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

• 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
• 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

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.

项目摘要/摘要 肺纤维化是一个鲜为人知的过程，被认为涉及先前的免疫阶段 浸润和炎症。博来霉素是一种DNA损伤诱导剂，通常用于实验诱导 小鼠的肺纤维化，表明核酸的免疫敏感性可能与 纤维化肺部疾病。 CGAS刺是一种胞质DSDNA传感途径，紧密调节 通过区分对病原体或病原体或 遗传毒性应激和对惰性生理信号的免疫耐受性。该法规始终如一地打破 活跃的刺激突变，引起自身炎症综合征，称为刺激性 婴儿期（SAVI）发作的血管病，患者会出现免疫异常。与 核酸传感失调的观念促进了肺纤维化。萨维患者迅速屈服 耐药性炎症性肺纤维化。为了满足急需萨维肺疾病疗法的需求， 我们开发了以基因为靶向的小鼠，表达了savi突变StingV154M（VM），发现这些小鼠 小鼠概括了人类疾病的各个方面，包括炎性肺纤维化。研究我们的实用性 SAVI小鼠模型不仅在于其对研究萨维疾病的影响，而且广泛地了解 免疫缺陷驱动肺纤维化，这一主题迄今已受到局限性的限制 当前的纤维化肺部疾病模型。我们的中心假设是获得savi纤维化肺疾病 由自动反应性B细胞介导。以下关键发现支持此假设：（i）VM小鼠拥有 淋巴细胞的严重免疫异常，这些淋巴细胞具有与淋巴细胞的伴随过度激活 在剩余的淋巴细胞中，这一特征也在萨维亚患者中也可见。 （ii）使用B和T的遗传消融 RAG1缺乏症的淋巴细胞，我们发现VM小鼠肺部疾病需要淋巴细胞。 但是，当我们通过TCRβ缺乏症在VM小鼠中特异性消灭αβT细胞时，我们发现这些小鼠 坚持发展暴发性肺部疾病。 （iii）此外，我们的初步数据表明VM B细胞 积聚在肺部血管外空间中，并与αβT细胞无关。在此提案中， AIM 1将确定B细胞使用小鼠通用的B细胞对VM SAVI纤维化肺注射的贡献 通过靶向抗体治疗对B细胞的B细胞缺乏和药理耗竭的模型。 AIM 2意志 确定VM SAVI肺B细胞是否使用小鼠模型通过自动反应来促进疾病 将BCR曲目限制为外国抗原，并表征BCR曲目和抗体反应性 在VM小鼠中。该方法包括：生存研究，肺组织病理学分析，肺功能测试， 小鼠肺切片的流式细胞仪，BCR曲目测序和抗体染色。我们的研究将 识别B细胞在VM savi肺纤维化中的作用，并将广泛地洞悉B细胞驱动 纤维化肺部疾病的机制。