The role of MIF in hookworm infection and disease

描述（由申请人提供）：钩虫感染是发展中国家营养不良和贫血的主要原因。超过10亿人感染了这些吸血线虫寄生虫，它们附着在肠粘膜上，从撕裂的毛细血管中进食。钩虫可以在肠道内存活数年，尽管存在宿主炎症反应。迄今为止，很少有人知道的机制，成年钩虫块的先天性和获得性宿主免疫反应的组成部分，以生存。最近从人钩虫Ancylostoma ceylanicum中克隆了一个对应于哺乳动物细胞因子巨噬细胞迁移抑制因子（MIF）同源物的eDNA。初步数据表明，重组A.锡兰霉MIF（rAceMIF）具有酶活性，并与人蛋白质竞争结合最近鉴定的MIF受体CD74。我们假设钩虫MIF同源物有效地调节宿主的免疫反应，以促进寄生虫在粘膜表面的生存。本项目的目的是描述MIF在钩虫感染和疾病发病机制中的作用。AceMIF的作用机制将使用MIF功能的体外研究来表征，包括互变异构酶活性、巨噬细胞迁移和促炎细胞信号传导。将表征rAceMIF与CD74结合的动力学，并使用X射线晶体学阐明其三维结构。将在体内表征AceMIF基因表达以记录其阶段特异性，并将通过免疫组织化学表征成虫钩虫内AceMIF产生的来源。平行研究将分析组织特异性表达的主机MIF响应钩虫感染使用完全许可的动物模型的A。锡兰AceMIF在钩虫贫血和生长迟缓发病机制中的作用也将使用疫苗和靶向基因沉默方法来表征。将通过ELISA监测免疫应答，并使用临床参数和蠕虫负荷测量评估针对AceMIF的抗体对钩虫贫血和生长延迟的保护程度。这些研究将描述这种新的蠕虫同源物的多功能人类细胞因子，最终确定的作用，MIF钩虫病的发病机制。

DESCRIPTION (provided by the applicant): Hookworm infection is a leading cause of malnutrition and anemia in the developing world. More than one billion people are infected with these bloodfeeding nematode parasites, which attach to the intestinal mucosa and feed from lacerated capillaries. Hookworms may survive for years within the intestine, despite the presence of a host inflammatory response. To date, little is known about the mechanisms by which adult hookworms block components of the innate and acquired host immune responses in order to survive. A eDNA corresponding to a homologue of the mammalian cytokine Macrophage Migration Inhibitory Factor (MIF) has recently been cloned from the human hookworm Ancylostoma ceylanicum. Preliminary data suggest that the recombinant A. ceylanicum MIF (rAceMIF) is enzymatically active and competes with the human protein for binding to the recently identified MIF receptor CD74. We hypothesize that the hookworm MIF homologue effectively modulates the host immune response in order to facilitate parasite survival at the mucosal surface. The aim of this project is to characterize the role of MIF in the pathogenesis of hookworm infection and disease. The mechanism of action of AceMIF will be characterized using in vitro studies of MIF function, including tautomerase activity, macrophage migration, and pro-inflammatory cell signaling. The kinetics of rAceMIF binding to CD74 will be characterized, and its three dimensional structure will be elucidated using X-ray crystallography. AceMIF gene expression will be characterized in vivo in order to document its stage specificity, and the source of AceMIF production within the adult hookworm will be characterized by immunohistochemistry. Parallel studies will analyze tissue specific expression of host MIF in response to hookworm infection using a fully permissive animal model of A. ceylanicum. The role of AceMIF in the pathogenesis of hookworm anemia and growth delay will also be characterized using both vaccine and targeted gene silencing approaches. The response to immunization will be monitored by ELISA, and the degree to which antibodies directed at AceMIF protect against hookworm anemia and growth delay will be assessed using clinical parameters and worm burden measurements. These studies will characterize this novel helminth homologue of a multi functional human cytokine, ultimately determining the role of MIF in the pathogenesis of hookworm disease.