Regulating Anti-Endothelial T Cell Responses in Graft Arteriosclerosis

描述（由申请人提供）：移植物动脉硬化（GA）是晚期同种异体心脏移植衰竭的主要原因，无法治疗，因此改善临床结果将取决于预防。我们提出GA是由慢性延迟型超敏反应引起的，其中宿主T细胞识别移植物内皮细胞（ECs）呈递的非自身抗原并产生IFN-3， IFN-3是一种细胞因子，在移植到免疫缺陷小鼠的人动脉段中产生GA样病变，并且在GA的临床标本中发现。该项目将探索三种方法，通过人体记忆T细胞在体内对移植的小鼠宿主异体人动脉段或体外培养的异体人内皮细胞作出反应来减少IFN-3的产生。首先，我们将在体内对人动脉段进行控制缺氧后再灌注，或在体外对培养的人内皮细胞（ECs）进行缺氧后再氧合，表征对异体T细胞反应的影响，并确定由这些条件诱导的特定血管细胞源性介质的中和是否可以减少IFN-3的产生。其次，我们将确定抗体是否与EC抗原反应，特别是HLA-A，B，C，以一种增加异体T细胞反应的方式改变EC，确定补体激活是否参与其中，并确定中和补体或抗体诱导的EC衍生介质是否可以逆转这种作用。第三，我们将确定ec诱导T调节细胞（i-Tregs）的发育或功能的条件，这些细胞可以通过效应细胞减少IFN-3的产生，表征这些i-Tregs，并制定在体内产生这些i-Tregs的策略。同时，我们将通过转染FoxP3蛋白将效应T细胞转化为i-Tregs。我们关于体液和细胞免疫相互作用的假设是新颖的，我们创建的新的人源化小鼠模型和我们使用蛋白质转染将T效应细胞转化为i- treg样细胞的方法是创新的。成功完成这些目标可能会导致针对GA的新的预防疗法。

DESCRIPTION (provided by applicant): Graft arteriosclerosis (GA), the major cause of late cardiac allograft failure, is untreatable so that improved clinical outcomes will depend upon prevention. We have proposed that GA is caused by chronic delayed type hypersensitivity in which host T cells recognize non-self antigens presented by graft endothelial cells (ECs) and produce IFN-3, a cytokine that produces GA-like lesions in human artery segments transplanted into immunodeficient mice and that is found in clinical specimens of GA. This project will explore three approaches to reduce IFN-3 production by human memory T cells responding in vivo to transplanted allogeneic human artery segments in mouse hosts or in vitro to cultured allogeneic human ECs. First, we will subject human arterial segments to controlled hypoxia followed by reperfusion in vivo or subject cultured human endothelial cells (ECs) to hypoxia followed by reoxygenation in vitro, characterize the effect on allogeneic T cell responses, and determine if neutralization of specific vascular cell-derived mediators induced by these conditions can reduce IFN-3 production. Second, we will determine if antibodies reactive with EC antigens, especially HLA-A,B,C, alter ECs in a manner that increases allogeneic T cell responses, determine if complement activation is involved, and determine if neutralizing complement or EC-derived mediators induced by antibodies can reverse this effect. Third, we will determine conditions under which ECs induce the development or function of T regulatory cells (i-Tregs) that can reduce IFN-3 production by effector cells, characterize such i-Tregs, and develop strategies to generate such i-Tregs in vivo. In parallel, we will convert effector T cells to i-Tregs by FoxP3 protein transfection. Our hypothesis regarding the interactions of humoral and cellular immunity is novel and our creation of new humanized mouse models and our use of protein transfection to convert T effector cells to i-Treg-like cells are methodologically innovative. Successful completion of these aims may lead to new preventative therapies that target GA. PUBLIC HEALTH RELEVANCE: Heart transplantation is the most effective therapy for end stage heart failure, but most heart grafts themselves eventually fail due to a peculiar form of rejection called graft arteriosclerosis (GA) that involves progressive narrowing of the arteries that nourish the heart muscle. GA cannot be effectively treated and effort has focused on prevention. This project uses novel approaches, such as humanized mice, to study how GA develops and how the T cells that cause it can be regulated, providing a firm basis for new preventative strategies.