Oxygen sensation in human-parasitic skin-penetrating nematodes

项目总结/摘要 该提案的目标是利用分子神经科学技术来定义氧气（O2）的作用。 作为一个生物学相关的化学感受线索，在人类感染性线虫粪类圆线虫。 在全球范围内，S。粪绦虫感染约6.1亿人，在资源贫乏的环境中造成很高的疾病负担。 类圆线虫病，被认为是一种新出现和/或重新出现的疾病，可以表现为一个惰性的几十年 胃肠道感染;免疫功能低下的个体处于过度感染综合征的高风险中， 传播性疾病-其中大多数病例是致命的。考虑到驱虫药耐药性的威胁， 需要化疗策略来治疗和治愈患有类圆线虫病的个体。 寄生线虫依赖于神经元检测到的感觉线索来主动寻找宿主， 在东道国以外的环境中，并根据当地情况协调其发展。S. Stercoralis，as a soil土壤- 传播蠕虫，蓬勃发展的O2浓度范围从大气水平（~21%）在土壤表面 在宿主的肠道里接近厌氧状态。然而，O2感觉仍然完全没有研究， S.粪线虫或任何其它寄生线虫。这项提议假设，神经和分子 在S.粪蝇可能产生易受干预的有希望的目标。 本研究旨在探讨S.在行为、神经元和分子水平上对粪蝇进行研究。的 该建议的第一个目的是试图描述O2如何作为化学感觉线索来塑造运动 S.寄生虫的整个生命周期。寄生虫行为的定量分析 将执行不同的O2上下文。此外，在第一个目标中提出的工作将询问 改变氧气水平作为发育线索，使寄生。在本建议的第二个目标中， 化学发生神经元沉默和钙成像技术将被用来识别O2敏感 神经元，并描述了这些神经元中的寄生虫特异性编码特性。在提案的第三个目标中， CRISPR/Cas9介导的诱变和异位表达系统将用于确定分子生物学特性。 S.并探讨其作用机制。这一提议将产生新的见解 寄生虫化学感受神经生物学，并可能揭示预防线虫感染的新策略。 该提案将支持申请人成为致力于研究的医生-科学家的目标， 寄生虫感染性疾病的临床管理。在完成拟议目标时，申请人将增加 在寄生虫学和分子生物学的培训与神经科学研究的新技能的发展。 这项工作将在研究寄生线虫神经生物学的唯一实验室之一进行; 申请人还将寻求加州大学洛杉矶分校丰富的寄生虫学家和神经科学家社区的指导。

PROJECT SUMMARY / ABSTRACT The goal of this proposal is to leverage molecular neuroscience techniques to define the role of oxygen (O2) as a biologically relevant chemosensory cue in the human-infective threadworm Strongyloides stercoralis. Globally, S. stercoralis infects ~610 million people, with a high disease burden in resource-poor settings. Strongyloidiasis, considered an emerging and/or re-emerging disease, can manifest as an indolent multi-decade gastrointestinal infection; immunocompromised individuals are at high risk of hyperinfection syndrome and disseminated disease – of which most cases are fatal. Given the threat of anthelmintic resistance, novel chemotherapeutic strategies are needed to treat and cure individuals with strongyloidiasis. Parasitic nematodes rely upon neuronally detected sensory cues to actively seek hosts, navigate intra- and extra-host environments, and coordinate their development with their local context. S. stercoralis, as a soil- transmitted helminth, thrives in O2 concentrations that range from atmospheric levels (~21%) at the soil surface to near-anaerobic conditions in the host intestinal tract. However, O2 sensation remains completely unstudied in S. stercoralis or any other parasitic nematode. This proposal hypothesizes that the neural and molecular machinery mediating O2 sensation in S. stercoralis may yield promising targets vulnerable to intervention. This proposal will explore O2 sensation in S. stercoralis at the behavioral, neuronal, and molecular levels. The first aim of this proposal seeks to characterize how O2 serves as a chemosensory cue to sculpt the motile behaviors of S. stercoralis throughout its parasitic life cycle. Quantitative analysis of parasite behaviors in different O2 contexts will be performed. Additionally, work proposed in the first aim will interrogate the role of shifting O2 levels as a developmental cue that enables parasitism. In the second aim of this proposal, chemogenetic neuronal silencing and calcium imaging techniques will be employed to both identify O2-sensing neurons and describe parasite-specific encoding properties in these neurons. In the proposal’s third aim, CRISPR/Cas9-mediated mutagenesis and ectopic expression systems will be used to determine the molecular sensors of O2 in S. stercoralis and explore their mechanism of action. This proposal will generate new insights into parasite chemosensory neurobiology and may reveal novel strategies for preventing nematode infections. This proposal will support the applicant’s goal of becoming a physician-scientist dedicated to the study and clinical management of parasitic infectious diseases. In completing the proposed aims, the applicant will augment prior training in parasitology and molecular biology with the development of new skills in neuroscience research. This work will be performed in one of the only laboratories studying neurobiology in parasitic nematodes; the applicant will also seek mentorship from the rich community of parasitologists and neuroscientists at UCLA.