Toll样受体2和4在金黄色葡萄球菌α-毒素诱导人单核-巨噬细胞凋亡过程中的作用

Role of Toll-like receptor 2 and 4 in α-toxin from Staphylococcus aureus-induced apoptosis on human monocytic cells

目的研究金黄色葡萄球菌的α-毒素阳性菌株Wood46、RN6390和金黄色葡萄球菌主要毒力因子α-毒素感染人外周血单核细胞后Toll样受体(TLRs)的表达及细胞凋亡情况。方法用Annexin V/磺化丙啶双染流式细胞仪检测人单核细胞凋亡;反转录-聚合酶链反应(RT-PCR)检测TLRs在信使核糖核酸(mRNA)的表达情况。结果金黄色葡萄球菌α-毒素阳性菌株Wood46、RN6390和α-毒素感染人外周血单核细胞后发生凋亡,TLR2和TLR4在Wood46和RN6390感染后的表达均明显增加(P<0.01),α-毒素感染人单核细胞后,TLR2和TLR4的表达呈时间依赖性升高。结论α-毒素可诱导人单核细胞凋亡,增加TLR2和TLR4的表达,在金黄色葡萄球菌的致病过程中起重要作用。

Objective To investigate the expressions of Toll-like receptors （TLRs） and apoptosis rate in human mono- cytic cells induced by Wood46 and RN6390 or α-toxin from Staphylococcus aureus. Methods The apoptosis rate of human monoeytic cells was detected by Annexin V/propidium iodide flow cytometry. The mRNA expressions of TLRs were detected by reverse transcriotion-polymerase chain reaction （RT-PCR）. Results The apoptosis was found in human monocytic cells induced by Wood46 and RN6390 or α-toxin from Staphylococcus aureus. It was also found that the expressions of TLR2 and TLR4 significantly increased after treatment by Wood46 and RN6390 （ P 〈 0.01 ） , and the expressions of TLR2 and TLR4 increased in a time-dependent manner in human monocytic induced by α-toxin. Conclusion These results suggest that α-toxin could induce apoptosis and increase the expressions of TLR2 and TLR4, and play an important role in the pathogenic process of Staphylococcus aureus.