MIP-1α及MCP-1在沙眼衣原体肺感染小鼠中的表达及意义

Expression and significance of MIP-1α and MCP-1 in mice with lung infection of chlamydia trachomatis

目的探讨巨噬细胞炎症蛋白-1(MIP-1α)及单核细胞趋化蛋白-1(MCP-1)在沙眼衣原体肺感染小鼠中的表达及意义。方法选取6～8周健康C57BL/6小鼠30只,应用沙眼衣原体小鼠肺炎株通过鼻腔感染小鼠,分别于感染前、感染后7 d和14 d随机处死10只小鼠,采用HE染色观察肺组织,采用Western blot和RT-PCR检测肺组织MIP-1α和MCP-1 mRNA和蛋白表达,采用ELISA法检测肺组织匀浆中IFN-γ和IL-12水平。结果感染后7 d小鼠肺组织单核-巨噬细胞比例明显高于感染前(P <0. 05),感染后10 d小鼠肺组织单核-巨噬细胞比例较感染后7 d有所下降(P <0. 05);感染后7 d小鼠肺组织MIP-1α、MCP-1 mRNA和蛋白相对表达量、IFN-γ和IL-12明显高于感染前(P <0. 05),而感染后10 d小鼠肺组织MIP-1α、MCP-1 mRNA和蛋白相对表达量、IFN-γ和IL-12较感染后7 d有所下降(P <0. 05); MIP-1α、MCP-1 mRNA和蛋白相对表达量与单核-巨噬细胞比例、IFN-γ、IL-12呈正相关(r值分别为0. 402、0. 387、0. 311、0. 304、0. 305、0. 361、0. 391、0. 380、0. 402、0. 376、0. 378、0. 316,P <0. 05)。结论 MIP-1α及MCP-1在沙眼衣原体肺感染小鼠中表达增强,在细胞免疫及Th1/Th2免疫应答中有一定作用。

Objective To investigate the expression and significance of macrophage inflammatory protein-1(MIP-1α)and monocyte chemoattractant protein-1(MCP-1)in mice with chlamydia trachomatis lung infection.Methods Thirty healthy C57BL/6 mice aged 6 to 8 weeks were enrolled in the study,and these mice were infected with Chlamydia trachomatis pneumoniae strain through nasal cavity.Ten mice were randomly sacrificed before infection,at 7 and 14 d after infection respectively,and lung tissues were observed by HE staining.The expressions of MIP-1αand MCP-1 mRNA and proteins in lung tissues were detected by Western blot and RT-PCR.The levels of IFN-γand IL-12 in lung homogenate were detected by ELISA.Results The proportion of mononuclear-macrophage in lung tissue of mice at 7 d after infection was significantly higher than that before infection(P<0.05),which was then decreased at 10 d after infection(P<0.05).The relative expression levels of MIP-1αand MCP-1 mRNA and protein,IFN-γand IL-12 in lung tissues of mice at 7 d after infection were significantly higher than those before infection(P<0.05),which were reduced at 10 d after infection(P<0.05).The relative expression levels of MIP-1αand MCP-1 mRNA and protein were positively correlated with the ratio of mononuclear-macrophage,IFN-γand IL-12(r=0.402,0.387,0.311,0.304,0.305,0.361,0.391,0.380,0.402,0.376,0.378,0.316,respectively,P<0.05).Conclusion The expression levels of MIP-1αand MCP-1 are increased in mice with chlamydia trachomatis lung infection,which plays a certain role in cellular immunity and Th1/Th2 immune response.