APOPTOSIS:A MEANS OF IMMUNE REGULATION TO TREAT DIABETES

细胞凋亡：治疗糖尿病的免疫调节手段

基本信息

批准号：
6612650
负责人：
Haval Shirwan
金额：
$ 21.6万
依托单位：
UNIVERSITY OF LOUISVILLE
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-08-15 至 2005-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6612650
关键词：
B lymphocyte T lymphocyte apoptosis autoantigens autoimmunity cysteine endopeptidases cytokine receptors diabetes mellitus therapy gene expression immunoregulation insulin dependent diabetes mellitus interleukin 2 laboratory mouse pancreatic islets tissue mosaicism

项目摘要

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.

描述（由申请人提供）：这笔赠款的主要目的是通过以下方式特异性诱导自身和同种异体淋巴细胞凋亡激活内源性半胱天冬酶。物理消除这些淋巴细胞 NOD 小鼠有望消除糖尿病前期的自身免疫过程动物并防止患病动物的胰岛同种异体移植排斥，导致以预防和治疗糖尿病。 I 型胰岛素依赖型糖尿病（IDDM）是一种慢性自身免疫性疾病影响全世界许多人的疾病。进展了解 IDDM 发病机制的分子和细胞基础医疗实践的改进带来了有效的治疗预防 IDDM 的方法。尽管医学治疗取得了进步， IDDM 仍然是长期发病和死亡的主要原因。它是需要移植的肾衰竭的最常见原因。移植整个胰腺或纯化的胰岛，其中含有产生胰岛素的β细胞有望成为实现这一目标的有效方法 IDDM 患者的血糖正常。然而，免疫排斥限制了长期移植物生存。诱导胰岛特异性耐受，无需因此，慢性免疫抑制将带来重大进步。 T 细胞针对独特的胰腺 β 细胞抗原，发挥着最大的作用在胰岛细胞破坏和 IDDM 发展中起关键作用。在这笔补助金中应用中，我们建议诱导自身反应性和同种反应性细胞凋亡淋巴细胞通过 IL-2R 靶向递送 caspase 激活分子治疗糖尿病。细胞凋亡是最有效的生理性细胞死亡调节免疫稳态和对自身抗原的耐受性。失调细胞凋亡过程会导致自身免疫，包括糖尿病。胱天蛋白酶是调节细胞凋亡机制的最重要的分子。胱天蛋白酶在身体的所有细胞中合成为无活性的酶原。这一个半胱天冬酶分子的激活足以使细胞死亡因为它可以通过反式催化激活其他半胱天冬酶（在哺乳动物中>13）。一旦激活，半胱天冬酶就会凌驾于所有调控过程之上，并提交细胞死亡。由于激活的自身反应性和同种反应性 T 细胞表达高亲和力 IL-2R，我们假设这些细胞可以被靶向使用与 caspase 激活蛋白嵌合的 IL-2R 进行细胞凋亡。身体的消除自身和同种反应性 T 细胞预计会导致糖尿病前期疾病的预防和糖尿病动物的治疗移植胰岛同种异体移植物。该方法可能具有直接的临床意义应用，因为嵌合蛋白可以很容易地大量产生使用重组DNA技术。该提案的具体目标包括：1）构建重组基因编码 IL-2 与 caspase 激活分子的嵌合体并评估用于自身反应性和同种反应性特异性细胞凋亡的嵌合蛋白体外淋巴细胞； 2) 体内测试嵌合蛋白以进行预防糖尿病前期 NOD 小鼠的糖尿病； 3）研究嵌合能力诱导对自身抗原和同种异体抗原耐受的蛋白质预防胰岛同种异体移植排斥和自身免疫复发。