STRATEGIES FOR LARGE SCALE ISLET REPLACEMENT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 在报告期间，我们已经表明，通过使用LEA29Y和Chi220靶向CD28/CD80/CD86和CD40/CD154共刺激通路，可以延长猕猴的同种异体移植物存活时间。基于这些结果，我们研究了同样抑制CD28/CD80/CD86和CD40/CD154通路的CTLA4Ig和3A8的作用。在这个队列中的所有受者都有立即的同种异体移植功能，空腹血糖正常化，同种异体移植物存活时间延长，这表明基于共刺激阻断的方案在胰岛移植中继续取得成功。 在使用链脲佐菌素过渡到新的糖尿病诱导模型后，实验开始确定胰岛移植的最佳胰岛质量和解剖位置。其中一只动物将15000IE/kg的同种异体胰岛移植到斜方肌和背阔肌中，取得了一定的成功。在本报告期间，由于对更理想的生物免疫抑制方案的渴望，没有进行进一步的胰岛肿块或解剖部位实验。为了寻找一种更具临床相关性、毒性更低的方案，单独使用抗LFA-1单抗和贝拉泰普，可立即逆转糖尿病，并使胰岛存活367、223、373、73和269天。 这种生物疗法有望成为一种临床相关的、可耐受的疗法，有可能转化为临床。此外，我们还进一步研究了3A8的使用，3A8是一种针对CD40的非耗竭鼠单抗。在3A8、巴利昔单抗和西罗莫司的覆盖下移植的同种异体胰岛动物的移植物存活时间分别为155、312、208、120和45天，证实了在移植中以非耗竭的方式阻断CD40途径的可能性。 未来的计划包括在我们的胰岛模型和移植中测试重组抗CD40抗体以更好地表征CD40阻断，以及使用基于抗CD40的生物方案来建立临床前数据以便转化到临床。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. During the reporting period, we have shown that targeting the CD28/CD80/CD86 and CD40/CD154 costimulatory pathways, by using LEA29Y and Chi220, prolongs allograft survival in rhesus macaques. Based on these results, we investigated the effects of CTLA4Ig and 3A8, which likewise inhibit the CD28/CD80/CD86 and CD40/CD154 pathways, respectively. All recipients in this cohort had immediate allograft function with normalization of fasting blood sugars and prolonged allograft survival, showing costimulation blockade-based regimens continue to yield success in islet transplantation. After transitioning to a new diabetes induction model with the use of streptozocin, experiments began to determine the optimal islet mass and anatomic site for islet transplantation. One animal was transplanted with15,000IE/kg of allogeneic islets intramuscularly into the trapezius and latissimus dorsi muscles with moderate success. In this report period, no further islet mass or anatomic site experiments have been done due to the desire for a more optimal biologic immunosuppressive regimen. In search of a more clinically relevant, less toxic regimen, anti-LFA-1 mAb and belatacept alone, resulted in immediate reversal of diabetes and islet survival for 367, 223, 373, 73 and 269 days. This biologic regimen promises to be a clinically relevant, tolerable regimen with potential for translation into the clinic. Additionally, we have further investigated the use of 3A8, a non-depleting mouse monoclonal antibody targeting CD40. Animals transplanted allogeneic islets under cover of 3A8, basiliximab and sirolimus had graft survivals of 155, 312, 208, 120, 45 days, establishing the potential of blocking the CD40 pathway in a non-depleting fashion in transplantation. Future plans include the testing of recombinant anti-CD40 antibodies for better characterization of CD40-blockade in our islet model and transplantation, and using anti-CD40-based biologic regimens to establish preclinical data for translation into the clinic.