BIOLOGY OF TREMATODE-SNAIL ASSOCIATIONS

吸虫-蜗牛协会的生物学

• 批准号: 7365243
• 负责人: ERIC SAMUEL LOKER
• 金额: $ 32.15万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-12-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7365243
• 关键词: Address; Area; Attenuated; Biological Models; Biology; Biomphalaria; Complement; Data; Detection; Development; Echinostoma; Exposure to; Failure; Fibrinogen; Foundations; Fresh Water; Funding; Future; Gene Expression; Genes; Goals; Health; Helminths; Host Defense Mechanism; Human; Immunosuppressive Agents; Individual; Infection; Laboratories; Larva; Learning; Legal patent; Measures; Methodology; Methods; Molecular; Monitor; Natural Resistance; Nature; Nested PCR; Numbers; Parasites; Population; Proteins; Proteomics; Radiation; Rate; Reaction; Reagent; Research; Research Personnel; Resistance; Schistosoma; Schistosoma mansoni; Snails; Sporocysts; Techniques; Testing; Transcript; Trematode Infections; Work; abstracting; base; defense response; design; experience; field study; genome sequencing; interest; pathogen; programs; research study; response; tool

ABSTRACT: The long-term goal of this project is to better understand the biology of snail-borne helminth parasites such as Schistosoma mansoni that continue to impose a significant burden or. 'human health in much of the developing world. We intend to learn how the freshwater snail BiomphalariJrfj/labrata defends itself from infection by S. mansoni and the related trematode, Echinostoma paraensei. By understanding the underlying mechanisms of host defense and parasite infectivity, we will increase the chances of achieving effective new control measures. Another important goal is to develop and maintain expertise in the area of snail-borne pathogens. In this extensively revised proposal, using new methods we have developed, and exploiting powerful tools such as qPCR, microarrays and proteomics, we address three specific aims that relate directly to what have always been the foundation of this research program, snail defenses against trematode infection, and how these are overcome or modified by trematodes. For most of the outlined studies, we emphasize before and after infection comparisons of snails of a particular strain, thus avoiding extraneous variables associated with inter-strain comparisons. For the first aim,we hypothesize that prior exposure to trematode larvae can provoke a state of acquired resistance in B. glabrata. This provides a unique vantage point from which to understand resistance in general, and we propose to compare the responses to trematode challenge of snails with acquired resistance to those of naive snails, to learn how a state of heightened resistance is achieved. Our second aim is devoted to revealing the mechanisms used by larval trematodes in subverting snail defenses. We propose to test our earlier hypothesis that S. mansoni is a "stealth" parasite that largely avoids detection in the snail host whereas E. paraensei provokes a dramatic response but then relies on immunosuppressive tactics for survival. We will also examine how E. paraensei interferes with the innate resistance shown by the Salvador strain of B. glabrata to S. mansoni. The first part of our third aim is to develop molecular techniques to more precisely monitor the fate of S. mansoni sporocysts in snails. This work is a necessary prelude to the second part of this aim which is to understand an underappreciated yet important phenomenon that likely limits the number of schistosome-infected snails in nature, namely the inevitable failure of a significant percentage of schistosome infections in individual snails from populations otherwise considered to be susceptible. By using methods new to trematode-snail studies, we will gain broad and inclusive new overviews of these host-parasite interactions. Also, the tools generated will be useful for future studies of schistosome-snail interactions in the field. Our studies will also provide a valuable complement to the upcoming genome sequencing project for B. glabrata.

摘要：本项目的长期目标是更好地了解螺源性蠕虫的生物学 曼氏血吸虫等寄生虫继续造成重大负担或。人类健康在 许多发展中国家。我们打算了解淡水蜗牛BiomphalariJrfj/labrata如何防御 感染S。mansoni和相关的吸虫，Echinostoma paraensei。通过了解 宿主防御和寄生虫感染性的潜在机制，我们将增加实现 新的有效控制措施。另一个重要目标是发展和保持在以下领域的专门知识： 蜗牛传播的病原体在这一广泛修订的提案中，使用我们开发的新方法， 利用强大的工具，如qPCR，微阵列和蛋白质组学，我们解决了三个具体目标， 直接关系到什么一直是这个研究计划的基础，蜗牛防御， 吸虫感染，以及如何克服或修改吸虫。对于大多数概述的 研究，我们强调感染前和感染后的比较蜗牛的一个特定的菌株，从而避免 与菌株间比较相关的无关变量。对于第一个目标，我们假设先验 接触吸虫幼虫可引起B的获得性抗性状态。光滑的这提供了 从一个独特Vantage来理解一般的阻力，我们建议比较 获得性抗性钉螺对吸虫攻击的反应，以了解获得性抗性钉螺对吸虫攻击的反应。 实现了高抵抗力的状态。我们的第二个目标是致力于揭示使用的机制， 幼虫吸虫在破坏蜗牛防御方面的作用。我们建议测试我们先前的假设，S。Mansoni是一个 “隐形”寄生虫，在很大程度上避免检测蜗牛宿主，而E。paraensei激起了戏剧性的 反应，但随后依赖于免疫抑制策略生存。我们还将研究E.帕拉恩塞 干扰由B的萨尔瓦多菌株显示的先天抗性。glabrata到S. mansoni第一部分 我们的第三个目标是发展分子技术来更精确地监测S。曼氏 蜗牛的孢子囊。这项工作是必要的前奏，第二部分的目的是了解 这是一个被低估的重要现象，可能会限制受寄生虫感染的蜗牛的数量， 在自然界中，即个体中相当大比例的严重感染不可避免地失败， 来自其他被认为是易感人群的蜗牛。通过使用吸虫-蜗牛新的方法 研究，我们将获得这些宿主-寄生虫相互作用的广泛和包容性的新概述。此外，工具 所产生的将是有用的，在该领域的寄生虫蜗牛相互作用的未来研究。我们的研究也将 为即将到来的B基因组测序计划提供了有价值的补充。光滑的