Translational studies of hookworm infection in Ghana

项目摘要 钩虫感染是贫穷国家营养不良和生长迟缓的主要原因，特别是在亚热带国家。 在撒哈拉非洲，数百万人感染了美洲钩虫。人类研究数据 提示慢性钩虫感染也会损害常规疫苗效力，并在全球范围内加剧其他疾病 重要的地方性传染病。目前控制钩虫的策略主要依靠大众药物 管理标准驱虫药物，虽然最近的证据提出了质疑的长期 这一方法对控制和消除地方性人群中钩虫病的有效性。自2007年以来，耶鲁 加纳大学和加纳大学野口纪念医学研究所 合作描述地方性社区钩虫感染的流行病学特征。纵向 目标1中提出的实地研究将通过确定以下风险因素进一步探讨钩虫的流行病学： 感染、驱虫反应和治疗后再感染。 目标2中概述的实验将侧重于表征电阻频率的变化 相关突变的N.美洲β-微管蛋白基因，使用下一代测序方法，以及 由于药物压力对人类钩虫遗传多样性和群体遗传学的影响， 好的钩虫发病机制的详细研究的关键是一个简单的动物模型的可用性， 是可重复的，并且准确地反映了人类疾病的主要临床特征。知之甚少 N.美洲菌株起源于非洲人群，导致我们的理解存在重大差距 钩虫生物学、基因组学和进化论。根据维持实验室模式的经验， 锡兰钩口线虫（Ancylostoma ceylanicum hookworms）、锡兰钩口线虫（N.年从加纳的研究对象中培养出的 2019年已用于在仓鼠中建立专利感染。在目标3概述的实验研究中， 临床参数和用N.美国将全面 在仓鼠模型中表征。对原发感染的细胞、体液和粘膜抗体应答， 将定义再感染和钩虫蛋白的疫苗接种。此外，新的蛋白质组学方法将是 应用于定义与感染状态、强度和再感染风险相关的人抗体谱。 本提案中概述的研究总体目标是：（1）确定与 加纳Beposo居民钩虫感染情况（2），以说明驱虫的影响 对加纳钩虫的耐药性标记和遗传多样性的压力;（3）描述 第一个实验室适应的非洲N. americanus及其在人类钩虫研究中的应用 流行病学、发病机理和疫苗开发。这些创新研究的结果将提高我们的 了解非洲钩虫的发病机制，并为今后开发公共卫生工具提供信息， 减轻这一被忽视的热带疾病的全球负担。

PROJECT SUMMARY Hookworm infection is a leading cause of malnutrition and growth delay in poor countries, especially in sub- Saharan Africa where millions of people are infected with Necator americanus. Data from human studies suggest chronic hookworm infection also impairs routine vaccine efficacy and exacerbates other globally important, co-endemic infectious diseases. Current strategies to control hookworm rely primarily on Mass Drug Administration of standard anthelminthic drugs, although recent evidence calls into question the long-term effectiveness of this approach to control and eliminate hookworm in endemic populations. Since 2007, Yale University and the Noguchi Memorial Institute for Medical Research at the University of Ghana have collaborated to characterize the epidemiology of hookworm infection in endemic communities. The longitudinal field study proposed in Aim 1 will further probe the epidemiology of hookworm by defining risk factors for infection, response to deworming, and reinfection following treatment in the Bono East Region, Ghana. Experiments outlined in Aim 2 will be focused on characterizing changes in the frequency of resistance associated mutations in the N. americanus β-tubulin gene using Next Generation Sequencing methods, as well as the impact of drug pressure on genetic diversity and the population genetics of human hookworms in Beposo. Critical to the detailed study of hookworm pathogenesis is the availability of a facile animal model that is both reproducible and accurately reflects the major clinical features of human disease. Little is known about N. americanus strains originating from populations in Africa, resulting in a significant gap in our understanding of hookworm biology, genomics and evolution. Building on experience in maintaining the laboratory model of Ancylostoma ceylanicum hookworms, field isolates of N. americanus cultured from study subjects in Ghana in 2019 have been used to establish patent infections in hamsters. In the experimental studies outlined in Aim 3, clinical parameters and the kinetics of primary infection with the Ghana strain of N. americanus will be fully characterized in the hamster model. Cellular, humoral and mucosal antibody responses to primary infection, reinfection and vaccination with hookworm proteins will be defined. In addition, novel proteomic methods will be applied to define human antibody profiles that correlate with infection status, intensity and risk of reinfection. The overarching goals of the research outlined in this proposal are (1) to identify factors associated with hookworm infection among people living in Beposo, Ghana, (2) to characterize the impact of deworming pressure on drug resistance markers and genetic diversity of hookworms in Ghana and (3) to characterize the first laboratory adapted African strain of N. americanus and optimize its utility for the study of human hookworm epidemiology, pathogenesis and vaccine development. Results from these innovative studies will enhance our understanding of hookworm pathogenesis in Africa and inform future development of public health tools to reduce the global burden of this neglected tropical disease.