Autoimmunity to LINE-1-encoded antigens in SLE pathogenesis

SLE 发病机制中对 LINE-1 编码抗原的自身免疫

• 批准号: 9908850
• 负责人: Felipe Andrade
• 金额: $ 24.56万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-07 至 2022-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9908850
• 关键词: Address; Affinity; Antibodies; Antigens; Attention; Autoantigens; Autoimmune Diseases; Autoimmunity; C-terminal; Cells; Clinical; Consensus Sequence; DNA Transposable Elements; DNA Transposons; Data; Development; Diagnosis; Disease; Elements; Endogenous Retroviruses; Etiology; Family; Foundations; Gene Expression Profiling; Genes; Genetic Transcription; Genome; Genomic DNA; Genomics; Goals; Human; Human Genome; Immune response; Immune system; Infectious Agent; Inflammation; Interferon Type I; Interferons; Kidney; Lead; Length; Link; Long Terminal Repeats; Lupus Nephritis; Measures; Mediating; Messenger RNA; Names; Nuclear; Nucleic Acid Binding; Nucleic Acids; Open Reading Frames; Outcome Study; Parasites; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Prevalence; Prevention; Production; Proteins; RNA Recognition Motif; RNA-Binding Proteins; RNA-Directed DNA Polymerase; Regulation; Repetitive Sequence; Research Project Grants; Retroelements; Retrotransposon; Ribonucleoproteins; Role; Sequence Homology; Serological; Source; Sterility; Systemic Lupus Erythematosus; Time; Variant; Viral; Virus; Work; base; cohort; differential expression; endonuclease; genetic element; immunogenic; innovation; insight; mammalian genome; microbial; monomer; neutrophil; new therapeutic target; novel; novel diagnostics; novel therapeutics; particle; peripheral blood; prospective; response; sensor; seropositive; systemic autoimmune disease; tool; transcriptome sequencing; Address; Affinity; Antibodies; Antigens; Attention; Autoantigens; Autoimmune Diseases; Autoimmunity; C-terminal; Cells; Clinical; Consensus Sequence; DNA Transposable Elements; DNA Transposons; Data; Development; Diagnosis; Disease; Elements; Endogenous Retroviruses; Etiology; Family; Foundations; Gene Expression Profiling; Genes; Genetic Transcription; Genome; Genomic DNA; Genomics; Goals; Human; Human Genome; Immune response; Immune system; Infectious Agent; Inflammation; Interferon Type I; Interferons; Kidney; Lead; Length; Link; Long Terminal Repeats; Lupus Nephritis; Measures; Mediating; Messenger RNA; Names; Nuclear; Nucleic Acid Binding; Nucleic Acids; Open Reading Frames; Outcome Study; Parasites; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Prevalence; Prevention; Production; Proteins; RNA Recognition Motif; RNA-Binding Proteins; RNA-Directed DNA Polymerase; Regulation; Repetitive Sequence; Research Project Grants; Retroelements; Retrotransposon; Ribonucleoproteins; Role; Sequence Homology; Serological; Source; Sterility; Systemic Lupus Erythematosus; Time; Variant; Viral; Virus; Work; base; cohort; differential expression; endonuclease; genetic element; immunogenic; innovation; insight; mammalian genome; microbial; monomer; neutrophil; new therapeutic target; novel; novel diagnostics; novel therapeutics; particle; peripheral blood; prospective; response; sensor; seropositive; systemic autoimmune disease; tool; transcriptome sequencing

PROJECT SUMMARY/ABSTRACT While an infectious etiology has been hypothesized in systemic lupus erythematosus (SLE) for more than a century, all studies have failed to identify a microbial cause of this autoimmune disease. This has led to the search for endogenous drivers of sterile inflammation and type I interferon (IFN-I) production in SLE. Over 40 percent of the human genome is made up of hundreds of thousands of repetitive sequences that evolved from genetic elements called transposons, which contain virus-like sequences. Retrotransposons are the predominant class of transposable elements in most mammalian genomes. In recent years, it has been found that similar to viral products, nucleic acids derived from these genomic “parasites” can activate cytosolic nucleic acid sensors. These findings have linked dysregulated expression of retrotransposons with diseases characterized by sustained IFN-I production, such as SLE. In particular, defective regulation of a subclass of non-LTR retrotransposon, the long interspersed nuclear element-1 (LINE1 or L1), has been associated to SLE pathogenesis. To gain further insights into the potential role of L1 elements in SLE, we focused on neutrophils and IFN-I, two important players in SLE pathogenesis. L1 contains two open-reading frames (ORF1 and ORF2). Using SLE neutrophils with evidence of IFN-I activation, we initially identified a novel polymorphic variant of ORF1. Using the protein (ORF1p) encoded by this variant as an antigen in preliminary studies, we identified for the first time that patients with SLE have antibodies to L1-ORF1p. This supports the notion that L1 elements are active and their products stimulate the immune response in SLE. In addition to these innovative findings, our data provide novel hypotheses related to the role of L1 in SLE pathogenesis. It focus attention on neutrophils as a potential source of L1-ORF1p, suggests that polymorphic variants of ORF1p (which could be mistakenly recognized as “viral-derived” products) may trigger the humoral response against this protein, and opens the possibility that anti-ORF1p antibodies may be pathogenic in SLE. The major goal of this exploratory proposal is to gain further insights into the potential significance of these novel hypotheses and preliminary findings in the context of SLE pathogenesis. In Aim 1, we will use capture-based enrichment of L1-ORF1 combined with RNA- Seq to determine whether unique ORF1 transcriptional variants are differentially expressed in control and IFN- activated SLE neutrophils. In addition, we will define whether ORF1p variants are preferentially recognized by antibodies in SLE. In Aim 2, we will determine the prevalence and clinical associations of antibodies to ORF1p and their relationship to the IFN-signature in a prospective observational cohort of patients with SLE, for which extensive clinical and serologic data is available, as well as IFN-induced gene expression analysis. Together, these studies seek to enhance our understanding of self-immunogenic pathways underlying sterile inflammation in SLE. The final goal of this work is to gain new insights into disease mechanisms, thus laying the foundation to explore novel therapies.

项目摘要/摘要 虽然在全身性红斑狼疮（SLE）中假设一种传染病学已被假设 世纪，所有研究都无法确定这种自身免疫性疾病的微生物原因。这导致了 在SLE中搜索无菌注射和I型干扰素（IFN-I）的内源驱动因素。超过40 人类基因组的百分比是由数十万的重复序列组成的 遗传元素称为转座子，其中包含病毒样序列。逆转座子是主要的 大多数哺乳动物基因组中的一系列可转座元素。近年来，发现与 源自这些基因组“寄生虫”的病毒产物，核酸可以激活胞质核酸传感器。 这些发现已将逆转录盆地的失调表达与以疾病为特征 持续的IFN-I生产，例如SLE。特别是，非LTR子类的有缺陷调节 逆转录座子是长散布的核元件-1（LINE1或L1），已与SLE相关联 发病。为了进一步了解L1元素在SLE中的潜在作用，我们专注于中性粒细胞 和IFN-I，这是SLE发病机理中的两个重要参与者。 L1包含两个开读帧（ORF1和ORF2）。 使用SLE中性粒细胞和IFN-I激活的证据，我们最初确定了一种新型的多态性变体 ORF1。使用该变体编码的蛋白质（ORF1P）作为初步研究中的抗原，我们确定了 SLE患者首次对L1-ORF1P抗体。这支持了L1元素是 活性及其产品刺激SLE中的免疫响应。除了这些创新的发现，我们的 数据提供了与L1在SLE发病机理中的作用相关的新型假设。它将注意力集中在中性粒细胞上 L1-ORF1P的潜在来源表明ORF1P的多态性变体（可能是错误的 被认为是“病毒衍生的”产品）可能会触发针对该蛋白质的体液反应，并打开 在SLE中，抗ORF1P抗体可能是致病性的可能性。该探索性建议的主要目标是 为了进一步了解这些新假设的潜在意义和初步发现 SLE发病机理的背景。在AIM 1中，我们将使用基于捕获的L1-ORF1富集与RNA- SEQ确定唯一的ORF1转录变体在对照和IFN-中是否有不同的表达 活化的SLE中性粒细胞。此外，我们将定义ORF1P变体优选地通过 SLE中的抗体。在AIM 2中，我们将确定抗ORF1P抗体的患病率和临床关联 以及他们与SLE患者的前瞻性观察队列中与IFN签名的关系，为此 可获得广泛的临床和血清学数据，以及IFN诱导的基因表达分析。一起， 这些研究旨在增强我们对无菌注射潜在的自我免疫原性途径的理解 在SLE。这项工作的最终目标是获得对疾病机制的新见解，从而为 探索新颖的疗法。