PANCREATIC TRANSPLANTATION AND DIABETES MELLITUS

对我们目前用于分离人类的技术的进一步改进 提出了小岛的建议。该程序将使用标准的酶 消化结合外分泌的化学和机械干扰 将胰岛从胰腺的致密纤维状气孔中解放出来。 我们将产生更多的抗人胰腺的单抗 腺泡细胞和导管细胞。这些试剂将被用来溶解那些 一般污染孤立的人类胰岛，以获得高度 纯化的胰岛制剂可以移植到小鼠的肝脏中 IDDM患者。已经启动的临床移植试验， 将会被扩展。在狗身上，我们将扩大目前的努力，以削弱或 用抗Ia单抗杀伤胰岛内免疫刺激细胞 抗体和新产生的抗树突状细胞单抗。 这些试剂和紫外线的免疫调节作用 光照射将在体外对淋巴细胞-胰岛进行测试 同种异体胰岛移植后的淋巴组织增殖检测及体内观察 胰腺切除和自发性糖尿病的狗。一种假定的自身免疫性 为这些同种异体移植建立犬糖尿病模型 学习。我们将继续探索对胰岛的耐受机制 环孢素诱导的犬同种异体抗原。在体外，我们将研究 犬、猪和人的分泌动力学和结构完整性 在组织培养中保存在微囊中的胰岛 很长一段时间。在体内，我们将评估药物的代谢反应。 微囊化同种异体胰岛移植和异种猪胰岛移植 胰腺切除和自发性糖尿病的狗。我们还将检查 是否下调可能的糖受体，胰岛的质量 移植，或移植部位影响长期功能 同种异体胰岛移植在犬体内的存活。最后，我们还将定义 胰岛Ia单核/巨噬细胞、树突状细胞的相对重要性 细胞和含Ia的毛细血管内皮细胞对免疫刺激的影响 人类胰岛的影响。因此，目前的提案将涉及 可能限制胰岛移植应用的潜在问题 在人类身上，即(A)改善胰岛的分离和保存，(B) 通过移植物和/或受体的免疫调节来防止排斥反应， 或通过将同种异体胰岛从宿主免疫系统中分离出来，以及(C) 移植后自身免疫过程复发的可能性 小岛。

Further refinements in the technique we currently use to isolate human islets are proposed. The procedure will utilize standard enzymatic digestion combined with chemical and mechanical disruption of the exocrine pancreas to liberate islets from the dense fibrous stoma of the pancreas. We will generate additional monoclonal antibodies against human pancreatic acinar and ductal cells. These reagents will be used to lyse cells that generally contaminate isolated human islets, in order to obtain highly purified islet preparations that can be transplanted into the liver of patients with IDDM. Clinical transplantation trials, already initiated, will be expanded. In dogs we will expand our current effort to impair or kill the immunostimulatory cells within islets using anti-Ia monoclonal antibodies and newly generated anti-dendritic cell monoclonal antibodies. The immunomodulatory effects of these reagents as well as ultra-violet light irradiation will be tested in vitro in lymphocyte-islet lymphoproliferative assays and in vivo following islet allografting in pancreatectomized and spontaneously diabetic dogs. A putative autoimmune canine model of diabetes will be developed for these allotransplantation studies. We will continue to explore the mechanism of tolerance to islet alloantigens induced by cyclosporine in dogs. In vitro, we will study secretory kinetics and structural integrity of canine, porcine, and human islets that have been maintained in microcapsules in tissue culture for long periods of time. In vivo we will evaluate the metabolic responses of microencapsulated islet allografts and porcine xenografts in pancreatectomized and spontaneously diabetic dogs. We will also examine whether down-regulation of putative glucoreceptors, the mass of islet transplanted, or the site of transplantation influence long term functional survival of islet allografts in dogs. Finally, we will also define the relative importance of islet Ia-bearing monocytes/macrophages, dendritic cells, and Ia-bearing capillary endothelium on the immunostimulatory effects of human islets. Thus, the current proposal will address the potential problems that may limit the application of islet transplantation in humans namely (a) improvement in islet isolation and preservation, (b) prevention of rejection by immunomodulation of the graft and/or recipient, or by isolation of allografted islets from the host immune system, and (c) the possibility of recurrence of the autoimmune process in transplanted islets.