Genetic Modification of Mouse Islets for Transplantation

用于移植的小鼠胰岛基因改造

• 批准号: 6553141
• 负责人: JIDE TIAN
• 金额: $ 15.25万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6553141
• 关键词: NOD mouse; T lymphocyte; autoimmunity; diabetes mellitus; histocompatibility; immunogenetics; ligands; pancreatic islet transplantation; protein structure function; reporter genes; transfection; transplant rejection; transplantation immunology

DESCRIPTION (provided by applicant): The success of islet transplantation therapy for Type I diabetes mellitus (T1DM) depends on its ability to control both T cell-mediated alloreactivity and the ¿-cell autoimmunity. Inducible costimulator (ICOS)/B7-related protein 1(B7RP-1) signaling is crucial for regulation of effector Th1 and Th2 cell function. Treatment with ICOS antagonist inhibits Th1 and Th2 mediated inflammation, EAE, allergic airway disease, and mucosal inflammatory disease, and protects allogeneic heart grafts from immunorejection. We hypothesize that genetic modification of the islets to locally express soluble ICOS-Ig may protect the islet-grafts from immunorejection. The mechanism(s) underlying this protection may involve the inactivation of effector T cells by promoting their apoptosis and/or anergy. We will use recombinant adeno-associated virus (rAAV) to deliver the ICOS-Ig or other control genes to the islet cells. AAV is a non-pathogenic virus and has little immunogenicity, may therefore be safe in clinical applications. Recent studies have demonstrated that genetic modification of the islets by rAAV transduction results in the long-term expression of reporter genes in vivo, which does not interfere with insulin production. Finally, the local expression of ICOS-Ig may not affect systemic immunological function, providing a safe means to prolong transplanted islet survival. Therefore, immunotherapy based on transplantation with ICOS-Ig expressing islets to inhibit effector T cells may be especially effective for maintaining syngeneic and allogeneic islet-graft tolerance.In this application, we will: 1). optimize conditions for generation of genetically modified mouse islets which express costimulation inhibitor ICOS-Ig; 2). examine whether transplantation of ICOS-Ig expressing syngeneic and allogeneic islets prevents the recurrence of diabetes; and 3). determine the action of ICOS-Ig in the functional maintenance of transplanted islets. These studies will address fundamental questions concerning the regulatory function of ICOS/B7RP-1 signaling on alloreactive and autoimmune T cell responses. Our findings may provide the basis for novel immunotherapies for the prevention and inhibition of immunorejection of islet grafts in man.

描述(申请人提供)：胰岛移植治疗I型糖尿病(T1 DM)的成功取决于其控制T细胞介导的同种异体反应和细胞自身免疫的能力。诱导共刺激分子(ICOS)/B7相关蛋白1(B7RP-1)信号转导通路在调节Th1和Th2细胞功能中起着至关重要的作用。ICOS拮抗剂治疗可抑制Th1和Th2介导的炎症、EAE、过敏性呼吸道疾病和粘膜炎症，并保护同种异体心脏移植物免受免疫排斥。我们推测，对胰岛进行基因改造以局部表达可溶性ICOS-Ig可能会保护胰岛移植物免受免疫排斥。这种保护的机制(S)可能涉及到通过促进效应T细胞的凋亡和/或无能来使其失活。我们将使用重组腺相关病毒(RAAV)将ICOS-Ig或其他控制基因转移到胰岛细胞。AAV是一种非致病性病毒，几乎没有免疫原性，因此临床应用可能是安全的。最近的研究表明，通过rAAV转导对胰岛进行基因修饰会导致报告基因在体内的长期表达，而不会干扰胰岛素的产生。最后，ICOS-Ig的局部表达可能不影响系统的免疫功能，为延长移植胰岛的存活提供了一种安全的手段。因此，基于ICOS-Ig表达的胰岛移植抑制效应性T细胞的免疫治疗在维持同基因和同种异体胰岛移植耐受方面可能特别有效。优化表达共刺激抑制因子ICOS-Ig的转基因小鼠胰岛的生成条件；检测表达同基因和同种异体胰岛的ICOS-Ig移植是否能预防糖尿病复发；确定ICOS-Ig在移植胰岛功能维持中的作用。 这些研究将解决与ICOS/B7RP-1信号对同种异体反应和自身免疫T细胞反应的调节功能有关的基本问题。我们的发现可能为预防和抑制人胰岛移植物的免疫排斥反应提供新的免疫疗法的基础。