Functions of Transmembrane and Soluble Fas ligand

跨膜和可溶性 Fas 配体的功能

• 批准号: 6473902
• 负责人: Ann Marshak-Rothstein
• 金额: $ 11.75万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-14 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6473902
• 关键词: SCID mouse; antigen presenting cell; apoptosis; cytotoxic T lymphocyte; enzyme activity; eye; gene deletion mutation; genetically modified animals; helper T lymphocyte; inflammation; leukocyte activation /transformation; lung; lymphoma; membrane proteins; metalloendopeptidases; neoplasm /cancer immunology; neutrophil; ovalbumin

DESCRIPTION: (Provided by applicant) Fas ligand (FasL) is a transmembrane protein originally described as a proapoptotic molecule inducibly expressed on cytotoxic T cells. Recent studies have shown that FasL expression can also trigger an inflammatory response, depending on the nature and status of the Fas+ target population. As such, it is evident that FasL expression must be stringently regulated. One aspect of this regulation is the ability of the membrane-bound form of FasL to be cleaved by a metalloproteinase; such cleavage rapidly reduces the level of FasL cell expression and releases a soluble protein that serves as an antagonist. Thus the overall impact of FasL expression is a balance between the membrane-bound and soluble forms.FasL can also be constitutively expressed by non-lymphoid tissues and, in some of these cases, FasL expression has been linked to the immune privilege of certain tissues or immune evasion of certain tumors. The significance of cleavage at these sites are unknown. The functional properties of transfected cell lines that express either wildtype FasL (wtFasL), membrane-only FasL (mFasL), or soluble-only FasL (sFasL) have been compared, and cells expressing mFasL were found to be remarkably more potent effectors than their wtFasL counterparts. For example, mFasL cells kill Fas+ target cells 5-10 times more effectively than wtFasL cells; mFasL cells induce greater neutrophil extravasation into the peritoneum than wtFasL cells; and mFasL lymphoma cells injected into syngeneic mice via the "immunoprivileged" anterior chamber of the eye are rejected and induce long-term immunity. Based on these observations, the goals of the current application will be two-fold. First, to analyze the cell types responsible for FasL-triggered tumor rejection and long term immunity and to further explore potential applications of mFasL expression to tumor immunotherapy regimens and secondly, to determine how cleavage moderates the function of FasL expressed by lymphoid and non-lymphoid tissues.This analysis will be facilitated by the use of a knock-in mouse strain rendered incapable of FasL cleavage as a result of gene-targeted deletion of the FasL metalloproteinase site. These studies will help to assess the feasibility of clinical applications of forced FasL expression and they should further reveal the significance of FasL expression by non-lymphoid tissues.

描述：（申请人提供）Fas配体（FasL）是一种跨膜配体 蛋白质最初被描述为诱导表达的促凋亡分子 细胞毒性T细胞。最近的研究表明 FasL 表达还可以 触发炎症反应，具体取决于炎症的性质和状态 Fas+ 目标人群。因此，很明显 FasL 表达必须是 严格监管。该法规的一个方面是 FasL 的膜结合形式可被金属蛋白酶切割；这样的分裂 迅速降低 FasL 细胞表达水平并释放可溶性 作为拮抗剂的蛋白质。因此 FasL 的总体影响 表达是膜结合形式和可溶形式之间的平衡。FasL 可以 也可由非淋巴组织组成型表达，并且在其中一些组织中 在某些情况下，FasL 表达与某些特定的免疫特权有关 组织或某些肿瘤的免疫逃避。裂解的意义 这些网站未知。转染细胞系的功能特性 表达野生型 FasL (wtFasL)、仅膜 FasL (mFasL) 或 比较了仅可溶性 FasL (sFasL)，表达 mFasL 的细胞 发现它们是比 wtFasL 对应物更有效的效应器。 例如，mFasL 细胞杀死 Fas+ 靶细胞的效率提高 5-10 倍 比 wtFasL 细胞； mFasL 细胞诱导更多的中性粒细胞外渗到 腹膜细胞优于wtFasL细胞；和 mFasL 淋巴瘤细胞注射到同系 通过“免疫特权”前房的小鼠被排斥并 诱导长期免疫力。根据这些观察，该项目的目标 当前的应用程序将有两个方面。首先，分析细胞类型 负责 FasL 触发的肿瘤排斥和长期免疫，并 进一步探索mFasL表达在肿瘤中的潜在应用 其次，确定裂解如何调节免疫治疗方案 淋巴组织和非淋巴组织表达的FasL的功能。本分析 将通过使用无法进行的敲入小鼠品系来促进 FasL 基因靶向删除导致 FasL 裂解 金属蛋白酶位点。这些研究将有助于评估可行性 强迫FasL表达的临床应用，应该进一步揭示 非淋巴组织 FasL 表达的意义。