Mechanisms of T cell activation in cardiac fibrosis and non-ischemic heart failure

心脏纤维化和非缺血性心力衰竭中 T 细胞激活的机制

基本信息

批准号：
10092213
负责人：
Maria Pilar Alcaide Alonso
金额：
$ 65.94万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-02-01 至 2024-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10092213
关键词：
Adhesions Adoptive Transfer Anti-Inflammatory Agents Antigen-Presenting Cells Antigens Biochemical Biological Assay CD4 Positive T Lymphocytes Cardiac Cause of Death Cell Adhesion Cells Clone Cells Coculture Techniques Complement Factor B Data Experimental Models Fibroblasts Fibrosis Goals Heart Heart failure Hospitalization Immune response Immunity Impairment In Vitro Inflammation Inflammation Mediators Inflammatory Knowledge Lead Location Major Histocompatibility Complex Maps Mediastinal lymph node group Mediating Modeling Molecular Mus Myocardial Myocardial dysfunction Myofibroblast Pathogenesis Pathogenicity Pathway interactions Patients Pattern Pharmaceutical Preparations Phenotype Prevention approach Process RNA Reporting Role Signal Pathway Signal Transduction Site Source Sterility Syndrome T cell receptor repertoire sequencing T-Cell Activation T-Cell Receptor T-Lymphocyte T-cell receptor repertoire Testing Time Transforming Growth Factors Translating Tumor-infiltrating immune cells Work antifibrotic treatment base cell type clinical practice constriction coronary fibrosis draining lymph node experimental study heart function immune activation immunomodulatory strategy immunomodulatory therapies immunoregulation in vitro Assay in vivo inhibitor/antagonist innovation knock-down mortality new therapeutic target novel prevent response spatiotemporal stem systemic inflammatory response time use

项目摘要

The goal of this new R01 application is to investigate the mechanisms of T cell activation and the consequences in the progression of cardiac fibrosis (CF) in the deadly syndrome of heart failure (HF), currently the leading cause of mortality and hospitalizations in the USA. We were the first to report cardiac T cell infiltration associated with CF in patients with non-ischemic HF, and using the well- established experimental model of HF induced by transverse aortic constriction (TAC), we and others described a major role for CD4+ T cells as major contributors to non-ischemic HF. However, due to the complexity of the mechanisms of T cell activation resulting in inflammation, CF and HF, no immunomodulatory or anti-fibrotic therapies have yet translated to clinical practice to treat HF. Our preliminary data reveal the novel finding that T cell activation occurs in the mediastinal lymph nodes that drain the heart (mLN), and also within the heart in a classic dependent manner that involves T cell receptor (TCR) engagement by antigens presented by Major histocompatibility complex II (MHC-II) expressed on antigen presenting cells (APC). We additionally demonstrate that activated cardiac fibroblasts (CFB) express MHC-II and thus could function as APC in the heart. Emerging evidence suggests that T cells can also be activated by alarmins, soluble inflammatory mediators produced in response to sterile inflammation, through TCR independent pathways in a “non classic" TCR- independent manner, and our in vitro and in vivo preliminary data is in support of this. Based on these findings, we will test the central hypothesis that classic and non-classic T cell activation mechanisms cooperate to initiate and sustain CF during the progression of HF. In aim 1, we will use Nur77GFP mice, in which T cells express GFP only when stimulated classically through the TCR, to map the specific location and timing of classic T cell activation during TAC. We will additionally perform single cell TCR sequencing on heart sorted GFP+CD4+ T cells to identify the immunodominant T cell clones in HF progression. The APC responsible for such activation and its effects in CF and HF over time will be evaluated in cell specific MHC-II-/- mice. In aim 2, we will perform adoptive transfer experiments of WT and alarmin sensing-impaired activated CD4+ T cells into MHC-II-/- recipient mice, which lack classic T cell activation and are normally protected from CF and HF. CF, cardiac function and the alarmins responsible for T cell activation will be characterized in in vivo and in vitro assays. In aim 3, based on our data indicating that activated T cell adhesion to CFB induces their transformation to pro-fibrotic myofibroblast in a TGFβ dependent manner, we will investigate the mechanisms of TGFβ synthesis, release and signaling in CFB in response to classically and non classically activated T cell adhesion. We will use in vitro biochemical and molecular assays. These important studies will result in a deeper understanding of how best to regulate T cell activation and T cell induced in HF and provide new perspectives on how to prevent, ameliorate and treat non-ischemic HF.

这个新的 R01 应用的目标是研究 T 细胞激活的机制和目前，致命的心力衰竭综合征（HF）中心脏纤维化（CF）进展的后果我们是第一个报告心脏 T 细胞的人。非缺血性心力衰竭患者中与 CF 相关的浸润，并使用成熟的实验在横向主动脉缩窄 (TAC) 诱发的 HF 模型中，我们和其他人描述了 CD4+ T 的主要作用细胞是非缺血性心力衰竭的主要贡献者，但由于 T 细胞机制的复杂性。激活导致炎症、CF和HF，目前还没有免疫调节或抗纤维化疗法我们的初步数据揭示了 T 细胞激活的新发现。发生在引流心脏的纵隔淋巴结 (mLN) 中，也发生在经典的心脏内涉及 T 细胞受体 (TCR) 与主要呈递的抗原结合的依赖方式组织相容性复合体 II (MHC-II) 在抗原呈递细胞 (APC) 上表达。证明活化的心脏成纤维细胞 (CFB) 表达 MHC-II，因此可以在心脏中发挥 APC 的作用新的证据表明，T 细胞也可以被警报素（可溶性炎症）激活。通过 TCR 独立途径以“非经典”方式响应无菌炎症而产生的介质 TCR 独立的方式，我们的体外和体内初步数据支持了这一点。研究结果，我们将检验经典和非经典 T 细胞激活机制合作的中心假设在 HF 进展期间启动和维持 CF 在目标 1 中，我们将使用 Nur77GFP 小鼠，其中 T 细胞。仅当通过 TCR 进行经典刺激时才表达 GFP，以绘制 GFP 的具体位置和时间图 TAC 期间的经典 T 细胞激活我们还将对心脏分选进行单细胞 TCR 测序。 GFP+CD4+ T 细胞可识别 HF 进展中的免疫显性 T 细胞克隆。在目标 2 中，将在细胞特异性 MHC-II-/- 小鼠中评估这种激活及其对 CF 和 HF 的影响。我们将进行 WT 和警报素感应受损的激活 CD4+ T 细胞的过继转移实验 MHC-II-/- 受体小鼠缺乏典型的 T 细胞激活，通常免受 CF 和 HF 的影响，心脏功能和负责 T 细胞激活的警报素将在体内和体外进行表征在目标 3 中，根据我们的数据表明，活化的 T 细胞粘附到 CFB 会诱导它们的发生。以 TGFβ 依赖性方式转化为促纤维化肌成纤维细胞，我们将研究其机制 CFB 中响应经典和非经典激活 T 细胞的 TGFβ 合成、释放和信号传导我们将使用体外生化和分析分子来进行这些重要的研究。更深入地了解如何最好地调节 HF 中的 T 细胞激活和 T 细胞诱导，并提供新的关于如何预防、改善和治疗非缺血性心力衰竭的观点。