Human DBR1 defines a new pathway of intrinsic antiviral immunity in the CNS

人类DBR1定义了中枢神经系统内在抗病毒免疫的新途径

基本信息

批准号：
8675975
负责人：
Shen-Ying Zhang
金额：
$ 20.98万
依托单位：
ROCKEFELLER UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8675975
关键词：
Alleles Antiviral Agents Child Childhood Collection Complication Country Dermal Disease Encephalitis Enzymes Fibroblasts Gene Mutation Genes Genetic Predisposition to Disease Genetic Recombination Goals Herpes encephalitis Herpesvirus 1 Human Immune response Immunity In Vitro Inborn Genetic Diseases Infection Interferons Introns Investigation Laboratories Lesion Life Light Mediating Missense Mutation Molecular Mutation Neuraxis Neurons Oligodendroglia Pathogenesis Pathway interactions Patients Pattern Phenotype Play Predisposition Proteins RNA Binding Research Research Project Grants Role STAT1 gene TBK1 gene TLR3 gene TNF receptor-associated factor 3 Testing Trigeminal System Viral Viral Encephalitis Virus Work Yeasts exome sequencing in vitro Assay in vivo induced pluripotent stem cell mRNA Decay mRNA Precursor mutant novel novel therapeutics nuclease poly A specific exoribonuclease public health relevance viral RNA

项目摘要

DESCRIPTION (provided by applicant): Childhood herpes simplex virus 1 (HSV-1) encephalitis (HSE) is a life-threatening complication of primary infection by HSV-1, a common virus that causes innocuous infections in most children. The pathogenesis of HSE remained unclear until we recently showed that the disease may result from single-gene mutations impairing TLR3-dependent, IFN-¿/¿-mediated immunity to HSV-1 in the central nervous system (CNS), in some children. We described 10 patients, each carrying homozygous or heterozygous mutations in a TLR3 pathway gene. We also demonstrated that patient-specific induced pluripotent stem cells (iPSC)-derived TLR3-deficient neurons and oligodendrocytes were highly susceptible to HSV-1 infection, suggesting that impaired TLR3-IFN-mediated CNS intrinsic anti-HSV-1 immunity underlies the pathogenesis of HSE in patients with inborn errors of TLR3 immunity. HSE in other children may therefore result from a collection of single-gene inborn errors of CNS- intrinsic immunity against HSV-1, probably but not necessarily related to the TLR3-IFN circuit. Surprisingly, out of the 100 HSE children recently studied by whole exome sequencing (WES), four carry homozygous (two patients) or heterozygous (two patients) missense mutations in the gene encoding human debranching enzyme 1 (DBR1). Human DBR1 has been proposed to play a key role in the rapid turnover of lariat introns excised from pre-mRNA. Related to this observation, seven other HSE children studied carry heterozygous nonsense (two patients) or missense (five patients) mutations in the gene encoding 5'-3' exoribonuclease 1 (XRN1), a molecule closely connected to DBR1 in a host pre-mRNA decay pathway. Both DBR1 and XRN1 have particular CNS expression patterns. Although yeast Xrn1 is known as an essential antiviral molecule, it is completely unknown how DBR1 and XRN1 can control anti-HSV-1 immunity in the human CNS. We hypothesize that human DBR1 and XRN1 define a new, CNS-specific mechanism of intrinsic anti-HSV-1 immunity. The goal of the present application is to test this hypothesis at the molecular and cellular levels. The proposed work will be focused on the exploration of the specific role of DBR1 and its related genes (mainly XRN1) in CNS-intrinsic anti-viral immunity. The preliminary results further showed that dermal fibroblasts from one patient homozygous for a DBR1 I120T mutation express only very low levels of DBR1 protein and enhanced HSV-1 susceptibility, as comparing to the healthy controls tested. We will test fibroblasts from all patients carrying mutations in DBR1 or XRN1. We will investigate the antiviral activity of DBR1 and XRN1, indirectly via TLR3- or IFN-mediated immunity, or directly via the suppression of viral RNA recombination by DBR1 or XRN1, in in vitro assays. We will investigate anti-HSV-1 immune responses and HSV-1 susceptibility, both IFN-dependent or not, in patients' fibroblasts and iPSC-derived neurons deficient for DBR1 or XRN1, in comparison with those with impaired TLR3-, IFN-mediated immunity. This research will shed light on a novel molecule and cellular mechanism of the HSE pathogenesis, which will open new therapeutic avenues.

描述（由申请人提供）：儿童单纯疱疹病毒 1 (HSV-1) 脑炎 (HSE) 是 HSV-1 原发感染的危及生命的并发症，HSV-1 是一种常见病毒，可在大多数儿童中引起无害感染。 HSE 的发病机制。直到我们最近表明该疾病可能是由损害 TLR3 依赖性、IFN-¿ 的单基因突变引起的，这一点仍不清楚。 /¿在一些儿童中，我们描述了 10 名患者的中枢神经系统 (CNS) 介导的 HSV-1 免疫，每个患者都携带 TLR3 通路基因的纯合或杂合突变。 ) ) 衍生的 TLR3 缺陷神经元和少突胶质细胞对 HSV-1 感染高度敏感，表明受损的 TLR3-IFN 介导的 CNS 固有抗 HSV-1 免疫是导致 HSV-1 感染的基础。因此，患有先天性 TLR3 免疫缺陷的患者的 HSE 发病机制可能是由针对 HSV-1 的 CNS 固有免疫的单基因先天性错误的集合引起的，可能但不一定与 TLR3-IFN 回路相关。令人惊讶的是，最近通过全外显子组测序 (WES) 研究的 100 名 HSE 儿童中，有 4 名在编码人类基因的基因中携带纯合子（两名患者）或杂合子（两名患者）错义突变。脱支酶 1 (DBR1) 被认为在从前体 mRNA 中切除的套索内含子的快速周转中发挥着关键作用，与此观察相关的是，研究的其他 7 名 HSE 儿童携带杂合无义基因（两名患者）或错义基因（2 名患者）。 5 名患者）编码 5'-3' 核糖核酸外切酶 1 (XRN1) 的基因发生突变，XRN1 是一种与宿主前 mRNA 衰变途径中的 DBR1 密切相关的分子。 DBR1 和 XRN1 具有特定的 CNS 表达模式，尽管酵母 Xrn1 被认为是一种重要的抗病毒分子，但完全未知 DBR1 和 XRN1 如何控制人类 CNS 中的新的 CNS 特异性内在抗病毒机制。 -HSV-1免疫。本申请的目的是在分子和细胞水平上检验这一假设。重点探索DBR1及其相关基因（主要是XRN1）在CNS固有抗病毒免疫中的具体作用初步结果进一步表明，来自一名DBR1 I120T突变纯合子的患者的真皮成纤维细胞仅表达非常低的水平。与测试的健康对照相比，DBR1 蛋白的增加和 HSV-1 易感性增强。我们将测试所有携带 DBR1 或突变的患者的成纤维细胞。 XRN1。我们将通过 TLR3 或 IFN 介导的免疫间接研究 DBR1 和 XRN1 的抗病毒活性，或通过 DBR1 或 XRN1 直接抑制病毒 RNA 重组，我们将研究抗 HSV-1 免疫。与那些缺乏 DBR1 或 XRN1 的患者的成纤维细胞和 iPSC 衍生神经元中的反应和 HSV-1 易感性（无论是否依赖 IFN）相比这项研究将揭示 HSE 发病机制的新分子和细胞机制，从而开辟新的治疗途径。