目的:探讨结核分枝杆菌融合蛋白Ag85B-Hspl6.3、Ag85B-ESAT6及分泌蛋白Hspl6-3对人肝癌细胞HepG-2的作用。方法:将已构建的含3种目的基因的表达载体pProEXHTa-Ag85B-Hspl6.3、pProEXHTa-Ag85B-ESAT6和pProEXHTb-Hspl6.3,分别转入宿主菌EcoliDH5α中,诱导表达后分别获得Ag85B-Hspl6.3、Ag85B-ESAT6和Hspl6.3三种蛋白,采用Ni^2+亲和层析柱进行纯化,并用透析方法进行目的蛋白的复性。复性的蛋白按照不同浓度和作用时间分别与肝癌细胞HepG-2反应,用MTT法检测细胞生长情况。结果:三种蛋白被成功纯化并复性。MTT数据统计分析显示,终浓度101xg/ml的三种蛋白对HepG-2细胞生长没有明显作用,当三种蛋白的终浓度分别为20、40、801μg/ml时均能够抑制HepG-2细胞的生长,并且抑制作用随着蛋白终浓度的增大以及作用时间的延长而增强。不同类别的蛋白抑制作用没有明显差别。结论:结核分枝杆菌的部分分泌蛋白能够抑制肝癌细胞HepG-2的生长。
To investigate the effect of Ag85B-Hsp16.3, Ag85B-ESAT6 and Hspl6.3 of Mycobacterium tuberculosis (MTB) on HepG-2 in vitro. Methods:The three recombinant plasmids (pProEXHTa-Ag85B-Hsp 16.3, pProEXHTa-Ag85B-ESAT6 and pProEXHTb-Hspl6.3) were transfered into E.coli DH5a respectively. The three proteins were induced by IPTG and purified by Ni-NTA purification system under denaturing condition. Following renaturation by dialysis and filtration, the three proteins were respectively added into HepG-2 cells of various concent ration (101xg/ml,201xg/ml,401μg/ml and 801μg/ml). The cells were incubated for 24h or 48h, and then the inhibition rate was examined by MTT test assay. Results:The proteins were successfully purified and all had a moderate killing effect on Hepg-2 cells. The effect was dependent on the concent ration of the protein as well as the action time.But there was no statistical difference between different proteins. Conclusion: Some of the secreted proteins of Mycobacterium tuberculosis can inhibit cell growth of liver caricer cell HepG-2.