EFFECTS OF FAS LIGAND ON TISSUE GRAFT REJECTION

FAS 配体对组织移植排斥的影响

• 批准号: 2568999
• 负责人: A S ROSENBERG
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2568999
• 关键词: Langerhans' cell; MHC class II antigen; T cell receptor; T lymphocyte; cellular immunity; enzyme activity; immune tolerance /unresponsiveness; laboratory mouse; lymphatic tissue transplantation; receptor expression; surface antigens; transfection /expression vector; transplant rejection

The fas/fas-ligand system is an important receptor-ligand system that regulates cell death in the immune system. Expression of functional fas ligand on activated T lymphocytes induces death of lymphocytes expressing fas and thus limits proliferation of antigen specific T and B cells. In contrast mutation of fas ligand to a nonfunctional form leads to a syndrome of lymphoproliferation and immunodeficiency due to the accumulation of lymphocytes. Recently, it was observed that expression of fas ligand on tissue transplants conferred protection from rejection, presumably by inducing death of alloreactive lymphoid populations. This project explores the feasibility of inducing tolerance to tissue allografts and xenografts by engineered expression of fas ligand on tissues for transplantation. In the first phase of the project, human and murine fas ligand are being targeted to professional antigen presenting cells (APC) such as Langerhans cells by cloning into an expression vector containing the MHC class II Ealpha promoter and constructing transgenic mice with this construct. Thus, professional APCs in all tissues should express fas ligand and transplantation of organs such as skin onto allogeneic or xenongeneic animals will be performed to test the ability of such organs to survive and induce tolerance. We will take advantage of mice in whom the vast majority of T cells express a unique receptor for alloantigen to assess the effect of expression of fas ligand on alloantigen expressing tissue. Controls will consist of a mutated fas ligand construct which is functionally inert or the vector alone. The second part of the project explores the feasibility of inducing tolerance to tissue allografts or xenografts by directly inoculating the tissue with the gene for fas ligand via gene gun. We have cloned the gene for human or for murine fas ligand into a mammalian expression vector, PCI, which has been used in gene gun protocols to induce immunity to viral antigens. In this protocol, a segment of skin from a donor animal will be "shot" with fas ligand DNA and transplanted onto allogeneic animals to assess for effects on graft rejection.

Fas/Fas-配体系统是一种重要的受体-配体系统， 调节免疫系统中的细胞死亡。功能Fas的表达 活化T淋巴细胞上的配体诱导表达的淋巴细胞死亡 Fas，从而限制抗原特异性T和B细胞的增殖。在……里面 Fas配体的非功能形式的对比突变导致 淋巴增殖和免疫缺陷综合征 淋巴细胞聚集。最近，人们观察到， 在组织移植上的Fas配体提供了防止排斥反应的保护， 可能是通过诱导同种异体反应淋巴种群的死亡。这 该项目探索了诱导组织耐受的可行性 Fas配体在同种和异种移植物中的工程表达 供移植用的组织。在该项目的第一阶段，人类 和小鼠Fas配体被作为专业抗原的靶标 呈现细胞(APC)，如朗格汉斯细胞 含有MHC II类Epha启动子和 用该构建物构建转基因小鼠。因此，专业人士 所有组织中的APC都应该表达Fas配体，并移植到 将皮肤等器官移植到同种或异种动物身上 以测试这些器官存活和诱导的能力 宽容。我们将利用老鼠，其中绝大多数是 T细胞表达一种独特的同种异体抗原受体来评估疗效 Fas配体在表达同种异体抗原的组织上的表达。控制 将由突变的Fas配体结构组成，该结构在功能上 惰性或单独的载体。该项目的第二部分探讨了 诱导同种或异种组织移植耐受的可行性 通过基因途径将Fas配体基因直接接种组织 枪。我们已经将人类或小鼠Fas配体的基因克隆到一个 已用于基因枪的哺乳动物表达载体pCI 诱导对病毒抗原免疫的方案。在该协议中，一个 捐献动物的皮肤片段将被注射Fas配体DNA 并移植到同种异体动物身上以评估对移植的影响 拒绝。