Modulating endothelial cell immunometabolism and mitochondrial morphology- implications for organ transplantation

摘要：器官移植是器官衰竭患者的主流治疗方法；然而，尽管 尽管在这一领域取得了重大进展，但移植的两个主要组成部分-- 器官保存和维持免疫抑制。尽管是必要的，免疫抑制疗法 带来严重的副作用负担，通常会导致患者死亡和移植物失败。此外，这一过程 器官获取最常包括使用脑死亡供者的移植物，其次是低温 将器官保存在储存液中。在这些事件中，器官中的内皮细胞(EC) 同种异体移植物经过免疫学准备，然后受到再灌流的侮辱。这是早期的损伤 使EC容易受到不适当的抗原提呈和慢性移植物功能障碍的影响，包括移植物 导致长期移植物失败的血管病变。低温保存改变了细胞的新陈代谢 同种异体移植，这又被假设为改变最终影响细胞的内皮细胞的免疫原性 功能结果。这种级联反应的中心是线粒体在塑造免疫代谢过程中的作用。 同种异体移植在面对冷缺血再灌注损伤时的环境。在这项提案中，我们第一次， 探讨线粒体形态与免疫代谢的机制关系 移植环境中的ECS及其免疫原性。我们根据自己的数据来评估 强制线粒体超微结构改变对EC保存过程中免疫原性的影响 移植阶段。我们认为，通过抑制ECs的早期免疫原性效应，我们可以创造 通过使用减少的免疫抑制方案来诱导同种异体移植耐受的机会 减少这些必要药物的有害后果。我们将采用科学的前提 通过改变内皮细胞的代谢核心，使其诱导 同种异体反应性T细胞的致炎改变减少。使用临床相关的体内模型 移植后，我们预计改变EC线粒体将提高移植物的存活率并消除病理。 与同种异体移植排斥反应有关。以我们的初步数据为基础，我们假设冷缺血 通过改变线粒体形态加剧EC的免疫原性和代谢特征 导致同种异体移植物损伤。此外，根据以下目标，我们的目标将是保护器官移植和 使EC偏向更能耐受的表型。 目的1.我们将确定器官保存过程中线粒体形态对 体外培养内皮细胞的免疫原性。 目的2.评价线粒体形态在缺血再灌注损伤中的作用 和体内急性移植排斥反应。 线粒体融合疗法的预治疗将改变目前移植治疗的标准。

ABSTRACT: Organ transplantation is a mainstream therapy for patients with organ failure; however, despite major advances in the field, there has been little progress regarding two major components of transplantation -- organ preservation and maintenance immunosuppression. Although essential, immunosuppressive therapy carries a significant side-effect burden, often leading to patient death and graft failure. In addition, the process of organ procurement most often includes use of grafts from brain dead donors followed by hypothermic preservation of the organs in storage solutions. During these events, the endothelial cells (EC) in the organ allografts are primed immunologically and are then subjected to the insults of reperfusion. This early injury predisposes the EC to inappropriate antigen presentation and effects of chronic graft dysfunction, including graft vasculopathy leading to long-term graft failure. Hypothermic preservation changes the metabolism of the allograft, which in turn is hypothesized to alter the immunogenicity of the ECs ultimately affecting cellular functional outcomes. Central to this cascade is the role of the mitochondria in shaping the immunometabolic milieu of the allograft in the face of cold ischemia and reperfusion injury. In this proposal we, for the first time, explore the mechanistic relationship between the mitochondrial morphology and immunometabolism of ECs and their immunogenicity in the setting of transplantation. We build upon our own data to assess the effects of forcing mitochondrial ultrastructural changes on the immunogenic profile of EC during the preservation phase of transplantation. We propose that by dampening the early immunogenic effects of ECs, we can create the opportunity to induce allograft tolerance with the use of reduced immunosuppressive regimens thereby reducing the deleterious consequences of these necessary drugs. We will employ the scientific premise of reprograming ECs to a more tolerogenic state by altering their metabolic core such that their ability to induce proinflammatory changes from alloreactive T cells are diminished. Using clinically relevant in vivo models of transplantation, we anticipate that altering EC mitochondria will improve graft survival and abrogate the pathology associated with allograft rejection. Using our preliminary data as a backbone we hypothesize that cold ischemia exacerbates the immunogenic capacity and metabolic profile of EC by altering mitochondrial morphology resulting in allograft injury. Additionally, with the following aims, our goal will be to protect organ allografts and skew the EC to a more tolerogenic phenotype. Aim 1. We will determine the impact of mitochondrial morphology during organ preservation on the immunogenicity of endothelial cells in vitro. Aim 2. We aim to assess the impact of mitochondrial morphology on ischemia reperfusion injury and acute transplant rejection in vivo. Pre-treatment with mitochondrial fusion therapeutics will shift the current standard of care in transplantation.