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（由适用提供）：单纯疱疹病毒1（HSV-1）脑炎（HSE）是HSV-1原发性感染的一种威胁生命的并发症，HSV-1是一种常见病毒，会引起大多数儿童无害的感染。直到我们最近表明该疾病可能是由于单基因突变损害了中枢神经系统（CNS）中HSV-1的HSV-1，因此HSE的发病机理一直尚不清楚。我们还描述了10例在TLR3途径基因中携带纯合或杂合突变的患者。 We also demonstrated that patient-specific induced pluripotent stem cells (iPSC)-derived TLR3-deficiency neurons and oligodendrocytes were highly susceptible to HSV-1 infection, suggesting that impaired TLR3-IFN-mediated CNS intrinsic anti-HSV-1 immunology underlies the pathogenesis of HSE in patients with inborn errors of TLR3 immunology.因此，其他儿童中的HSE可能是由针对HSV-1的CNS内部免疫学的单基因天生误差引起的，可能但不一定与TLR3-IFN电路有关。令人惊讶的是，在最近由整个外显子组测序（WES）研究的100名HSE儿童中，有四个携带纯合（两名患者）或杂合子（两个患者）的错义突变，编码人类脱支酶1（DBR1）。已提出人类DBR1在pre-mRNA的出色套索内含子的快速周转中发挥关键作用。与这一观察结果相关的是，其他七个HSE儿童携带杂合胡须（两名患者）或错义（五个患者）突变，编码5'-3'骨核酸酶1（XRN1），这是一个与宿主前MRNA衰变途径密切相关的分子。 DBR1和XRN1均具有特定的CNS表达模式。尽管酵母XRN1被称为必不可少的抗病毒分子，但完全未知DBR1和XRN1如何控制人类中枢神经系统中的抗HSV-1免疫力。我们假设人DBR1和XRN1定义了一种内在的抗HSV-1免疫性的新的，CNS特异性的机制。本应用的目的是在分子和细胞水平上检验该假设。拟议的工作将专注于探索DBR1及其相关基因（主要是XRN1）在中枢神经系统抗病毒免疫中的特定作用。初步结果进一步表明，与所测试的健康对照组相比，DBR1 I120T突变的一名患者的皮肤成纤维细胞仅表达DBR1 I120T突变表达的DBR1蛋白水平很低，并增强了HSV-1易感性。我们将测试所有携带DBR1或XRN1突变患者的成纤维细胞。我们将通过TLR3-或IFN介导的免疫学间接研究DBR1和XRN1的抗病毒活性，或直接通过在体外测定中直接通过DBR1或XRN1抑制病毒RNA重组。与患者的成纤维细胞和IPSC衍生的DBR1或XRN1缺乏IPSC的神经元相比，与患者的成纤维细胞和IPSC衍生的神经元相比，与患者的抗HSV-1免疫调查和HSV-1敏感性相比，与TLR3-，IFN-3-介导的IFN介导的免疫免疫可免疫免疫可相比。这项研究将阐明HSE发病机理的一种新的分子和细胞机制，该机制将打开新的治疗途径。