Improving Porcine Islet Function and In Vivo Survival with Lisofylline

描述（由申请人提供）：用于治疗I型糖尿病（T1 D）的包封猪（异种）胰岛移植目前被认为是胰岛移植的下一代产品。组织短缺的问题很容易通过使用猪胰岛来解决，然而，在各种体内模型中损害移植物存活的免疫组分还没有被容易地确定。当在没有免疫抑制剂的情况下将藻酸盐包封的猪胰岛移植到大鼠和非人灵长类动物的腹膜中时，出现了大量的免疫障碍。我们在MicroIslet，Inc.正在积极研究与早期排斥有关的免疫学事件。有趣的是，我们在灵长类动物中的工作表明，短暂使用常规T细胞特异性免疫抑制剂如FK 506和雷帕霉素可延长移植物存活时间，并使胰岛素需求减少50-60%。在我们优化长期移植物功能的努力中，我们计划研究一种合成的、非致糖尿病的、抗炎的甲基黄嘌呤分子，称为异茶碱（LSF），是否会在体内对包封的猪胰岛移植物的存活提供显著的有益作用。 IL-12信号通路通过称为“信号转导子和转录激活子4”（STAT 4）的主基因开关，对于介导免疫反应的早期阶段以及自身免疫性疾病至关重要。STAT 4的激活导致产生高度促炎细胞因子的基因的转录。LSF是参与阻断STAT 4的IL-12受体依赖性活化的小分子。体内和体外研究均表明，LSF可以保护胰岛免受细胞因子诱导的凋亡，并增强功能。用LSF预处理胰岛可减少糖尿病动物达到正常血糖所需的移植物尺寸。在自身免疫性疾病方面，STAT 4缺陷型非肥胖糖尿病（NOD）小鼠不发展自发性糖尿病。LSF的短期全身给药阻断（糖尿病）NOD的疾病发作和疾病进展。我们有兴趣在体内探索LSF对包封的猪胰岛的功能增强、细胞保护和免疫调节作用，如以下三个具体目标所述。将使用自发性糖尿病NOD小鼠来比较对具有和不具有LSF的藻酸盐包封的猪胰岛的植入的免疫应答。将评估LSF的3种不同应用对降低早期体内免疫应答的有效性。公共卫生相关性：MicroIslet，Inc有兴趣探索LSF的瞬时利用或LSF与肠促胰岛素模拟物（如exendin 4）的组合在我们的工艺中可能增强我们的产品（包封猪胰岛）的性能，并证明延长移植物功能和存活期，以实现I型糖尿病的最佳治疗。

DESCRIPTION (provided by applicant): Encapsulated porcine (xeno) islet transplantation for the treatment of Type I Diabetes (T1D) is currently considered to be the next generation product for islet transplantation. The issue of tissue shortage is easily addressed by the use of porcine islets, however the immune component that compromises graft survival in various in vivo models has not been readily defined. A significant number of immunological obstacles arise when transplanting alginate encapsulated porcine islets into the peritoneum of rats and non-human primates in the absence of immunosuppressants. We at MicroIslet, Inc. are actively studying the immunological events involved in the early rejection. Interestingly, our work in primates indicates that transient use of conventional T-cell specific immunosuppressants such as FK506 and Rapamycin confers prolonged graft survival and a 50-60% reduction in insulin requirements. In our effort to optimize long-term graft function we plan to study whether a synthetic, non-diabetogenic, anti- inflammatory methyl-xanthine molecule, termed lisofylline (LSF), will provide a significant beneficial effect in vivo, on the survival of encapsulated porcine islet transplantation. IL-12 signaling path via the master gene switch termed "signal transducers and activators of transcription 4" (STAT 4) is critical for mediating early phases of immune reaction as well as autoimmune diseases. The activation of STAT 4 results in the transcription of genes that produce highly pro-inflammatory cytokines. LSF is a small molecule that participates in blocking IL-12 receptor dependent activation of STAT 4. It has been demonstrated both in vivo and in vitro studies that LSF can protect islets from cytokine induced apoptosis as well as enhance function. Pretreatment of islets with LSF reduces the graft size necessary to achieve normoglycemia in diabetic animals. In terms of autoimmune disorders, STAT 4 deficient non-obese diabetic (NOD) mice do not develop spontaneous diabetes. Short term systemic administration of LSF blocks disease onset and disease progression in (diabetic) NODs. We are interested in exploring the function enhancing, cytoprotective and immunomodulatory effects of LSF on encapsulated porcine islets in vivo as described in the following three Specific Aims. Spontaneously diabetic NOD mice will be used to compare the immunological response to implantation of alginate encapsulated porcine islets with and without LSF. The effectiveness of 3 different applications of LSF on the reduction of the early in vivo immune response will be assessed. PUBLIC HEALTH RELEVANCE: MicroIslet, Inc is interested in exploring the transient utilization of LSF or the combination of LSF and an incretin mimetic such as exendin 4 in our process may enhance the performance of our product, encapsulated porcine islets, and demonstrate prolonged graft function and survival for the optimal treatment of type I diabetes.