Splenic Marginal Zone Macrophages in Chronic Ischemic Heart Failure

慢性缺血性心力衰竭中的脾边缘区巨噬细胞

• 批准号: 9211359
• 负责人: Sumanth D Prabhu
• 金额: $ 36.75万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-10 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9211359
• 关键词: Ablation; Adoptive Transfer; Antibodies; Antigen-Presenting Cells; Antigens; Apoptosis; Arthritis; Atherosclerosis; Blood; C57BL/6 Mouse; Cardiac; Cardiac Myocytes; Cell Separation; Cells; Chronic; Clinical; Clinical Trials; Congestive Heart Failure; Coronary; Data; Dendritic Cells; Development; Dichloromethylene Diphosphonate; Diphtheria Toxin; Disease; Disease Progression; Dose; Encephalitis; Fibrosis; Flow Cytometry; Genes; Genetic; Glomerulonephritis; Heart; Heart Transplantation; Heart failure; Heterotopic Transplantation; Home environment; Homing; Human; Hypertrophy; Immune; Immune Tolerance; Immunohistochemistry; In Vitro; Infarction; Infiltration; Inflammation; Inflammatory; Injury; Kinetics; Left; Left Ventricular Dysfunction; Left Ventricular Remodeling; Leukocytes; Ligation; Liposomes; Macrophage Activation; Measures; Mediastinal lymph node group; Mediator of activation protein; Modeling; Mononuclear; Mus; Myocardial Ischemia; Myocardium; Natural Immunity; PTPRC gene; Pathogenesis; Pathologic; Patients; Phagocytes; Play; Population; Progressive Disease; Role; Signal Transduction; Spleen; Splenectomy; Splenocyte; T-Lymphocyte; TNF gene; TNFRSF5 gene; Testing; Therapeutic; Time; Tissues; Transgenic Mice; Translating; Ventricular; Work; adaptive immunity; base; cell type; cellular targeting; clinical practice; cytokine; diphtheria toxin receptor; immune activation; immunoregulation; in vitro Assay; innovation; loss of function; macrophage; monocyte; mortality; mouse dectin-2; neovascularization; novel; novel strategies; outcome forecast; public health relevance; receptor; response; therapeutic target; trafficking

DESCRIPTION (provided by applicant): To date, no immunomodulatory therapies for chronic heart failure (HF) have been successfully translated to clinical practice. Recently, we described a heretofore unappreciated adverse cardiosplenic axis in ischemic HF, with pro-inflammatory splenocytes homing to the failing heart to induce tissue injury. This exciting discovery supports a new approach to immunomodulation - one that directly targets specific leukocyte and/or splenocyte populations. Our recent studies suggest an important role for splenic marginal zone (MZ) macrophages in the genesis of inflammation and LV remodeling in ischemic HF. Comprised of two cell types - CD-169+ marginal metallophilic macrophages (MMMs) and SIGN-R1+MARCO+ MZ macrophages (MZMs) - these specialized macrophages are pro-inflammatory and broad immune activators. Based on our preliminary data, we hypothesize that MZ macrophage activation is essential for chronic inflammation, LV remodeling, and disease progression in HF, and thereby are key cellular targets for immunomodulation. We outline three Aims to test this hypothesis. In Aim 1, we will delineate trafficking of MMMs/MZMs in chronic HF using a murine coronary ligation model and sham-operated controls. MZ macrophages and their activation profiles will be measured in heart, blood, spleen, and mediastinal lymph nodes by flow cytometry and immunohistochemistry at several time points after ligation, both in the absence and presence of splenectomy, and correlated with LV remodeling and inflammation. The infiltration dynamics of MZ macrophages will be determined by heterotopic transplantation of CD45.2 failing hearts into CD45.1 HF mice with or without splenectomy, and measuring the temporal kinetics of donor- and recipient-derived MZM and MMM loss vs. accumulation in the transplanted heart. In Aim 2, we will define the role of MZ macrophages in the pathogenesis of inflammation and LV remodeling by selectively (and reversibly) depleting MMMs and MZMs during HF using both liposomal (clodronate) and genetic (CD169-DTR Tg mice) approaches, and then evaluating the effects of loss-of-function on inflammation, immune cell profiles, and LV and splenic remodeling. In Aim 3, we will establish whether MZ macrophages are essential drivers of the detrimental cardiosplenic axis in ischemic HF. CD45.2 mononuclear splenocytes from CD169-DTR Tg mice with HF will be adoptively transferred into CD45.1 naive mice, with or without prior MZ macrophage ablation. We will also transfer CD45.1 HF splenocytes into CD45.2 CD169-DTR Tg mice and then chronically deplete MZ macrophages in recipients. The effects of splenocyte transfer on LV/splenic remodeling, inflammation, and immune cell profiles will be measured in recipient mice. In parallel, we will evaluate the ability of MZ macrophages from HF and sham mice to activate naive splenic T- lymphocytes in vitro. These important studies will further our understanding of the cellular basis for inflammatory and immune activation in chronic ischemic HF, and provide innovative perspectives as to the fundamental underpinnings of the recently discovered pro-inflammatory and tissue-injurious cardiosplenic axis.

描述（由申请方提供）：迄今为止，尚未将慢性心力衰竭（HF）的免疫调节疗法成功转化为临床实践。最近，我们描述了一个迄今未被认识到的不良心脾轴缺血性HF，与促炎性脾细胞归巢衰竭的心脏，以诱导组织损伤。这一令人兴奋的发现支持了 免疫调节的新方法-一种直接针对特定白细胞和/或脾细胞群体的方法。我们最近的研究表明脾边缘区（MZ）巨噬细胞在缺血性HF的炎症和LV重塑的发生中起重要作用。由两种细胞类型组成- CD-169+边缘嗜金属巨噬细胞（MMM）和SIGN-R1+MARCO+ MZ巨噬细胞（MZM）-这些特化巨噬细胞是促炎和广泛的免疫激活剂。基于我们的初步数据，我们假设MZ巨噬细胞活化对慢性炎症、LV重塑和HF疾病进展至关重要，因此是免疫调节的关键细胞靶点。我们概述了三个目的来测试这个假设。在目的1中，我们将使用小鼠冠状动脉结扎模型和假手术对照来描述慢性HF中MMM/MZM的运输。在结扎后的几个时间点，在不存在和存在脾切除术的情况下，通过流式细胞术和免疫组织化学测量心脏、血液、脾和纵隔淋巴结中的MZ巨噬细胞及其活化特征，并与LV重塑和炎症相关。MZ巨噬细胞的浸润动力学将通过将CD45.2衰竭的心脏异位移植到有或没有脾切除术的CD45.1 HF小鼠中，并测量供体和供体来源的MZM和MMM损失相对于移植心脏中积累的时间动力学来确定。在目标2中，我们将通过使用脂质体（氯膦酸盐）和遗传（CD 169-DTR Tg小鼠）方法在HF期间选择性（可逆）消耗MMM和MZM，然后评估功能丧失对炎症、免疫细胞特征以及LV和脾脏重塑的影响，来确定MZ巨噬细胞在炎症和LV重塑发病机制中的作用。在目标3中，我们将确定MZ巨噬细胞是否是缺血性HF中有害的心脾轴的重要驱动因素。将来自患有HF的CD 169-DTR Tg小鼠的CD45.2单核脾细胞过继转移到CD45.1未处理小鼠中，进行或不进行先前的MZ巨噬细胞消融。我们还将CD45.1 HF脾细胞转移到CD45.2 CD 169-DTR Tg小鼠中，然后慢性消耗受体中的MZ巨噬细胞。将在受体小鼠中测量脾细胞转移对LV/脾重塑、炎症和免疫细胞谱的影响。同时，我们将评估来自HF和假手术小鼠的MZ巨噬细胞在体外激活幼稚脾T淋巴细胞的能力。这些重要的研究将进一步加深我们对慢性缺血性HF炎症和免疫激活的细胞基础的理解，并为最近发现的促炎和组织损伤性心脾轴的基本基础提供创新的观点。