Pain and Neuro-immune Signaling in S. pyogenes pathogenesis

项目摘要 疼痛（Dolor）是炎症的四个主要症状之一，通常伴随着细菌感染。 伤害感受器神经元是介导疼痛的外周感觉神经元，密集地支配屏障 暴露于病原体的组织，包括皮肤和软组织。化脓性链球菌是导致 坏死性筋膜炎的原因，一种侵入性和危及生命的感染形式，其中疼痛发生早期， 与其他症状“不成比例”我们假设，疼痛起着主要的致病作用， 致病性S.化脓性链球菌，通过诱导神经介导的先天免疫细胞募集抑制， 杀死细菌。本研究主要探讨：1）S.化脓性感染， 重点是链球菌成孔毒素链球菌溶血素S（SLS）和链球菌溶血素O（SLO），和2） 伤害感受器和疼痛信号在调节中性粒细胞功能和宿主防御S.化脓 我们测试的假设，靶向疼痛信号将导致增强先天免疫反应。给定 疼痛在诊断坏死性筋膜炎中的重要性，以及镇痛药的广泛使用，我们 疼痛与S.化脓性链球菌宿主防御可能具有重要的临床意义。两个目标 这项研究的目的是利用Chiu博士和Wessels博士的互补技能，结合神经生物学， 免疫学和微生物学方法来研究疼痛在宿主防御中的作用。具体目标 1，我们将确定在S.两种化脓性感染 临床分离株。我们使用同基因突变菌株和质粒互补策略一起 通过神经行为学分析来确定SLS和SLO是否介导S.化脓引起的疼痛我们将 确定炎性小体和IL-1β是否参与神经元对成孔毒素的识别， 疼痛信号此外，我们确定了非甾体抗炎药（NSAID）在 影响S.化脓性感染。在具体目标2中，我们将确定如何针对 使用RTX处理或Trpv 1-cre/DTA小鼠的TRPV 1+伤害感受器的消融增强了宿主对 S.化脓我们将确定如何在时间和空间上控制TRPV 1+神经活动的调制 使用光遗传学或DREADD策略影响S.化脓性感染。我们还将利用 阿片类药物阻断中枢疼痛感知或肉毒杆菌毒素阻断外周疼痛信号传导，以确定 神经成分调节抗S.化脓在我们的分析中，我们阐明了 伤害感受器衍生的神经肽如CGRP抑制中性粒细胞吞噬和杀死S. 化脓这项研究分析了疼痛信号的诱导，先天性神经阻滞和神经传导之间的重要联系。 免疫和增强S.化脓性细菌的发病机制。靶向疼痛和神经免疫 抑制可能导致治疗这种和其他侵入性细菌感染的新方法。

PROJECT SUMMARY Pain (Dolor) is one of the four cardinal signs of inflammation, and often accompanies bacterial infections. Nociceptor neurons are the peripheral sensory neurons that mediate pain, which densely innervate barrier tissues including the skin and soft tissues that are exposed to pathogens. Streptococcus pyogenes is a leading cause of necrotizing fasciitis, an invasive and life-threatening form of infection, in which pain occurs early and “out of proportion” with other symptoms. We hypothesize that pain plays a major causative role in the pathogenesis of S. pyogenes, by inducing neural mediated suppression of innate immune cell recruitment and killing of bacteria. Here, we will determine: 1) The molecular mechanisms of pain during S. pyogenes infection, with a focus on streptococcal pore-forming toxins streptolysin S (SLS) and streptolysin O (SLO), and 2) The role of nociceptors and pain signaling in regulating neutrophil function and host defense against S. pyogenes. We test the hypothesis that targeting pain signaling would lead to enhanced innate immune responses. Given the importance of pain in the diagnosis of necrotizing fasciitis, and the widespread use of analgesics, our findings connecting pain to S. pyogenes host defense could have important clinical implications. The two aims of this study leverage the complementary skills of Dr. Chiu and Dr. Wessels, combining neurobiological, immunological, and microbiological approaches to investigate the role of pain in host defense. In Specific Aim 1, we will determine the critical molecular mechanisms of pain production during S. pyogenes infection by two clinical isolates. We use isogenic mutant bacterial strains and plasmid complementation strategies together with neurobehavioral assays to determine whether SLS and SLO mediate S. pyogenes-induced pain. We will determine whether the inflammasome and IL-1β are involved in neuronal recognition of pore-forming toxins or pain signaling. In addition, we determine the effectiveness of non-steroidal anti-inflammatory drugs (NSAIDs) in impacting pain perception during S. pyogenes infection. In Specific Aim 2, we will determine how targeted ablation of TRPV1+ nociceptors using RTX treatment or Trpv1-cre/DTA mice enhances host defenses against S. pyogenes. We will determine how temporally and spatially controlled modulation of TRPV1+ neural activity using optogenetic or DREADD strategies affects the outcome of S. pyogenes infection. We will also utilize opioids to block central pain perception or Botulinum toxin to block peripheral pain signaling to determine which neural component modulates immune responses against S. pyogenes. In our analysis, we elucidate the role of nociceptor-derived neuropeptides such as CGRP in suppressing neutrophil phagocytosis and killing of S. pyogenes. This study analyzes a significant link between induction of pain signaling, neural blockade of innate immunity, and the potentiation of S. pyogenes bacterial pathogenesis. Targeting pain and neuro-immune suppression could lead to novel approaches to treatment of this and other invasive bacterial infections.