Establishing the single chain antibody-transgenic mice to study the role of autoantibody in lupus

• Main Authors: Yih-Horng Chen, 陳昱宏
• Other Authors: Kuang-Hui Sun
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/88801794065391536455

碩士 === 國立陽明大學 === 醫學生物技術暨檢驗學系暨研究所 === 97 === Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organ systems in association with a spectrum of autoantibodies against numerous nuclear antigens. In addition, SLE is usually accompanied by the bacterial infections. Lipopolysaccharide (LPS) derived from bacteria can accelerate and exacerbate lupus nephritis. In previous studies, we have found the 9D7 monoclonal anti-dsDNA autoantibody (9D7 mAb) derived from lupus-prone mice and established 9D7 single chain variable fragment (scFv) transgenic mice in FVB. The levels of antinuclear antibodies (ANA), anti-dsDNA antibodies, proteinuria, and blood urea nitrogen (BUN) were significantly higher in LPS-injected one-year-old 9D7 transgenic mice than nontransgenic mice. Moreover, there was IgG immune complexes deposition and IL-10 accumulation in the kidney of 9D7 transgenic mice. In addition, the survival rate was also observed to decrease in LPS-injected 9D7 transgenic mice. In order to estimate potential role of autoantibodies in the pathogenesis of SLE, we generated transgenic mice expression of 9D7-scFv in C57BL/6 and investigated the young LPS-stimulated 9D7 transgenic mice to analyze the autoantibodies response and cytokine profiles. 9D7 transgenic mice at 8 weeks of age were intraperitoneal administered LPS twice weekly. We found that levels of anti-dsDNA Abs and proteinuria were significantly higher in LPS-injected 9D7 transgenic mice than the nontransgenic mice. Furthermore, LPS-stimulated splenocytes and bone marrow-derived dendritic cells (DCs) from 9D7 transgenic mice secreted more IL-6 and IL-10. To ascertain whether bacteria infection by which LPS accelerates lupus, we injected MRLlpr/lpr mice with LPS antagonist (LPS-RS) to block Toll-like receotor 4 (TLR4) activation. After injection with LPS-RS, skin lesions and lymphadenopathy were attenuated and proteinuria was also reduced in MRLlpr/lpr mice. The peritoneal B1a cell numbers were slightly increased. The splenic B cells and DCs were slightly decreased but the Treg number was increased. In lymph nodes, B cell numbers were slightly decreased but Treg and DCs increased. These results suggest that young mice not easily break self-tolerance. Moreover, bacteria infection may play an important role in the pathogenesis of SLE and inhibition of TLR4 may be a therapeutic target.