Abstract: Objective · To study the of transcription factor BTB and CNC homology 2 (Bach2) in CD4+CD25+CD45RA-T cells patients with systemic lupus erythematosus (SLE) and its effect on cell function. Methods · The CD4+CD25+CD45RA-T cells active SLE patients and healthy volunteers were sortedflow cytometry. The of Bach2 in CD4+CD25+CD45RA-T cells was detectedfluorescence 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 cells was compared with that inIL-17-CD4+CD25+CD45RA-T cellsflow cytometry. In Bach2 over system, the of IL-17 in CD4+CD25+CD45RA- T cells was detectedflow cytometry and the concentration of IL-17 in the culture supernants was detectedELISA. Results · The mRNA and protein s of Bach2 in CD4+CD25+CD45RA-T cells 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 (R20.433, P0.001) in patients with SLE. The of Bach2 in IL17+CD4+CD25+CD45RA-T cells was significantly lower than that in IL-17-CD4+CD25+CD45RA-T cells (P0.013). When Bach2 was overexpressed, the percentage of CD4+CD25+CD45RA-T cells SLE patients expressing inflammatory factor IL-17 decreased significantly (P0.032) and the IL-17concentration in cell culture supernatants markedly decreased (P0.008). Conclusion · The of Bach2 in CD4+CD25+CD45RA-T cells SLE patients decreases, and over of Bach2 in the cells leads to the falling of IL-17.

Key words: systemic lupus erythematosus, CD4+CD25+CD45RA-T cell, BTB and CNC homology 2 (Bach2), interleukin-17