类风湿性关节炎新型自身抗原视黄醇结合蛋白1类似蛋白相关分析研究

Research of RBP1 like protein——a novel autoantigen in RA

目的:类风湿性关节炎(RA)是一种全身性自身免疫性疾病,但其发病原因尚不清楚。因此,迫切需要找到诱发此病的相关抗原,但国内外鲜有关于新的自身抗原的报道,本课题组运用克隆技术发现新型自身抗原。方法:从滑膜细胞中提取mRNA,构建c DNA文库,取类风湿性关节炎患者关节滑膜液中的抗体作为探针,筛选c DNA基因库,得到阳性克隆后测序分析,寻找已知相似基因,进而分析蛋白质的构造和Northern印迹杂交(Northern blotting)。结果:发现新型自身抗原c DNA克隆,其与视黄醇结合蛋白1(RBP1)有36.5%的氨基酸序列相同,并发现AT-rich interaction domain,chromo domain,A+T-hook以及TAF homology domain这些特殊的蛋白质构造。因此将其命名为视黄醇结合蛋白1类似蛋白(RBP1 like protein,Rbik)。Rbik RNA不仅表达于滑膜,也表达于心脏、小肠、肌肉等多个器官组织中。结论:此自身抗原的发现可为类风湿性关节炎的实验诊断和治疗提供新的可能指标和靶点。

Objective：Rheumatoid arthritis（RA） is a systemic autoimmune disease, but its etiology is unclear. Therefore, it is urgent to search antigens which is relate to induce this disease, however, there are few reports about the new self-antigens at home and a- broad. In this study, we investigate new autoantigen through cloning. Methods： We used antigens in synovium of patients with rheumatoid arthritis as probe, extracted mRNA from synoviocyte, performed cDNA library immunological screening and sequence, and analyzed the conformation and performed Northern blotting. Results： We found that new autoantigen had 36. 5% homology with retino- blastoma binding protein 1 （ RBP1 ） and it was found that these special protein structure such as AT-rich interaction domain, chromo domain,A＋T-hook and TAF homology domain. Therefore,it will be named RBPl-like Protein（Rbik）. Rbik RNA is not only expressed in the synovial membrane, but also in the heart, small intestine, muscle and other organs. Conclusion： We report that the discovery of the new autoantibodies to RBPl-like Protein（Rbik） may provide a new possible index and target in diagnosis and therapy.