A Novel Approach to Prevent and Treat Type 1 Diabetes

描述（由申请人提供）： 本基金的主要目的是使用一种具有强凋亡活性的新型Fas配体分子（SA-FasL）和一种独特的方法（ProtExTM），在抗原呈递细胞（APC）或胰岛上快速有效地在蛋白水平展示SA-FasL，作为预防和/或治疗胰岛素依赖型I型糖尿病（T1 D）的免疫调节方法。 T1 D是一种慢性自身免疫性疾病，影响全世界大量人群。全胰腺或纯化胰岛移植有望成为T1 D患者实现血糖正常的有效方法。然而，免疫排斥限制了移植物的长期存活。胰岛细胞破坏主要由针对独特的胰腺β细胞抗原的T细胞介导。在本申请中，我们提出使用SA-FasL诱导致病性自身反应性和同种异体反应性T细胞的凋亡，用于预防和治疗糖尿病。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，也是对自身抗原的耐受性的重要。文献中有证据表明，FasL不仅通过诱导抗原活化淋巴细胞的凋亡而对耐受的诱导很重要，而且通过促进免疫调节淋巴细胞的产生和功能而对耐受的维持也很重要。因此，我们假设用SA-FasL进行免疫调节将有效地消除致病性自身反应性和同种异体反应性淋巴细胞，并诱导维持耐受性的免疫调节机制。 我们最近已经产生了具有有效凋亡活性的FasL分子的修饰形式SA-FasL，并且开发了在短时间段（~ 2小时）内在任何感兴趣的细胞表面上以蛋白质水平展示SA-FasL的新方法。在初步研究中，我们证明SA-FasL也可以有效地展示在胰岛表面上而没有毒性，并且这些胰岛在移植到同基因糖尿病小鼠中后恢复了正常。在本申请中，我们建议使用SA-FasL与ProtExTM技术来预防糖尿病前期NOD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中的糖尿病将通过用SA-FasL作为可溶性蛋白或在用胰岛抗原脉冲的APC上展示的SA-FasL治疗糖尿病前期小鼠来预防。NOD中的糖尿病将通过移植C57 BL/6同种异体胰岛来治疗，所述同种异体胰岛展示SA-FasL，具有或不具有FasL-APC。预期在SA-FasL的背景下对自身/同种异体抗原的识别导致致病性自身/同种异体反应性T细胞的物理/功能消除和维持耐受性的保护性免疫机制的产生。诱导耐受性之后将进行一系列研究，以阐明相关机制。在细胞或组织上快速持久地展示功能性蛋白质为自身免疫、移植和疫苗领域的干预提供了一种全新的手段。这种方法具有简单、安全和有效性，使其成为治疗广谱免疫性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.