Deciphering the complexities of inflammasome activation following RSV infection

破译 RSV 感染后炎症小体激活的复杂性

• 批准号: 10807884
• 负责人: Steven M Varga
• 金额: $ 38.99万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10807884
• 关键词: Deciphering; complexities; inflammasome; activation; following

Abstract Respiratory syncytial virus (RSV) is a leading cause of severe respiratory disease in children, the elderly and immunocompromised individuals and there is currently no licensed RSV vaccine. The host inflammatory response is believed to contribute to disease severity following RSV infection. Much less is currently known regarding the role of RSV strains in modulating the host inflammatory response. The production of proinflammatory cytokines IL-1β and IL-6 have been found to be significantly increased in the respiratory tract of infants with severe disease. In addition, RSV infection has been reported to promote hypermetabolism in the upper respiratory cells of RSV-infected children. IL-1β is a key proinflammatory cytokine and its secretion is tightly regulated by multi-protein complexes named inflammasomes. Activation of the inflammasome is a two- step process, including priming and activation steps, that requires metabolic reprogramming of the cell. Previous studies have demonstrated that RSV A2 infection induces the activation of the NLRP3 inflammasome. Our preliminary data illustrate that infection with the RSV 2-20 strain results in significantly increased IL-1β production as compared to infection with the A2 strain. We also observe an increase in glycolysis in RSV 2-20 infected macrophages as compared to A2 infected macrophages. Unexpectedly, when we infect cells with a recombinant RSV A2 strain engineered to express the 2-20 fusion (F) protein, termed A2/2-20F, we observe a significant increase in both IL-1β production and glycolysis in macrophages. Thus, our exciting new preliminary data indicate that RSV strains differentially activate the inflammasome and this strain- dependent increased inflammasome activation is mediated by the F protein. Thus, important knowledge gaps exist regarding how RSV-derived genes modulate the host inflammatory response. Our long-term goal is to understand the virus-derived factors that modulate the host immune response and disease severity following RSV infection. The objective of this application is to determine the changes that occur in inflammasome signaling and metabolism following RSV infection. Moreover, we will explore how these changes impact innate cell recruitment into the lung and shape the subsequent adaptive immune response. Our central hypothesis is that the RSV 2-20 strain enhances both inflammasome priming and activation signals resulting in increases in both neutrophil influx and the Th17 response. We will achieve the goals outlined above by pursuing the following two specific aims: Aim 1. Determine the mechanism of RSV F protein-mediated inflammasome activation. Aim 2. Examine the role of differential inflammasome activation on immune cell recruitment and disease following RSV infection. The knowledge gained from these studies will provide a mechanistic understanding of RSV-mediated inflammatory responses. In addition, these studies will greatly impact the evaluation of therapeutic targets and design of future RSV vaccine candidates.

抽象的 呼吸道合胞病毒（RSV）是儿童、老年人和儿童严重呼吸道疾病的主要原因。 免疫功能低下的个体，目前还没有获得许可的 RSV 宿主炎症疫苗。 据信，RSV 感染后的反应会导致疾病严重程度，目前知之甚少。 关于 RSV 菌株在调节宿主炎症反应中的作用。 已发现呼吸道促炎细胞因子 IL-1β 和 IL-6 显着增加 此外，据报道，RSV 感染会促进患有严重疾病的婴儿的代谢亢进。 RSV 感染儿童的上呼吸道细胞 IL-1β 是一种关键的促炎细胞因子，其分泌是 受到称为炎症小体的多蛋白复合物的严格调节，炎症小体的激活是一个两方面的过程。 步骤过程，包括启动和激活步骤，需要细胞的代谢重编程。 先前的研究表明，RSV A2 感染会诱导 NLRP3 的激活 我们的初步数据表明，RSV 2-20 菌株的感染会导致显着的结果。 与 A2 菌株感染相比，IL-1β 产量增加，我们还观察到 IL-1β 产量增加。 出乎意料的是，与 A2 感染的巨噬细胞相比，RSV 2-20 感染的巨噬细胞中的糖酵解。 我们用重组 RSV A2 菌株感染细胞，该菌株经过改造可表达 2-20 融合 (F) 蛋白，称为 A2/2-20F，我们观察到巨噬细胞中 IL-1β 的产生和糖酵解显着增加。 令人兴奋的新初步数据表明 RSV 菌株差异性地激活炎症小体，并且该菌株- 依赖性增加的炎症小体激活是由F蛋白介导的，因此，重要的知识差距。 关于 RSV 衍生基因如何调节宿主炎症反应的问题存在，我们的长期目标是 了解调节宿主免疫反应和疾病严重程度的病毒衍生因素 RSV 感染的目的是确定炎症体中发生的变化。 此外，我们将探讨这些变化如何影响先天性。 我们的中心假设是细胞募集到肺部并形成随后的适应性免疫反应。 RSV 2-20 菌株增强炎性体启动和激活信号，导致 我们将通过追求中性粒细胞流入和 Th17 反应来实现上述目标。 以下两个具体目标： 目标 1. 确定 RSV F 蛋白介导的炎症机制 目标 2. 检查差异炎症小体激活对免疫细胞募集和激活的作用。 从这些研究中获得的知识将提供 RSV 感染后疾病的机制。 此外，这些研究将极大地影响RSV介导的炎症反应。 评估治疗靶点和设计未来的 RSV 候选疫苗。