Sensory Neuron-Bacteria Interactions in Modulating Pain and the Host Microbiota

项目摘要 疼痛是生物体躲避危险的基本保护性神经信号。伤害性感受器是特定的 检测有害/有害刺激并将疼痛信号传输到大脑的外周感觉神经元的子集。 慢性疼痛是一种主要的社会经济负担，但其潜在的分子机制尚不清楚。 明白了。我之前发现，细菌病原体通过直接激活伤害性感受器来产生疼痛 感染过程中的神经元。此外，我发现伤害性感受器在抑制局部免疫细胞方面发挥了作用 招募和淋巴结病。这些发现增加了神经系统可以发挥作用的可能性 在东道主防守中的直接参与作用。伤害性感受器神经元密集地支配皮肤和肠道，这是 被共生细菌大量滋生。然而，组织驻留之间的双向串扰 对于具有感觉神经系统的微生物，人们知之甚少。在NIH导演的新创新者奖中，我 验证寄主微生物区系和伤害性感受器神经元之间的分子相互作用起关键作用的假设 在控制疼痛产生和微生物区系组成方面的作用。本研究是在基础研究的推动下进行的 有关宿主-微生物相互作用的作用的问题将帮助我们深入了解哺乳动物的生理： I)特定的共生肠道或皮肤细菌种类(致病菌或共生菌)是否为 伤害性感受器神经元活动与慢性疼痛的发展？二)我们能否识别特定的细菌分子 调节伤害性感受器神经活动和疼痛的介体？Iii)在辣味中做伤害性感受器相关配体 食物(如辣椒素、芥子油)对微生物区系的组成和质量有重大影响吗？ 四)伤害性感受器神经元是否产生直接影响微生物区系或组织驻留的分子介质 免疫细胞？为了解决这些问题，我将结合神经生物学、免疫学和微生物学 分析伤害性感受器神经元和驻留微生物区系之间相互作用的方法。 无菌和细菌单集落实验将确定不同的共生或致病 共生细菌菌株影响疼痛的发展。神经元钙离子流量，多电极阵列 分析和蛋白质化学技术将定义调节伤害性感受器活动的细菌媒介。 这些分析将导致识别潜在的新的疼痛分子介体。相反，我会 分析体内的伤害性感受器活动是否在调节宿主微生物区系中发挥作用。使用转基因技术， 专门耗尽、激活或沉默伤害性感受器的药理学和光遗传策略，我将 确定感觉神经元是否调节皮肤和肠道微生物区系的组成。基于我的 免疫学和神经生物学的基础培训，以及进行跨学科研究的能力 科学的方法，我是唯一有资格领导这项工作的人。我已经表现出了挑战的意愿 常规范式，将我的研究集中在对人类健康具有潜在影响的问题上。使用 这个提议的NIH主任新创新者奖，我将进行研究，以产生对主持人的新见解- 微生物相互作用促进慢性疼痛和微生物失调治疗的发展。

PROJECT ABSTRACT Pain is a fundamental protective neuronal signal for organisms to avoid danger. Nociceptors are the specific subset of peripheral sensory neurons that detect harmful/noxious stimuli and transmit pain signals to the brain. Chronic pain is a major socio-economic burden, but the underlying molecular mechanisms are not well understood. I previously found that bacterial pathogens produced pain by directly activating nociceptor neurons during infection. Moreover, I found that nociceptors played a role in suppressing local immune cell recruitment and lymphadenopathy. These findings raise the possibility that the nervous system can play a direct participatory role in host defense. Nociceptor neurons densely innervate the skin and gut, which are heavily colonized by commensal bacteria. However, the bidirectional crosstalk between the tissue-resident microbes with the sensory nervous system is poorly understood. In this NIH Director's New Innovator Award, I test the hypothesis that molecular interactions between the host microbiota and nociceptor neurons play a key role in governing pain production and the composition of the microbiota. This research is motivated by basic questions about the role of host-microbe interactions that will help us gain insights into mammalian physiology: i) Do specific commensal gut or skin bacterial species (pathobionts or symbionts) set the threshold for nociceptor neuron activity and development of chronic pain? ii) Can we identify specific bacterial molecular mediators that modulate nociceptor neural activity and pain? iii) Do nociceptor-associated ligands in spicy foods (e.g. capsaicin, mustard oil) have a significant impact on the composition and quality of the microbiota? Iv) Do nociceptor neurons produce molecular mediators that directly impact the microbiota or tissue-resident immune cells? To address these questions, I will combine neurobiological, immunological, and microbiological approaches to analyze the reciprocal interactions between nociceptor neurons and the resident microbiota. Germ-free and bacterial monocolonization experiments will determine if distinct symbiotic or pathobiotic commensal bacterial strains influence the development of pain. Neuronal calcium flux, multi-electrode array analysis, and protein chemical techniques will define the bacterial mediators that modulate nociceptor activity. These analyses will lead to the identification of potential novel molecular mediators of pain. Conversely, I will analyze if nociceptor activity in vivo plays a role in regulating the host microbiota. Using transgenic, pharmacological, and optogenetic strategies to specifically deplete, activate or silence nociceptors, I will ascertain whether sensory neurons modulate the composition of the skin and gut microbiota. Based on my foundational training in Immunology and Neurobiology, along with the ability to carry out cross-disciplinary scientific approaches, I am uniquely qualified to lead this effort. I have demonstrated a willingness to challenge convential paradigms, focusing my research on questions that have potential impacts on human health. With this proposed NIH Director's New Innovator Award, I will carry out studies to produce novel insights into host- microbe interactions facilitating the development of treatments for chronic pain and microbial dysbiosis.