The Influences of Pre-injection of Donor Apoptotic Cells on Survival of Islet Grafts and Function of T Lymphocytes / 天津医药

ABSTRACT

Objective To study the influence of pre-injection of donor apoptotic cells in the survival of islet grafts and the function of T lymphocytes in the peripheral blood. Methods The donor apoptotic cells and necrotic cells were ob-tained respectively by X-irradiation from electron linear accelerator and a heat-shock procedure (water bath box 56℃, 1 h). The diabetic rats for islet transplantation (n=42) were induced by a single intraperitoneal injection of streptozotocin (STZ), then were randomly divided into four groupsrats were injected by physiological saline group (n=9), normal cells group (n=12), apoptotic donor cell group (n=12) and necrotic donor cell group (n=9). On the seventh day, each group received islet transplantation under the renal capsule. The blood glucose level was detected to reflect the survival of the islets. The periph-eral blood samples of three rats in each group were obtained at different observation times. The proliferative activity of T lym-phocytes was determined by MTT method. The levels of cytokines interferon (IFN)-γ, interleukin (IL)-10 in peripheral blood were measured by Luminex 100 Integrated System, and transforming growth factor (TGF)-β1 by ELISA respectively at 0 d, 1 week, 2 weeks and after rejection. Results The survival time of islets was significantly prolonged by the pre-intervention of apoptotic cells, and the proliferative activity of T lymphocytes stimulated by ConA was inhibited. Meanwhile, the extent of the increased level of IFN-γwas inhibited significantly at 1 week and 2 weeks after transplantation (P<0.05), the levels of IL-10 and TGF-β1 were significantly increased before transplantation, 1 week and 2 weeks after transplantation (P<0.05). Conclusion Our results demonstrated that the pre-treatment of donor apoptotic cells can regulate the recipient’s immune reactive state by inhibiting the proliferative activity of T lymphocytes and changing the levels of cytokines from different sub-sets of T lymphocytes, and finally resulted in the prolonging of the survival of islet grafts.