RESUMO
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 1×103IFU (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.