Expression Levels Of Myeloid-derived Suppressor Cells And Regulatory B Cells In Renal Transplant Recipients Under Different Immune States

ObjectiveTo explore the changes of myeloid-derived suppressor cells?MDSCs?and regulatory B cells in renal transplant recipients under different immune states and to analyze the correlation between those cells,so as to assess their roles under different immune states in renal transplantation.Methods1.To collect the peripheral blood of the 30 recipients undergoing renal transplantation in our hospital from October 2016 to May 2017,at the 1st day before surgery and 1st day,7th day,14th day,30th day,and 90th day after surgery.Flow cytometry was used to detect the dynamic changes of MDSCs and regulatory B cells;2.Flow cytometry was used to compare the levels of MDSCs and regulatory B cells in peripheral blood of stable graft function group,pathogen infection group and acute rejection group after renal transplantation;3.The correlation between MDSC and regulatory B cells was analyzed under different immune conditions in renal transplantation.Results1.The levels of MDSCs,Mo-MDSCs,and G-MDSCs cells in peripheral blood of renal transplant recipients showed the similiar changes:Regarding the levels at 1st day before transplantation?2.02%±1.90%,0.39%±0.30%,1.63%±1.48%?as the baseline,the percentage of all cell groups rose to the peak?6.76%±4.85%,1.21%±0.85%,5.55%±3.01%?on the 1st day postoperative,which was statistically higher than the preoperative level?P<0.001?;From 1st to 30th day after surgery,the cell level showed a downward trend,and the proportions of each cell subpopulation?2.01%±1.84%,0.53%±0.36%,1.49%±1.01%?at 30th day after surgery are similar with the proportions at 1st day before transplantation.Then,the proportions of cells gradually increased from 30th day to 90th day after surgery?2.34%±1.38%,0.68%±0.39%,1.67%±1.01%?,which was higher than those before transplantation,but the difference was not statistically significant?P>0.05?.CD19⁺CD24^hiCD38^hiIL-10⁺B cells and CD19⁺CD24^hiCD27⁺IL-10⁺B cells increased significantly at first day and maintained at high levels to 7th day after renal transplantation?3.74%±2.02%?,?3.01%±1.96%?,significantly higher than the 1st day before surgery?0.48%±0.45%?,?0.54%±0.41%??P<0.001?;the proportions of cells decreased to?0.58%±0.51%?,?0.49%±0.40%?at 30th day after surgery,compared with preoperative levels,there was no statistically different;from 30th day to 90th day after surgery,the proportions of cells gradually increased to?1.31%±1.24%?,?1.41%±1.13%?,higher than those before transplantation,the difference was statistically significant?P<0.05?.2.The levels of Mo-MDSCs and G-MDSCs in the stable graft function group were?0.62%±0.42%?and?1.68%±1.59%?,which were higher than those in the control group?0.34%±0.29%?,?1.45%±1.17%?and in the uremic group?0.39%±0.29%?,?1.52%±1.20?,but the difference was not statistically significant.The level of Mo-MDSCs?1.90%±1.72%?was significantly higher in post-operatively infected patients than in normal people,uremic patients,and stable recipients after transplantation?P<0.05?;patients with acute rejection have lower levels of G-MDSCs?0.47%±0.53%?than recipients with stable graft function.There was a statistically significant difference between the two groups?P<0.05?.At the same time,it was lower than normal and pretransplantation levels,but the difference was not statistically significant.The levels of CD19⁺CD24^hiCD38^hiIL-10⁺B cells?1.31%±1.25%?and CD19⁺CD24^hiCD27⁺IL-10⁺B cells?1.42%±1.40%?in the stable graft function group were significantly higher than the levels in the control group?0.55%±0.59%??0.69%±0.63%??P<0.01?and the uremia group?0.48%±0.74%??0.53%±0.81%??P<0.01?.The proportions of two types of cells in patients with infection?0.62%±1.21%?,?0.64%±0.34%?and acute rejection?0.27%±0.27%?,?0.24%±0.25%?was significantly lower than those of transplantation,and the difference was statistically significant.3.The proportion of MDSC in peripheral blood of the recipients with stable graft function was correlated with the proportion of CD19⁺CD24^hii CD38^hi IL-10⁺B cells and the proportion of CD19⁺CD24^hi CD27⁺IL-10⁺B cells,and the correlation was statistically significant.There was no correlation between peripheral blood MDSC and Breg cells in normal people,patients with uremia,postoperative infection,and acute rejection.Conclusion1.Early amplification and activation of MDSCs protects the body against inflammation,while Breg cells play an important role in inhibiting rejection and regulating immune remodeling.And they together play an immunomodulatory role in the immune balance of the graft.2.Mo-MDSCs mainly play an inhibitory role in the inflammatory response of infected recipients.G-MDSCs mobilization is likely to protect against acute rejection.Breg cells are the main cells that maintain immune balance in immune tolerance.3.In the steady state of graft function,MDSCs may induce the production of Breg cells and assist in the formation of immune balance.MDSCs and Breg cells can serve as important cells for monitoring the immune status of patients after renal transplantation.