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Transstadial inhibition of Rift Valley Fever virus infection in Ae. aegypti mosquitoes

伊蚊裂谷热病毒感染的跨斯塔迪抑制。

基本信息

批准号：
10088402
负责人：
Rebekah Crockett Kading
金额：
$ 22.8万
依托单位：
COLORADO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-24 至 2022-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10088402
关键词：
Address Adult Africa American Animals Antiviral Agents Arboviruses Area Bunyavirales Candidate Disease Gene Cell Cycle Cessation of life Climate Country Culicidae Data Development Developmental Process Disease Outbreaks Double-Stranded RNA Droughts Economics Elements Ensure Epidemic Event Exposure to Flavivirus Gene Expression Genus Phlebovirus Goals Habitats Health Human Immune Individual Infection Kenya Laboratories Larva Life Link Livestock Maintenance Mediating Messenger RNA Modeling Molecular Mosquito Control Nature North America Oral Orthobunyavirus Ovarian Tissue Oviposition Pathway interactions Pattern Phenotype Population Probability Production Publishing Pupa Quantitative Reverse Transcriptase PCR RNA Interference RNA Interference Pathway Regulation Rift Valley fever virus Risk Role Seasonal Variations Statistical Data Interpretation Temperature Testing Time Tissue-Specific Gene Expression Titrations United States Vertical Disease Transmission Viral Hemorrhagic Fevers Viral Load result Virus Virus Diseases Virus Replication WNT Signaling Pathway beta catenin egg food security gene function infection rate knock-down novel predictive modeling response transcriptome sequencing transmission process vector vector control vector mosquito viral RNA

项目摘要

Project Summary Rift Valley fever virus (RVFV) (Phenuiviridae: Phlebovirus) is an emerging mosquito-transmitted virus with a high probability of introduction to new areas, including the United States. Significant questions remain regarding the inter-epidemic maintenance of RVFV in endemic countries, and the ecological importance of North American mosquitoes in the establishment and transmission of RVFV. In particular, RVFV is currently believed to be maintained in natural mosquito vector populations through vertical transmission, however published laboratory evidence documenting this phenomenon is completely lacking. We recently demonstrated high RVFV dissemination rates and infection of ovarian tissues in both Ae. aegypti and Cx. tarsalis mosquitoes orally exposed to an epidemic strain of RVFV from Kenya. The infection rate of the 1st instar larvae of Cx. tarsalis mosquitoes was 87% (Bergren, preliminary data). This is the first time transovarial transmission of RVFV has been experimentally demonstrated in any mosquito species. Interestingly, transstadial transmission of RVFV from eggs to F1 adult life stages was inhibited in Ae. aegypti due to an unknown mechanism. This project will address the hypotheses that the efficiency of transstadial transmission of RVFV is mediated by larval habitat temperature (Aim 1), as well as mosquito anti-viral effectors and Wnt signalling during immature developmental stages (Aim 2). For Aim 1, both Cx. tarsalis and Ae. aegypti mosquitoes derived from RVFV- infected parental mosquitoes will be reared at low (18°C) standard (28°C), and high (35°C) temperatures. Transstadial virus persistence in each mosquito species will be quantified by qRT-PCR and plaque titration of 1st instar, 4th instar, pupal, and F1 adult mosquitoes reared at each temperature. Statistical analysis of infection rates as well as virus titer in each life stage as a function of mosquito species and temperature will inform whether or not larval rearing temperature significantly influences transstadial persistence of RVFV. To support these environmental data, RNA-Seq will be employed in Aim 2 to identify the underlying molecular pathways contributing to our preliminary phenotypic observations. Differential gene expression will be analyzed in individual mosquitoes of each species throughout the developmental process. The function of top-candidate genes during RVFV transstadial transmission will be confirmed by specific double-stranded RNA knock-down in mosquito larvae. The data generated in these studies will collectively elucidate environmental and molecular drivers of RVFV persistence in North American mosquito populations. This project will also directly address shortcomings in current predictive models regarding the environmental persistence and establishment potential of RVFV in mosquitoes.

项目概要裂谷热病毒 (RVFV)（Phenuiviridae：Phlebovirus）是一种新兴的蚊子传播病毒，具有引入新领域的可能性很大，包括美国。仍然存在重大问题关于裂谷热病毒流行国家的流行间维持及其生态重要性北美蚊子参与 RVFV 的建立和传播。特别是，RVFV 目前然而，据信通过垂直传播在自然蚊媒种群中得以维持完全缺乏记录这种现象的已发表的实验室证据。我们最近展示了 RVFV 传播率和卵巢组织感染率均较高。埃及伊蚊和 Cx。跗蚊经口接触来自肯尼亚的裂谷热病毒流行株。 Cx 1龄幼虫感染率。跗蚊为 87%（Bergren，初步数据）。这是首次经卵巢传播 RVFV 已在任何蚊子物种中得到实验证实。有趣的是，跨空间传输 RVFV 从卵到 F1 成虫生命阶段的 RVFV 在 Ae 中受到抑制。埃及伊蚊的机制未知。这该项目将解决以下假设：RVFV 跨体育场传播的效率是由以下因素介导的：幼虫栖息地温度（目标 1），以及未成熟期间的蚊子抗病毒效应和 Wnt 信号传导发展阶段（目标 2）。对于目标 1，都是 Cx。跗节和 Ae。源自 RVFV 的埃及蚊子受感染的亲代蚊子将在低（18°C）标准（28°C）和高（35°C）温度下饲养。 Transstadial 病毒在每种蚊子中的持久性将通过 qRT-PCR 和斑块滴定进行量化各温度下饲养的 1 龄、4 龄、蛹和 F1 成蚊。感染统计分析每个生命阶段的比率以及病毒滴度作为蚊子种类和温度的函数将提供信息幼虫饲养温度是否显着影响 RVFV 的跨斯塔持续性。支持根据这些环境数据，目标 2 将采用 RNA-Seq 来识别潜在的分子途径有助于我们的初步表型观察。差异基因表达将被分析每个物种的个体蚊子在整个发育过程中。最佳候选函数 RVFV 跨斯塔传播过程中的基因将通过特异性双链 RNA 敲除来确认在蚊子幼虫中。这些研究中产生的数据将共同阐明环境和分子 RVFV 在北美蚊子种群中持续存在的驱动因素。该项目还将直接解决当前预测模型在环境持久性和建立潜力方面的缺陷蚊子中的 RVFV。