重组结核分枝杆菌38KDa蛋白抗原制备及其血清学诊断价值

目的通过基因工程技术获取纯化的结核分枝杆菌重组38KDa蛋白并评价其血清学诊断价值。方法在大肠杆菌中表达38KDa蛋白，通过亲和层析纯化并复性后用于ELISA检测结核患者血清中特异性抗结核抗体。结果38KDa蛋白表达量占总蛋白的22．80％，以包涵体的形式存在。纯化复性后的蛋白抗原检测54例肺结核患者敏感性为62．96％，其中检测痰涂阳性和痰涂阴性患者的敏感性分别为64.29％和62．50％，二者无显著性差异（X^2=0.02，P〉0．05），检测38KDa抗体特异性为84．38％。另外，通过与结核蛋白芯片检测，结果比较发现研制的重组38KDa蛋白免疫活性与国外进口的蛋白免疫活性相当。结论制备的重组38KDa蛋白抗原具有血清学诊断价值，可用于结核病诊断试剂的开发。

Expression and purification of Mycobacterium tuberculosis 38KDa,and its value as a reagent in serological diagnosis

Objective To obtain he sufficient quantity of recombinant 38KDa protein and evaluate it as a capturing reagent in ELISA. Methods The 38KDa protein was expressed in E. coli and purified it by affinity chromatography. After renatured, the immunogenieity of 38KDa protein was evaluated by ELISA. Results Recombinant 38KDa was about 22.80% of total protein and it existed in inclusion bodies. The sensitivity and specificity of the ELISA assay were 62.96% and 84.38% respectively. The positive rates of anti-38KDa among the smear - positive and the smear - negative TB patients were 64.29% and 62. 50% respectively. There was no significant difference between the two groups （X^2=0.02, P 〉 0.05 ）. In addition, the immune activity of recombinant 38KDa antigen was identical to the imported recombinant protein. Conclusion The recombinant 38KDa protein could be over - expressed inclusion bodies in E. coli. This protein may become an effective antigen in serodiag-nosis of TB and it is quite helpful in developing new specific diagnostic test.