组胺对肺上皮细胞Toll样受体表达的上调作用

目的: 观察组胺对肺上皮细胞中Toll样受体(TLR)表达的影响. 方法: 体外培养人肺上皮细胞株A549,用RT-PCR和实时定量PCR检测静息状态或组胺作用下的A549细胞中TLR1～TLR10 mRNA的变化,并用流式细胞术进一步确定组胺对TLR3表达的调节作用. 结果: A549细胞有TLR1～TLR10 mRNA的组成型表达,组胺对TLR3 mRNA和蛋白的上调作用具有时间和剂量依赖性,并且H1受体阻断剂可抑制组胺对TLR3的上调作用. 结论: 组胺可上调肺上皮细胞中TLR3的表达,提示当呼吸道存在变态反应性病变时,增多的组胺可能会增加肺上皮细胞对病毒感染的敏感性.

Up-regulatory effect of histamine on Toll-like receptor expression in pulmonary epithelia cells

AIM: JP3]To investigate the up-regulatory effect of histamine on Toll-like receptor (TLR) expression in pulmonary epithelia cells. METHODS: TLR1-TLR10 mRNA expressions were determined by RT-PCR in resting A549 cells, and by real-time quantitive PCR in the cells following stimulation with histamine at various concentrations and at various periods of time. Furthermore, the up-regulatory effect of histamine on TLR3 was examined by flow cytometry. RESULTS: TLR1-TLR10 mRNA were constitutively expressed in A549 cells. Histamine significantly enhanced TLR3 expression at both mRNA and protein levels in a concentration- and time-dependent manner. This effect of histamine was blocked by the H1 receptor antagonist. CONCLUSION: TLR3 expression can be up-regulated by histamine in A549 cells, which suggests that excessive histamine can enhance the sensitivity of pulmonary epithelium to virus infection when the allergic diseases exist in the respiratory tract.