结核分枝杆菌对人急性白血病单核细胞株THP-1凋亡和死亡水平的影响

Influences of Mycobacterium Tuberculosis on the Levels of Human Acute Monocytic Leukemia Cell Line THP-1 Apoptosis and Death

目的通过对不同毒力的结核分枝杆菌感染细胞后的细胞凋亡和死亡程度的检测,以期发现结核分枝杆菌和细胞相互作用的新的方向和观点,以及对结核病免疫学发病机制的新认识。方法选用不同毒力的结核分枝杆菌H37Ra、H37Rv及北京基因型敏感菌株(BJTB)分别感染人的巨噬细胞THP-1细胞株,模拟细胞体外感染的过程。以流式细胞仪检测细胞凋亡水平,免疫荧光检测细胞的凋亡蛋白的分布,末端脱氧核糖核酸转移酶介导的dUTP缺口末端标记染色检测细胞晚期凋亡的变化,台盼兰染色检测细胞死亡水平的变化。结果H37Ra引起THP-1细胞的凋亡水平最高,H37Rv次之,BJTB引起的凋亡水平最低。BJTB引起的死亡水平最高,H37Rv次之,H37Ra最低。结论毒力不同的结核分枝杆菌刺激细胞后和细胞的相互作用不同,毒力越高引起的凋亡水平越低,毒力越低引起的凋亡水平越高;对死亡水平的影响是毒力越高的结核分枝杆菌引起的死亡水平越高,毒力越低引起的死亡水平越低。

Objective To explore the influences of Mycobacterium tuberculosis on the levels of human acute monocytic leukemia cell line THP-1 apoptosis and death. Methods Human acute monocytic leukemia cell line THP-1 were infected with Mycobacterium tuberculosis strains H37Ra, H37Rv, or Beijing genotype （ BJTB）, respectively, to construct the infection models. Cell apoptosis was detected using flow cytometry. The distribution of the apoptotic proteins was detected using immunofluorescent staining assays. The cells late apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining assays. The change of cell death was determined by Tyrpan blue staining assays. Results THP-1 apoptosis was in- duced by Mycobacterium tuberculosis strains H37Ra, H37Rv, and BJTB. H37Ra strongly induced THP-1 apop- tosis, H37Rv weakly induced THP-1 apoptosis, and BJTB induced THP-1 apoptosis at the lowest level among these three Mycobacterium tuberculosis strains. On the contrary, BJTB strongly induced THP-1 death, H37Rv weakly induced THP-1 death, and H37Ra induced THP-1 death at the lowest level. Conclusions Mycobacterial strains with different virulence induce different levels of apoptosis and death of THP-1 cells. Compared with highly virulent strains, attenuated strains induce more apoptosis and less death.