腺病毒55型抗原表位分析及评价

目的:筛选腺病毒55型(Ad55)抗原表位,为研制腺病毒免疫诊断试剂提供基础。方法:采用生物信息学方法预测Ad55六邻体、纤突的B细胞抗原表位;利用大肠杆菌优势密码子获得相应基因,插入载体pBVIL-1克隆表达后获得重组Ad55表位抗原;用临床疑似腺病毒呼吸道感染患者血清对重组Ad55表位抗原活性进行检测,用ROC曲线分析重组Ad55抗原的诊断意义;采用ClustalX软件进行多序列比较。结果:Ad55六邻体含有6个主要抗原表位,纤突含有2个主要抗原表位;采用退火延伸法获得上述8种表位基因,片段长度为90~180 bp;获得上述8种重组基因工程抗原,相对分子质量为18×103~21×103;血清学检测的ROC曲线分析显示,270~320、410~460和135~165氨基酸残基抗原表位的AUC面积超过0.75,具有一定的诊断意义(P0.05);序列比较结果显示,上述3种抗原表位与腺病毒11型序列高度同源,与3型存在较大差异。结论:获得了3个Ad55主要抗原,对研制通用性呼吸道传播腺病毒免疫诊断试剂具有一定的意义。

Characterization of the Immunodominant Epitopes of Hexon and Fi- ber Protein from Human Adenovirus Type 55

Objective： To select the immunodominant epitope of adenovirus type 55（Ad55） and make prepara- tions for human adenovirus immunoassay. Methods： Bioinformatic analysis was used to detect immunodominant epit opes of hexon and fiber, and the E.coli preferred codons were used to design the DNA sequences of the selected epitopes. After inserted into the pBVIL-1 vector, the gene of the epitopes were expressed and the recombinant epi topes were purified using ionexchange chromatography. ROC curve was used to evaluate the diagnostic significance of AdS5 antigen and the amino acid sequences of selected epitopes were compared by ClustalX software. Results： Hexon of AdS5 contains six major epitopes and fiber contains two major epitopes. The eight epitope genes were expressed in E.coli by vector pBVIL-1 with respective molecular weight range from 18 to 21 kD. ROC curve anal- ysis showed that the AUC area of three antigens 270-320, 410-460 and 135-165 aa were more than 0.75 with significant diagnosis value（P〈O.05）. Sequence comparisons revealed that the three epitopes had highly homogeneity with adenovirus type 11, and heterogeneity with adenovirus type 3. Conclusion： Three major epitopes of AD55 have been obtained with significant diagnosis value, which is essential to develop immunodiagnostic reagents of ade novirus infection with respiratory symptoms