RIPK3-dependent suppression of excitotoxicity during neuronal flavivirus infection

摘要 虽然神经元以前被认为是免疫惰性的，但最近的进展重新定义了 我们对这种细胞的内在免疫活性的理解。值得注意的是，神经元表现出强大的先天 病毒感染的免疫反应，通常采用抗病毒过程的适应，反映其独特的 细胞生物学我们和其他人最近描述了一种这样的适应，其中受体相互作用的激活 黄病毒感染期间神经元中的蛋白激酶-3（RIPK 3）不导致坏死性细胞死亡， 这种蛋白质的典型功能。相反，神经元RIPK 3激活驱动细胞死亡无关的 在一些实施方案中，转录程序包括多种抗病毒和免疫调节基因。虽然 RIPK 3在协调神经元炎症反应中的作用现已确立， RIPK 3对神经元细胞生物学的其他特征（包括神经传递）的激活仍然未被探索。在 初步实验表明，神经元寨卡病毒感染后RIPK 3激活支持 参与突触调节的一大类基因的表达，包括神经递质受体 贩运和国际化。我们还表明，增加神经元细胞死亡和动物死亡的神经元， 缺乏RIPK 3的培养物和小鼠可以通过离子型谷氨酸受体的药理学阻断来挽救 NMDAR。因此，我们假设RIPK 3在寨卡病毒感染期间通过抑制 NMDAR依赖性兴奋性细胞死亡我们将使用以下创新组合来测试这一想法： 药物遗传学、成像、分子生物学和电生理学方法。如果成功，这些 研究将为神经元中的典型细胞死亡蛋白定义一种新的促生存功能， 先天免疫信号对神经传递的影响。

Abstract While neurons were previously believed to be immunologically inert, recent advances have redefined our understanding of the intrinsic immunological activity of this cell type. Notably, neurons exhibit robust innate immune responses to viral infection, often employing adaptations of antiviral processes that reflect their unique cell biology. We and others recently described one such adaptation, in which activation of receptor interacting protein kinase-3 (RIPK3) in neurons during flavivirus infection does not result in necroptotic cell death, the canonical function of this protein. Instead, neuronal RIPK3 activation drives a cell death-independent transcriptional program that includes a broad variety of antiviral and immunoregulatory genes. However, while roles for RIPK3 in coordinating neuronal inflammatory responses are now established, the potential impact of RIPK3 activation on other features of neuronal cell biology, including neurotransmission, remain unexplored. In preliminary experiments, we have shown that RIPK3 activation following neuronal Zika virus infection supports expression of a broad class of genes involved in synapse regulation, including neurotransmitter receptor trafficking and internalization. We also show that increased neuronal cell death and animal mortality in neuron cultures and mice lacking RIPK3 can be rescued by pharmacologic blockade of the ionotropic glutamate receptor NMDAR. We thus hypothesize that RIPK3 protects neuronal viability during Zika virus infection via suppression of NMDAR-dependent excitotoxic cell death. We will test this idea using an innovative combination of pharmacogenetics, imaging, molecular biology, and electrophysiological approaches. If successful, these studies will define a new, pro-survival function for a canonical cell death protein in neurons, as well as bring new clarity to the impact of innate immune signaling on neurotransmission.