5种结核分枝杆菌分泌性蛋白的纯化及血清学特性

The purify and serologic characteristics of 5 types of secretory proteins from mycobacterium tuberculosis

[目的]分离纯化结核分枝杆菌分泌性蛋白30-kDa,38-kDa,ESAT-6,Rv3872,HBHA,并比较此5种蛋白及其3种联合蛋白38-kDa-30-kDa Ag,38-kDa-ESAT-6Ag,38-kDa-HBHA Ag的免疫学特性,并评价在结核血清学诊断中的应用价值.[方法]利用间接酶联免疫吸附试验评价肺结核患者组和健康对照组血清中5种蛋白及3种联合蛋白的抗原性.[结果]成功分离纯化了5种分泌性蛋白;酶联免疫吸附试验结果表明,与其他4种结核分枝杆菌分泌性蛋白比较,38-kDa抗原具有较强的敏感性和特异性,尤其在抗IgM抗体的诱导免疫反应最强(P<0.000 1),敏感性和特异性分别为44.44%和95%,而38-kDa-30-kDa联合抗原的敏感性高达80.00%,并且也具有较高的特异性;ESAT-6抗原和HBHA抗原在与3种抗体的反应中具有相似的敏感性与特异性;Rv3872抗原的敏感性和特异性与其他4种抗原相比均较低.[结论]作为结核分枝杆菌分泌性蛋白单一抗原,38-kDa抗原的免疫原性优于30-kDa,ESAT-6,Rv3872,HBHA,而38-kDa-30-kDa联合抗原有望成为结核血清学新型诊断试剂有效的候选抗原.

OBJECTIVE To isolate and purify 5 types of secretory proteins （30-kDa, 38-kDa, ESAT-6, Rv3872 and HBHA） from M. tuberculosis, and to compare the immunologic characteristics of 5 types of secretory proteins and 3 types of combined proteins （38-kDa-30-kDa Ag, 38-kDa-ESAT-6 Ag, 38-kDa-HBHA Ag）, and to evaluate the applicative value in serological diagnosis. METHODS The antigenicity of 5 types of secretory proteins and 3 types of combined proteins in serum of pulmonary tuberculosis and normal controls were detected by using the indirect enzyme linked immunoabsorbant assay （ELISA）. RESULTS 5 types of secretory proteins were isolated and purified from M. tuberculosis. The sensitivity and specificity of 38-kDa antigen were 44.4% and 95%, respectively, as compared with the other 4 secreted proteins, especially the immune response induced by anti-IgM antibody （P〈0. 000 1） had most stronger, and moreover, the sensitivity of 38-kDa and 30-kDa combined antigen increased to 80.00 % and specificity remained high level as well. The sensitivity and specificity of ESAT-6 antigen was similar to HBHA antigen in responses with 3 types of anti-human antibodies, and the Rv3872 antigen had lower sensitivity and specificity than the other 4 secreted proteins. CONCLUSION As a single antigen of secretory proteins from M. tuberculosis, the immunogenicity of 38-kDa antigen is better than the other antigens of 30-kDa, Rv3872, ESAT-6 and HBHA, and the 38-kDa and 30-kDa combined antigen is promising candidates to novel immunodiagnostic assays for tuberculosis.