The role of HLA and its coreceptors in endothelial cell activation and leukocyte recruitment in antibody-mediated transplant rejection

HLA 及其辅助受体在抗体介导的移植排斥中内皮细胞激活和白细胞募集中的作用

• 批准号: 10462514
• 负责人: ELAINE F REED
• 金额: $ 62.16万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2024-03-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10462514
• 关键词: Acute; Adherence; Allografting; Antibodies; Binding; Blood Vessels; Cardiac; Cell Culture Techniques; Cell Survival; Cells; Cessation of life; Chronic; Clinical; Complement Activation; Complex; Data; Deposition; Development; Dialysis procedure; Diffuse; Disease; Dissection; Endothelial Cells; Endothelium; Etiology; Exhibits; Exocytosis; Fibrosis; Functional disorder; Graft Rejection; Heart Transplantation; Histocompatibility Antigens Class II; Human; ITGB4 gene; Immunoglobulin G; In Vitro; Inflammation; Inflammatory; Injury; Integrin beta4; Integrins; Investigation; Knowledge; Lesion; Leukocytes; Lymphocyte; Mediating; Modeling; Molecular; Mus; Organ; Organ Transplantation; Outcome; P-Selectin; Pathogenesis; Patients; Phenotype; Process; Production; Proliferating; Research; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Smooth Muscle Myocytes; TLR4 gene; Testing; Time; Toll-like receptors; Transplantation; Tumor-infiltrating immune cells; Vascular Diseases; Vasculitis; allograft rejection; antibody-mediated rejection; cell injury; combat; crosslink; fibrogenesis; graft failure; heart allograft; in vivo; macrophage; migration; monocyte; mouse model; neointima formation; novel; polarized cell; programs; receptor; recruit; therapeutic target; therapy development; transplant model; treatment strategy

ABSTRACT The production of donor specific HLA class I and class II antibodies is associated with development of chronic antibody-mediated rejection (cAMR) and transplant vasculopathy (TV). Two key features of cAMR are endothelial cell (EC) dysfunction and infiltration of immune cells, particularly macrophages. The proposed research will explore the novel paradigm that antibody crosslinking of HLA class I with ITGB4 and TLR4 and HLA class II with ITGB1 orchestrate divergent intracellular signaling programs in allograft endothelium inducing functions that promote monocyte recruitment to the graft and macrophage polarization. We propose infiltrating monocytes encounter local EC-derived factors and IgG-FcγR signals that prime them for differentiation. In the graft, the proangiogenic/profibrotic macrophages drive neointimal thickening. Antagonizing EC activation and/or monocyte recruitment may represent viable therapeutic targets to arrest cAMR and protect grafts from TV. We will employ a primary human EC culture model, a mouse cardiac allograft model of TV and human cardiac explants with TV to dissect the HLA I and II signaling pathways and mechanisms of monocyte recruitment and polarization. Aim 1: Define the structural requirements for complex formation and functional crosstalk between HLA Class I and its co-receptors ITGB4 and TLR4 in mediating endothelial cell activation, monocyte recruitment and macrophage polarization in cardiac TV. We will: (1a) determine how HLA I Ab- activated EC poise infiltrating monocytes to polarize to macrophages with distinct phenotypes and functions in vitro; (1b) characterize monocyte recruitment, TV lesion formation and phenotypes of infiltrating macrophages during MHC I antibody-mediated allograft injury and development of TV; (1c) define the structural requirements and functional effects of molecular crosstalk between ITGB4, TLR4 and HLA I on monocyte recruitment and macrophage polarization by Ab-activated EC in vitro; and (1d) characterize the requirement for MHC I co- receptors TLR4 and ITGB4 in monocyte recruitment, macrophage polarization and TV lesion formation in murine cardiac transplants. Aim 2. Define the structural requirements for complex formation and functional crosstalk between HLA class II and its co-receptor ITGB1 in mediating endothelial cell activation, monocyte recruitment and macrophage polarization in cardiac TV. We will: (2a) determine how HLA II Ab-activated EC poise infiltrating monocytes to polarize to macrophages with divergent phenotypes and functions in vitro; (2b) characterize monocyte recruitment, vascular lesion formation and phenotypes of infiltrating macrophages in a murine cardiac transplant model of MHC II cAMR and TV; (2c) define the structural requirements and functional effects of molecular crosstalk between ITGB1 and HLA II on monocyte recruitment and macrophage polarization by Ab-activated EC in vitro; (2d) characterize the requirement for MHC II coreceptor ITGB1 in monocyte recruitment, macrophage polarization and TV lesion formation in murine cardiac transplants; and (2e) define the phenotype profile of intragraft macrophages in human cardiac transplants with TV.

抽象的 供体特异性 HLA I 类和 II 类抗体的产生与慢性病的发生有关 抗体介导的排斥反应 (cAMR) 和移植血管病变 (TV) 是 cAMR 的两个主要特征。 内皮细胞（EC）功能障碍和免疫细胞（特别是巨噬细胞）浸润。 研究将探索 HLA I 类与 ITGB4 和 TLR4 的抗体交联的新范例 HLA II 类与 ITGB1 在同种异体移植内皮诱导中协调不同的细胞内信号传导程序 促进单核细胞募集到移植物和巨噬细胞极化的功能。 单核细胞遇到局部 EC 衍生因子和 IgG-FcγR 信号，为它们的分化做好准备。 移植物中，促血管生成/促纤维化巨噬细胞驱动新生内膜增厚，拮抗 EC 激活。 和/或单核细胞募集可能代表可行的治疗靶点，以阻止 cAMR 并保护移植物免受 TV。我们将采用原代人类 EC 培养模型，即 TV 和人类的小鼠心脏同种异体移植模型。 心脏外植体与电视剖析单核细胞的 HLA I 和 II 信号通路和机制 目标 1：定义复杂结构和功能的结构要求。 I 类 HLA 与其共受体 ITGB4 和 TLR4 之间的串扰介导内皮细胞激活， 心脏 TV 中的单核细胞募集和巨噬细胞极化 我们将： (1a) 确定 HLA I Ab- 如何进行。 激活 EC 平衡浸润单核细胞极化为具有不同表型和功能的巨噬细胞 体外；(1b) 表征单核细胞募集、TV 损伤形成和浸润巨噬细胞的表型 (1c) 定义 MHC I 抗体介导的同种异体移植物损伤和 TV 发育过程中的结构要求； ITGB4、TLR4 和 HLA I 之间的分子串扰对单核细胞募集和功能的影响 Ab 激活的 EC 体外巨噬细胞极化；以及 (1d) 表征 MHC I 共聚的需要 受体 TLR4 和 ITGB4 在单核细胞募集、巨噬细胞极化和 TV 病变形成中的作用 目标 2. 确定复杂形成和功能的结构要求。 HLA II 类与其共同受体 ITGB1 之间的串扰介导内皮细胞活化、单核细胞 心脏 TV 中的募集和巨噬细胞极化 我们将： (2a) 确定 HLA II Ab 激活 EC 的方式。 平衡浸润单核细胞在体外极化为具有不同表型和功能的巨噬细胞； 表征单核细胞募集、血管病变形成和浸润巨噬细胞的表型 MHC II cAMR 和 TV 的小鼠心脏移植模型 (2c) 定义结构要求和 ITGB1 和 HLA II 之间的分子串扰对单核细胞募集和巨噬细胞的功能影响 Ab 激活的 EC 体外极化；(2d) 表征 MHC II 辅助受体 ITGB1 的需求 小鼠心脏移植中的单核细胞募集、巨噬细胞极化和 TV 损伤形成； (2e) 定义了 TV 人心脏移植物中移植物内巨噬细胞的表型特征。