Expression of transcription factor Bach2 in CD4+CD25+CD45RA- T cells in patients with systemic lupus erythematosus and its effect / 上海交通大学学报（医学版）

ABSTRACT

Objective: To study the expression of transcription factor BTB and CNC homology 2 (Bach2) in CD4+CD25+CD45RA- T cells 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 cells 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 cells 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.