自身抗原gp210融合蛋白的重组表达及其临床应用研究

目的 重组表达人核包膜蛋白自身抗原gp210融合蛋白,以用于原发性胆汁性肝硬化（PBC）的临床诊断和病情监测。方法 针对基因库中人gp210的cDNA序列设计引物,从正常人的淋巴细胞中提取RNA,通过反转录PCR方法扩增得到相应的基因片段,经测定序列验证后插入表达载体PET28a（＋）,构建重组表达载体PET28a（＋）-gp210,转化大肠杆菌BL21（DE3）后诱导表达蛋白质,并经SDS-PAGE、Western-blot鉴定重组表达的gp210融合蛋白,进一步经Ni2＋亲合层析柱纯化。应用重组gp210融合蛋白建立间接ELISA,检测PBC患者血清中的抗gp210抗体。结果 经核苷酸序列测定和酶切鉴定结果表明,成功地构建了PET28a（＋）-gp210重组质粒。经SDS-PAGE、Western-blot鉴定,获得了具有免疫原性的重组gp210融合蛋白。经ELISA检测,PBC患者中抗gp210抗体的阳性率为40.5%,与疾病对照组及正常对照组比较有显著性差异（P〈0.05）。PBC患者临床资料分析表明,抗gp210阳性患者中IgM浓度显著高于抗gp210阴性患者;经UDCA治疗后,28位PBC患者中,3例抗gp210抗体由阳性转为阴性,9例抗gp210抗体持续阳性,1例抗gp210抗体由阴性转为阳性,16例抗gp210抗体持续阴性;其他临床症状与抗gp210抗体无显著相关。结论 应用重组gp210融合蛋白建立ELISA检测自身抗体,对PBC诊断具有较好的特异性,为PBC的临床诊断和病情监测提供了有力依据。

The recombinant Expression and clinlcal application of Autoantigen gp210

Objective To express gp210 recombinant fusion protein in E.coli and apply to clinical assay.Methods The cDNA encoding gp210 was obtained by RT-PCR,confirmed by DNA sequencing,subcloned into the bacterial expression plasmid pET28a(+) and then transformed into E.coil.BL21(DE3) to express the recombinant fusion protein induced by IPTG.ELISA was established to detected anti-gp210 antibody in PBC patients.Results The recombinant fusion protein was 69kDa as expected and exhibited the antigenicity of gp210 by Western-blot.The positive ratio of anti-gp210 antibody in PBC was 40.5%.The concentrations of IgM in patients with anti-gp210 antibody were significantly higher than patients without anti-gp210 antibody.Conclusion The recombinant gp210 fusion protein could be used for monitoring the course of Primary biliary cirrhosis.