The Study Of Fas-mediated Foxp3 + CD4 + CD25 + Treg Cell Apoptosis In SLE Patients

BackgroundSystemic lupus erythematosus (SLE) is a autoimmune disease with multi‐organ damaged. Patients'normal self‐tolerance can not maintain because the function of immune regulation was damaged. Many of its normal tissues become target antigens, which resulting in organs and tissues damaged. Foxp3+CD4+CD25+ regulatory T cell is the key part of the peripheral immune tolerance. The excessive apoptosis of these cells is one of pathogenic mechanisms in SLE. Fas/fasL system is one of the most important signal molecules in apoptosis pathways. Foxp3 is the key marker in the detection of CD4+ CD25+ Treg. The expression of Foxp3 on peripheral blood CD4+CD25+ Treg in SLE patients was detected by flow cytometric method. Role of fas apoptosis signal transduction pathway in abnormal apoptosis of Foxp3 + CD4 + CD25 + Treg and disease activity of SLE were analyzed in this study.ObjectivesTo explore the role of fas apoptosis signal transduction pathway in the abnormal apoptosis of Foxp3+CD4+CD25+ Treg in SLE patients.MethodsTwenty‐five patients with active SLE and twenty patients with remission of SLE were included in this study. Twenty normal volunteers were also enrolled as control group. Expression of fas on peripheral blood Foxp3+CD4+CD25+Treg cells were detected by flow cytometric method. The expression rate of Foxp3 on CD4+CD25+T cells was also analyzed.Results1. The expression rate of fas on Foxp3+CD4+CD25+Treg cells in active SLE group was higher than that in the remission group [(23.72±2.35)% VS (14.0±2.07)%. P=0.003], and healthy controls [(23.72±2.35)% VS (10.13±1.21)%, P <0.001]. While there were no statistical differences between the remission patients and healthy controls. The expression of fas on the Foxp3+CD4+ CD25+Treg was positively correlated with the SLEDAI score (r=0.336, P <0.05).2. The expression rate of Foxp3 on CD4+CD25+T cells in active SLE group was significantly lower than that in remission SLE group [(2.83±0.30)% VS (5.38±0.63)%, P=0.008], and healthy controls [(2.83±0.30)% VS (8.12±0.70)%, P <0.001]. Meanwhile the Foxp3 expression on CD4+CD25+T cells of remission group was also lower than that of the control group (P=0.04). The expression of Foxp3 on CD4+CD25+T cells was negatively correlated with the SLEDAI score (r=‐0.581, P <0.001).ConclusionThere is high expression of fas on peripheral blood Foxp3+ CD4+ CD25+ Treg cells in active SLE patients. Abnormal apoptosis of Foxp3+ CD4+ CD25+ Treg mediated by the fas apoptosis signal transduction pathway may be one of the pathogenic mechanisms in SLE.