Functions of Transmembrane and Soluble Fas ligand

描述：（由申请人提供）Fas配体（FasL）是一种跨膜 一种最初被描述为促凋亡分子的蛋白质，可诱导表达于 细胞毒性T细胞最近的研究表明，FasL表达也可以 引发炎症反应，这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。这项规定的一个方面是， 金属蛋白酶切割的FasL的膜结合形式;这种切割 快速降低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，在其中一些组织中， 例，FasL表达已与某些免疫赦免有关。 组织或某些肿瘤的免疫逃避。卵裂的意义 这些网站是未知的。转染细胞系的功能特性 表达野生型FasL（wtFasL）、仅膜FasL（mFasL）或 已经比较了仅可溶性FasL（sFasL），并且表达mFasL的细胞被 被发现比它们的wtFasL对应物显著更有效的效应物。 例如，mFasL细胞杀死Fas+靶细胞的有效性是其5 - 10倍 与wtFasL细胞相比，mFasL细胞诱导更多的中性粒细胞外渗到 腹膜比wtFasL细胞;和mFasL淋巴瘤细胞注射到同基因 通过眼的"免疫豁免的"前房排斥小鼠， 诱导长期免疫。根据这些观察， 目前的应用将是双重的。首先，分析细胞类型 负责FasL触发的肿瘤排斥和长期免疫， 进一步探索mFasL表达在肿瘤中的潜在应用 免疫治疗方案，其次，以确定切割如何缓和 淋巴组织和非淋巴组织表达的FasL的功能。 将通过使用敲入小鼠品系来促进， 由于基因靶向缺失FasL而导致的FasL切割 金属蛋白酶位点这些研究将有助于评估 强制FasL表达的临床应用，他们应该进一步揭示 非淋巴组织FasL表达的意义。

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.