The Role of the RIP Kinases in Coordinating Neuroinflammation and Host Defense

坏死性下垂是细胞程序性死亡的一种形式，通过激活相互作用的受体来执行 蛋白激酶(RIPK)、RIPK1和RIPK3。虽然这条细胞死亡途径一直是激烈的 在研究中，重要的生理环境仍然难以捉摸。我们发现老鼠缺乏 RIPK3对神经侵袭性黄病毒西尼罗河病毒(WNV)非常敏感。RIPK3 基因敲除动物无法控制中枢神经系统(CNS)内的病毒生长，因为它们 在免疫细胞进入这个组织的过程中显示出一个严重的缺陷。值得注意的是，RIPK3缺陷小鼠 也未能控制寨卡病毒(ZIKV)感染，表现为神经功能障碍和上行性瘫痪 一旦感染了这种病原体。令人惊讶的是，在这种情况下，RIPK3的保护作用完全是 不依赖于它在诱导程序性细胞死亡中的作用；相反，RIPK3是正常生产 西尼罗河病毒感染中枢神经系统中的炎性趋化因子和免疫细胞转运。鉴于这些意想不到的事情 初步数据，这一应用的中心假设是病毒诱导的RIPK3在 中枢神经系统不会触发细胞死亡，而是激活需要的炎性转录程序 用于神经炎症、免疫细胞招募和宿主保护。此应用程序将对此进行调查 通过关注三个目标来提出假设。首先，我们将努力了解RIPK3在CNS中是如何参与的 为了促进宿主保护，在该组织中使用RIPK3的条件删除和转基因表达 与尖端成像方法相结合。接下来，我们将使用生化方法和新的小鼠 了解RIPK3下游目标的模型，这些目标负责协调 神经炎。最后，我们将研究RIPK3在宿主抵抗ZIKV感染中的作用，以及 研究在感染ZIKV的RIPK3基因敲除小鼠中观察到的意外的运动功能缺陷。 总之，这项工作将定义一条新的信号通路，负责宿主防御神经侵袭 对全球健康构成重大威胁的病毒病原体。

Necroptosis is a form of programmed cell death that is executed by activation of the Receptor Interacting Protein Kinases (RIPKs), RIPK1 and RIPK3. While this cell death pathway has been the subject of intense study, physiological settings in which it is important have remained elusive. We have found that mice lacking RIPK3 are highly susceptible to infection by the neuroinvasive flavivirus West Nile virus (WNV). RIPK3 knockout animals are unable to control viral growth within the central nervous system (CNS), because they display a profound defect in the recruitment of immune cells into this tissue. Notably, RIPK3-deficient mice also fail to control Zika virus (ZIKV) infection, and display neurological impairments and ascending paralysis upon infection with this pathogen. Surprisingly, the protective role of RIPK3 in this setting is wholly independent of its role in inducing programmed cell death; rather, RIPK3 is required for normal production of inflammatory chemokines and immune cell trafficking in the WNV-infected CNS. Given these unexpected preliminary data, the central hypothesis of this application is that virus-induced RIPK3 activation within the CNS does not trigger cell death, but rather activates an inflammatory transcription program is required for neuroinflammation, immune cell recruitment, and host protection. This application will investigate this hypothesis by focusing on three Aims. First, we will work to understand how RIPK3 is engaged within the CNS to promote host protection, using conditional deletion and transgenic expression of RIPK3 within this tissue in combination with cutting-edge imaging approaches. Next, we will use biochemical methods and novel mouse models to understand the downstream targets of RIPK3 that are responsible for the coordination of neuroinflammation. Finally, we will investigate the role of RIPK3 in host protection against ZIKV infection, and investigate the unexpected defects in motor function observed in ZIKV-infected RIPK3 knockout mice. Together, this work will define a novel signaling pathway responsible for host defense against neuroinvasive viral pathogens that represent a significant threat to global health.