MOLECULAR MECHANISMS UNDERLYING ACAID INDUCTION

描述（由申请方提供）：对眼部抗原的免疫应答是独特的，因为其选择性缺乏介导迟发型超敏反应（DTH）的Th 1效应子和补体固定免疫球蛋白，而非补体固定免疫球蛋白和细胞毒性T细胞仍然可检测。这种与常规免疫应答的偏离被称为前房相关免疫偏离（ACAID）。已知这种免疫应答有助于眼睛的免疫赦免状态。常驻眼抗原呈递细胞（APC）被赋予以抗原特异性方式诱导这种应答的能力，其通过迁移到受体脾脏并以产生调节细胞的方式将抗原呈递给应答者T细胞。这些细胞反过来又被称为防止DTH反应。眼APC的ACAID诱导能力主要归因于它们在眼中暴露于TGF β。还已知来源于非眼部来源的常规APC在暴露于TGF β时获得这种独特的ACAID诱导性质。理解APC中这种功能转化的分子机制提供了开发治疗策略以预防眼部炎症以及离体产生调节性APC以用于需要调节不期望的免疫应答的各种临床应用的潜力。为此，我们尝试鉴定在TGF β处理的APC中选择性表达的基因。应用差异基因分析（RAP-PCR和基因芯片微阵列）从未经处理的APC和TGF β处理的APC中分离的RNA，我们分离出几个差异表达的基因，这些基因可能与APC的ACAID诱导特性有关。这种方法使我们能够选择到目前为止尚未被怀疑与ACAID诱导相关的潜在重要基因。开始，我们选择基因的基础上，他们的已知属性，因为他们涉及到现有的信息可利用的各个方面的ACAID和APC参与其诱导，以及独特的眼睛微环境。我们现在建议分析这些基因产物（血小板反应蛋白，TNFR II和IkappaBetaalpha）的参与及其在TGF β处理的APC诱导ACAID中的作用。首先，这些分子在ACAID各个方面的发展中的意义将被评估，然后分析这些基因产物调控的个体机制。通过比较这些基因的作用和评估相关的机制，我们建议测试的可能性，有效地使用TGF β处理的APC，以防止实验性自身免疫性葡萄膜炎（EAU）和皮肤移植排斥反应。

DESCRIPTION (provided by applicant): Immune response to ocular antigens is unique in that it is selectively deficient in delayed type hypersensitivity (DTH) mediating Th1 effectors and complement fixing immunoglobulins, while non-complement fixing immunglobulins and cytotoxic T cells remain detectable. Such deviation from a conventional immune response is referred to as Anterior Chamber Associated Immune Deviation (ACAID). This immune response is known to contribute to the immune privilege status of the eye. Resident ocular antigen presenting cells (APCs) are endowed with the ability to induce this response in an antigen specific manner by migrating out to the recipient spleen and presenting antigen to the responders T cells in a manner that generates regulatory cells. These cells in turn are known to prevent DTH responses. The ACAID-inducing ability of ocular APCs is mainly attributed to their exposure to TGFbeta in the eye. Conventional APCs derived from non-ocular sources are also known to acquire such unique ACAID-inducing properties when exposed to TGFbeta. Understanding molecular mechanisms underlying this functional transformation in APCs offers potential to develop therapeutic strategies to prevent ocular inflammation as well as to generate regulatory APCs ex vivo to be used for various clinical applications that require regulation of an undesirable immune response. To this end we have attempted identification of genes that are selectively expressed in TGFbeta-treated APCs. Applying differential analysis of genes (RAP-PCR and Genechip Microarrays) to RNA isolated from untreated APCs and TGFbeta-treated APCs, we isolated several differentially expressed genes that can be relevant in ACAID-inducing properties of APCs. Such an approach has allowed us to select potentially significant genes that have been unsuspected, so far, to be relevant in ACAID-induction. To begin with, we have chosen genes based on their known properties and as they relate to existing information available regarding various aspects of ACAID and APCs involved in its induction as well as the unique ocular microenvironment. We now propose to analyze the participation of these gene products (thrombospondin, TNFR II and IkappaBetaalpha) and their role in ACAID induction by TGFbeta-treated APCs. First, significance of these molecules in development of various aspects of ACAID will be evaluated followed by analysis of individual mechanisms regulated by these gene products. By comparing the effects of these genes and assessing interrelated mechanisms we propose to test a possibility to effectively use TGFbeta-treated APCs to prevent experimental autoimmune uveitis (EAU) and skin allograft rejection.