Gao Huiguang, Bian Aina, Zheng Yingru, Li Rongfen, Ji Qing, Huang Gang, Hu Daqiang, Zhang Li, Gong Wei, Hu Ying, He Fengtian
Department of Biochemistry and Molecular Biology, Third Military Medical University, Chongqing 400038, China.
FEBS Lett. 2007 Feb 20;581(4):581-6. doi: 10.1016/j.febslet.2006.12.060. Epub 2007 Jan 17.
B cell activating factor belonging to the TNF family (BAFF) is a novel member of the tumor necrosis factor (TNF) ligand family and plays an important role in B lymphocyte maturation and survival. Overexpression of BAFF is closely involved in the pathogenesis and progression of many kinds of autoimmune disorders; therefore, BAFF has been considered as an ideal therapeutic target for these conditions. In this study, we generated several candidate immune inhibitors of human BAFF by conjugating foreign immunodominant T-helper cell (Th) epitopes to the N- or C-terminus of five BAFF mutants. The recombined proteins were successfully expressed in Escherichia coli (E. coli) and purified by Ni-NTA chromatography. BALB/c mice immunized with the recombinant proteins produced high levels of anti-BAFF antibodies, and their sera inhibited the lymphocyte proliferation-inducing activity of recombinant soluble BAFF and natural soluble BAFF. Moreover, antibodies cross-reactive with BAFF were detected in sera from hu-SCID mice immunized with the recombinant proteins. These results indicated that the recombinant BAFF mutants modified with Th epitopes could induce neutralizing antibodies against BAFF in vivo. This study may provide a valuable strategy for treating BAFF-associated autoimmune diseases.
肿瘤坏死因子家族的B细胞活化因子（BAFF）是肿瘤坏死因子（TNF）配体家族的一个新成员，在B淋巴细胞成熟和存活中起重要作用。BAFF的过表达与多种自身免疫性疾病的发病机制和进展密切相关；因此，BAFF被认为是这些疾病的理想治疗靶点。在本研究中，我们通过将外源免疫显性辅助性T细胞（Th）表位与五个BAFF突变体的N端或C端偶联，生成了几种人BAFF的候选免疫抑制剂。重组蛋白在大肠杆菌中成功表达，并通过镍-亚氨基二乙酸（Ni-NTA）层析纯化。用重组蛋白免疫的BALB/c小鼠产生了高水平的抗BAFF抗体，其血清抑制了重组可溶性BAFF和天然可溶性BAFF的淋巴细胞增殖诱导活性。此外，在用重组蛋白免疫的人源化严重联合免疫缺陷（hu-SCID）小鼠血清中检测到了与BAFF交叉反应的抗体。这些结果表明，用Th表位修饰的重组BAFF突变体可以在体内诱导针对BAFF的中和抗体。本研究可能为治疗与BAFF相关的自身免疫性疾病提供一种有价值的策略。
