MIP-1α和MCP-1在沙眼衣原体肺感染中的产生及与机体防御的关系

Production of MIP-1α and MCP-1 chemotactic cytokines following Chlamydia trachomatis lung infection and its relationship with host immune defence

目的 :探讨趋化性细胞因子巨噬细胞炎症蛋白 1(MIP 1α)和单核细胞趋化蛋白 1(MCP 1)在沙眼衣原体肺感染中的产生及与机体防御的关系。方法 :用沙眼衣原体小鼠肺炎株 (MoPn)通过鼻腔感染小鼠 ,酶消化法制备小鼠肺组织炎症细胞 ,Wright Giemsa染色计数巨噬细胞占肺炎症细胞的百分率 ;用RT PCR检测小鼠肺组织趋化性细胞因子及细胞因子mRNA表达 ;ELISA法检测肺组织匀浆中细胞因子分泌。结果 :MoPn感染后 7及 14天 ,MIP 1α和MCP 1及其相应的受体CCR1、CCR2在小鼠肺组织中的表达明显增高。与之趋化作用有关的单核 巨噬细胞在肺组织中的浸润也随之增高 ;而且MoPn感染上调Th1细胞因子IFN γ及IL 12的表达及分泌 ,未见Th2细胞因子IL 4在肺组织中的基因表达及分泌 ;但具有免疫抑制作用的Th2细胞因子IL 10在感染后 7天明显表达。结论 :衣原体呼吸道感染诱导CC趋化性细胞因子MIP 1α和MCP 1高表达 ,可能与单核细胞免疫防御及Th1/Th2免疫应答调节有关。

Objective:To investigate the production of MIP-1α and MCP-1 chemotactic cytokines followingChlamydia trachomatislung infection in mice and its relationship with host immune defence.Methods:A muring model of pneumonia induced by intranasal inoculation with Chlamydia trachomatis mouse pneumonitis(MoPn) biovar was used for this study.Local inflammatory cells were prepared by enzyme digestion of the lung and the infiltration of macrophages was determined by Wright-Giemsa staining.Chemotactic cytokines and cytokines mRNA expression in the lung were assayed by RT-PCR and cytokine protein levels in the lung supernatants were quantiated by ELISA.Results:mRNA expression for MIP-1α(Macrophage inflammatory protein-1α),MCP-1(Monocyte chemoattractant protein-1)and their receptors CCR1/CCR2 were significantly increased in the lungs on day 7 and 14 postinfection.Macrophage infiltration in the lung was also significantly increased in this period.At the same time,MoPn induced up-regulation of Th1 cytokines,IFN-γ and IL-12 in the lungs,but not IL-4.IL-10 mRNA expression was significantly high on day 7 postinfection.Conclusion: Chamydia trachomatisinduce local MIP-1α and MCP-1 mRNAs expression,which may contribute to monocyte-dependent host defence and T cell-mediated immuno regulation.