Graft extracellular vesicles as promoters of anti-donor immunity in cardiac and skin transplantation

移植细胞外囊泡作为心脏和皮肤移植中抗供体免疫的促进剂

• 批准号: 10707137
• 负责人: Adrian E. Morelli
• 金额: $ 66.56万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-19 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10707137
• 关键词: Adult; Affect; Allogenic; Allografting; Antigen-Presenting Cells; Antigens; Apoptotic; B-Lymphocytes; Biogenesis; Biological Markers; Biology; Blood group antigen S; Cardiac; Caring; Cells; Childhood; Chronic; Communication; Development; Disease; Disease Marker; Distant; Electron Microscopy; Experimental Models; Family; Future; Generations; Genetically Engineered Mouse; Goals; Graft Rejection; Heart; Heart Transplantation; Heart failure; Human; Immune; Immune response; Immune system; Immunity; Immunosuppression; Immunosuppressive Agents; In Situ; Innate Immune Response; Intervention; Investigation; Investments; Knowledge; Leukocytes; Lipids; Lung; Lymphoid Tissue; MHC antigen; Malignant Neoplasms; Mediating; Mediator; Medical; Messenger RNA; Methodology; Mus; Organ; Patients; Peptides; Proteins; Regimen; Resolution; Risk; Role; Secondary to; Signal Transduction; Skin; Skin Transplantation; Structure of germinal center of lymph node; T memory cell; T-Lymphocyte; Testing; Therapeutic immunosuppression; Tissue Grafts; Tissue Transplantation; Transplantation; Travel; Untranslated RNA; Vascularization; Vesicle; adaptive immune response; allograft rejection; bioimaging; clinical translation; clinically relevant; conditioning; exosome; extracellular vesicles; heart allograft; horizontal cell; humanized mouse; immunoreaction; immunoregulation; improved; in vivo; infection risk; isoimmunity; microvesicles; mouse model; novel; novel therapeutic intervention; prevent; promoter; response; side effect; skin allograft; translational model; transplant model; two photon microscopy; ultra high resolution; vesicular release

SUMMARY The innate and adaptive immune response against allografts is the main impediment to successful transplantation. Heart transplantation is the best option for selected pediatric and adult patients with end-stage heart failure, however, the threat of rejection remains high, despite improvements in immunosuppressive therapies, conditioning regimens and medical care. Importantly, currently used interventions are not donor-specific and therefore may cause increased risk of infections and cancer. A deeper understanding of the basis of allo-recognition is needed for the development of novel donor-specific therapies to treat graft rejection minimizing the harmful side effects. Recent studies have challenged the dogma that initiation or re-activation of anti-donor immunity in graft- draining secondary lymphoid tissues (SLTs) depends mainly on donor Ag-presenting cells (APCs) mobilized from the grafts. Increasing evidence and our preliminary studies indicate that heart and non-vascularized skin allografts release extracellular vesicles (EVs) carrying donor-Ag that traffic to the SLTs where the graft EVs stimulate donor- reactive B cells and T cells. Despite increasing information during the past 5 years on the role of graft EVs on elicitation of anti-donor immunity and their potential use as biomarkers in transplantation, the mechanisms in vivo by which graft EVs interact with recipient’s immune cells in graft-draining SLTs and promote anti-donor immunity remain largely unknown. The family of EVs encompasses vesicles with different biogenesis, size and composition that includes exosomes and microvesicles. Although growing evidence indicates that EVs represent a mechanism by which cells horizontally transfer proteins, mRNAs, non-coding RNAs and lipids, the function of EVs in vivo remains an enigma. Therefore, we propose to investigate the mechanisms in vivo by which graft EVs initiate or re-activate in graft-draining SLTs, the innate and adaptive immune responses that lead to rejection of allografts. We will analyze these mechanisms in mouse experimental models of cardiac and non-vascularized skin allografts. We hypothesize that “graft EVs constitute a cell-free platform that by multiple mechanisms initiates or re-activates the anti-donor immune response in the recipient’s SLTs”. This application will investigate these mechanisms in situ and in vivo using transplant models in mice and a translational model in humanized mice. We will test our hypothesis in the following aims: Aim 1 will investigate the origin of graft EVs and their effects on recipient APCs in graft-draining SLTs, Aim 2 will analyze the mechanisms by which graft EVs generate anti-donor B cell immunity in SLTs and Aim 3 will analyze how graft EVs elicit anti-donor T cell immunity in SLTs and its relevance to transplantation in humans. Our long-term goal is to understand how graft EVs function in vivo to provide new grounds for development of EV-based therapies and disease markers of clinical relevance to transplantation and immune-mediated disorders.

概括 针对同种异体移植物的先天性和适应性免疫反应是成功移植的主要障碍。 心脏移植是某些患有终末期心力衰竭的儿童和成人患者的最佳选择， 然而，尽管免疫抑制疗法、调理疗法有所改进，但排斥反应的威胁仍然很高 治疗方案和医疗护理。重要的是，目前使用的干预措施不是针对捐助者的，因此可能 导致感染和癌症的风险增加。需要更深入地了解同种异体识别的基础 开发新型供体特异性疗法来治疗移植物排斥反应，最大限度地减少有害副作用。 最近的研究挑战了移植物中抗供体免疫的启动或重新激活的教条。 次级淋巴组织（SLT）的引流主要依赖于从供体动员的抗原呈递细胞（APC） 移植物。越来越多的证据和我们的初步研究表明，心脏和非血管化皮肤同种异体移植物 释放携带供体 Ag 的细胞外囊泡 (EV)，这些囊泡运输至 SLT，移植物 EV 刺激供体 Ag 反应性 B 细胞和 T 细胞。尽管在过去 5 年里关于移植电动车的作用的信息越来越多 抗供体免疫的引发及其作为移植生物标志物的潜在用途、体内机制 移植物 EV 与移植物引流 SLT 中受体的免疫细胞相互作用并促进抗供体免疫 仍然很大程度上不为人所知。 EV家族包含具有不同生物发生、大小和组成的囊泡，其中包括 外泌体和微泡。尽管越来越多的证据表明电动汽车代表了一种机制 细胞水平转移蛋白质、mRNA、非编码RNA和脂质，EV在体内的功能仍然是一个重要因素 谜。因此，我们建议研究移植物 EV 启动或重新激活的体内机制 在移植物引流 SLT 中，先天性和适应性免疫反应导致同种异体移植排斥。我们将 在心脏和非血管化皮肤同种异体移植小鼠实验模型中分析这些机制。 我们假设“移植 EV 构成了一个无细胞平台，通过多种机制启动 或重新激活受体 SLT 中的抗供体免疫反应”。该应用程序将调查 使用小鼠移植模型和人源化转化模型在原位和体内研究这些机制 老鼠。我们将在以下目标中检验我们的假设： 目标 1 将调查移植 EV 的起源及其 移植引流 SLT 中对受体 APC 的影响，目标 2 将分析移植 EV 产生的机制 SLT 中的抗供体 B 细胞免疫和 Aim 3 将分析移植 EV 如何在 SLT 中引发抗供体 T 细胞免疫 及其与人体移植的相关性。我们的长期目标是了解移植电动汽车如何在 vivo 将为开发基于 EV 的疗法和临床相关疾病标志物提供新的基础 移植和免疫介导的疾病。