Opioid-Mediated Fas Expression in Lymphocyte Apoptosis

描述（由申请人提供）：太空飞行对地球有着深远的影响。 人类、猴子和啮齿动物的免疫系统。等因素 微重力、缺乏承重、应力、加速力，以及 辐射已被提出有助于改变免疫 系统然而，这些因素影响免疫的确切机制 制度尚待建立。用地面动物模拟这些因素 模型（例如，后肢悬挂在啮齿类动物）已被用来复制 太空飞行对免疫系统的影响我们最近的研究表明， 阿片类药物可诱导Fas表达。此外，小鼠的束缚应激 诱导Fas介导的脾细胞凋亡， 方式由于空间飞行的条件既类似于物理条件， 对人类和动物的压力，我们假设免疫抑制在 太空飞行是由于Fas的表达诱导增加， 内源性阿片类物质的产生。我们提出以下目标来检验这一点 假设： 1)确定内源性阿片类物质在由 后肢悬吊在悬浮后的不同时间，将对小鼠进行处理 阿片受体拮抗剂将从外周血中分离淋巴细胞 血液、脾和淋巴结，并测定淋巴细胞数， 对促有丝分裂刺激的反应性和细胞因子的产生 （INF-γ、TNF和IL-2）和抗体。凋亡细胞的数量在 将测定脾脏和淋巴结。2)由于内源性阿片类药物 在太空飞行期间的生产还没有研究，我们将确定 内源性阿片类物质水平，如β-内啡肽、强啡肽和脑啡肽 在后肢悬吊后的不同时间。3)我们将 确定是否施用抗Fas配体抗体或可溶性 重组Fas蛋白可阻断后肢悬吊诱导的淋巴细胞 还原此外，Fas和FasL的表达在动物中经历了 后肢悬吊也将通过北方印迹分析和表面 染色此外，将使用具有Fas或FasL突变的小鼠来验证 Fas在这一过程中的作用。这些研究的总体目标是 确定与接地相关的免疫抑制机制 通过内源性阿片调节淋巴细胞模拟空间飞行 凋亡研究结果将有助于人们了解太空的影响 飞行环境对人体免疫系统的影响

DESCRIPTION (provided by applicant): Space flight has profound effects on the immune system of humans, monkeys and rodents. Several factors including microgravity, lack of load-bearing, stress, acceleration forces, and irradiation have been proposed to contribute to the changes of the immune system. However, the exact mechanisms by which these factors affect the immune system remain to be established. Simulation of these factors with ground animal models (e.g., hindlimb suspension in rodents) has been used to replicate the effects of space flight on immune system. Our recent studies have shown that opioids could induce Fas expression. In addition, restraint stress in mice induces Fas-mediated apoptosis in splenocytes in an endogenous opioid-dependent manner. Since space flight conditions resemble both physical and psychological stress to humans and animals, we hypothesize that immunosuppression during space flight is a result of the expression of Fas induced by increased production of endogenous opioids. We propose the following aims to test this hypothesis: 1) Determine the role of endogenous opioids in lymphocyte reduction induced by hindlimb suspension. At different times after suspension, mice will be treated with opioid receptor antagonists. Lymphocytes will be isolated from peripheral blood, spleen, and lymph nodes, and assayed for lymphocyte number, responsiveness to mitogenic stimulation, and the production of cytokines (INF-gamma, TNF, and IL-2) and antibodies. The number of apoptotic cells in the spleen and lymph nodes will be determined. 2) Since endogenous opioid production during space flight has not been studied, we will determine the level of endogenous opioids such as beta-endorphins, dynorphin, and enkephalin at different times after subjection to hindlimb suspension. 3) We will determine whether administration of anti-Fas ligand antibody or soluble recombinant Fas protein could block hindlimb suspension-induced lymphocyte reduction. In addition, the expression of Fas and FasL in animals subjected to hindlimb suspension will also be examined by northern blot analysis and surface staining. Furthermore, mice with Fas or FasL mutation will be used to verify the role of Fas in this process. The overall goal of these studies is to determine the mechanism(s) underlying immunosuppression associated with ground simulation of space flight, via endogenous opioids-modulated lymphocyte apoptosis. The results should lead to an understanding of the effects of space flight environment on human immune system.