不同毒力Mtb感染对巨噬细胞凋亡的影响研究

Study on the effects of Mycobacterium tuberculosis with different levels of virulence on macrophage apoptosis

目的建立结核分枝杆菌(Mtb)感染巨噬细胞Ana-1株模型,探讨不同毒力Mtb对巨噬细胞凋亡的影响及相关分子机制,为阐明结核病(TB)的发病机制提供依据。方法用结核分枝杆菌标准减毒株(H37Ra株)和大理临床分离株(D11)分别感染巨噬细胞Ana-1株感染后1、3、6、12及24h用流式细胞技术(FCM)检测各组感染巨噬细胞的凋亡率并分析其变化。实验设空白对照。结果与空白对照组比较,H37Ra组和D11组巨噬细胞Ana-1凋亡率显著升高(P<0.05);H37Ra组在感染1h后Ana-1细胞凋亡率为(14.45±2.45)%、3h后(6.79±1.84)%、6h后(4.00±1.67)%均明显高于D11组(P<0.05);H37Ra组和D11组Ana-1细胞凋亡率在感染后1、3、6、12h呈下降趋势(P<0.05),在24h略有升高;空白对照组Ana-1细胞凋亡率在1h为(3.50±0.87)%,而在3、6、12、24h时的细胞凋亡率差异无统计学意义(P>0.05)。结论不同毒力的Mtb感染巨噬细胞后诱导不同程度的细胞凋亡,凋亡率与菌株毒力呈负相关。

Objective To create a model of Mycobacterium tuberculosis infection in macrophages to study the effects of Mycobacterium tuberculosis with different levels of virulence on the apoptosis of macrophages and the molecular mechanism of those effects in order to determine the pathogenesis of tuberculosis（TB） Methods The ANA-1 macrophage cell line was infected with the standard attenuated strain of Mycobacterium tuberculosis（H37 Ra strain）and a clinical isolate from Dali（D11 strain）.Uninfected macrophages served as a blank control group.Flow cytometry was used to detect the apoptosis of macrophages 1,3,6,12,and 24 hafter infection. Results The rate of apoptosis was higher in ANA-1 macrophages infected with the H37 Ra strain or the D11 strain compared to that in the blank control group（P 〈0.05）.The rate of apoptosis of ANA-1 macrophages infected with the H37 Ra strain was higher than that in macrophages infected with the D11 strain after 1 h（14.45±2.45%）,3 h（6.79±1.84%）,and 6 h（4.00±1.67%）（P 〈0.05）.The rate of apoptosis of ANA-1 macrophages infected with the H37 Ra strain or the D11 strain decreased significantly after 1,3,6,and 12 h（P〉0.05）,but it increased slightly after 24 h.The rate of apoptosis in the blank control group increased only after 1 h（3.50±0.87%）and the rate of apoptosis did not differ significantly after 3,6,12,or 24 h（P0.05）. Conclusion M.tuberculosis with different levels of virulence caused different levels of apoptosis in infected macrophages,and the rate of apoptosis was inversely correlated with the level of virulence.