Immune Tolerance; Sigma Receptor as a Therapeutic Target

描述（由申请人提供）：本项目的目标是收集 支持诱导免疫耐受的新策略的证据， 即使用σ 1受体作为潜在的治疗靶点。Sigma 1 受体被定义为各种精神活性药物的特异性结合位点 例如氟哌啶醇和喷他佐辛。 这种受体最近已被克隆 和表征了 这是一个 膜结合蛋白，主要存在于 胞内位点。它在包括免疫细胞在内的各种组织中表达 和胎盘。有令人信服的证据表明， σ 1受体特异性配体。该受体在免疫中的作用 近年来，由于它已成为 显然孕酮是该受体的假定内源性配体。 这个项目的目标是描绘参与的分子事件， sigma 1受体的免疫抑制功能，并探讨可能的 孕酮在维持母体对胎盘耐受性中的作用 同种异体移植本研究将验证以下假设：1）预测 并且几种药理学配体抑制了 T淋巴细胞通过作为σ 1受体的特异性配体; 2）σ 1受体通过影响其他细胞的功能而发挥作用。 通过蛋白质-蛋白质相互作用在T淋巴细胞和胎盘中的蛋白质; 3） 通过靶向破坏σ 1受体基因的表达来消除σ 1受体基因的表达。 小鼠模型中的基因会导致母体对胎盘不耐受， 同种异体移植提出了三个具体目标来检验这些假设。具体 目的：1.研究静止期和静止期海马神经元中sigma 1受体的表达， 活化的T淋巴细胞，并建立这种受体在 抑制T细胞功能。这将通过分析表达式 T淋巴细胞中sigma 1受体的分子和功能水平 在激活之前和之后σ 1受体在T细胞中的专性作用 将通过分析sigma 1的生物学效应来评估功能 σ 1受体阳性（对照）和σ 1 受体阴性（表达反义σ 1受体的稳定转染子 mRNA）Jurkat细胞。具体目标2是鉴定人类中的蛋白质 胎盘和T淋巴细胞与sigma 1受体相互作用， 酵母双杂交系统 相互作用的靶蛋白的鉴定 与sigma 1受体的相互作用将有助于揭示细胞凋亡的分子机制。 由σ 1受体介导的信号传导。具体目标3是确定，使用 σ 1受体敲除小鼠，无论受体的缺失是否表现为 胚胎的致命性，胚胎无法保护自己， 针对母体免疫系统，或作为母体免疫系统的无能， 系统来维持对胎盘移植物的耐受性。这个项目可能 具有重要的生理、临床和治疗相关性。 的 拟议的研究可能会导致更好地了解诱导 母体对胎盘同种异体移植物的耐受性，并可能为 未来 努力 到 审查 治疗 潜在 的 Sigma 1 受体特异性配体作为有效的免疫抑制剂。

DESCRIPTION (provided by applicant): The goal of this project is to gather evidence in support of a novel strategy for the induction of immune tolerance, namely to use sigma 1 receptor as a potential therapeutic target. Sigma 1 receptor is defined as a specific binding site for various psychoactive drugs such as haloperidol and pentazocine. This receptor has been recently cloned and characterized. It is a membrane-bound protein found primarily in intracellular sites. It is expressed in various tissues including immune cells and placenta. There is compelling evidence for an immunosuppressive role of sigma 1 receptor-specific ligands. The role of this receptor in immune function has received increasing attention in recent years as it has become apparent that progesterone is a putative endogenous ligand for this receptor. The goal of this project is to delineate the molecular events involved in the immunosuppressive function of sigma 1 receptor and to investigate the possible role of progesterone in the maintenance of maternal tolerance toward placental allograft. This project will test the following hypotheses: 1) Progesterone and several pharmacological ligands suppress the function and proliferation of T lymphocytes by acting as specific ligands for the sigma 1 receptor; 2) sigma 1 receptor produces its effects by influencing the function of other cellular proteins in T lymphocytes and placenta via protein-protein interaction; 3) Abolition of sigma 1 receptor gene expression by targeted disruption of the gene in a mouse model will lead to maternal intolerance of the placental allograft. Three specific aims are proposed to test these hypotheses. Specific Aim 1 is to study the expression of sigma 1 receptor in quiescent and activated T lymphocytes and to establish the role of this receptor in the suppression of T cell function. This will be done by analyzing the expression of sigma 1 receptor at the molecular and functional level in T lymphocytes before and after activation. The obligatory role of sigma 1 receptor in T cell function will be evaluated by analyzing the biological effects of sigma 1 receptor-specific ligands in sigma 1 receptor-positive (control) and sigma 1 receptor-negative (stable transfectants expressing antisense sigma 1 receptor mRNA) Jurkat cells. Specific Aim 2 is to identify the proteins in human placenta and in T lymphocytes that interact with sigma 1 receptor using the yeast two-hybrid system. Identification of the target proteins that interact with sigma 1 receptor will help to unravel the molecular mechanisms of cell signaling mediated by sigma 1 receptor. Specific Aim 3 is to determine, using sigma 1 receptor knockout mice, whether the absence of the receptor manifests itself as embryo lethality, an inability of the embryo to defend itself against maternal immune system, or as an inability of the maternal immune system to maintain tolerance toward the placental allograft. This project may have significant physiological, clinical, and therapeutic relevance. The proposed studies may lead to a better understanding of the induction of maternal tolerance toward placental allograft and may provide the basis for future efforts to examine the therapeutic potential of sigma 1 receptor-specific ligands as effective immunosuppressants.