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.

项目摘要/摘要 该研究建议的总体目标是表征皮肤渗透的机理性行为 寄生的线虫使宿主生物的位置和入侵。皮肤穿透寄生虫 线虫，包括螺纹虫的刺刺刺，在全球范围内感染了近10亿人 是被忽视的热带疾病的主要来源。通常在土壤中被发现是感染性的第三 阶段幼虫（IL3S）；居住土壤的IL3从事各种被认为会增加可能性的行为 主机联系。稳定链球菌IL3和随后的机械刺激的感觉的假设 行为反应是宿主寻求和皮肤渗透不可或缺的一部分，但长期以来已经假设 未经测试。此外，基本的机械转导途径和机械感觉神经元 电路尚不清楚。该提案中的实验将解决Knowle中的这一差距。第一组 实验将表征S. stercoralis IL3S对类似于这些振动的行为响应 人类在土壤上行走产生。具体而言，振动吸引力IL3和促进的程度 将详细检查促进宿主依恋（包括审判）的行为。并行，深度 对皮肤穿透行为范式的分析将使用人皮肤进行。提议 实验还将确定人皮肤特定的刚度或质地是否会促进皮肤 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研究 寄生线虫 - 皮肤穿透的人寄生虫钩虫ceylanicum和 被动摄入的鼠寄生虫heligmosomoides polygyrus和自由生命的线虫Caenorhabditis 秀丽隐杆线以识别皮肤穿透线虫的特定规范行为适应。此外，这项工作 将确定通过使用宿主寻求和皮肤穿透的机理感知基因和电路 方法的组合：编码预测机制受体的基因的转录报告基因 确定推定的机理感知神经元；具有CRISPR/CAS9的相同基因的靶向诱变 然后跟踪行为；使用该潜在机制敏感神经元的化学发生沉默 组胺门控氯化物通道HISCL1随后进行了行为研究；和钙瞬变的成像 刺激后相同的神经元。该提案中的工作将共同确定机制的行为 特定于皮肤穿透寄生线虫，可实现宿主接触和宿主入侵。现存的 治疗较强的山地病不能阻止再感染；这项工作可以通过发现 用于开发预防驱虫药物和局部乳霜的新型分子靶标。