Changes of CD4+ CD25+ regulatory T cells and Foxp3 mRNA expression in mice with experimental anti-phospholipid syndrome fed with recombinant human β2-glycoprotein 1.

Objective:To observe the quantitative and functional changes of CD4+CD25+ regulatory T cells(CD4+CD25+Treg)in experimental anti-phospholipid syndrome(EAPS)mice fed with recombinant human β2-glycoprotein 1(rhβ2-GP1).Methods:EAPS model was established by immunizing BALB/c mice with rhβ2-GP1.In tolerized groups,EAPS mice were fed with rhβ2-GP1 10 days before immunization.Anti-β2-glycoprotein 1(anti-β2GPI),anticardiolipin(aCL)titers in the sera,rate of the fetal resorptions,activated partial thromboplastin time(aPTT)and platelet counts were assayed after 12 weeks.Percentage of CD4+CD25+Treg in peripheral blood mononuclear cells in mice from each groups were determined by flow cytometry,the expressions levels of Foxp3 mRNA were detected by RT-PCR.Results:In tolerized mice anti-β2GPI and aCL Abs decreased significantly(P0.05),resorption percentage decreased(P0.05),aPTT shortened(P0.05),and platelet counts elevated(P0.05).The expressing levels of Foxp3 mRNA in the tolerized group were higher than those of control group(P0.05)on the fourth,eighth,twelfth weeks after immunization(P0.05),but they began to decrease after twelfth week and there were no significant differences on twentieth weeks between tolerized groups and control group(P0.05).The expressing levels of Foxp3 mRNA in the tolerized group were paralleled to model group on fouth week(P0.05)and the latter began to decrease after eighth week and were lower than those of control group significantly after twelfth week(P0.05).The percentage of CD4+CD25+Treg cells from PBMC in tolerized group were paralleled to those of control group during oral tolerance induction(P0.05).Conclusion:CD4+CD25+Treg cells play roles in the induction of oral tolerance in EAPS.