APOPTOSIS:A MEANS OF IMMUNE REGULATION TO TREAT DIABETES

描述(由申请人提供)：这项资助的主要目的是 特异性地诱导自身和同种异体反应淋巴细胞的凋亡 激活内源性caspase。这些淋巴细胞在体内的物理消除 NOD小鼠有望消除糖尿病前期患者的自身免疫过程 并防止患病动物的胰岛移植排斥反应，领导 对糖尿病的预防和治疗。 I型胰岛素依赖型糖尿病是一种慢性自身免疫性疾病 世界范围内影响大量人的疾病。最新进展 了解IDDM发病机制的分子和细胞学基础 医疗实践的改进带来了有效的治疗方法 预防IDDM的方法。尽管医学疗法取得了进步， IDDM仍然是长期发病率和死亡率的主要原因。它是世界上 肾功能衰竭的单一最常见原因需要移植。 全胰腺或纯化的胰岛移植 产生胰岛素的β细胞有望成为一种有效的方法 胰岛素依赖型糖尿病患者的正常血糖。然而，免疫排斥反应限制了长期移植。 生死存亡。诱导胰岛特异性耐受不需要 因此，慢性免疫抑制将带来重大进步。 针对独特的胰岛β细胞抗原的T细胞发挥的作用最大。 在IDDM的胰岛细胞破坏和发展中的关键作用。在这笔赠款中 应用，我们建议在自身反应和同种异体反应中诱导细胞凋亡 IL-2R靶向递送caspase激活分子对淋巴细胞的影响 治疗糖尿病。细胞凋亡是最有效的生理性细胞死亡 调节免疫平衡和对自身抗原的耐受性。失调症 细胞凋亡过程会导致自身免疫，包括糖尿病。半胱氨酸酶是 调节细胞凋亡机制的最重要的分子。半胱氨酸酶 在身体的所有细胞中都合成为非活性的酶原。这个 一个caspase分子的激活足以使细胞死亡。 因为它可以通过转催化激活其他半胱氨酸酶(哺乳动物中的~gt；13)。 一旦激活，caspase就会凌驾于所有的调控过程之上，并将 细胞死亡。由于激活的自身反应T细胞和同种异体反应T细胞 表达高亲和力的IL-2R，我们假设这些细胞可以被靶向 使用IL-2R与半胱氨酸天冬氨酸酶激活蛋白嵌合进行细胞凋亡。物理 消除自体和同种异体反应的T细胞有望导致 糖尿病前期疾病的预防和糖尿病动物的治疗 用同种异体胰岛移植。这种方法可能会有直接的临床应用 作为嵌合蛋白的应用很容易大量产生 使用重组DNA技术。 该方案的具体目标包括：1)构建重组基因 半胱氨酸天冬氨酸酶激活分子编码IL-2嵌合体的研究 自身反应和同种异体反应特异性细胞凋亡的嵌合蛋白 体外淋巴细胞；2)体内检测嵌合蛋白以预防 糖尿病前期NOD小鼠的糖尿病；3)研究嵌合体的能力 诱导人对自身抗原和同种异体抗原耐受的蛋白质 预防同种异体胰岛移植排斥和自身免疫复发。

DESCRIPTION (provided by applicant): The main objective of this grant is to induce apoptosis specifically in auto and alloreactive lymphocytes by activating endogenous caspases. Physical elimination of these lymphocytes in NOD mouse is expected to abrogate the autoimmune process in prediabetic animals and to prevent islet allograft rejection in diseased animals, leading to the prevention and treatment of diabetes. Type I insulin-dependent diabetes mellitus (IDDM) is a chronic autoimmune disorder that affects a large number of people worldwide. Advances in understanding of the molecular and cellular basis of IDDM pathogenesis and improvements in medical practice have resulted in effective therapeutic approaches for the prevention of IDDM. Despite advances in medical therapies, IDDM remains a major cause of long-term morbidity and mortality. It is the single most common cause of renal failure requiring transplantation. Transplantation of whole pancreas or purified islets containing insulin-producing beta-cells promises an efficient approach to achieving euglycemia in IDDM patients. However, immune rejection limits long-term graft survival. Induction of islet-specific tolerance without the requirement for chronic immunosuppression would, therefore, offer a major advancement. T cells, directed at unique pancreatic beta-cell antigens, play the most critical role in islet cell destruction and development of IDDM. In this grant application, we propose to induce apoptosis in autoreactive and alloreactive lymphocytes by IL-2R-targeted delivery of caspase-activating molecules to treat diabetes. Apoptosis is the most potent physiological cell death that regulates immune homeostasis and tolerance to self-antigens. Dysregulation of the apoptotic process leads to autoimmunity, including diabetes. Caspases are the most important molecules that regulate the apoptotic machinery. Caspases are synthesized as inactive proenzymes in all the cells of the body. The activation of one caspase molecule is sufficient to commit the cell to death since it can activate the other caspases (>13 in mammals) by transcatalysis. Once activated, caspases override all the regulatory processes and commit the cell to death. Inasmuch as activated autoreactive and alloreactive T cells express high affinity IL-2R, we hypothesize that these cells can be targeted for apoptosis using IL-2R chimeric with caspase-activating proteins. Physical elimination of auto and alloreactive T cells is expected to result in the prevention of disease in prediabetic and treatment in diabetic animals transplanted with islet allografts. This approach may have direct clinical application as chimeric proteins can easily be generated in large quantities using recombinant DNA technology. The Specific Aims of this proposal include: 1) constructing recombinant genes encoding IL-2 chimeric with caspase-activating molecules and assessing chimeric proteins for specific apoptosis of autoreactive and alloreactive lymphocytes in vitro; 2) testing chimeric proteins in vivo for the prevention of diabetes in prediabetic NOD mice; 3) investigating the ability of chimeric proteins to induce tolerance to autoantigens and alloantigens for the prevention of islet allograft rejection and recurrence of autoimmunity.