肺炎克雷伯菌生物膜对小鼠腹腔巨噬细胞TLRs受体表达的影响

Influence of Klebsiella pneumoniae biofilm on expression of Toll like receptors in mouse peritoneal macrophage

目的研究肺炎克雷伯菌生物膜对小鼠腹腔巨噬细胞TLRs受体表达的影响,探索机体抗生物膜(biofilm,BF)感染免疫的特点。方法将雄性昆明种小鼠40只随机分成2组,一组腹腔植入体外形成肺炎克雷伯菌生物膜的硅胶片,建立留置性医疗装置BF感染模型实验组,另一组植入与实验组同等量的浮游菌作为对照组。实时定量PCR分析2组巨噬细胞TLRs mRNA的表达水平,流式细胞仪检测分析蛋白的表达水平。结果实验生物膜组巨噬细胞TLR2、TLR4 mRNA相对表达量是对照浮游菌组的0.23和0.24倍;实验组TLR2、TLR4蛋白表达率分别是(23.27±2.73)%和(15.83±2.04)%,明显低于对照组的(33.42±3.72)%、(21.75±1.25)%(P<0.05)。结论与浮游菌相比,BF能下调小鼠腹腔巨噬细胞TLR2、TLR4表达,从而影响机体的免疫功能,这可能是BF相对浮游菌更容易逃脱机体免疫防御系统、引起慢性感染的机制之一。

Objective To study the influence of Klebsiella pneumoniae biofilm on the expression of Toll like re- ceptors in mouse peritoneal macrophage. Method Forty Kunming mice were randomly divided into experiment group and control group. The mRNA expression level of TLR2 was detected by real-time polymerase chain reaction and protein expres- sion level was measured by FACS Calibur. Result The relative expression of TLR2 and TLR4 mRNA of macrophage in experiment group were 0.23 fold and 0.24 fold respectively, compared to the control group. The protein expression of experi- ment group decreased significantly compared to the control group （P 〈 O. 05）, Conclusion Compared to bacterioplankton , bacterial biofilm reduced the TLR2 and TLR4 expression levels. This may be one mechanism for bacterial biofilm to escape from host immune defense.