The molecular effects of anti-ds-DNA autoantibody on IL-2 production

• Main Authors: Wen-Chian Hung, 洪文倩
• Other Authors: Kuang-Hui Sun
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/42892351642028210968

碩士 === 國立陽明大學 === 醫學生物技術研究所 === 95 === T cells from patients and mice with systemic lupus erythematosus (SLE) produce decreased amounts of IL-2. IL-2 is essential for both the promotion suppression of the immune response. Decreased amounts of IL-2 would increase infections whereas decrease activation-induced cell death and regulatory T cells, which were considered to be important in the control of the systemic autoimmune response typified in SLE. Anti-dsDNA autoantibodies are not only specific for systemic lupus erythematosus (SLE) but also play an important role in the pathogenesis and activity of this disease. In our previous studies, the anti-DNA monoclonal antibodies (anti- DNA mAb) 9D7 derived from lupus-prone mice have been demonstrated to suppress the promoter activity, IL-2 gene expression ,and protein production in Jurkat T cells. We found that in Jurkat T cells pretreated with 9D7 mAb for 48 h and activated with phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) for 24h, 9D7 mAb inhibited up to 25％ of IL-2 production at 100 μg/ml. However, the IL-2 inhibition could be reversed by treatment with Arginine10 peptide in a dose dependent manner but not with IgG2b. In Jurkat T cells pre-incubated with 9D7 for 24 h then activated with PHA and PMA for 20, 30 and 60 min, the levels of p-AKT and p-GSK3 a/b were reduced, whereas the level of phospho-ERK was significantly increased. Moreover, 9D7 had no effects on the PHA/PMA-induced pCREB expression in total cellular extracts and NFkB, pCREB and CREM expression in nuclear extracts. Furthermore, we demonstrate that the inhibition of IL-2 production by 9D7 mAb can be counteracted if the cells were pretreated with LiCl (GSK3 a/b inhibitor) before co-cultured with 9D7 mAb and activation. However, no significant differences in the level of IL-2 were observed in the cells pre-treated with MAPK, PI3K, or NFkB inhibitors. After transfecting luciferase reporter construct, we incubated Jurkat T cells with 9D7 for 24h followed by activation with PHA/PMA for 48 h. Our data showed 9D7 suppressed the activity of the IL-2 promoter and CRE reporter. These findings suggest that anti-dsDNA autoantibodies may inhibit IL-2 secretion by decreasing T cell p-AKT, and p-GSK3 a/b activities as well as DNA binding affinity of CREB, in turn, decreasing transcription of IL-2 gene. Anti-dsDNA antibodies occur in 50-70% of patients with SLE and are almost specific for this disease. We demonstrated that GSK3 may play an important role in Jurkat T cell treated with Anti-dsDNA antibodies. Moreover, GSK3 may become a new therapeutictarget of SLE.