Mechanisms of Enhanced Arbovirus Infection by Mosquito Saliva

描述(申请人提供)：节肢动物传播的病毒(虫媒病毒)在世界范围内造成了重大的疾病负担。在这里，我们将研究蚊子-病毒-宿主的相互作用--这是所有蚊媒病毒的一个重要研究领域。根据蚊子种类、病毒和实验系统的不同，蚊子唾液可促进几种不同虫媒病毒的病毒复制；然而，促进病毒复制的机制(S)尚不清楚。研究这些机制(S)并找出负有责任的唾液因素是这项建议的目标。我们这些研究的模型将是西尼罗河病毒(WNV)，它的一种地方性媒介--塔萨库蚊，以小鼠为脊椎动物宿主。我们之前的研究表明，在这个模型中，蚊子唾液可以促进病毒的早期复制。我们将在这些研究的基础上，追求三个相关目标：1)确定蚊子唾液如何影响病毒的产生。由于更多的病毒产生是由于感染的细胞数量更多和/或每细胞产量更高，我们将在这些研究中探索这两种可能性。2)使用系统生物学方法研究在蚊子唾液存在的情况下宿主对西尼罗河病毒的反应。由于病毒复制的增强发生在感染后的早期，我们假设先天免疫反应受到蚊子唾液的抑制。我们将使用微阵列研究来检测在有和没有蚊子唾液的情况下西尼罗河病毒感染过程中靶组织表达谱的差异。3)确定导致西尼罗河病毒感染增加的蚊子唾液成分(S)。我们的初步研究已经将可能的候选蛋白家族缩小到在塔氏库蚊和埃及伊蚊中发现的两个蛋白质家族，但在冈比亚按蚊中没有发现。我们将确定这些候选病毒中的哪一个负责病毒增强，并随后将其作为可能的疫苗进行测试。这些目标完成后，我们将在蚊子传播背景下理解虫媒病毒的发病机制方面做出重大贡献，并为开发减少病毒传播的新靶点奠定基础。

DESCRIPTION (provided by applicant): Arthropod-borne viruses (arbovirus) are responsible for a significant disease burden worldwide. Here, we will investigate the mosquito-virus-host interaction - an important area of research for all mosquito- borne viruses. Mosquito saliva potentiates viral replication for several different arboviruses, depending on the mosquito species, virus and experimental system; however, the mechanism(s) of enhanced viral replication is not well understood. Investigating these mechanism(s) and identifying the responsible salivary factors are the objectives of this proposal. Our model for these studies will be West Nile virus (WNV), one of its enzootic vectors, Culex tarsalis, and mice as the vertebrate host. Our previous studies showed that mosquito saliva enhances early viral replication in this model. We will build on these studies by pursuing three related aims: 1) Determine how mosquito saliva affects viral production. Since greater viral production is due to either greater numbers of cells infected and/or greater yield per cell, we will explore both possibilities in thes studies. 2) Use a systems biology approach to examine the host response to WNV in the presence of mosquito saliva. Since the enhanced viral replication occurs early after infection, we hypothesize that the innate immune response is inhibited by mosquito saliva. We will use microarray studies to examine differences in expression profiles in target tissues during WNV infection with and without mosquito saliva. 3) Identify the mosquito salivary component(s) responsible for enhancement of WNV infection. Our preliminary studies have narrowed the possible candidates to two protein families found in Culex tarsalis and Aedes aegypti, but not in Anopheles gambiae. We will determine which of these candidates is responsible for viral enhancement and subsequently test it as a possible vaccine. Upon the completion of these aims, we will have made significant contributions to understanding arbovirus pathogenesis in the context of mosquito transmission and laid the groundwork for the development of novel targets to reduce viral transmission.