A Novel Approach to Prevent and Treat Type 1 Diabetes

描述(由申请人提供)： 这项赠款计划的主要目标是使用一种具有强大的凋亡活性的新型Fas配体分子(SA-FasL)和一种名为ProtExTM的独特方法，在抗原提呈细胞(APC)或胰岛上快速有效地在蛋白质水平显示SA-FasL，作为预防和/或治疗胰岛素依赖型I型糖尿病(T1D)的免疫调节方法。 T1D是一种慢性自身免疫性疾病，影响全球大量人群。全胰腺或纯化胰岛移植有望成为治疗T1D患者血糖正常的有效方法。然而，免疫排斥反应限制了移植物的长期存活。胰岛细胞破坏主要是由针对独特的胰岛β细胞抗原的T细胞介导的。在这一应用中，我们建议使用SA-FasL诱导病理性自身反应性和同种异体反应性T细胞凋亡，以预防和治疗糖尿病。FasL诱导的细胞凋亡是激活诱导的细胞死亡的主要机制，负责免疫稳态，也是对自身抗原耐受的重要机制。有文献表明，FasL不仅通过诱导抗原激活的淋巴细胞的凋亡而诱导耐受，而且通过促进免疫调节淋巴细胞的生成和功能而维持耐受。因此，我们假设SA-FasL的免疫调节将有效地消除病理性自身反应和同种异体反应的淋巴细胞，并诱导维持耐受的免疫调节机制。 我们最近开发了一种具有很强的凋亡活性的修饰形式的FasL分子SA-FasL，并开发了一种新的方法，可以在短时间内(-2小时)在任何感兴趣的细胞的表面上在蛋白质水平上展示SA-FasL。在初步研究中，我们证明SA-FasL也可以有效地显示在胰岛表面，并且没有毒性，这些胰岛移植到同基因糖尿病小鼠体内后恢复了正常血糖。在这项应用中，我们建议使用SA-FasL和ProtExTM技术来预防糖尿病前期结节的糖尿病，并使用同种异体胰岛移植治疗糖尿病动物的糖尿病。NOD中的糖尿病可以通过用SA-FasL作为可溶性蛋白或显示在用胰岛抗原冲击的APC来治疗糖尿病前期小鼠来预防。NOD中的糖尿病将通过移植表达SA-FasL的C57BL/6同种异体胰岛来治疗，无论是否有FasL-APC。在SA-FasL的背景下识别自身/同种异体抗原有望导致致病的自身/同种异体反应性T细胞的物理/功能消除，并产生维持耐受的保护性免疫机制。在诱导耐受之后，将进行一系列研究，以描绘其所涉及的机制。在细胞或组织上快速和持久地展示功能蛋白为自身免疫、移植和疫苗领域提供了一种全新的干预手段。这种方法具有所需的简单性、安全性和有效性，使其成为治疗广泛的基于免疫的疾病的基因治疗的临床相关替代方案。

DESCRIPTION (provided by applicant): The primary objective of this grant proposal is to use a novel Fas Ligand molecule (SA-FasL) with potent apoptotic activity and a unique method, designated as ProtExTM, to rapidly and effectively display SA-FasL at the protein level on antigen-presenting cells (APCs) or pancreatic islets as an immunomodulatory approach to prevent and/or treat insulin-dependent Type I diabetes mellitus (T1D). T1D is a chronic autoimmune disorder that affects a large number of people worldwide. Transplantation of whole pancreas or purified islets promises an efficient approach to achieving euglycemia in T1D patients. However, immune rejection limits long-term graft survival. Islet cell destruction is primarily mediated by T cells directed at unique pancreatic beta cell antigens. In this application, we propose to use SA-FasL to induce apoptosis in pathogenic autoreactive and alloreactive T cells for the prevention and treatment of diabetes. FasL-induced apoptosis is the main mechanism of activation-induced cell death responsible for immune homeostasis and is also important for tolerance to self-antigens. There is evidence in the literature suggesting that FasL is not only important for the induction of tolerance by inducing apoptosis in antigen-activated lymphocytes, but also for the maintenance of tolerance by facilitating the generation and function of immunoregulatory lymphocytes. Therefore, we hypothesize that immunomodulation with SA-FasL will effectively eliminate pathogenic autoreactive and alloreactive lvmphocytes and induce immunoregulatory mechanisms that will maintain tolerance. We have recently generated a modified form of FasL molecule, SA-FasL, with potent apoptotic activity and developed a novel approach to display SA-FasL at the protein level on the surface of any cell of interest within a short period of time (-2 hrs). In preliminary studies, we demonstrated that SA-FasL can also be effectively displayed on the surface of pancreatic islets without toxicity and these islets restored euglycemia upon transplantation into syngeneic diabetic mice. In this application, we propose to use SA-FasL with the ProtExTM technology to prevent diabetes in prediabetic NOD and treat diabetes in diabetic animals using allogeneic islet transplantation. Diabetes in NOD will be prevented by the treatment of prediabetic mice with SA-FasL as soluble protein or displayed on APCs pulsed with islet antigens. Diabetes in NOD will be treated by the transplantation ofC57BL/6 allogeneic islets displaying SA-FasL with and without FasL-APCs. The recognition of auto/alloantigens in the context of SA-FasL is expected to result in physical/functional elimination of pathogenic auto/alloreactive T cells and generation of protective immune mechanisms that maintain tolerance. Induction of tolerance will be followed by a series of studies to delineate the implicated mechanisms. Rapid and durable display of functional proteins on cells or tissues offers a whole new means of intervention in the areas of autoimmunity, transplantation, and vaccines. This approach possesses the simplicity, safety, and efficacy required to make it a clinically relevant alternative to gene therapy in the treatment of a broad spectrum of immune-based diseases.