肺炎克雷伯菌生物膜对单核细胞株THP-1 TLR2受体表达的影响

Influence of Klebsiella pneumoniae biofilm on expression of Toll-like receptor 2 in monocytic line THP-1

目的研究肺炎克雷伯菌生物膜对单核细胞株THP-1 TLR2受体表达的影响,探索细菌生物膜逃脱宿主免疫防御的机制。方法以体外建立肺炎克雷伯菌生物膜的合成分泌物处理单核细胞株THP-1作为实验组,以等量浮游细菌的合成分泌物处理单核细胞株THP-1作为对照组。RT-PCR半定量分析THP-1 TLR2 mRNA的表达,流式细胞仪检测分析THP-1 TLR2蛋白的表达。结果实验组THP-1 TLR2 mRNA表达(0.453±0.06)明显低于对照组(4.872±0.36)(P<0.05);实验组TLR2蛋白表达率(8.42%±3.74%)明显低于对照组(12.35%±7.36%)(P<0.05)。结论细菌生物膜与浮游细菌不同的代谢产物能显著下调THP-1 TLR2的表达水平,影响固有免疫进而影响适应性免疫,可能是生物膜细菌逃脱机体免疫防御系统的又一机制。

Objective To study influence of bacterial biofilm on expression of Toll-like receptor 2 in monocytic line THP-1. Method Biofilm of Klebsiella pneumoniae was prepared in vitro. The supernatants of bacterial biofilm and bacterioplankton culture were incubated with THP-1. The mRNA expression level of TLR2 was detected by reverse transcription-polymerase chain reaction and protein expression level was measured by FACS Calibur. Result The TLR2 expression levels of THP-1 in experiment group decreased significantly in regard to both mRNA and protein, compared to those of control group （P 〈 0.05 ）. Conclusion Bacterial biofilm reduced the TLR2 expression level. This may be one mechanism for bacterial biofilm to escape from host immune defense.