NOD2^(-/-)小鼠H37Ra感染后对肺组织Toll样受体表达的影响

Effect of H37Ra Infection on the Expression of Toll-like Receptors in the Lungs of NOD2^(-/-)Mice

目的探讨NOD2(nucleotide-binding oligomerization domain 2)基因缺陷(NOD2^(-/-))小鼠感染结核分枝杆菌H37Ra后Toll样受体(toll like receptor,TLR)2、TLR4的变化。方法通过PCR技术鉴定NOD2^(-/-)小鼠和野生型C57BL/6(WT)小鼠,气管滴注分枝杆菌减毒株H37Ra建立肺部感染模型,滴注等量生理盐水(NS)为阴性对照。感染1、8周后,无菌取肺脏。抗酸染色观察模型构建是否成功、HE染色观察小鼠肺部病变程度;利用荧光定量PCR、Western blot技术检测小鼠肺组织中TLR2、TLR4的表达。结果H37Ra感染小鼠1周,NOD2^(-/-)组与WT组小鼠肺组织均出现少量结核分枝杆菌菌体,感染8周,出现结核分枝杆菌聚集成团现象;1周感染组的TLR2和TLR4的基因与蛋白表达与生理盐水组相比,差异均无统计学意义(P均>0.05),8周NOD2^(-/-)与WT感染组TLR2和TLR4的基因与蛋白表达均高于对照组(P均<0.05),NOD2^(-/-)小鼠TLR2和TLR4的基因与蛋白水平高于WT小鼠(P均<0.05)。结论H37Ra感染NOD2^(-/-)小鼠后TLR2、TLR4表达升高。

Objective To investigate the changes of Toll-like receptor(TLR)2 and TLR4 in nucleotide-binding oligomerization domain 2(NOD2)gene-deficient(NOD2^(-/-))mice infected with mycobacterium tuberculosis H37Ra.Methods NOD2^(-/-)mice and wild-type C57BL/6 mice(WT)were identified by PCR technology.Attenuated Mycobacterium H37Ra was injected into trachea to establish an infection model in lungs,and normal saline was the negative control.After 1 week and 8 weeks of infection,the lungs were isolated aseptically.Acid-fast staining was used to observe whether the model was successfully constructed,and HE staining was used to observe the degree of pulmonary lesions in mice.Fluorescence quantitative PCR and Western blot were used to detect the expressions of TLR2 and TLR4 in the lung tissue of mice.Results After 1 week of H37Ra infection,a small amount of Mycobacterium tuberculosis was appeared in the lung tissues of both NOD2^(-/-)and WT mice.After 8 weeks of infection,Mycobacterium tuberculosis aggregation was appeared in the infected group.The expressions of TLR2 and TLR4 at week one showed no statistical difference compared with normal saline group(P all>0.05).The expressions of TLR2 and TLR4 at week 8 in the infected group were significantly higher than those in the control group(P all<0.05).TLR2 and TLR4 in NOD2^(-/-)mice were higher than those in WT mice(P all<0.05).Conclusion Expressions of TLR2 and TLR4 were increased after H37Ra infection with NOD2^(-/-)mice.