类风湿关节炎抗IgG/CCP双特异自身抗体在中性粒细胞NETosis中的作用研究

Animal model for the production of natural bispecific antibody has been constructed in the previous studies. Further, we successfully identified a kind of natural bispecific autoantibody in rheumatoid arthritis (RA) which could bind both IgG and cyclic citrullinated peptide (CCP), called anti-IgG/CCP bispecific autoantibody. This anti-IgG/CCP bispecific autoantibody is very different from those monospecific autoantibody which may result in distinct biological behavior. NETosis is a unique process of cell death that is characterized by the release of decondensed chromatin and granular contents to the extracellular space, forming neutrophil extracellular traps (NETs). It is indicated that anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF) from RA patients could in vitro induce NETosis, and the NETs may subsequently activate the fibroblast-like synoviocytes to secrete pro-inflammatory cytokines. In this study, we aim to investigate the roles of anti-IgG/CCP bispecific autoantibody in NETosis by means of ELISA, antibody purification, fluorescence microscope, cell culturing, and molecular biological techniques, and to verify the assumption that anti-IgG/CCP bispecific autoantibody can not induce NETosis and may block the pro-inflammatory pathway. Our study will lay foundation for further researches on the significance of natural bispecific antibody, and enrich the research context of NETosis.

本人在前期研究中建立了一种产生天然双特异抗体的动物模型，并在人类风湿关节炎（RA）患者血清中鉴定出了一种称之为抗IgG/CCP的双特异自身抗体。双特异自身抗体与一般所指单特异自身抗体结构上的差异决定了它们生物学行为上的差异。NETosis是中性粒细胞释放颗粒蛋白和染色质形成胞外诱捕网（NETs）的过程。研究表明，RA患者体内抗瓜氨酸蛋白抗体（ACPA）和类风湿因子（RF）可以体外诱导NETosis，其形成的NETs能进一步激活成纤维样滑膜细胞分泌促炎细胞因子。本研究拟采用ELISA、抗体纯化、荧光显微镜、细胞培养及分子生物学等技术，探讨抗IgG/CCP双特异自身抗体在中性粒细胞NETosis中的作用，验证该抗体不能有效诱导NETosis形成并能抑制NETs促炎作用的假设。本研究不仅为更进一步研究天然双特异抗体在疾病中的作用和意义奠定基础，同时还将丰富中性粒细胞NETosis的研究内容。