Endothelial control of IFN-gamma and i-NOS in pathogenic T cells

移植物动脉硬化(GA)是晚期心脏移植失败的主要原因。尽管准确地说 临床GA的发病机制尚不清楚，相当多的证据支持干扰素-γ和 一氧化氮合酶(NOSS)调节失调。在过去的资助周期中，我们使用我们的 人源化的GA小鼠模型，我们发现了一氧化氮合酶异常的一个意想不到的成分 涉及移植物动脉浸润性T细胞对诱导型一氧化氮合酶(I)-NOS的表达。中环 该项目的假设是同种异体动脉移植时内皮细胞(ECs)的状态 与宿主效应器或效应器记忆T细胞的接触决定了这些T细胞是否占据 停留在血管壁内会分泌干扰素-γ和/或表达i-NOS，这是T细胞的两个特征 调节GA的细胞。在本文中，我们的目标是：(1)确定两种重要的先天免疫 组织损伤信号，即C5a或HMGB1，作用于内皮细胞或T细胞，促进其分化 表达干扰素-γ或诱导型一氧化氮合酶的致病T细胞；(2)识别特定的EC分子 在体外或体内募集致病T细胞；(3)阐明i-NOS表达的调控和 人类T细胞的活性，并确定参与其调节的EC信号；以及(4)确定是否和 巨噬细胞或树突状细胞(DC)对T细胞免疫应答的影响 同种异体内皮细胞及其如何影响干扰素-γ或i-一氧化氮合酶的表达。这些 实验将利用体外检测(共培养和流动室)和体内检测，包括我们的 建立了HuPBL-SCID/BG小鼠同种异体动脉移植GA模型和两种模型正在研制中。 即(1)过继移植人T记忆细胞与植入人造血细胞相结合 来自同一志愿捐赠者的干细胞，以引入巨噬细胞和DC，以及(Ii)移植 将含有转基因内皮细胞的人造人动脉植入HuPBL-SCID/BG小鼠体内 以评估特定EC分子的作用。成功完成这些研究可能会导致 进一步洞察GA的发病机制和预防或治疗的新方法。

Graft arteriosclerosis (GA) is the major cause of late cardiac allograft failure. Although the precise pathogenesis of clinical GA is unknown, considerable evidence supports a role for IFN-gamma and for dysregulation of nitric oxide synthases (NOSs). In studies conducted during the past funding cycle using our humanized mouse model of GA, we have found that an unexpected component of NOS dysregulation involves IFN-gamma-dependent expression of inducible (i)-NOS by graft artery infiltrating T cells. The central hypothesis of this project is that the status of the endothelial cells (ECs) of an allograft artery at the time of their encounter with host effector or effector memory T cells determines whether those T cells that take up residence within the vessel wall will secrete IFN-gamma and/or express i-NOS, two characteristic features of T cells that mediate GA. In this continuation, our aims are: (1) to determine if two important innate immune signals of tissue injury, namely C5a or HMGB1, act on ECs or T cells to favor the differentiation of pathogenetic T cells that express IFN-gamma or i-NOS; (2) to identify specific EC molecules that contribute to the recruitment of pathogenetic T cells in vitro or in vivo; (3) to elucidate the control of i-NOS expression and activity in human T cells and to identify EC signals that contribute to its regulation; and (4) to determine if and how macrophages or dendritic cells (DCs) autologous to T cells influence their responses to allogeneic ECs in general and how they influence IFN-gamma or i-NOS expression in particular. These experiments will utilize both in vitro assays (co-cultures and flow chambers) and in vivo assays, including our established huPBL-SCID/bg mouse human allograft artery model of GA and two models under development, namely (i) combining adoptive transfer of human T memory cells with engraftment of human hematopoietic stem cells from the same volunteer donor in order to introduce macrophages and DCs, and (ii) transplantation of tissue-engineered synthetic human arteries containing genetically modified ECs into huPBL-SCID/bg mice in order to assess the role of specific EC molecules. Successful completion of these studies may lead to further insights into pathogenesis and to new approaches for prevention or treatment of GA.