TLR2、TLR4及MyD88高表达与Cm呼吸道感染肺组织炎症相关

Overexpression of TLR2,TLR4 and MyD88 is associated with inflammation in C3H mice during Chlamydia respiratory infection

目的:探讨沙眼衣原体呼吸道感染过程中C3H/HeN(C3H)小鼠过度炎症反应的机制。方法:C3H与C57BL/6(C57)小鼠鼻腔吸入1×10~3IFU沙眼衣原体小鼠肺炎菌株(Cm),建立沙眼衣原体小鼠肺炎模型,使用RT-PCR检测感染后不同时间点小鼠肺组织Toll样受体TLR2、TLR4及转导蛋白MyD88 mRNA的表达。结果:使用1×10~3IFU的Cm呼吸道感染C3H与C57BL/6(C57)诱导小鼠衣原体肺炎,Cm感染在高易感性的C3H小鼠及低易感的C57小鼠均诱导Toll样受体的表达,但在感染后第7天及第14天,高易感的C3H小鼠肺组织中TLR2和TLR4 mRNA的表达均显著高于C57小鼠,尤其TLR2(P<0.001或P<0.05),进一步研究发现Cm呼吸道感染C3H小鼠肺组织My D88mRNA的表达也显著高于C57小鼠,并在感染后第14天仍维持高表达。结论:Cm呼吸道感染诱导TLR2、TLR4及MyD88在高易感的C3H小鼠肺组织高表达,可能与C3H小鼠肺组织过度炎症反应相关。

Objective： To investigate the mechanism of excessive inflammation in the lung of C3H/HeN（ C3H） mice following Chlamydia muridarum（ Cm） airway infection. Methods： Chlamydial pneumonitis was induced in C3H and C57 BL/6（ C57） mice by intranasal inoculation with 1×10~3 IFU（ inclusion forming unites） of Cm strains. The expression of TLR2,TLR4 and MyD88 mRNA in the lung at different time point post-infection was measured by RT-PCR. Results： Cm infection induced Toll-like receptors expression in two strains of mice. The expression of TLR2 and TLR4 mRNA,especially TLR2 mRNA（ P〈0. 001 or P〈0. 05）,were significantly higher in highly susceptible C3H mice on day 7 and day 14 d post-infection compared with C57 mice. Further studies showed that the expression of My D88 mRNA was also significantly higher in C3H mice on day 7 post-infection,and maintained high expression untill the day14. Conclusion： Cm lung infection induced high level of TLR2,TLR4 and MyD88 mRNA expression in C3H mice,which may associate with excessive inflammation in C3H mice.