PANCREATIC TRANSPLANTATION AND DIABETES MELLITUS

进一步改进我们目前用来分离人类的技术 提出了小岛。 该程序将使用标准酶 消化结合外分泌的化学和机械破坏 从胰腺的致密纤维造口释放胰岛。 我们将产生另外的抗人胰腺癌的单克隆抗体， 腺泡和导管细胞。 这些试剂将用于裂解细胞， 通常污染分离的人类胰岛，以获得高度 纯化的胰岛制剂，可以移植到肝脏， 糖尿病患者。 临床移植试验已经开始， 将扩大。 在狗身上，我们将扩大我们目前的努力， 使用抗Ia单克隆抗体杀死胰岛内的免疫刺激细胞 抗体和新产生的抗树突细胞单克隆抗体。 这些试剂的免疫调节作用以及紫外线 将在淋巴细胞-胰岛中进行体外光照射试验 淋巴细胞增殖试验和胰岛同种异体移植后的体内试验 胰腺切除和自发性糖尿病犬。 一种假定的自身免疫性疾病 为这些同种异体移植建立糖尿病犬模型 问题研究 我们将继续探索胰岛耐受的机制 环孢素诱导的同种异体抗原。 在体外，我们将研究 犬、猪和人的分泌动力学和结构完整性 在组织培养中保持在微囊中的胰岛， 更长时间。 在体内，我们将评估的代谢反应， 微囊化胰岛同种异体移植物和猪异种移植物 胰腺切除和自发性糖尿病犬。 我们亦会研究 是否下调假定的葡萄糖受体，胰岛的质量 移植或移植部位影响长期功能 犬胰岛移植物的存活率。 最后，我们还将定义 携带胰岛Ia的单核细胞/巨噬细胞的相对重要性，树突状细胞 细胞和载Ia的毛细血管内皮细胞对免疫刺激 人体胰岛的影响。 因此，目前的建议将涉及 可能限制胰岛移植应用的潜在问题 即（a）胰岛分离和保存的改善，（B） 通过移植物和/或受体的免疫调节来预防排斥， 或通过从宿主免疫系统中分离同种异体移植的胰岛，和（c） 移植的自体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.