An.gambiae immune signaling gene SNPs and natural P. falciparum infection

冈比亚按蚊免疫信号基因SNPs与天然恶性疟原虫感染

• 批准号: 8197064
• 负责人: GREGORY C. LANZARO
• 金额: $ 65.44万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-15 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8197064
• 关键词: Address; Affect; Africa South of the Sahara; Alleles; Anopheles gambiae; Cameroon; Cell Line; Cells; Central Africa; Chemicals; Chromosome inversion; Code; Codon Nucleotides; Country; Culicidae; Data; Development; Exhibits; Gene Conversion; Gene Targeting; Gene Transfer Techniques; Genes; Genetic; Genetic Polymorphism; Genetic Variation; Genotype; Geographic Distribution; Goals; Human; Immune; Immune response; Immune system; Immunity; In Vitro; Infection; Insulin; Karyotype; Laboratory Study; Light; Malaria; Mali; Maps; Mediating; Methods; Midgut; Molecular; Nature; O' nyong-nyong virus; Parasites; Phenotype; Plasmodium falciparum; Population; Population Genetics; Predisposition; Protocols documentation; Regulation; Sampling; Screening procedure; Signal Pathway; Signal Transduction; Single Nucleotide Polymorphism; Site; Techniques; Testing; Transfection; Translations; Work; base; forest; gene function; genetic analysis; in vivo; inhibitor/antagonist; insight; interest; knock-down; novel; overexpression; protein function; protein structure; public health relevance; reproductive; response; transmission process; vector

DESCRIPTION (provided by applicant): Significant data implicate the Toll/imd, insulin, and TGF-¿ signaling pathways in the regulation of malaria parasite development in the Anopheles gambiae midgut. However, no data are available to confirm that these signaling pathways regulate parasite development in nature. We have chosen to address this issue using a SNP association mapping approach with field-collected mosquitoes from Mali and Cameroon, countries with high malaria transmission that include the geographic distribution of the most genetically diverged An. Gambiae populations yet described. We will pursue this goal through two specific aims. The first Aim includes population genetic analyses. Plasmodium falciparum infected and uninfected An. gambiae will be collected from sites in Mali and Cameroon. These sites were carefully selected to include all of the genetic diversity known to exist in the region (three molecular forms and chromosome inversion polymorphism). Mosquito samples will be grouped by site with respect to infection, molecular form and karyotype. Each mosquito will then be genotyped for roughly 384 immune signaling gene SNPs and those SNPs correlated with infection identified by association mapping. This analysis will identify SNPs putatively involved in susceptibility to P. falciparum infection. In the second Aim, selected SNPs of interest will be analyzed to determine their effects on mosquito protein function and on susceptibility to P. falciparum infection. Specifically, we will utilize immortalized An. gambiae cell lines and a combination of over expression, knock-down, and gene conversion techniques to confirm predictions of function from sequence and to prioritize SNPs for in vivo studies. For the in vivo studies, we will use two genetically distinct strains of An. gambiae, which have been genotyped for the SNPs of interest. We will use inhibitors and transfection (knockdown, O'nyong-nyong infectious clone mediated overexpression) protocols to mimic the effects of SNP-containing alleles on P. falciparum development in infected mosquitoes. Our work will take functional data from our lab and from the labs of our colleagues to examine the importance of the selected immune signaling pathways in field-collected mosquitoes. In this light, the studies proposed herein will facilitate selection of appropriate gene targets for transgenesis strategies and provide critical new insights into the population genetics of immunity in An. gambiae that to our knowledge are not currently available. PUBLIC HEALTH RELEVANCE: The mosquito Anopheles gambiae transmits the human malaria parasite Plasmodium falciparum in sub-Saharan Africa. Many laboratory studies have focused on how the mosquito immune system responds to and destroys these parasites, but there is little to no information on whether these responses are important in nature. Our studies will identify responses that are important in natural populations of An. gambiae with the long-term goal that this information can contribute to novel malaria control methods.

描述(由申请人提供)：重要数据表明Toll/IMD、胰岛素和转化生长因子-β信号通路在冈比亚按蚊中肠疟疾寄生虫发育的调节中起作用。然而，没有数据可以证实这些信号通路在自然界中调控寄生虫的发展。我们选择使用来自马里和喀麦隆的现场采集蚊子的SNP关联地图方法来解决这个问题，这两个国家的疟疾传播率很高，包括遗传差异最大的蚊子的地理分布。冈比亚亚纲种群尚未描述。我们将通过两个具体目标来实现这一目标。第一个目标包括种群遗传分析。已感染和未感染的恶性疟原虫。冈比亚将从马里和喀麦隆的地点收集。这些地点经过精心挑选，包括了该地区已知的所有遗传多样性(三种分子形式和染色体倒置多态)。蚊子样本将按感染地点、分子形式和核型进行分组。然后，将对每只蚊子进行大约384个免疫信号基因SNPs的基因分型，并通过关联图谱确定那些与感染相关的SNPs。这一分析将确定SNPs可能与恶性疟原虫感染的易感性有关。在第二个目标中，将分析选定的感兴趣的SNPs，以确定它们对蚊子蛋白功能和对恶性疟原虫感染的易感性的影响。具体地说，我们将利用不朽的AN。冈比亚细胞系以及过度表达、基因敲除和基因转化技术的组合，以确认根据序列预测的功能，并为体内研究确定SNPs的优先顺序。在体内研究中，我们将使用两种遗传上不同的AN菌株。冈比亚，已经对感兴趣的SNPs进行了基因分型。我们将使用抑制剂和转基因(敲除，O‘nyong-Nyong感染性克隆介导的过表达)方案来模拟含有SNP的等位基因对受感染蚊子恶性疟原虫发育的影响。我们的工作将从我们的实验室和我们的同事的实验室中获取功能数据，以检查现场采集的蚊子中选定的免疫信号通路的重要性。鉴于此，本文提出的研究将有助于为转基因策略选择合适的基因靶点，并为研究人群免疫的群体遗传学提供重要的新见解。据我们所知，冈比亚目前还没有。 公共卫生相关性：冈比亚按蚊在撒哈拉以南非洲传播人类疟疾寄生虫恶性疟原虫。许多实验室研究都集中在蚊子免疫系统如何应对和消灭这些寄生虫，但很少或根本没有关于这些反应在自然界中是否重要的信息。我们的研究将确定在自然种群中重要的反应。冈比亚的长期目标是，这些信息可以有助于新的疟疾控制方法。