ABSTRACT
Objective·To study the expression of transcription factor BTB and CNC homology 2 (Bach2) in CD4+CD25+CD45RA-T ceils from patients with systemic lupus erythematosus (SLE) and its effect on cell function.Methods·The CD4+CD25+CD45RA T cells from active SLE patients and healthy volunteers were sorted by flow cytometry.The expression of Bach2 in CD4+CD25+CD45RA T cells was detected by fluorescence quantitative PCR and Western blotting.The correlation between the median flourscence indensity (MFI) of Bach2 in CD4+CD25+CD45RA-T cells and the disease activity index of SLE (SLEDAI) was analyzed.The MFI of Bach2 in IL-17+CD4+CD25+CD45RA-T ceils was compared with that in IL-17-CD4+CD25+CD45RA-T cells by flow cytometry.In Bach2 overexpression system,the expression of IL-17 in CD4+CD25+CD45RA T ceils was detected by flow cytometry and the concentration of IL-17 in the culture supernants was detected by ELISA.Results·The mRNA and protein expressions of Bach2 in CD4+CD25+CD45RA-T cells from SLE patients were significantly lower than those in healthy controls (P＜0.01).There was a significant negative correlation between the MFI of Bach2 and SLEDAI (R2=0.433,P=-0.001) in patients with SLE.The expression of Bach2 in IL-17+CD4+CD25+CD45RA-T cells was significantly lower than that in IL-17-CD4+CD25+CD45RA-T cells (P=-0.013).When Bach2 was overexpressed,the percentage of CD4+CD25+CD45RA-T cells from SLE patients expressing inflammatory factor IL-17 decreased significantly (P=0.032) and the IL-17 concentration in cell culture supernatants markedly decreased (P=0.008).Conclusion·The expression of Bach2 in CD4+CD25+CD45RA-T cells from SLE patients decreases,and overexpression of Bach2 in the cells leads to the falling expression of IL-17.