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）是晚期心脏移植物衰竭的主要原因，无法治疗，因此临床结局的改善将取决于预防。我们提出GA是由慢性迟发型超敏反应引起的，其中宿主T细胞识别由移植物内皮细胞（EC）呈递的非自身抗原并产生IFN-3，IFN-3是一种细胞因子，其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来减少IFN-3的产生，通过人记忆T细胞在体内对小鼠宿主中移植的同种异体人动脉段或体外对培养的同种异体人EC的反应。首先，我们将人体动脉段进行控制缺氧，然后再灌注在体内或受试者培养的人内皮细胞（EC）缺氧，然后再氧合在体外，表征对同种异体T细胞反应的影响，并确定是否中和这些条件下诱导的特定血管细胞衍生的介质可以减少IFN-3的生产。其次，我们将确定抗体与EC抗原，特别是HLA-A，B，C，改变EC的方式，增加同种异体T细胞反应，确定是否涉及补体激活，并确定是否中和补体或EC衍生的介质诱导的抗体可以逆转这种效果。第三，我们将确定条件下，内皮细胞诱导的发展或功能的T调节细胞（i-T细胞），可以减少IFN-3的产生效应细胞，这种i-T细胞的特点，并制定战略，以产生这样的i-T细胞在体内。平行地，我们将通过FoxP 3蛋白转染将效应T细胞转化为i-T细胞。我们关于体液和细胞免疫相互作用的假设是新颖的，并且我们创建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样细胞在方法上是创新的。这些目标的成功完成可能会导致针对GA的新的预防性疗法。

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.