在本课题中，我们拟利用电纺丝技术构建携带负性共刺激因子VISTA的人造骨架载具，通过在移植部位定点释放VISTA实现抑制T细胞介导的排斥反应的目的，从而有效保护胰岛移植物免于排斥损伤。人造骨架载具由PGA（聚乙醇酸）和胶原蛋白组成，胰岛细胞在人造骨架内培植后，与肾脏一并植入糖尿病小鼠体内。随着人造骨架在体内的降解，VISTA分子将被释放并作用在移植部位形成免疫抑制环境、抑制CD4+和CD8+ T细胞的免疫学功能。术后我们将追踪检测小鼠的多项生理和免疫学功能指标，包含血糖、胰岛素、血液肌酐酸和尿素氮，从而能够准确评估人造骨架和VISTA在胰岛、肾脏联合移植的糖尿病小鼠中的治疗效果。最后，通过病理切片和流式细胞仪，我们将分析评估胰岛和肾脏组织中的炎症反应程度以及CD4+和CD8+ T细胞的数量和功能。

In this study, we plan to use electrospinning technology to construct artificial scaffold carrying co-inhibitory molecule VISTA, through the site-directed release of VISTA at the transplantation site to achieve the purpose of inhibiting T cell-mediated rejection so as to effectively protect islet transplantation objects from allograft rejection. Artificial scaffold consists of PGA (polyglycolide acid) and collagen. Islet cells cultured in the scaffold, and kidney were implanted into diabetic mice simultaneously. As the artificial scaffold degrades in vivo, VISTA molecules are released and create an immunosuppressive environment at the site of transplantation, inhibiting the immunological function of CD4+ and CD8+ T cells. After the operation, we will trace a number of physiological and immunological function indexes of mice, including blood glucose, insulin, blood creatinine and urea nitrogen, so as we are able to accurately evaluate the effects of the scaffold and VISTA in diabetic mice co-transplanted with islets and kidneys. Finally, we will analyze and assess the degree of inflammatory response and the number and function of CD4+ and CD8+ T cells in islets and kidney tissue by pathology and flow cytometry.