Objective: Myeloid-derived suppressor cells (MDSCs) play an important role in immune tolerance.The aim of this study is to investigate different feature of MDSCs in the long-term survival with kidney transplant recipients.
Methods: From January 1989 to November 2008, a total number of 35 Recipients operated in kidney transplantation department of the first affiliated hospital of Xi’an Jiaotong university, were selected. They all had stable kidney function now. Recipients were divided into 4 Four three groups: Aza +Pred (n=5; Tacrolimus inhibitors group (FK506 + MMF + Pred) (n=10; Cyclosporine inhibitors group (CsA + MMF + Pred) (n=10); rapamycin group (RAPA + MMF + Pred) (n=10). The expression of MDSCs in peripheral blood was determined by flow cytometry. The expression of serum HLA-G5 and sCD30 was detected by ELLISA. MDSCs of mice were also induced in vitro, which were also treated with different immunosuppression as above.
Results: The percentage of MDSCs was significantly higher in calcineurin inhibitors group than rapamycin inhibitors group. The level of MDSCs between Cyclosporine group and tacrolimus group was no significant difference. Rapamycin significantly reduces the immunosuppressive function of MDSCs on T cells compared with CNI group and reduces the number of MDSCs induced in vitro. No significant difference was observed between Cyclosporine group and tacrolimus group.
Conclusions: 1. Rapamycin inhibits the differentiation and function of MDSCs in vitro and in vivo, which maybe bad for immune tolerance. When select rapamycin as immunosuppression, should be careful in Long-term survival with kidney transplant recipents. 2. MDSCs , HLA-G5, CD30 may act an effective method to evalute immune status of kidney recipents.