Molecular Basis of Flavivirus Neurovirulence

黄病毒神经毒力的分子基础

• 批准号: 6803173
• 负责人: WILLIAM SM WOLD
• 金额: $ 42.68万
• 依托单位: SAINT LOUIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-15 至 2008-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6803173
• 关键词: Flaviviridae; Japanese encephalitis virus; SCID mouse; host organism interaction; laboratory mouse; molecular cloning; pathologic process; plaque assay; polymerase chain reaction; viral myelinopathy; viral vaccines; virulence; virus envelope; virus infection mechanism; virus protein; virus replication; yellow fever virus

DESCRIPTION (provided by applicant): The objectives of this proposal are to advance understanding of the viral molecular determinants governing replication and virulence of flaviviruses in human hosts. Information from these studies may be used to design and improve live-attenuated viral vaccines for viruses of public health importance, as well as to gain insight into the mechanisms of viral pathogenesis. Flaviviruses are a diverse group of mosquito- and tick-transmitted RNA viruses which cause a range of disease syndromes in humans including hemorrhagic fever and acute encephalitis. Due to their continuing emergence and re-emergence on a global scale, there is growing demand for the availability of vaccines against those flavivirus infections which present unpredictable and serious threats to human populations. Because of the lack of any effective antiviral therapies against flaviviruses, vaccination in conjunction with mosquito control measures, remains the principal strategy for the prevention of disease. However there is a need to improve the efficacy and in some cases the safety of certain flavivirus vaccines. In this proposal molecular clones of yellow fever (YFV) and Japanese encephalitis (JEV) viruses will be used to define the molecular basis of neurovirulence in a mouse model, and to test the effects of attenuating mutations on the properties of experimental YFV and JEV vaccines. In Aim 1 the goal is to determine if the neurovirulence of YFV is mainly controlled by determinants encoded within the viral envelope (E) protein, both in the context of neuroadapted YF 17D vaccine, as well as the highly neurovirulent French neurotropic vaccine (FNV). In Aim 2, the YF 17D molecular clone will be modified by introduction of novel attenuating mutations in the E protein and their effects on neurovirulence properties and immunogenicity will be compared to 17D vaccine. In Aim 3 the molecular basis of JE virus neurovirulence will be investigated by constructing intertypic viruses between the attenuated JE SA14-14-2 vaccine currently used for human vaccination in China, and a highly neurovirulent JE-Nakayama strain, and testing their virulence properties in mice. The results of these studies are expected to yield data relevant to the use of molecular clone technology as an approach to vaccine development, and therefore have long-term implications for reducing the worldwide disease burden asssociated with flavivirus infections.

描述（由申请人提供）：本提案的目标是促进对人类宿主中控制黄病毒复制和毒力的病毒分子决定因素的理解。来自这些研究的信息可用于设计和改进对公共卫生具有重要意义的病毒的减毒活疫苗，以及深入了解病毒发病机制。黄病毒是一种由蚊子和蜱传播的RNA病毒，可引起人类一系列疾病综合征，包括出血热和急性脑炎。由于黄病毒在全球范围内不断出现和重新出现，对这些对人类构成不可预测和严重威胁的黄病毒感染的疫苗的需求日益增加。由于缺乏针对黄病毒的有效抗病毒疗法，疫苗接种与蚊虫控制措施相结合仍然是预防疾病的主要战略。然而，有必要提高某些黄病毒疫苗的效力，并在某些情况下提高其安全性。在本建议中，将使用黄热病（YFV）和日本脑炎（JEV）病毒的分子克隆来确定小鼠模型中神经毒力的分子基础，并测试减毒突变对YFV和日本脑炎实验疫苗特性的影响。在Aim 1中，目的是确定YFV的神经毒性是否主要由病毒包膜(E)蛋白内编码的决定因素控制，无论是在神经适应性yf17d疫苗的背景下，还是在高度神经毒性的法国嗜神经疫苗（FNV）的背景下。在Aim 2中，将通过在E蛋白中引入新的减毒突变来修饰YF 17D分子克隆，并将其对神经毒力特性和免疫原性的影响与17D疫苗进行比较。在第三部分中，将通过构建中国目前用于人接种的乙脑SA14-14-2减毒疫苗与高度神经毒力的乙脑-中山毒株之间的型间病毒，并在小鼠中测试它们的毒力特性，来研究乙脑病毒神经毒力的分子基础。这些研究的结果预计将产生与使用分子克隆技术作为疫苗开发方法相关的数据，因此对减少与黄病毒感染相关的全球疾病负担具有长期影响。