TLR2、TLR4 及 MyD88 高表达与 Cm 呼吸道感染肺组织炎症相关

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伊103 IFU 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伊103 IFU 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MyD88mRNA 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。

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

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 C57BL/6(C57) mice by intranasal inoculation with 1’103 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 MyD88 mRNA was also significantly higher in C3H mice on day 7 post-infection,and maintained high expression untill the day 14.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.