The effect of cytokines on promoter activity of human BAFF gene / 中华风湿病学杂志

ABSTRACT

Objective To explore the effect of several cytokines, including interferon-γ, interleukin-10 and interlekin-4, on promoter activity of human BAFF (B-cell activating factor belonging to tumor necrosis factor family) gene. Methods A construct of phBAFF 1.02 containing sequence form -1349 bp to -329 bp of human BAFF gene, linking with chloramphenicol acetyltransferase (CAT) as reporter gene, was transiently transfected into human HL-60 cells, a kind of myeloid tumor cell lines. The cells were subsequently treated with IFN-γ, IL-10 and IL-4, and the CAT activity was assessed 24 hours after stimulation with each cytokines. Results IFN-γ of 5 ng/ml, IL-10 of 100 ng/ml could increase the CAT activity of phBAFF 1.02 to 4.18 and 2.13 folds respectively compared to the control. IL-4 at 100 ng/ml had no effect on promoter activity of human BAFF gene. Combination of IFN-γ, IL-10 and IL-4 could increase the CAT activity of phBAFF 1.02 to 3.41 and 1.58 folds respectively compared with controls. Conclusion IFN-γ and IL-10 can increase the promoter activity of human BAFF gene. IL-4 treatment can not affect the CAT activity driven by BAFF promoter. However, IL-4 can decrease the upregulating effect of IFN-γ and IL-10 on phBAFF1.02. These provide essential evidence for future study on the interaction mechanism of cytokines and BAFF in autoimmune diseases.