Pain and Neuro-immune Signaling in S. pyogenes pathogenesis

项目总结 疼痛(多彩)是炎症的四大标志之一，常伴有细菌感染。 伤害性感受器神经元是介导疼痛的外周感觉神经元，它密集地支配屏障。 接触病原体的组织，包括皮肤和软组织。化脓性链球菌是一种主要的 坏死性筋膜炎的原因，这是一种侵袭性和危及生命的感染形式，疼痛出现在早期和 与其他症状“不成比例”。我们假设疼痛在 化脓性链球菌的发病机制，通过诱导神经介导的抑制天然免疫细胞募集和 杀灭细菌。在这里，我们将确定：1)化脓性链球菌感染过程中疼痛的分子机制， 重点介绍链球菌致孔毒素S(SLS)和溶链素O(SLO)，以及2) 伤害性感受器和疼痛信号在调节中性粒细胞功能和宿主防御化脓性链球菌中的作用。 我们测试了以疼痛信号为靶点会导致先天免疫反应增强的假设。vt.给出 疼痛在坏死性筋膜炎诊断中的重要性，以及止痛药的广泛使用，我们的 将疼痛与化脓性链球菌宿主防御联系起来的发现可能具有重要的临床意义。两个目的 这项研究利用了赵博士和韦塞尔博士的互补技能，结合了神经生物学， 研究疼痛在宿主防御中的作用的免疫学和微生物学方法。以特定的目标 1，我们将从两个方面确定化脓性链球菌感染过程中产生疼痛的关键分子机制。 临床分离株。我们同时使用同基因突变细菌菌株和质粒互补策略。 通过神经行为测定确定SLS和SLO是否介导化脓性链球菌引起的疼痛。我们会 确定炎症体和IL-1β是否参与神经元对致孔毒素的识别或 疼痛信号。此外，我们还确定了非类固醇抗炎药(NSAIDs)在 化脓性链球菌感染对痛觉的影响。在具体目标2中，我们将确定如何确定目标 使用RTX治疗或TRPV1-cre/DTA小鼠消融TRPV1伤害性感受器可增强宿主对 化脓性链球菌。我们将确定如何在时间和空间上控制TRPV1神经活动的调制 使用光遗传或DREADD策略会影响化脓性链球菌感染的结局。我们还将利用 阿片类药物阻断中枢痛觉或肉毒杆菌毒素阻断外周疼痛信号以确定哪种 神经成分调节对化脓性链球菌的免疫反应。在我们的分析中，我们阐明了 CGRP等伤害性感受器衍生神经肽抑制中性粒细胞吞噬和杀伤沙门氏菌 化脓性。这项研究分析了疼痛信号的诱导、先天神经阻断之间的一个重要联系 免疫，加强化脓性链球菌的致病作用。靶向疼痛与神经免疫 抑制可能导致治疗这种和其他侵袭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.