Studies On The Change Of The Percent Of CD4⁺CD25⁺CD127^lo/- Regulatory T Cells And Th1/Th2 Cells In Dermatomyositis Patients

Objective To observe the change of the percent of CD4⁺CD25⁺127^lo/- regulatory T cells(Treg)in dermatomyositis(DM)patients.To confirm differentiation of Th1/Th2 on the mRNA levels of transcription factors and cytokines in CD4⁺ T cells of peripheral blood mononuclear cells (PBMC)from DM patients,and to reveal immune mechanism of the pathogenesis in the DM.Methods(1)The percent of CD4⁺CD25⁺127^lo/-T cells in the peripheral blood of DM patients was analyzed by flow cytometry(FCM).(2) CD4⁺ T cells and CD8⁺T cells were isolated from peripheral blood of DM patients and controls group by immunomagnetic beads.The ability of proliferation of CD4⁺ and CD8⁺T cells were deteced by[³H]-TdR incorporation.The expression levels of Th1/Th2 type cytokines(IFN-γand IL-4),transcription factors(T-bet and GATA3)were determined by RT-PCR.Results(1)Compared with health controls,an decrease of the percent of CD4⁺CD25⁺127^lo/-T cells was showed in the peripheral blood of DM patients(3.91%±1.09%vs 2.36%±0.35%,P＜0.01).There was negative correlation between CD4⁺CD25⁺CD127^lo/-T cells and serum CK (r=-0.528,P＜0.05).(2)The ability of proliferation of CD4⁺ T cells of DM patients were significantly increased than those from controls group, however the result of CD8⁺ T cells were opposite(P＜0.05).There was no difference between DM patients and controls group about the expression levels of T-bet(0.389±0.257 vs 0.306±0.222, P＞0.05).The expression levels of IFN-γ,GATA3 and IL-4 of DM patients were higher than controls group(0.680±0.441 vs 0.369±0.205, P＜0.05;0.951±0.137vs 0.717±0.212,P＜0.05;1.018±0.412 vs 0.640±0.237,P＜0.05),respectively.There was no correlation between T-bet and IFN-γ(r=0.485,P＞0.05),IFN-γand serum CK (r=0.213,P＞0.05).But positive correlation between GATA3 and IL-4,IL-4 and serum CK.(r=0.592,P＜0.05;r=0.677,P＜0.01).Conclusions(1)The percent of CD4⁺CD25⁺127^lo/-Treg cells in peripheral blood from DM patients is significantly decreased,which may caused the disorder of immunine system in DM.(2)The CD4⁺T cells of DM patients were activated significantly,and Th1/Th2 cytokines possibly play a important role in the pathogenesis of DM.Neither Th1 nor Th2 clear polarization was found in DM.