Change Of Percentage Of CD4~+ CD25~+ Treg And Foxp3 Expression Level In Unexplained Recurrent Spontaneous Abortion

Objective: To investigate the role of CD4~+CD25~+Treg in unexplained recurrentspontaneous abortion.Methods: An immunological model of abortion was used, in which the mating combinationCBA/J DBA/2J represents the abortion group, using the combination CBA/J BALB/c as anormal pregnancy control. On 14thday of pregnancy, the females were sacrificed. We use FlowCytometry to analyze the percentage of CD4~+CD25~+Treg in spleen cells , extracte proteins fromCD4~+CD25~+T cells, and detect the expression level of Foxp3 by Western Blot, and then calculatethe ratio of abortions (resorption plus normal implantation sites).Results:（1）In spleen, the percentage of CD4~+CD25~+Treg in CD4~+T cells was significantlylower in mice in abortion group compared with those in control group [10.1（9.41～10.69）% vs15.5(14.72～16.28)%（P<0.05)].（2）Embryo resorption in abortion group was significantlyhigher than that in the control group [19.7% 0.88% vs 5.7% 0.15%（P <0.01）].（3）Relativevalue of Foxp3 band density in abortion group is significantly lower than the normal group [0.68±0.025 vs 0.30±0.018,(P <0.05) ].Conclusion:（1）A model of spontaneous abortion was established.（2）In the abortiongroup, there maybe a deficiency in the function of CD4~+CD25~+Treg.（3）Pregnancy outcome ofthe mice is likely be related to the low number and functional defects of CD4~+CD25~+Tregs,and itmay be the key factor.