Investigating the role of B cells in pulmonary fibrosis resulting from STING gain-of-function autoinflammation

研究 B 细胞在 STING 功能获得性自身炎症引起的肺纤维化中的作用

基本信息

批准号：
10462470
负责人：
Kevin MingJie Gao
金额：
$ 3.32万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-04 至 2023-09-03
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10462470
关键词：
Ablation Address Age Antibodies Antibody Formation Antibody Therapy Antigens Atypical lymphocyte Autoantibodies B cell repertoire B-Lymphocytes B-cell receptor repertoire sequencing Bleomycin Blood Vessels Bronchoalveolar Lavage Fluid CD8-Positive T-Lymphocytes Characteristics Clonality DNA Damage Data Defect Disease Disease Progression Disease model Etiology Exhibits Fibrosis Flow Cytometry Gene Targeting Genetic Genetic Models Genotoxic Stress Heterogeneity Histologic Histology Homeostasis Hyperactivity Immune Immune Tolerance Immune response Immunoglobulin Class Switching Immunoglobulin M Impairment Inflammation Inflammatory Lead Lung Lung Inflammation Lung diseases Lymphocyte Lymphocyte Subset Lymphocytic Infiltrate Lymphopenia Mediating Modeling Mucous Membrane Mus Mutation Myeloid Cells Nucleic Acids Pathology Pathway interactions Patients Pharmacology Physiological Play Plethysmography Process Production Publishing Pulmonary Fibrosis Pulmonary function tests Rag1 Mouse Regulation Reporting Resistance Role Serum Signal Transduction Specificity Stains Stimulator of Interferon Genes Study of serum Syndrome Systemic Scleroderma T-Lymphocyte Testing Transgenic Organisms Tumor-infiltrating immune cells Vascular Diseases Work autoinflammation autoinflammatory autoreactive B cell autoreactivity cytokine ds-DNA effective therapy expectation experimental study gain of function gain of function mutation human disease humoral immunity deficiency idiopathic pulmonary fibrosis improved infancy insight mouse genetics mouse model novel pathogen pediatric patients pilot trial preservation prophylactic pulmonary function rituximab stress tolerance tositumomab γδ T cells

项目摘要

PROJECT SUMMARY/ABSTRACT Pulmonary fibrosis is a poorly understood process that is thought to involve a preceding stage of immune infiltration and inflammation. Bleomycin, a DNA damage inducing agent, is often used to experimentally induce pulmonary fibrosis in mice, indicating that immune sensing of nucleic acids may be tied to the etiology of fibrotic lung disease. cGAS-STING is a cytosolic dsDNA sensing pathway, which is tightly regulated to preserve immune homeostasis by discriminating immune response to danger signals like pathogens or genotoxic stress and immune tolerance to inert physiologic signals. This regulation is broken by constitutively active STING mutations, which cause an autoinflammatory syndrome known as STING Associated Vasculopathy with onset in Infancy (SAVI), in which patients develop immune abnormalities. Consistent with the notion that dysregulated nucleic acid sensing promotes pulmonary fibrosis; SAVI patients rapidly succumb to treatment resistant inflammatory lung fibrosis. To address the urgent need for SAVI lung disease therapy, we have developed gene-targeted mice that express the SAVI mutation STINGV154M(VM) and found that these mice recapitulate aspects of human disease including inflammatory lung fibrosis. The utility of studying our SAVI mouse model lies not only in its impact on studying SAVI disease, but broadly for understanding the immune defects that drive pulmonary fibrosis, a topic that has thus far been constrained by the limitations of current fibrotic lung disease models. Our central hypothesis is that the acquisition of SAVI fibrotic lung disease is mediated by autoreactive B cells. The following key findings support this hypothesis: (i) VM mice possess severe immune abnormalities of lymphocytes characterized by lymphopenia with concomitant hyperactivation of remaining lymphocytes, a feature also seen in SAVI patients. (ii) Using genetic ablation of B and T lymphocytes by Rag1 deficiency, we found that lymphocytes are required for lung disease in VM mice; however, when we specifically ablated αβ T cells by TCRβ deficiency in VM mice, we found that these mice persisted in developing fulminant lung disease. (iii) Additionally, our preliminary data indicates that VM B cells accumulate in the lung extravascular space and become activated independent of αβ T cells. In this proposal, Aim 1 will determine the contribution of B cells to VM SAVI fibrotic lung inflammation using mouse genetic models of B cell deficiency and pharmacologic depletion of B cells by targeted antibody treatment. Aim 2 will determine whether VM SAVI lung B cells promote disease through autoreactivity using mouse models that restrain the BCR repertoire to foreign antigens and by characterizing the BCR repertoire and antibody reactivity in VM mice. The approach includes: survival studies, lung histopathologic analysis, pulmonary function testing, flow cytometry, BCR repertoire sequencing, and antibody staining of mouse lung sections. Our studies will discern the role of B cells in VM SAVI lung fibrosis and will broadly provide insight into B cell driven mechanisms of fibrotic lung disorders.

项目概要/摘要肺纤维化是一个人们知之甚少的过程，人们认为它涉及免疫的前一阶段博莱霉素是一种 DNA 损伤诱导剂，常用于实验诱导。小鼠肺纤维化，表明核酸的免疫感应可能与肺纤维化的病因有关 cGAS-STING 是一种胞质 dsDNA 传感途径，受到严格调节通过区分对病原体等危险信号的免疫反应来保持免疫稳态遗传毒性应激和对惰性生理信号的免疫耐受性被组成性打破。活跃的 STING 突变，会导致称为 STING 相关的自身炎症综合征婴儿期发病的血管病（SAVI），患者出现与免疫异常一致的情况。核酸传感失调会促进 SAVI 患者迅速死亡的观点；治疗耐药性炎症性肺纤维化解决 SAVI 肺病治疗的迫切需求，我们开发了表达 SAVI 突变 STINGV154M(VM) 的基因靶向小鼠，并发现这些小鼠概括了人类疾病的各个方面，包括炎症性肺纤维化。 SAVI 小鼠模型不仅在于其对研究 SAVI 疾病的影响，还在于广泛地了解 SAVI 疾病导致肺纤维化的免疫缺陷，这一话题迄今为止一直受到以下因素的限制：目前纤维化肺病模型的中心假设是 SAVI 纤维化肺病的获得性。是由自身反应性 B 细胞介导的，以下主要发现支持这一假设：(i) VM 小鼠具有淋巴细胞严重免疫异常，其特征是淋巴细胞减少并伴有过度激活剩余的淋巴细胞，这一特征在 SAVI 患者中也可见到 (ii) 使用 B 和 T 的基因消融。由于Rag1缺陷，我们发现淋巴细胞是VM小鼠肺部疾病所必需的；然而，当我们通过 VM 小鼠中 TCRβ 缺陷特异性消除 αβ T 细胞时，我们发现这些小鼠 (iii) 此外，我们的初步数据表明 VM B 细胞。在肺血管外空间中积聚并独立于 αβ T 细胞而被激活。目标 1 将利用小鼠遗传确定 B 细胞对 VM SAVI 纤维化肺部炎症的贡献 Aim 2 将建立 B 细胞缺陷模型和通过靶向抗体治疗对 B 细胞进行药理耗竭的模型。使用小鼠模型确定 VM SAVI 肺 B 细胞是否通过自身反应促进疾病通过表征 BCR 库和抗体反应性来抑制 BCR 库对外来抗原的影响该方法包括：生存研究、肺组织病理学分析、肺功能测试、我们的研究将进行流式细胞术、BCR 库测序和小鼠肺切片的抗体染色。辨别 B 细胞在 VM SAVI 肺纤维化中的作用，并将广泛提供对 B 细胞驱动的见解纤维化肺疾病的机制。