MGT-30蛋白cDNA克隆与表达及其在诊断胸腺瘤重症肌无力中的意义

cDNA Cloning, Expression of MGT-30 and its Significance in Myasthenia Gravis with Thymoma

通过基因工程合成重症肌无力胸腺瘤特异性 3 0kD抗原 (MGT 3 0 ) ,并研究MGT 3 0在诊断胸腺瘤重症肌无力 (MGT )中的意义。应用逆转录 聚合酶链反应 (RT PCR )技术 ,以MGT患者骨骼肌总RNA为模板 ,扩增出MGT 3 0的cDNA ;并重组到pET 3 0a载体 ;然后用大肠杆菌BL2 1诱导表达MGT 3 0蛋白 ,相对分子质量为 4 4 0 0 0。采用ELISA法检测了 2 65名正常人、2 8例经病理证实为MGT患者和 2 5例非MG其他疾病患者血清中的Titin抗体滴度。正常人与MGT患者血清中Titin抗体滴度有显著性差异 (P <0 0 1) ;2 8例MGT患者中Titin抗体阳性率达 78 6% ,2 5例非MG其它疾病患者中Titin抗体均为阴性。提示重组MGT 3 0蛋白可作为Titin抗体的特异性抗原 。

To clone,express and purify the protein 'myasthenia gravis/thymoma specific 30kD antigen (MGT 30) 'and investigate the clinical significance of MGT 30 in diagnosing MGT The cDNA encoding MGT 30 was amplified from the skeletal muscle of a MGT patient by RT PCR and sequenced The cloned MGT 30 cDNA was ligated into the expression vector pET 30a and MGT 30 peptide was induced via E coli BL21 The purified MGT 30 peptide with molecular weight of about 44 000,was thus obtained Anti Titin antibody was examined in the sera of 265 normal controls,28 MGT patients and 25 non MG disease controls by ELISA The titer of anti Titin antibody in the sera of MGT patients was significantly higher than that of normal controls ( P <0 01) and the positivity of anti Titin antibody was 78 6% in 28 MGT patients All 25 non MG disease controls were negative We concluded that recombinant MGT 30 peptide,which can be used as a specific antigen to detecting Titin antibody,has important significance in diognosing of MGT