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)是晚期心脏移植失败的主要原因，无法治疗，因此临床结果的改善将取决于预防。我们认为GA是由慢性迟发性超敏反应引起的，宿主T细胞识别移植物内皮细胞(ECs)呈递的非自身抗原，并产生干扰素-3，一种细胞因子，在移植到免疫缺陷小鼠的人动脉节段中产生GA样病变，在GA的临床标本中发现。该项目将探索三种方法来减少人类记忆T细胞在体内对移植的同种异体人类动脉节段的反应，或在体外对培养的同种异体人内皮细胞产生干扰素-3。首先，我们将在体内将人动脉段置于控制性低氧后再灌注，或使培养的人内皮细胞(ECs)在体外处于低氧后复氧，以表征其对同种异体T细胞反应的影响，并确定这些条件下诱导的特定血管细胞衍生介质是否可以减少干扰素-3的产生。其次，我们将确定与EC抗原，特别是HLA-A，B，C反应的抗体是否能以增加同种异体T细胞反应的方式改变EC，确定是否涉及补体激活，并确定抗体诱导的中和补体或EC衍生的介质是否可以逆转这一效应。第三，我们将确定ECs诱导T调节细胞(I-Tregs)发育或功能的条件，以减少效应细胞产生干扰素-3，表征这种I-Tregs，并开发在体内产生这种I-Tregs的策略。同时，我们将通过FoxP3蛋白转染将效应性T细胞转化为I-Tregs。我们关于体液免疫和细胞免疫相互作用的假设是新颖的，我们创造了新的人源化小鼠模型，并使用蛋白质转染将T效应细胞转化为I-Treg样细胞，这在方法上是创新的。这些目标的成功完成可能会导致针对GA的新的预防性治疗。

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.