Mechanisms for Human TLR8 induced pregnancy loss in a mouse model of SLE

人 TLR8 诱导 SLE 小鼠模型妊娠失败的机制

基本信息

批准号：
10434117
负责人：
Anne Davidson
金额：
$ 25.44万
依托单位：
FEINSTEIN INSTITUTE FOR MEDICAL RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-18 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10434117
关键词：
Address Amino Acids Antibodies Antigen-Antibody Complex Antiphospholipid Antibodies Attenuated Autoantibodies Autoimmune Diseases Autoimmunity B-Lymphocyte Subsets B-Lymphocytes Bacterial Artificial Chromosomes Binding Binding Sites Blood Vessels Cell Line Cell Lineage Cells Characteristics Development Dose Exposure to Female Fetal Death Fetal Resorption Gene Expression Genetic Polymorphism Genetic study Goals Human IL8 gene Immune Immunologic Receptors In Vitro Inflammation Inflammatory Injury Innate Immune System Interferon Type I Lead Ligand Binding Ligands Lupus Lymphocyte Mediating Memory B-Lymphocyte Messenger RNA MicroRNAs Modeling Morphology Mus Myelogenous Myeloid Cells Nucleic Acids Pathogenicity Pathway interactions Patients Pattern Phenotype Phospholipids Physiological Placenta Plasma Cells Pregnancy Pregnancy Outcome Pregnancy loss Production Purines Quality of life RNA RNA Binding Ribonucleases Role SLEB1 gene Susceptibility Gene Syndrome Systemic Lupus Erythematosus TLR7 gene TLR8 gene Testing Tissues Toll-like receptors Transgenes Transgenic Mice Uridine Woman antagonist cell injury cytokine effective therapy experimental study exposed human population fetal fetal loss fetus cell improved outcome in vivo inflammatory milieu lupus prone mice macrophage monocyte mortality mouse model neutrophil novel novel strategies pathogenic autoantibodies placental morphology prevent promoter receptor recruit response sensor therapeutic target transgene expression trophoblast

项目摘要

Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disease that causes a significant decrease in quality of life and early mortality. Genetic studies have identified activation of the innate immune system, with excess production of Type I interferons as a major causative pathway. RNA-sensing Toll-like receptors are crucial protective receptors of the innate immune system but are also implicated in autoimmunity because they can recognize nucleic acids released from damaged cells and within nucleic acid containing immune complexes. Functional polymorphisms of the endosomal RNA-recognizing innate receptors TLR7 and TLR8 predispose to SLE and excess mouse TLR7 and human TLR8 accelerate lupus in mouse models. Human TLR8 differs in its function from TLR7 because it recognizes different ligands and is expressed on different immune cell subsets. TLR8 is not an RNA sensor in mice because of a 5 amino acid deletion that attenuates its RNA-binding site. We therefore bred a human TLR8 BAC transgene (huTLR8) into mice in which a mild lupus phenotype is conferred by the susceptibility locus Sle1. Expression of the transgene is physiologically regulated such that huTLR8 is expressed at high levels in myeloid DCs and monocytes but at 50-100-fold lower levels in lymphocytes. We found that huTLR8 induces an anti- phospholipid like syndrome in Sle1 mice that leads to spontaneous placental inflammation, fetal resorptions and late-term pregnancy loss in up to 60% of female dams. In this proposal we will test the mechanism for huTLR8 mediated pregnancy loss by addressing the role of huTLR8 as a sensor of RNA in placental trophoblasts and immune cells. In Aim 1 we will examine the role of autoantibodies in placental injury in mice with or without huTLR8 expression and determine whether huTLR8 expression in B cells results in the production of autoantibodies with enhanced pathogenicity. In Aim 2 we will determine the timing and characteristics of placental injury, the contribution of huTLR8 in maternal vs. fetal cells to injury and whether placental trophoblasts activated by anti-phospholipid antibodies release huTLR8 ligands that enhance local inflammation. In Aim 3 we will determine whether myeloid cells from huTLR8tg mice are intrinsically more pro-inflammatory than those of their wild-type counterparts and therefore amplify the effector response to antibody mediated placental injury. These experiments should allow us to distinguish the role of huTLR8 in maternal cells, trophoblasts and immune cell subsets in the induction of placental damage that leads to pregnancy loss. Our studies will inform us whether specific huTLR8 antagonists or antagonists of huTLR8 ligands should be tested for their ability to prevent or treat placental injury.

全身性红斑狼疮（SLE）是一种多系统的自身免疫性疾病，导致生活质量和早期死亡率的显着下降。遗传研究已经确定激活先天免疫系统，I型干扰素的产生过多致病途径。 RNA感应电话样受体是先天的关键保护受体免疫系统，但也与自身免疫有关，因为它们可以识别核酸从受损细胞和含有免疫复合物的核酸内释放。功能内体RNA识别的先天受体TLR7和TLR8易感性的多态性在小鼠模型中，sle和多余的小鼠TLR7和人类TLR8加速了狼疮。人类 TLR8的功能与TLR7不同，因为它识别不同的配体并表示在不同的免疫细胞子集上。 TLR8不是小鼠中的RNA传感器，因为5氨基酸缺失使其减弱 RNA结合位点。因此，我们将人类TLR8 BAC转基因（HUTLR8）繁殖到小鼠中易感性基因座SLE1赋予了轻度的狼疮表型。转基因的表达在生理方面受到调节，以使Hutlr8在髓样DC中以高水平表达单核细胞，但淋巴细胞的水平低50-100倍。我们发现hutlr8诱导了抗 SLE1小鼠中的磷脂综合征，导致自发胎盘炎症，胎儿多达60％的雌性大坝的吸收和晚期妊娠损失。在这个建议中，我们将通过解决HUTLR8作为一个胎盘滋养细胞和免疫细胞中RNA的传感器。在AIM 1中，我们将检查自身抗体在胎盘损伤中的作用，或没有HUTLR8表达，并确定B细胞中HUTLR8的表达是否导致具有增强致病性的自身抗体的产生。在AIM 2中，我们将确定时间安排和胎盘损伤的特征，母体与胎儿细胞中HUTLR8的贡献损伤以及抗磷脂抗体激活的胎盘滋养细胞是否释放 HUTLR8配体可增强局部炎症。在AIM 3中，我们将确定是否髓样来自Hutlr8TG小鼠的细胞本质上比其野生型的细胞更为促炎。因此，对应物，扩大对抗体介导的胎盘损伤的效应子反应。这些实验应该使我们能够区分HutlR8在母体细胞中的作用，诱导胎盘损伤的滋养细胞和免疫细胞子集，导致怀孕丧失。我们的研究将告知我们是特定的HUTLR8拮抗剂或拮抗剂 HUTLR8配体应测试其预防或治疗胎盘损伤的能力。