EPIDEMIC CHIKUNGUNYA VIRUS: MOSQUITO INFECTION DETERMINANTS

说明(申请人提供)：本建议书是根据PA-04-119号文件提交的。它包括两个优先研究领域：“节肢动物媒介生物学”和“感染自然史”。它建立在我们团队在基孔肯雅病毒(CHIKV)方面的非凡专业知识的基础上，这种病毒最近在留尼汪岛导致了超过255,000例人类病例，在印度导致超过100,000例病例，以及从疫区返回欧洲的游客和中国的疾病。二次传播的可能性和建立涉及白纹伊蚊和伊蚊的传播周期。埃及伊蚊是一个可信的威胁，必须认真对待(Pearson，2006)。这项研究的长期目标是确定病毒糖蛋白与蚊子中肠细胞结合的潜在机制，并调查这些相互作用如何决定/增强病毒在蚊子中的感染和传播。这些知识可能有助于抗病毒策略的制定。中心假设：病毒基因决定CHIKV和中肠细胞表面蛋白的相互作用，这些蛋白促进Ae传播流行毒株LR2006 OPY1 2005。Aegypti和Ae.白纹伊蚊。目的：测定和比较留尼汪岛流行株CHIKV LR2006OPY1和中非株SG41855在Ae中的口服感染剂量(OID_(50))S和感染动态。Aegypti和Ae.白纹伊蚊。假设：当前印度洋CHIKV爆发的不同寻常的毒力和规模是由于病毒基因组的变化，导致蚊子感染和传播的增强。目的：建立表达绿色荧光蛋白(EGFP)的感染性克隆，并建立复制子系统以辅助确定鸡传染性支气管炎病毒的感染部位。Aegypti和Ae.白纹伊蚊。感染性克隆技术将为在分子水平上研究甲型病毒和蚊子的相互作用提供重要工具。目的3：鉴定Ae中可能的细胞表面受体蛋白。埃及伊蚊用于CHIKV，可调节CHIKV蚊子的感染性。假设：Ae中CHIKV结合细胞表面蛋白的表达水平受到抑制。埃及伊蚊可减少感染和传播。创新、成果和益处：这项研究将提供当前疫情中有关CHIKV的迫切需要的背景信息，并使我们能够生成进一步研究蚊子-病毒相互作用机制所需的工具和方案。Fuci等人(2005年)强调了与新出现的传染病相关的研究的重要性和价值，基孔肯雅病毒(CHIKV)是一个极好的例子，说明了新出现的病毒可能会对公共卫生产生重大影响。持续流行的基孔肯雅热已经在印度洋留尼汪岛(占总人口的30%)造成超过25万5千人感染病例，在印度造成超过10万人感染病例。这项拟议的研究将探索蚊子感染的机制，鉴定与CHIKV结合的蚊子中肠蛋白，并利用双链RNA方法结合新的分子工具来评估CHIKV在蚊子中的感染和传播动力学。

DESCRIPTION (provided by applicant): This proposal is submitted in response to PA-04-119. It encompasses two priority research areas: "biology of arthropod vectors" and "natural history of infection". It builds upon our groups unusual expertise on chikungunya virus (CHIKV), a virus that has recently caused over 255,000 human cases in La Reunion, over 100,000 cases in India, and disease in tourists returning from the endemic area to Europe and China. The potential for secondary spread and establishment of a transmission cycle involving Aedes albopictus and Ae. aegypti is a credible threat and must be treated seriously (Pearson, 2006). The long-term goal of this research is to identify the mechanism underlying the binding of viral glycoproteins to mosquito midgut cells and investigate how these interactions determine/enhance viral infection in, and transmission by mosquitoes. This knowledge may facilitate antiviral strategy development. Central Hypothesis: viral genes determine the interactions of CHIKV and midgut cell surface proteins that promote transmission of the epidemic strain LR2006 OPY1 2005 by Ae. aegypti and Ae. albopictus mosquitoes. Aim 1: To determine and compare oral infectious dose 50 (OID50)s and infection dynamics of the epidemic strain CHIKV LR2006 OPY1 obtained from La Reunion and of a Central African strain SG41855, in Ae. aegypti and Ae. albopictus mosquitoes. Hypothesis: the unusual virulence and magnitude of the current outbreak of CHIKV in the Indian Ocean is due to changes in the viral genome that cause enhanced infection in, and transmission by mosquitoes. Aim 2: To develop infectious clones which express EGFP and to develop a replicon system to aid in the determination of sites of CHIKV infection in Ae. aegypti and Ae. albopictus mosquitoes. Infectious clone technology will provide important tools to examine alphavirus and mosquito interactions at the molecular level. Aim 3: To identify putative cell surface receptor proteins in Ae. aegypti mosquitoes for CHIKV that can modulate CHIKV mosquito infectivity. Hypothesis: suppression of CHIKV-binding cell surface proteins expression levels in Ae. aegypti results in a decreased infection and dissemination. Innovation, outcomes, and benefits: This study will provide much needed background information on CHIKV from the current epidemic, and will allow us to generate tools and protocols required to further examine the mechanisms of mosquito-viral interactions. Fauci et al., (2005) highlighted the importance and value of research related to emerging infectious diseases, and chikungunya virus (CHIKV) is an excellent example of the substantial public health impact that a re-emerging virus can have. The ongoing epidemic of chikungunya has already caused over 255,000 human cases in the Indian Ocean island of La Reunion (>30% of the total population) and over 100,000 cases in India. The proposed research will investigate the mechanism of mosquito infection, identify mosquito midgut proteins that bind to CHIKV, and utilize a double-stranded RNA approach coupled with new molecular tools to evaluate infection, and dissemination dynamics of CHIKV in mosquitoes.