Role of the L1 retrotransposon in interferon-positive SLE

L1 逆转录转座子在干扰素阳性 SLE 中的作用

• 批准号: 10603189
• 负责人: Tomas M Mustelin
• 金额: $ 54.75万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-21 至 2028-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10603189
• 关键词: Adjuvant; Autoantibodies; Autoantigens; Autoimmunity; Automobile Driving; B-Lymphocytes; Biological Markers; Biology; Blocking Antibodies; Cell Aging; Cell Death; Cells; Childhood; Complement; Complex; Consumption; Crohn' s disease; DNA; Data; Dependence; Development; Disease; Elements; Event; FDA approved; Flare; Funding; Gender; Genetic Transcription; Goals; HIV; Human; IFNAR1 gene; IgG autoantibodies; Immune; Immune system; Interferon Type I; Interferon-beta; Interferons; Journals; L1 Elements; Lupus; Measures; Mediating; Methods; Molecular; Nephritis; Nuclear; Paper; Pathogenesis; Pathway interactions; Patients; Phase; Phase II Clinical Trials; Phase III Clinical Trials; Play; Process; Production; Protein Family; Proteins; RNA; RNA-Directed DNA Polymerase; Research; Retrotransposon; Reverse Transcription; Role; Serum; Signal Pathway; Signal Transduction; Stimulator of Interferon Genes; Systemic Lupus Erythematosus; Tenofovir; Testing; Transcript; Virus; Virus Diseases; Work; cancer cell; cell type; clinical development; density; ds-DNA; emtricitabine; experimental study; gene induction; granulocyte; immunogenic; inhibitor; monocyte; neutralizing monoclonal antibodies; neutrophil; protein complex; sensor; stress granule; targeted treatment; transcriptome sequencing; type I interferon receptor

Project Summary/Abstract The overall goal of our research is to elucidate the proximal molecular drivers and mechanisms of systemic lupus erythematosus (SLE) to enable the development of new and better therapies that target these processes but spare the broader immune system. This proposal will explore the role of the Long Interspersed Nuclear Element-1 (LINE-1, or L1) in type I interferon (IFN)-positive SLE. We have discovered that most SLE patients have high-titer autoantibodies against the first protein encoded by L1, ORF1p and that the titers of these autoantibodies correlate with disease activity as measured by SLEDAI score, complement consumption, presence of nephritis, anti- dsDNA and other autoantibodies, as well as with type I interferon gene induction. Our working hypothesis is that the biology of L1 is intimately connected with the pathogenesis of SLE by two mechanisms: i) driving autoimmunity to the virus-like L1 protein complexes that contain RNA and DNA; and ii) generating aberrant DNA by reverse-transcribing RNAs (including its own) and triggering DNA-sensor signaling to induce type I IFNs. AIM 1. To characterize the expression of L1 in SLE. The cell types that express the highest levels of L1 in SLE are the neutrophil and the low-density granulocyte. The L1-expressing neutrophils show signs of activation, and biomarkers of neutrophil NETosis are elevated in patient serum. By RNA-Seq we have identified one dominant (chr4q22.1) and six additional distinct human-specific L1 elements as the origins of the elevated transcripts and ORF1p protein. We will solidify these observations, detect and analyze their dependence on patient gender and disease parameters. We will examine factors that influence the transcription of these loci, and we will ask if stress granules containing ORF1p are released from neutrophils undergoing NETosis or other forms of cell death. These experiments will be complemented by asking if other proteins present in stress granules are also autoantigens in SLE. AIM 2. To elucidate the role of L1 ORF2p in type I IFN induction in SLE. Several recent papers in top journals have demonstrated a connection between L1 expression and the induction of IFN in cellular senescence, Crohn's disease, and in cancer cells. To determine how these findings apply to SLE, we will analyze L1-expressing neutrophils for activated DNA sensors, the signaling pathways from these sensors, and the type I IFN themselves. We will use an ultrasensitive method to quantitate ORF2p and then use inhibitors of the its RT activity to determine if it drives type I IFN production. Lastly, we will ask if silencing the DNA sensor DAI/ZBP1 blocks this IFN production.

项目摘要/摘要 我们研究的总体目标是阐明近端分子驱动因素和机制 全身性红斑狼疮（SLE），以实现新的疗法的发展 这是针对这些过程的，但要避免更广泛的免疫系统。该建议将探索 I型干扰素（IFN） - 阳性的长长的核元素-1（LINE-1或L1）的作用 sle。我们已经发现，大多数SLE患者对第一个患者具有高细胞自身抗体 由L1，ORF1P编码的蛋白质，这些自身抗体的滴度与疾病相关 通过SLEDAI评分，完成消耗，肾炎的存在，抗 - DsDNA和其他自身抗体，以及I型干扰素基因诱导。 我们的工作假设是L1的生物学与 通过两种机制进行SLE：i）驱动自身免疫到类似病毒的L1蛋白复合物， 包含RNA和DNA； ii）通过反向转录RNA产生异常DNA（包括 它自己的）并触发DNA传感器信号传导诱导I型IFN。 目标1。表征L1在SLE中的表达。表达最高的细胞类型 SLE中L1的水平是中性粒细胞和低密度粒细胞。表达L1 嗜中性粒细胞显示出激活的迹象，患者的嗜中性粒细胞的生物标志物升高 血清。通过RNA-seq，我们确定了一个主导地位（CHR4Q22.1）和六个不同的不同 人类特异性L1元素作为升高转录本和ORF1P蛋白的起源。我们将 巩固这些观察结果，检测和分析其对患者性别和疾病的依赖 参数。我们将研究影响这些基因座转录的因素，我们将询问 如果含有ORF1P的应力颗粒是从经历Netosis或其他其他的中性粒细胞中释放的 细胞死亡形式。这些实验将通过询问是否存在其他蛋白质来完成 在压力中，颗粒也是SLE中的自动抗原。 目标2。阐明L1 ORF2P在SLE中IFN诱导中的作用。最近的几个 顶级期刊中的论文证明了L1表达与诱导之间的联系 细胞感应，克罗恩病和癌细胞中的IFN。确定如何 调查结果适用于SLE，我们将分析激活DNA传感器的表达L1的中性粒细胞 这些传感器的信号通路以及I型IFN本身。我们将使用 定量ORF2P，然后使用其RT活性抑制剂的超敏感方法 确定它是否驱动I型IFN生产。最后，我们将问是否沉默DNA传感器 DAI/ZBP1阻止了此IFN产生。