中性粒细胞在沙眼衣原体小鼠肺炎易感性差异免疫学机制的研究
发布时间：2018-08-31 12:59
【摘要】： 目的: 用沙眼衣原体小鼠肺炎菌株(Chlamydia trachomatis mouse pneumonitis,CtMoPn)呼吸道感染遗传背景不同的小鼠,在感染的不同时期通过对感染肺组织及外周血中性粒细胞(polymorphonuclear neutrophils,PMN)活性以及与PMN浸润相关的粘附分子、TLR在肺组织中表达的检测,探讨PMN在Ct MoPn呼吸道感染易感性差异中的免疫学机制。 方法: 遗传背景不同的小鼠C57BL/6(C57)和C3H/HeN(C3H)鼻腔吸入3×10~3IFUCt MoPn,建立沙眼衣原体小鼠肺炎模型。通过用肺组织匀浆感染Hep-2细胞,检测衣原体包涵体形成单位(IFU),确定衣原体在肺组织中的生长;对感染后不同时期小鼠体重变化及死亡率的监测及肺组织病理学改变的检测,确定感染小鼠的疾病状态;通过肺组织炎症细胞计数、肺组织髓过氧化物酶(MPO)活性检测,确定PMN在肺组织中的浸润水平;利用RT—PCR技术,检测C57和C3H小鼠肺组织与PMN浸润相关的黏附分子ICAM-1、VCAM-1,选择素P-selectin、L-selectin、E-selectin以及Toll样受体TLR2、TLR4、MyD88 mRNA的表达;分离不同感染时期小鼠外周血及肺组织的PMN,用荧光素标记的抗鼠CD11b单克隆抗体进行染色,用流式细胞仪收获染色细胞,比较Ct MoPn感染不同时期C57和C3H小鼠PMN的活性差异。 结果: 用3×10~3 IFU Ct MoPn经鼻腔吸入建立了小鼠沙眼衣原体呼吸道感染模型,以小鼠体重下降、肺组织衣原体繁殖及大量炎症细胞浸润为特征。C3H和C57小鼠对Ct MoPn呼吸道感染存在明显的易感性差异。与C57小鼠比较,C3H小鼠感染后存在严重的体重降低、较高的死亡率、较长的疾病过程及严重的肺组织病理变化。与正常对照组小鼠相比,Ct MoPn感染在两组小鼠均诱导较高水平的黏附分子、选择素、Toll样受体的产生,诱导大量的PMN在感染小鼠肺组织的浸润。感染后7天及14天,高易感性的C3H小鼠肺组织黏附分子VCAM-1,选择素E-selectin、P-selectin、TLR2、MyD88表达及PMN在感染肺组织的浸润程度均高于C57小鼠。衣原体呼吸道感染,感染小鼠外周血及肺组织PMN活化分子CD11b表达明显升高,感染后第7天C3H小鼠PMN CD11b表达明显高于C57小鼠,感染后14天,C57小鼠PMN CD11b表达高于感染后第7天而C3H小鼠CD11b表达则明显降低。 结论: Ct MoPn鼻腔吸入感染小鼠引起典型的衣原体肺炎。不同种系的小鼠对沙眼衣原体呼吸道感染存在易感性差异,C3H小鼠是Ct MoPn呼吸道感染的易感表型,而C57小鼠是有抵抗的表型。Ct MoPn呼吸道感染在C3H小鼠肺组织诱导高水平的黏附分子及TLR表达,从而使大量PMN在肺组织浸润。而感染后期C3H小鼠肺组织PMN活性降低,不足以吞噬清除病原体,导致C3H小鼠持续的疾病过程及加重的肺组织病理,可能是C3H小鼠对衣原体感染高易感性的主要原因。
[Abstract]:Objective: to study the different genetic background of chlamydia trachomatis (Chlamydia trachomatis mouse pneumonitis,CtMoPn) respiratory tract infection in mice. The activity of neutrophils (polymorphonuclear neutrophils,PMN) in infected lung tissues and peripheral blood and the expression of the adhesion molecule TLR-associated with PMN infiltration in lung tissues were detected at different stages of infection. To investigate the immunological mechanism of PMN in the differential susceptibility to Ct MoPn respiratory tract infection. Methods: the model of chlamydia trachomatis pneumonia was established by nasal inhalation of C57BL/6 (C57) and C3H/HeN (C3H) in mice with different genetic backgrounds. Chlamydia chlamydial inclusion body formation unit (IFU),) was detected to determine the growth of chlamydia in lung tissue by infection of Hep-2 cells with lung tissue homogenate, and the changes of body weight and mortality and pathological changes of lung tissue in mice at different stages after infection were monitored. To determine the disease status of infected mice; to determine the infiltration level of PMN in lung tissue through the count of inflammatory cells in lung tissue and the detection of myeloperoxidase (MPO) activity in lung tissue; and to use RT-PCR technique, To detect the expression of ICAM-1,VCAM-1, selectin, L-selectinin E-selectin and Toll like receptor TLR2,TLR4,MyD88 mRNA in lung tissues of C57 and C3H mice, and to isolate PMN, from peripheral blood and lung tissues of mice at different infection stages by using fluorescein labeled anti-mouse CD11b monoclonal antibody, and to detect the expression of E-selectin and Toll like receptor TLR2,TLR4,MyD88 mRNA in lung tissues of C57 and C3H mice. The PMN activity of C57 and C3H mice in different stages of Ct MoPn infection was compared with that of C57 and C3H mice harvested by flow cytometry. Results: the model of chlamydia trachomatis respiratory tract infection was established by inhalation of 3 脳 10 ~ 3 IFU Ct MoPn through nasal cavity in mice. There were significant differences in susceptibility to Ct MoPn respiratory tract infection between C3H and C57 mice, characterized by proliferation of chlamydia and infiltration of a large number of inflammatory cells in lung tissue. Compared with C57 mice, C3H mice had severe weight loss, higher mortality, longer disease process and severe pathological changes of lung tissue after infection. Compared with normal control mice, MoPn infection induced higher levels of adhesion molecules and selectin Toll-like receptors in both groups, and induced a large number of PMN infiltration in the lung tissues of infected mice. On the 7th and 14th day after infection, the expression of VCAM-1, E-selectinin P-selectinine TLR2mD88 and the degree of PMN infiltration in infected lung tissues of C3H mice were higher than those of C57 mice. The expression of PMN activated molecule CD11b in peripheral blood and lung tissues of chlamydia infection mice was significantly higher than that in C57 mice on the 7th day after infection, and the expression of PMN CD11b was significantly higher in C3H mice than in C57 mice on the 7th day after chlamydia infection. On the 14th day after infection, the expression of PMN CD11b in C57 mice was higher than that in C3H mice on the 7th day after infection, while the expression of CD11b in C3H mice was significantly decreased. Conclusion the typical chlamydia pneumonia is caused by: Ct MoPn nasal cavity inhalation infection in mice. The susceptibility of C3H mice to chlamydia trachomatis respiratory tract infection is the susceptible phenotype of Ct MoPn respiratory tract infection. The resistant phenotype of C57 mice. Ct MoPn respiratory tract infection induced high levels of adhesion molecules and TLR expression in the lung tissues of C3H mice, thus making a large number of PMN infiltrate in the lung tissue. However, the decrease of PMN activity in lung tissue of C3H mice at the late stage of infection was not sufficient for phagocytosis of pathogens, which resulted in the continuous disease process and aggravated lung pathology in C3H mice, which may be the main reason for the high susceptibility of C3H mice to chlamydia infection.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R392
本文编号：2215062
[Abstract]:Objective: to study the different genetic background of chlamydia trachomatis (Chlamydia trachomatis mouse pneumonitis,CtMoPn) respiratory tract infection in mice. The activity of neutrophils (polymorphonuclear neutrophils,PMN) in infected lung tissues and peripheral blood and the expression of the adhesion molecule TLR-associated with PMN infiltration in lung tissues were detected at different stages of infection. To investigate the immunological mechanism of PMN in the differential susceptibility to Ct MoPn respiratory tract infection. Methods: the model of chlamydia trachomatis pneumonia was established by nasal inhalation of C57BL/6 (C57) and C3H/HeN (C3H) in mice with different genetic backgrounds. Chlamydia chlamydial inclusion body formation unit (IFU),) was detected to determine the growth of chlamydia in lung tissue by infection of Hep-2 cells with lung tissue homogenate, and the changes of body weight and mortality and pathological changes of lung tissue in mice at different stages after infection were monitored. To determine the disease status of infected mice; to determine the infiltration level of PMN in lung tissue through the count of inflammatory cells in lung tissue and the detection of myeloperoxidase (MPO) activity in lung tissue; and to use RT-PCR technique, To detect the expression of ICAM-1,VCAM-1, selectin, L-selectinin E-selectin and Toll like receptor TLR2,TLR4,MyD88 mRNA in lung tissues of C57 and C3H mice, and to isolate PMN, from peripheral blood and lung tissues of mice at different infection stages by using fluorescein labeled anti-mouse CD11b monoclonal antibody, and to detect the expression of E-selectin and Toll like receptor TLR2,TLR4,MyD88 mRNA in lung tissues of C57 and C3H mice. The PMN activity of C57 and C3H mice in different stages of Ct MoPn infection was compared with that of C57 and C3H mice harvested by flow cytometry. Results: the model of chlamydia trachomatis respiratory tract infection was established by inhalation of 3 脳 10 ~ 3 IFU Ct MoPn through nasal cavity in mice. There were significant differences in susceptibility to Ct MoPn respiratory tract infection between C3H and C57 mice, characterized by proliferation of chlamydia and infiltration of a large number of inflammatory cells in lung tissue. Compared with C57 mice, C3H mice had severe weight loss, higher mortality, longer disease process and severe pathological changes of lung tissue after infection. Compared with normal control mice, MoPn infection induced higher levels of adhesion molecules and selectin Toll-like receptors in both groups, and induced a large number of PMN infiltration in the lung tissues of infected mice. On the 7th and 14th day after infection, the expression of VCAM-1, E-selectinin P-selectinine TLR2mD88 and the degree of PMN infiltration in infected lung tissues of C3H mice were higher than those of C57 mice. The expression of PMN activated molecule CD11b in peripheral blood and lung tissues of chlamydia infection mice was significantly higher than that in C57 mice on the 7th day after infection, and the expression of PMN CD11b was significantly higher in C3H mice than in C57 mice on the 7th day after chlamydia infection. On the 14th day after infection, the expression of PMN CD11b in C57 mice was higher than that in C3H mice on the 7th day after infection, while the expression of CD11b in C3H mice was significantly decreased. Conclusion the typical chlamydia pneumonia is caused by: Ct MoPn nasal cavity inhalation infection in mice. The susceptibility of C3H mice to chlamydia trachomatis respiratory tract infection is the susceptible phenotype of Ct MoPn respiratory tract infection. The resistant phenotype of C57 mice. Ct MoPn respiratory tract infection induced high levels of adhesion molecules and TLR expression in the lung tissues of C3H mice, thus making a large number of PMN infiltrate in the lung tissue. However, the decrease of PMN activity in lung tissue of C3H mice at the late stage of infection was not sufficient for phagocytosis of pathogens, which resulted in the continuous disease process and aggravated lung pathology in C3H mice, which may be the main reason for the high susceptibility of C3H mice to chlamydia infection.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R392
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相关期刊论文 前2条
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