Changes of expression of inflammatory cytokine and Toil-like receptor signaling pathway in alveolar epithelial type II cells infected with different virulence of Mycobacterium tuberculosis
LIU Wei-guo, CUI Jun-wei, ZHANG Jing, WANG Yong-liang, LI Zhen-yun
Department of Tuberculosis Internal Medicine, the First Affiliated Hospital of Xinxiang Medical College, Weihui, Henan 453100, China
Abstract：Objective To study the changes of expression of inflammatory cytokine and Toil-like receptors (TLRs) signaling pathway during alveolar epithelial type II cells (AECⅡ) infected with different virulence of Mycobacterium tuberculosis, and to provide a basis for the immunotherapy of Mycobacterium tuberculosis. Methods We established the model of AEC II infected with Mycobacterium tuberculosis H37Rv strains and Bacillus Calmette-Guérin (BCG) strains. 12 hours after infection, real-time fluorescence quantitative PCR and Western-blot were used to detect the expression of TLRs signaling pathway and inflammatory cytokine. Results The relative expression of TLR2 and TLR4 mRAN in the AECⅡ cells infected by H37Rv at 12 hour time point was(1.73±0.35)and (1.87±0.52)respectively, while that of TLR2 and TLR4 mRAN in the AECⅡ cells infected by BCG was (1.18±0.34) and (1.33±0.28) respectively, showing statistically significant differences (both P<0.05). The protein expression levels of IL-6, IL-8 and TNF-a in the AECⅡ cells infected by H37Rv at 12 hour time point were (2.74±0.57), (2.95±0.43) and (5.12±0.71) respectively, while those of IL-6, IL-8 and TNF-a in the AECⅡ cells infected by BCG were(0.73±0.21), (0.87±0.22)and(1.85±0.30)respectively, with statistically significant differences (all P<0.05). There was a positive correlation between the expression of TLR2 and TLR4 mRAN and the protein expression levels of IL-6, IL-8 and TNF-a in the AECⅡ cells infected by H37Rv and BCG at 12 hour time point(P<0.05). Conclusions As compared with weak virulence Mycobacterium tuberculosis BCG infection, strong virulence Mycobacterium tuberculosis H37Rv infection can activate the TLRs signaling pathway of the AECII cells, and then the activated TLRs signaling pathway can promote the secretion of inflammatory cytokines, mediate the inflammation of the body and affect the immune function.
刘卫国, 崔俊伟, 张静, 王永亮, 李振云. AEC Ⅱ细胞不同毒力结核分枝杆菌感染后炎症因子及TLRs信号通路的表达变化[J]. 实用预防医学, 2017, 24(8): 992-995.
LIU Wei-guo, CUI Jun-wei, ZHANG Jing, WANG Yong-liang, LI Zhen-yun. Changes of expression of inflammatory cytokine and Toil-like receptor signaling pathway in alveolar epithelial type II cells infected with different virulence of Mycobacterium tuberculosis. , 2017, 24(8): 992-995.
2017, Vol. 24 
