STRATEGIES FOR LARGE SCALE ISLET REPLACEMENT

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 在本报告期间，我们已经证明，通过使用LEA 29 Y和Chi 220靶向CD 28/CD 80/CD 86和CD 40/CD 154共刺激通路，可以提高恒河猴同种异体移植物的存活率。基于这些结果，我们研究了CTLA 4 Ig和3A 8的作用，它们同样分别抑制CD 28/CD 80/CD 86和CD 40/CD 154途径。该队列中的所有受者均具有即时的同种异体移植物功能，空腹血糖正常化，移植物存活延长，表明基于共刺激阻断的方案继续在胰岛移植中取得成功。 在过渡到使用链脲佐菌素的新糖尿病诱导模型后，实验开始确定胰岛移植的最佳胰岛质量和解剖部位。一只动物将15，000 IE/kg的同种异体胰岛肌内移植到背阔肌和阔肌中，获得中等成功。在本报告期间，由于需要更佳的生物免疫抑制方案，未进行进一步的胰岛质量或解剖部位实验。在寻找更临床相关、毒性更小的方案时，单独使用抗LFA-1 mAb和贝拉西普导致糖尿病立即逆转和胰岛存活367、223、373、73和269天。 这种生物治疗方案有望成为临床相关、可耐受的治疗方案，并有可能转化为临床治疗。此外，我们还进一步研究了3A 8（一种靶向CD 40的非消耗性小鼠单克隆抗体）的使用。在3A 8、巴利昔单抗和西罗莫司覆盖下移植同种异体胰岛的动物具有155、312、208、120、45天的移植物存活，建立了在移植中以非消耗方式阻断CD 40途径的潜力。 未来的计划包括测试重组抗CD 40抗体，以更好地表征胰岛模型和移植中的CD 40阻断，并使用基于抗CD 40的生物方案来建立临床前数据，以转化为临床。

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.