Cellular RNAs in anti-viral immunity to HSV1 - Resubmission - 1

项目摘要 双链rna(Dsrna)是一种激活细胞的强效病原体相关分子模式。 抑制蛋白质合成和病毒复制的内在抗病毒防御系统。病毒RNA以前被认为是 然而，作为细胞dsrna传感器的主要配体，细胞rna最近被发现是 核酸PAMP反应的主要调节者能够抑制和促进其激活。尽管 单纯疱疹病毒1型受依赖于dsRNA的抗病毒效应物PKR和核糖核酸酶L的限制，是什么RNA激活了这些 酶和新表征的细胞校准剂对这些反应的贡献是完全 未知。我们的总体目标是了解细胞RNA如何有助于抗病毒免疫 单纯疱疹病毒1型感染。依赖dsRNA的反应被几种HSV1编码的蛋白质所抵消， 强调这项任务的重要性。其中包括VHS，一种加速mRNA衰退的内切核糖核酸酶 最大限度地减少dsRNA的积聚和与dsRNA结合的us11，从而阻止eif2α激酶PKR的激活 和RNase L.我们的初步结果表明存在两种相反的机制，细胞RNA也通过这两种机制 在HSV1感染细胞中调节依赖dsRNA的细胞本征防御。首先，我们假设细胞 环状(CIRC)RNA，由US11保护而不被RNA酶L激活，并选择性地保存而不被VHS切割， 抑制PKR的激活。其次，我们假设HSV1诱导的dsRNA不仅是病毒编码的，而且 取而代之的是含有依赖于cGAS-STING对胞浆DNA的感知的细胞RNA成分，该感知 诱导型干扰素(干扰素)对HSV1作出反应的途径。这将构成一种新的信号模式 致病DNA和RNA胞浆检测系统之间的扩增和串扰。我们将测试这些 两个特定目标的假设：(I)确定CircRNAs在HSV1感染生物学中的作用；和(Ii)定义 CGAS刺突dsDNA传感通路如何影响dsRNA丰度和/或抗病毒dsRNA依赖 先天免疫反应。这些特定目标的完成将揭示细胞固有的先天免疫 免疫应答受宿主RNA和平行的先天免疫信号通路的调节 HSV1，一种具有重要医学意义的人类病原体。这项探索性研究的结果可能适用于 多种致病的人类病毒，并可能揭示治疗病毒感染的新策略。在……里面 此外，它们将为先天性免疫信号通路之间的串扰提供重要的见解，包括 DsDNA和dsRNA是癌症和自身免疫性疾病的重要治疗靶点。

Project Summary Double-stranded RNA (dsRNA) is a potent pathogen-associated molecular pattern (PAMP) that activates cell intrinsic antiviral defenses that inhibit protein synthesis and viral replication. Viral RNAs were previously regarded as the primary ligands for cellular dsRNA sensors, however, cellular RNAs have recently been revealed to be major regulators of nucleic acid PAMP responses capable of inhibiting and promoting their activation. Though HSV1 is restricted by dsRNA-dependent antiviral effectors PKR and RNase L, what RNA activates these enzymes and the contribution of newly characterized cellular calibrators of these responses is completely unknown. Our overall objective is to understand how cellular RNAs contribute to antiviral immunity in HSV1 infection. DsRNA-dependent responses are counteracted by several HSV1-encoded proteins, underlining the importance of the task. These include vhs, an endoribonuclease which accelerates mRNA decay minimizing dsRNA accumulation and Us11, which binds dsRNA preventing activation of the eIF2α kinase PKR and RNase L. Our preliminary results indicate two opposing mechanisms exist by which cellular RNAs also regulate dsRNA-dependent cell intrinsic defenses in HSV1 infected cells. First, we hypothesize that cellular circular (circ) RNAs, protected from RNase L activation by Us11 and selectively preserved from vhs cleavage, inhibit PKR activation. Second, we hypothesize that HSV1-induced dsRNA is not exclusively virus-encoded and instead contains a cellular RNA component dependent on cytosolic DNA-sensing by cGAS-STING, the sensing pathway that induces type I interferon (IFN) in response to HSV1. This would constitute a novel mode of signal amplification and cross-talk between pathogenic DNA and RNA cytosolic detection systems. We will test these hypotheses in two specific aims that (i) determine the role of circRNAs in HSV1 infection biology; and (ii) define how the cGAS-STING dsDNA sensing pathway influences dsRNA abundance and/or antiviral dsRNA-dependent innate immune responses. Completion of these specific aims will reveal how cell intrinsic innate immune responses are regulated by host RNAs and parallel innate immune signaling pathways during infection with HSV1, a medically important human pathogen. The results of this exploratory study are potentially applicable to a wide variety of pathogenic human viruses and could reveal new strategies for treating virus infections. In addition, they will provide important insights into cross-talk between innate immune signaling pathways involving dsDNA and dsRNA that are important therapeutic targets for cancer and autoimmune disease.