productive replication. This proposal describes innovative, high-impact experimental approaches to elucidate the contribution of STAT3 to gammaherpesvirus latency, and, in turn, how the virus modulates STAT3 to promote infection. In Aim 1, the role of STAT3 in a pathogenic model system of gammaherpesvirus infection will be determined by examining the ability of MHV68 to establish and maintain latency in the presence or absence of STAT3. The STAT3-dependent cellular gene network that mediates latency will be determined. In Aim 2, we will define the mechanisms by which RTA modulates STAT3. Functional motifs required for STAT3 action will be identified, and the viral gene targets of STAT3 that influence the latent or lytic outcome of infection in culture and in the infected animal will be determined. These mechanistic investigations of the host:virus interface in the context of a gammaherpesvirus infection in a natural host will provide significant insight a to how gammaherpesviruses differentially use and subvert host signaling processes during latency and productive infection.