Mechanosensory Behaviors of Skin-Penetrating Parasitic Nematodes

皮肤穿透寄生线虫的机械感觉行为

• 批准号: 10606463
• 负责人: Ruhi Mushtaqh Ali
• 金额: $ 6.95万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10606463
• 关键词: Alginates; Ancylostoma (genus); Animals; Anthelmintics; Behavior; Behavioral; Behavioral Paradigm; CRISPR/Cas technology; Caenorhabditis elegans; Calcium; Candidate Disease Gene; Chloride Channels; Cream; Cues; Development; Enterobius; Esthesia; Exposure to; Frequencies; Gene Expression Profile; Generations; Genes; Genetic; Genetic Transcription; Glean; Goals; Head Movements; Health; Histamine; Hookworms; Human; Hydrogels; Image; Individual; Infection; Infection prevention; Infectious Skin Diseases; Ingestion; Invaded; Knowledge; Larva; Location; Lotion; Mechanoreceptors; Modeling; Molecular Target; Mus; Mutagenesis; Nematoda; Nematospiroides dubius; Neurons; Organism; Parasites; Parasitic nematode; Pathway interactions; Penetration; Persons; Pharmaceutical Preparations; Preventive; Probability; Process; Rattus; Reporter; Reporter Genes; Research; Research Proposals; Resource-limited setting; Role; Skin; Soil; Source; Stimulus; Strongyloides; Strongyloides ratti; Strongyloides stercoralis; Strongyloidiasis; Testing; Texture; Therapeutic; Time; Transgenic Organisms; Video Recording; Walking; Work; behavioral response; behavioral study; comparative genomics; drug development; experimental study; gastrointestinal; immunosuppressed; individual response; insight; mechanical properties; mechanical stimulus; mechanotransduction; migration; mutant; neglected tropical diseases; neural circuit; neuromechanism; neuronal circuitry; novel; response; vibration

PROJECT SUMMARY/ABSTRACT The overall goal of this research proposal is to characterize the mechanosensory behaviors of skin-penetrating parasitic nematodes that enable the location and invasion of a host organism. Skin-penetrating parasitic nematodes, including the threadworm Strongyloides stercoralis, infect nearly one billion people worldwide and are major sources of neglected tropical disease. S. stercoralis is normally found in the soil as infective third- stage larvae (iL3s); soil-dwelling iL3s engage in a variety of behaviors that are thought to increase the likelihood of host contact. The hypothesis that the sensation of mechanical stimuli by S. stercoralis iL3s and the ensuing behavioral response are together integral to host seeking and skin penetration has long been postulated but has not been tested. Furthermore, the underlying mechanotransduction pathways and mechanosensory neuronal circuits are not known. The experiments in this proposal will address this gap in knowledge. The first set of experiments will characterize the behavioral response of S. stercoralis iL3s to vibrations resembling those generated by humans walking on soil. Specifically, the extent to which vibration attracts iL3s and promotes behaviors that facilitate host attachment, including nictation, will be examined in detail. In parallel, an in-depth analysis of the behavioral paradigm of skin penetration will be conducted using human skin. The proposed experiments will also determine whether the stiffness or texture that is particular to human skin promotes skin penetration. Behaviors induced by exposure to vibration and host skin will also be studied in other species of parasitic nematodes – the skin-penetrating human-parasitic hookworm Ancylostoma ceylanicum and the passively ingested murine parasite Heligmosomoides polygyrus – and the free-living nematode Caenorhabditis elegans to identify species-specific behavioral adaptations of skin-penetrating nematodes. Additionally, this work will identify the mechanosensory genes and circuits that underlie host seeking and skin penetration by using a combination of approaches: transcriptional reporters for genes that encode predicted mechanoreceptors to identify putative mechanosensory neurons; targeted mutagenesis of the same genes with CRISPR/Cas9 followed by tracking of behavior; chemogenetic silencing of potential mechanosensory neurons using the histamine-gated chloride channel HisCl1 followed by behavioral studies; and imaging of calcium transients in the same neurons upon stimulation. Together, the work in this proposal will identify the mechanosensory behaviors that are specific to skin-penetrating parasitic nematodes that enable host contact and host invasion. Existing therapeutics for strongyloidiasis do not prevent re-infection; this work may alleviate the problem by uncovering novel molecular targets for the development of preventive anthelmintic drugs and topical creams.

项目总结/摘要 这项研究的总体目标是表征皮肤穿透的机械感觉行为， 能够定位和入侵宿主生物的寄生线虫。皮肤穿透性寄生虫 线虫，包括粪类圆线虫，感染了全世界近10亿人， 是被忽视的热带疾病的主要来源。S.粪蝇通常在土壤中作为第三种传染性病原体存在， 阶段幼虫（iL 3s）;土壤居住的iL 3s从事各种行为，这些行为被认为增加了 主机联系人。这一假说认为S. Stercoralis iL 3s和随之而来的 行为反应是寻找宿主和皮肤渗透的组成部分， 没有被测试过。此外，潜在的机械转导通路和机械感觉神经元 电路未知。本提案中的实验将填补这一知识空白。第一组 实验将表征S. stercoralis iL 3的振动类似于 是人类在土壤上行走产生的。具体地说，振动吸引iL 3并促进iL 3的程度 促进宿主附着的行为，包括眨眼，将被详细研究。与此同时， 将使用人的皮肤进行皮肤穿透的行为范例的分析。拟议 实验还将确定人类皮肤特有的硬度或纹理是否促进皮肤 渗透。暴露于振动和宿主皮肤引起的行为也将在其他物种中进行研究。 寄生线虫-穿透皮肤的人体寄生钩虫锡兰钩虫和 被动摄入的鼠类寄生虫Heligmosomoides polygyrus -和自由生活的线虫Cajumhabditis elegans来识别皮肤穿透线虫的物种特异性行为适应。此外，这项工作 将确定机械感觉基因和电路的基础主机寻求和皮肤渗透，通过使用 方法的组合：编码预测的机械感受器的基因的转录报告基因， 鉴定推定的机械感觉神经元;用CRISPR/Cas9靶向诱变相同的基因 然后跟踪行为;使用化学遗传学沉默潜在的机械感觉神经元， 组胺门控氯离子通道HisCl 1，随后进行行为研究; 同样的神经元受到刺激。总之，这项提案中的工作将确定机械感觉行为 其特异于皮肤穿透寄生线虫，其能够使宿主接触和宿主入侵。现有 类圆线虫病的治疗方法不能防止再感染;这项工作可能通过揭示 用于开发预防性驱虫药和外用乳膏的新分子靶点。