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。虽然精确的 临床GA的发病机制尚不清楚，大量证据支持IFN-γ和IFN-γ的作用。 一氧化氮合酶（NOS）的失调。在过去的资助周期中， 在GA的人源化小鼠模型中，我们发现了一种意想不到的NOS失调成分， 涉及移植动脉浸润T细胞诱导型（i）-NOS的IFN-γ依赖性表达。中央 该项目的假设是，同种异体移植动脉的内皮细胞（EC）在移植时的状态， 与宿主效应T细胞或效应记忆T细胞的接触决定了这些T细胞是否吸收了 驻留在血管壁内将分泌IFN-γ和/或表达i-NOS，这是T细胞的两个特征性特征。 介导GA的细胞。在这个延续中，我们的目标是：（1）确定两个重要的先天免疫 组织损伤的信号，即C5 a或HMGB 1，作用于EC或T细胞，以促进 表达IFN-γ或i-NOS的致病性T细胞;（2）鉴定有助于免疫应答的特异性EC分子。 在体外或体内的致病性T细胞的募集;（3）阐明i-NOS表达的控制， 活性，并鉴定有助于其调节的EC信号;和（4）确定是否和 巨噬细胞或T细胞自体树突状细胞（DC）如何影响它们对 同种异体内皮细胞的一般和他们如何影响IFN-γ或i-NOS的表达特别。这些 实验将利用体外试验（共培养和流动室）和体内试验，包括我们的 建立了huPBL-SCID/bg小鼠人同种异体移植动脉GA模型和两种正在开发的模型， 即（i）将人T记忆细胞的过继转移与人造血干细胞的植入相结合， 来自同一志愿者供体的干细胞，以便引入巨噬细胞和DC，和（ii）移植 将含有遗传修饰的EC的组织工程化合成人动脉植入huPBL-SCID/bg小鼠中， 以评估特定EC分子的作用。成功完成这些研究可能会导致 进一步深入了解发病机制和预防或治疗GA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.