RIP3 mediated restriction of neuropathogenesis during viral encephalitis

受体相互作用蛋白激酶-3（RIPK3）已在体外被广泛表征为 坏死性凋亡，程序性细胞死亡的非凋亡形式1。然而，坏死性凋亡的生理作用， 并通过RIPK 3的延伸，一直保持难以捉摸2。这项提案的目标是揭示新的功能， RIPK3信号传导在中枢神经系统（CNS）中的作用，并确定RIPK3信号传导在中枢神经系统（CNS）中的独特性质。 组织.为了实现这一目标，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，以及建立由RIPK3参与的细胞特异性转录程序的性质。 CNS中的信号。 与典型的细胞凋亡相反，坏死性凋亡具有高度免疫原性，并已被证明有助于 to antiviral抗病毒responses响应to diverse多样viruses病毒3 - 5.然而，新的证据也表明RIPK3可以诱导 炎症基因通过信号通路表达，这些信号通路不依赖于其在细胞中的典型作用 死亡6 - 9。我们最近的研究（修订版）确定了RIPK3在协调保护性细胞凋亡中的作用， WNV脑炎期间的神经炎症。然而，这种意想不到的信号的独特功能 目前，CNS的计划尚未完全确定。此外，RIPK3促进保护性的可能性也很小。 对全球关注的其他神经侵入性感染的反应尚不清楚。 自从最近引入西半球以来，ZIKV感染已成为一个重大威胁 公共卫生10. ZIKV感染的结果包括严重的出生异常，其特征在于 发育期间的神经病理损伤，随后是终身功能和认知障碍10，11。 虽然罕见，但成年人的症状感染可导致慢性神经病变和潜在致命性 脑膜脑炎12.在没有任何批准的疫苗或疾病特异性疗法的情况下， 迫切需要确定有助于疾病发病机制和保护的宿主因素， 神经侵袭性ZIKV感染13. 在初步研究中，我们证明RIPK3是限制ZIKV的关键宿主因子。 发病机制，因为Ripk3-/-小鼠表现出上行运动障碍和脊髓中病毒负荷增加 与WT对照组相比。在体外研究中，我们观察到一种独特的诱导炎症趋化因子， 表达依赖于RIPK1和RIPK3的激酶活性。然而，这种信号 出现独特的神经元，并没有发生在任何外周或驻地中枢神经系统髓样细胞，表明 RIPK3参与可能在不同发育阶段的CNS细胞中具有不同的功能结果， 个体发育在这些拟议的研究中，我们将定义RIPK3信号传导的细胞和谱系特异性功能， CNS，并建立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.