Initiation and regulation of RSV mRNA transcription and genome replication

描述（由申请人提供）：呼吸道合胞病毒（RSV）是一个重大的公共卫生问题。它是婴儿呼吸道疾病的主要原因。它还会对免疫功能低下、老年人或有潜在肺部疾病（如哮喘或慢性阻塞性肺病）的人造成严重疾病。目前还没有疫苗或有效的抗病毒药物来治疗感染RSV的患者。治疗仅限于支持性护理，严重情况下需要住院和重症监护。因此，显然需要抗RSV药物来限制RSV疾病的严重程度，以降低与RSV相关的死亡率，同时也需要强化治疗。RSV RNA依赖性RNA聚合酶（RdRp）是抗病毒药物的理想靶标，因为它具有独特而必需的酶活性。RdRp转录和复制非分段负义RNA基因组，并能够从同一病毒启动子启动这两种活性。该项目的目标是生成RSV RdRp关键功能和结构特性的详细分子信息。这项工作分为三个主要目标。Aim 1中的实验将阐明RdRp从同一启动子元件内的两个位点启动转录和RNA复制的机制，并确定使用小分子成功抑制这些步骤的可能性。目的2将确定RdRp是如何组装成完全胜任的转录酶和复制酶复合物的，并将研究这些复合物是如何被调节的。Aim 3的研究将利用阴性染色和冷冻电镜来深入了解RdRp单独以及与启动子RNA和核衣壳相关的结构特征。该研究将显著提高我们对RdRp的功能和结构特性的认识，并为合理开发抗病毒药物提供见解。

DESCRIPTION (provided by applicant): Respiratory syncytial virus (RSV) is a significant public health concern. It is the major cause of respiratory disease in infants. It also causes severe disease in individuals who are immunocompromised, elderly or have underlying lung disorders, such as asthma or chronic obstructive pulmonary disease. Currently there is no vaccine or effective antiviral drug to treat patients infected with RSV. Treatment is limited to supportive care, which in severe cases requires hospitalization and intensive care. Thus, there is a clear need for anti-RSV drugs that limit the severity of RSV disease to reduce the mortality associated with RSV, as well as the need for intensive treatment. An ideal target for antiviral drugs is the RSV RNA dependent RNA polymerase (RdRp), as it has unique and essential enzymatic activities. The RdRp transcribes and replicates the non-segmented negative sense RNA genome and is capable of initiating both activities from the same viral promoter. The goal of this project is to generate detailed molecular information about key functional and structural properties of the RSV RdRp. The work is divided into three major aims. The experiments in Aim 1 will elucidate the mechanisms by which the RdRp initiates transcription and RNA replication from two sites within the same promoter element, and determine the likelihood of using small molecules to successfully inhibit these steps. Aim 2 will determine how the RdRp is assembled into fully-competent transcriptase and replicase complexes, and will investigate how these complexes are regulated. The research in Aim 3 will utilize negative stain and cryo-electron microscopy to gain insight into the structural characteristics of the RdRp alone and in association with promoter RNA and the nucleocapsid. This research will significantly improve our understanding of the functional and structural properties of the RdRp and provide insights that could be exploited for rational development of antiviral drugs.