Role of insulin-like signaling in the hookworm infective process

类胰岛素信号在钩虫感染过程中的作用

• 批准号: 7846597
• 负责人: JOHN M HAWDON
• 金额: $ 3.83万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-05 至 2010-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7846597
• 关键词: Anthelmintics; Antigens; Biology; Caenorhabditis elegans; Cell Fractionation; Child; Communicable Diseases; Development; Disease; Drug Delivery Systems; Drug resistance; Elderly; Event; Genes; Hemorrhage; Hookworm Infections; Hookworms; Human; Infection; Insulin; Iron deficiency anemia; Larva; Life; Measures; Mediating; Messenger RNA; Molecular; Nematode infections; Parasitic nematode; Pharmaceutical Preparations; Phosphorylation; Pregnant Women; Process; Recombinant Vaccines; Recovery; Regulation; Role; Signal Transduction; Testing; Western Blotting; inhibitor/antagonist; insight; insulin signaling; parasitism; transcription factor

DESCRIPTION (provided by applicant): Hookworm disease continues to rank among the most important infectious diseases worldwide. Nearly 800 million people are infected with one or both species of hookworms. Blood loss in heavy hookworm infections causes iron-deficiency anemia that is especially devastating in growing children, pregnant women, and the elderly. During infection, the infective larva (L3) encounters a host-specific signal that re-activates its development. This activation of the free-living L3 to the parasitic L3 during infection is a critically important, but poorly understood, event. In the related C. elegans dauer, insulin-like signaling (ILS) and phosphorylation of the transcription factor DAF-16 mediates recovery from developmental arrest. ILS is required for hookworm activation, and a DAF-16 molecule has been identified in hookworms. This project will investigate the basic molecular mechanisms of hookworm L3 activation to parasitism, and specifically the role of insulin signaling and DAF-16, during infection. Aim 1 will investigate the mechanism of DAF-16 regulation during activation of hookworm L3. The phosphorylation status and cellular localization of DAF-16 in non-activated and activated L3 will be determined by cell fractionation and Western blots, and the effect of ILS inhibitors on these parameters established. Aim 2 will determine if ILS signaling through DAF-16 effects expression of activation-associated hookworm genes. Quantitative PCR will be used to measure mRNA levels of known developmentally regulated genes in non-activated, activated and ILS inhibited L3 to determine if they are regulated by DAF-16 and ILS. Aim 3 will determine if insulin signaling and DAF-16 phosphorylation are required for infection. Inhibited L3 will be tested for their ability to infect a permissive host. Insulin signaling and DAF-16 phosphorylation are predicted to be required for successful infection. Relevance: Hookworm control is limited to repeated treatment with anthelmintics drugs, which as a long-term strategy suffers from rapid re-infection and the potential for drug resistance. An effective recombinant vaccine is at least a decade away. The development of new control options, including better antigens and new drug targets, depends on a more detailed understanding of the basic biology of hookworm infection. This project will also provide insight into the basic molecular mechanisms operating during infection and the establishment of parasitic relationships that are relevant to other parasitic nematode infections of human significance.

描述(申请人提供)：钩虫病继续位居全球最重要的传染病之列。近8亿人感染了一种或两种钩虫。重度钩虫感染中的失血会导致缺铁性贫血，这种贫血对成长中的儿童、孕妇和老年人尤其具有破坏性。在感染期间，感染幼虫(L3)遇到宿主特有的信号，重新激活其发育。在感染期间，自由生活的L3对寄生的L3的激活是一个至关重要但知之甚少的事件。在相关的线虫Dauer中，胰岛素样信号(ILS)和转录因子DAF-16的磷酸化介导了从发育停滞中恢复。钩虫的激活需要ILS，已经在钩虫中发现了DAF-16分子。本项目将研究钩虫L3激活对寄生虫的基本分子机制，特别是胰岛素信号和DAF-16在感染过程中的作用。目的1探讨钩虫L3激活过程中DAF-16的调控机制。DAF-16在未激活和激活的L3中的磷酸化状态和细胞定位将通过细胞分级和Western blotts来确定，并建立ILS抑制剂对这些参数的影响。目的2将确定ILS信号通过DAF-16是否影响激活相关钩虫基因的表达。定量聚合酶链式反应将被用来检测非激活、激活和ILS抑制的L3中已知的发育调控基因的mRNA水平，以确定它们是否受DAF-16和ILS的调控。Aim 3将确定感染是否需要胰岛素信号和DAF-16的磷酸化。被抑制的L3将被测试它们感染允许宿主的能力。胰岛素信号和DAF-16的磷酸化被预测为成功感染所必需的。相关性：钩虫的控制仅限于使用驱虫药进行重复治疗，作为一项长期战略，这种药物可能会迅速再次感染并产生抗药性。一种有效的重组疫苗至少还需要十年的时间。开发新的控制方案，包括更好的抗原和新的药物靶点，取决于对钩虫感染的基本生物学的更详细了解。该项目还将深入了解感染过程中的基本分子机制，并建立与其他具有人类意义的寄生性线虫感染相关的寄生关系。