p53四价功能域架构抗环瓜氨酸肽小分子抗体(CCP-TeAb)的构建及其拮抗类风湿关节炎自身免疫炎症作用的研究

类风湿关节炎（RA）是以慢性进展性滑膜炎为主要病理改变的自身免疫性疾病。我国患病率0.32-0.38％，有较高致残率死亡率。抗环胍氨酸肽（CCP）抗体不仅是RA诊断的高特异性血清学标志，研究表明其可能在RA的发病机制中也有重要作用。RA遗传易感者在环境因素影响下瓜氨酸化自身抗原，使其空间构象表位发生改变，CCP是关键共同表位，与HLA-DRB1共同表位亲和力增加，递呈给自身免疫性Th17细胞，打破Th17/Treg调控平衡，进而活化B细胞产生抗CCP抗体，产生RA免疫应答环。本研究拟用噬菌体展示技术以p53四聚结构域来改造现有单价噬菌体抗CCP-ScFv抗体，构建四价小分子抗体（CCP-TeAb），以增加单链抗体的分子量和亲和力。由体外、体内试验两个方面来验证CCP-TeAb是否能够作为封闭抗体，阻断抗CCP抗体为介质的RA发病机制环路，抑制自身免疫炎症过程。为在生物制药开发奠定试验基础。

Rheumatoid arthritis(RA) is an autoimmune disease characterized by a pathological feature of chronic and progressive synovitis，affecting 0.32-0.38％of Chinese population with high disability and mortality. Anti-cyclic citrullinated peptide(CCP) antibodies has been suggested to be a specific serologic marker in the diagnosis of RA ,and to play an important role in the pathogenesis. Environmental factors induced the citrullination of self-antigen in the genetic susceptibly. Conformational modified citrullinated epitope increased affinity to HLA-DRB1 shared epitope(SE) and were presented to autoreactive helper T cell 17(Th17), the balance of Th17/Treg cells were broken, and then B cells were active to product anti-CCP antibodies. The RA pathological immune response cycle was formed. This study is aimed to construct a tetravalent miniantibody specifically binding to CCP (CCP-TeAb) on p53 tetramerization to improve the molecular weight and avidity of the single chain antibody by the phagemid display techniques. CCP-TeAb will be analyzed whether or not to act as a blocker of CCP to break the pathogenic RA circle with anti-CCP in vitro and vivo. It is of promise for the development of biological agent to inhibit the autoimmune inflammation of RA.