Hydroxamate-based therapy to target T cell homing in IDDM

描述(由申请人提供)：我们的目标是通过使用小分子羟胺酸抑制剂(MMPIs)来阻止胰岛素依赖型糖尿病(I型糖尿病；IDDM)的进展。透明质酸结合的CD44是一种黏附和信号受体。细胞表面相关CD44和膜型1基质金属蛋白酶(MT1-MMPs)之间的相互作用关系对于T杀伤细胞有效的黏附和跨内皮细胞向朗格汉斯胰岛的迁移都是必不可少的。细胞毒性T细胞进入胰岛后，会破坏产生胰岛素的p细胞。我们已经证明，MT1-MMP蛋白降解是动态调节T细胞CD44和随后的胰岛特异性归巢的一个关键因素。抑制剂诱导的MT1-MMP和CD44相互关系的改变干扰了T杀伤细胞对胰腺的黏附、迁移和归巢，并导致NOD小鼠糖尿病的显著延迟。这种啮齿动物模型发展出一种与人类IDDM非常相似的疾病。我们将扩展我们的发现，并开发一种经济高效和可靠的体内策略，通过使用现有的和可用的、无毒的羟基甲酸酯MMPIs来抑制T细胞CD44的MT1-MMP蛋白分解。这些MMPI已经在癌症患者身上进行了测试，证明是无毒的，而且很容易从主要制药公司获得。我们推测，小剂量MMPIs抑制T细胞CD44的MT1-MMP蛋白降解是一种新的、很有希望的方法和改进的IDDM治疗方法。我们的方法是基于我们对MMPs的广泛和深入的了解，特别是我们对MT1-MMPs/CD44相互作用在癌症和糖尿病中的功能作用的理解。作为“原则证明”，我们将测试可用的羟基甲酸酯GM6001和AG3340。作为对照，我们将使用非异羟甲酸酯SB3CT硫醇抑制剂，它对基质金属蛋白酶-2和基质金属蛋白酶-9有效，但对MT1-基质金属蛋白酶无效。我们的具体目标是：(1)确定T细胞CD44的MT1-MMP蛋白分解对IS-CD8*T杀伤细胞黏附和迁移的生理学影响；(2)验证MT1-MMP小分子拮抗剂(羟氨酸盐GM6001和AG3340，以及硫醇化合物SB3CT)在糖尿病过继转移啮齿类动物模型中的药理价值；(3)验证MT1-MMP小分子拮抗剂(羟氨酸盐GM6001和AG3340，以及硫醇化合物SB3CT)在糖尿病前期和新鲜病变小鼠中的药理价值。我们坚信， 我们的实验计划将为IDDM患者开发新的有效的抗糖尿病疗法。

DESCRIPTION (provided by applicant): Our goal is to block the progression of insulin-dependent diabetes mellitus (type I diabetes; IDDM) by using small molecule hydroxamate inhibitors (MMPIs). Hyaluronan-binding CD44 is an adhesion and signaling receptor. The reciprocal relationship between cell surface-associated CD44 and membrane-type 1 matrix metalloproteinase (MT1-MMP) is essential for both efficient adhesion and for transendothelial migration of T killer cells into the islets of Langerhans. After penetration into the islets, cytotoxic T cells cause the destruction of insulin-producing p cells. We have demonstrated that MT1-MMP proteolysis is a key factor in the dynamic regulation of T cell CD44 and the subsequent islet-specific homing of diabetogenic IS-CD8* T killer cells. Inhibitor-induced changes in the reciprocal relationship between MT1-MMP and CD44 interfere with adhesion, transmigration and homing of T killer cells to the pancreas, and cause a significant delay in the onset of diabetes in NOD mice. This rodent model develops a disease closely resembling human IDDM. We will extend our findings and develop a cost-efficient and reliable in vivo strategy to inhibit MT1-MMP proteolysis of T cell CD44 by using existing and available, non-toxic hydroxamate MMPIs. These MMPIs have been tested in cancer patients, proved to be non-toxic and are readily available from major pharmaceutical companies. We hypothesize that the inhibition of MT1-MMP proteolysis of T cell CD44 by low dosages of MMPIs is a novel, highly promising approach and improved therapy of IDDM. Our approach is soundly based on our extensive and in-depth knowledge of MMPs and, especially, on our understanding of the functional role of the MT1-MMP/CD44 interactions in cancer and diabetes. As a "proof-of-principal" we will test the available hydroxamates GM6001 and AG3340. As a control, we will use the non-hydroxamate SB3CT thiol inhibitor that is potent against MMP-2 and MMP-9 but it is not effective against MT1-MMP. Our specific aims are: (1) To determine the physiological impact of the MT1-MMP proteolysis of T cell CD44 on the adhesion and migration of IS-CD8* T killer cells, (2) To validate the pharmacological value of the small molecule antagonists of MT1-MMP (the hydroxamates GM6001 and AG3340, and the thiol compound SB3CT) in a rodent model of adoptive transfer of diabetes, and (3) To validate the pharmacological value of the small molecule antagonists of MT1-MMP (the hydroxamates GM6001 and AG3340, and the thiol compound SB3CT) in pre-diabetic and freshly diseased NOD mice. We strongly believe that the results of our experimental program will lead to the development of new and effective anti-diabetic therapies for IDDM patients.