RIP3 mediated restriction of neuropathogenesis during viral encephalitis

受体相互作用蛋白激酶-3(RIPK3)在体外被广泛鉴定为 坏死性下垂，一种非凋亡性形式的程序性细胞死亡1。然而，坏死性下垂的生理作用， 通过RIPK3的延伸，仍然难以捉摸2。这项提议的目标是发现 中枢神经系统(CNS)中的RIPK3信号，并定义RIPK3信号在中枢神经系统(CNS)中的独特性质 组织。为此，我们将评估RIPK3在介导寨卡病毒神经保护反应中的作用 (ZIKV)感染，以及确定RIPK3参与的细胞特异性转录程序的性质 中枢神经系统中的信号。 与典型的细胞凋亡不同，坏死性下垂是高度免疫原性的，并已被证明有助于 对不同病毒的抗病毒反应3-5。然而，新出现的证据也表明，RIPK3可以诱导 炎症基因通过独立于其在细胞中的规范作用的信号通路表达 死亡6胜9负。我们最近的研究(修订中)确定了RIPK3在协调保护中的死亡独立作用 西尼罗河病毒脑炎期间的神经炎症。然而，这种意想不到的信号的独特特征 程序在CNS中还没有得到充分的定义。此外，RIPK3促进保护的潜力 对其他全球关注的神经侵袭性感染的反应尚不清楚。 自最近进入西半球以来，寨卡病毒感染已成为一个重大威胁 对公共卫生的贡献10.寨卡病毒感染的后果包括严重的出生异常，其特征是 发育过程中的神经病理损害，随后是终生功能和认知损害10，11。 成人的症状感染虽然罕见，但可导致慢性神经病变，并有可能致命。 脑膜脑炎12.在没有任何批准的疫苗或疾病特异性治疗的情况下，有一种 迫切需要确定有助于疾病发病机制和预防的宿主因素 神经侵袭性寨卡病毒感染13。 在初步研究中，我们证明了RIPK3是限制ZIKV的关键宿主因子 发病机制，因为RIPK3-/-小鼠表现出上行性运动障碍和脊髓中病毒负荷增加 CORD与WT对照。在体外研究中，我们观察到一种独特的炎性趋化因子的诱导 表达依赖于RIPK1和RIPK3的激酶活性。然而，这一信号 似乎是神经元独有的，在外周或驻留的中枢神经系统髓系细胞中都没有出现，这表明 RIPK3参与在发育不同的中枢神经系统细胞中可能有不同的功能结果 个体发育。在这些拟议的研究中，我们将定义RIPK3信号的细胞和谱系特定功能 中枢神经系统，并确定这些功能如何协调对ZIKV感染的神经保护反应。

Receptor interacting protein kinase-3 (RIPK3) has been extensively characterized in vitro as the key initiator of necroptosis, a non-apoptotic form of programmed cell death1. However, the physiological role of necroptosis, and by extension of RIPK3, has remained elusive2. The goal of this proposal is to uncover novel functions for RIPK3 signaling in the central nervous system (CNS) and to define the unique nature of RIPK3 signaling in this tissue. In pursuit of this, we will assess the role of RIPK3 in mediating neuroprotective responses to Zika virus (ZIKV) infection, as well as establish the nature of cell-specific transcriptional programs engaged by RIPK3 signaling in the CNS. As opposed to canonical apoptosis, necroptosis is highly immunogenic and has been shown contribute to antiviral responses to diverse viruses3-5. However, emerging evidence also suggests that RIPK3 can induce inflammatory gene expression through signaling pathways that are independent of its canonical role in cell death6-9. Our recent study (in revision) identified a death-independent role for RIPK3 in coordinating protective neuroinflammation during WNV encephalitis. However, the unique features of this unexpected signaling program in the CNS have not yet been fully defined. Moreover, the potential for RIPK3 to promote protective responses to other neuroinvasive infections of global concern is unknown. Since its recent introduction to the Western hemisphere, ZIKV infection has become a significant threat to public health10. Among the outcomes of ZIKV infection are severe birth abnormalities characterized by neuropathological damage during development followed by lifelong functional and cognitive impairments10,11. Though rare, symptomatic infections in adults can lead to chronic neuropathy and potentially fatal meningoencephalitis12. In the absence of any approved vaccines or disease-specific therapies, there is an urgent need to identify host factors that contribute to disease pathogenesis and protection during neuroinvasive ZIKV infection13. In preliminary studies, we demonstrate that RIPK3 is a critical host factor in the restriction of ZIKV pathogenesis, as Ripk3-/- mice exhibit ascending motor impairments and increased viral burden in the spinal cord compared to WT controls. In in vitro studies, we observed a unique induction of inflammatory chemokine expression that was dependent on the kinase activities of both RIPK1 and RIPK3. However, this signaling appeared unique to neurons and did not occur in either peripheral or resident CNS myeloid cells, suggesting that RIPK3 engagement may have different functional outcomes in CNS cells of distinct developmental ontogenies. In these proposed studies, we will define cell- and lineage-specific functions for RIPK3 signaling in the CNS, and establish how these functions coordinate neuroprotective responses to ZIKV infection.