Mechanisms regulating fetal membrane and neutrophil responses to infection

调节胎膜和中性粒细胞对感染反应的机制

• 批准号: 10876528
• 负责人: Vikki M Abrahams
• 金额: $ 40.4万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-03 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10876528
• 关键词: Acetylmuramyl-Alanyl-Isoglutamine; Agonist; Allopurinol; Bacteria; Bacterial Infections; Cells; Chemotactic Factors; Communication; Complex; Data; Exposure to; Family; Fetal Membranes; Fetus; Grant; Human; IL8 gene; Immune; In Vitro; Infection; Inflammasome; Inflammation; Inflammatory; Inflammatory Response; Lipopolysaccharides; Maternal-Fetal Exchange; Mediating; Mediator; MicroRNAs; Modeling; Mus; Nature; Neutrophil Activation; Neutrophil Infiltration; Outcome; Pathologic; Pathology; Pattern recognition receptor; Peptidoglycan; Play; Pregnancy; Pregnancy Complications; Premature Birth; Process; Production; Regulation; Risk; Risk Factors; Role; Signal Pathway; Signal Transduction; Site; Source; TLR2 gene; TLR4 gene; TLR7 gene; TLR8 gene; Testing; Tissue membrane; Toll-like receptors; Uric Acid; Woman; Xanthine Oxidase; chemokine; cytokine; exosome; extracellular; in vitro testing; in vivo; inflammatory milieu; inhibitor; intraamniotic infection; mouse model; neutrophil; novel; premature; receptor; response; sensor; therapeutic target; tissue injury; xanthine oxidase inhibitor

Summary/Abstract Chorioamnionitis - inflammation of the fetal membranes (FM) - is characterized by neutrophil infiltration and is a major risk factor for preterm birth. Even in the absence of prematurity, chorioamnionitis can be detrimental to the fetus. Despite a strong association between bacterial infection, chorioamnionitis, and preterm birth, the mechanisms involved are not fully understood. Through expression of the innate immune pattern recognition receptors (PRR), Toll-like receptors (TLRs) and Nod-like receptors (NLRs), FMs have strategies to evade and protect against infection. However, depending upon the nature of signaling and regulation, these protective immune mechanisms may create an inflammatory milieu that can contribute to pathology. In particular, IL-8 is a major neutrophil chemoattractant and inflammasome-mediated IL-1b is a major inducer of tissue injury and mediator of preterm birth. We have found that the chorionic compartment is the primary site of FM IL-8 and IL- 1b production in response to bacterial lipopolysaccharide (LPS), peptidoglycan (PDG), and muramyl dipeptide (MDP) which activate TLR4, TLR2, and Nod2, respectively. While TLRs and NLRs can directly activate signaling pathways leading to inflammatory cytokine/chemokine production, there is the potential for far more complex modulation, regulation, and fine-tuning of these processes and the type of responses generated, particularly for IL-1b. This grant focusses on the requirement of two or more PRRs to be activated sequentially in FMs exposed to bacterial triggers via novel intermediates. A non-classical family of microRNAs (miRs) activate the ssRNA sensors, TLR7 and TLR8, to elicit an inflammatory response. These miRs can also be carried in exosomes and delivered to TLR7 or TLR8 in target cells. Our preliminary data supports the concept that TLR8-activating miR-146a-3p may acts as a novel intermediate signal that drives FM chemotactic and inflammatory responses to bacterial TLR and NLR agonists. We also have preliminary data demonstrating that FM-derived exosomes containing TLR8-activating miRs trigger neutrophil activation and release of neutrophil extracellular traps. Finally, we found that FM tissue and circulating exosomal TLR8-activating miR-146a-3p is elevated in women with preterm birth. Based on this, our central hypothesis is that TLR8-activating miRs mediate FM chemotactic IL-8 and inflammasome-mediated inflammatory IL-1b in response to bacterial triggers, and through their release and delivery via exosomes active maternal neutrophils. This leads to inflammation at the maternal-fetal interface, increasing the risk for chorioamnionitis. To test this, our specific aims are to determine if: Aim 1. TLR8-activating miRs mediate a FM chemotactic IL-8 response after exposure to bacterial triggers. Aim 2. TLR8-activating miRs contribute to FM inflammasome activation and inflammatory IL-1b production. Aim 3. FM exosomes containing TLR8-activating miRs induce neutrophil activation.

摘要/摘要 绒毛膜炎 - 胎儿膜（FM）的炎症 - 以中性粒细胞浸润为特征，IS 早产的主要危险因素。即使在没有早产的情况下，绒毛膜膜炎也可能有害 胎儿。尽管细菌感染，绒毛膜炎和早产之间有很强的联系，但 涉及的机制尚未完全理解。通过表达先天免疫模式识别 受体（PRR），Toll样受体（TLR）和点头样受体（NLR），FMS具有逃避和 防止感染。但是，根据信号和调节的性质，这些保护性 免疫机制可能会产生炎症环境，从而有助于病理学。特别是，IL-8是 主要嗜中性粒细胞化学吸收剂和炎性体介导的IL-1B是组织损伤的主要诱导剂， 早产的调解人。我们发现绒毛膜室是FM IL-8和IL-的主要部位 1b对细菌脂多糖（LPS），肽聚糖（PDG）和穆拉米基二肽的产生 （MDP）分别激活TLR4，TLR2和NOD2。而TLR和NLR可以直接激活 信号传导途径导致炎症性细胞因子/趋化因子产生，有更多的潜力 这些过程的复杂调制，调节和微调以及产生的响应类型， 特别是对于IL-1B。该赠款的重点是两个或多个PRR的要求，要依次激活 在FMS中，通过新型中间体暴露于细菌触发器。一个非古典的microRNA家族（mirs） 激活SSRNA传感器TLR7和TLR8，以引起炎症反应。这些mir也可以是 在外泌体中携带，并在靶细胞中递送至TLR7或TLR8。我们的初步数据支持该概念 TLR8激活的miR-146a-3p可能充当一个新型的中间信号，驱动FM趋化性和 对细菌TLR和NLR激动剂的炎症反应。我们还拥有初步数据，表明 含有TLR8激活miR的FM衍生的外泌体触发嗜中性粒细胞激活和中性粒细胞的释放 细胞外陷阱。最后，我们发现FM组织和循环的外泌体TLR8激活miR-146A-3P是 早产妇女的提升。基于此，我们的中心假设是TLR8激活mirs 介导FM趋化性IL-8和炎性体介导的炎症IL-1B，以响应细菌 触发，并通过外泌体活性母体嗜中性粒细胞释放和分娩。这导致 在母亲界面处发炎，增加了绒毛膜炎的风险。为了测试这一点，我们 具体目的是确定是否： AIM1。TLR8激活MIR介导暴露于细菌触发器后的FM趋化IL-8反应。 AIM2。TLR8激活的miR有助于FM炎症体激活和炎症IL-1B产生。 AIM 3。含有TLR8激活miR的FM外泌体诱导中性粒细胞激活。