中性粒細(xì)胞在沙眼衣原體小鼠肺炎易感性差異免疫學(xué)機(jī)制的研究
發(fā)布時(shí)間：2018-08-31 12:59
【摘要】： 目的: 用沙眼衣原體小鼠肺炎菌株(Chlamydia trachomatis mouse pneumonitis,CtMoPn)呼吸道感染遺傳背景不同的小鼠,在感染的不同時(shí)期通過對感染肺組織及外周血中性粒細(xì)胞(polymorphonuclear neutrophils,PMN)活性以及與PMN浸潤相關(guān)的粘附分子、TLR在肺組織中表達(dá)的檢測,探討PMN在Ct MoPn呼吸道感染易感性差異中的免疫學(xué)機(jī)制。 方法: 遺傳背景不同的小鼠C57BL/6(C57)和C3H/HeN(C3H)鼻腔吸入3×10~3IFUCt MoPn,建立沙眼衣原體小鼠肺炎模型。通過用肺組織勻漿感染Hep-2細(xì)胞,檢測衣原體包涵體形成單位(IFU),確定衣原體在肺組織中的生長;對感染后不同時(shí)期小鼠體重變化及死亡率的監(jiān)測及肺組織病理學(xué)改變的檢測,確定感染小鼠的疾病狀態(tài);通過肺組織炎癥細(xì)胞計(jì)數(shù)、肺組織髓過氧化物酶(MPO)活性檢測,確定PMN在肺組織中的浸潤水平;利用RT—PCR技術(shù),檢測C57和C3H小鼠肺組織與PMN浸潤相關(guān)的黏附分子ICAM-1、VCAM-1,選擇素P-selectin、L-selectin、E-selectin以及Toll樣受體TLR2、TLR4、MyD88 mRNA的表達(dá);分離不同感染時(shí)期小鼠外周血及肺組織的PMN,用熒光素標(biāo)記的抗鼠CD11b單克隆抗體進(jìn)行染色,用流式細(xì)胞儀收獲染色細(xì)胞,比較Ct MoPn感染不同時(shí)期C57和C3H小鼠PMN的活性差異。 結(jié)果: 用3×10~3 IFU Ct MoPn經(jīng)鼻腔吸入建立了小鼠沙眼衣原體呼吸道感染模型,以小鼠體重下降、肺組織衣原體繁殖及大量炎癥細(xì)胞浸潤為特征。C3H和C57小鼠對Ct MoPn呼吸道感染存在明顯的易感性差異。與C57小鼠比較,C3H小鼠感染后存在嚴(yán)重的體重降低、較高的死亡率、較長的疾病過程及嚴(yán)重的肺組織病理變化。與正常對照組小鼠相比,Ct MoPn感染在兩組小鼠均誘導(dǎo)較高水平的黏附分子、選擇素、Toll樣受體的產(chǎn)生,誘導(dǎo)大量的PMN在感染小鼠肺組織的浸潤。感染后7天及14天,高易感性的C3H小鼠肺組織黏附分子VCAM-1,選擇素E-selectin、P-selectin、TLR2、MyD88表達(dá)及PMN在感染肺組織的浸潤程度均高于C57小鼠。衣原體呼吸道感染,感染小鼠外周血及肺組織PMN活化分子CD11b表達(dá)明顯升高,感染后第7天C3H小鼠PMN CD11b表達(dá)明顯高于C57小鼠,感染后14天,C57小鼠PMN CD11b表達(dá)高于感染后第7天而C3H小鼠CD11b表達(dá)則明顯降低。 結(jié)論: Ct MoPn鼻腔吸入感染小鼠引起典型的衣原體肺炎。不同種系的小鼠對沙眼衣原體呼吸道感染存在易感性差異,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小鼠肺組織誘導(dǎo)高水平的黏附分子及TLR表達(dá),從而使大量PMN在肺組織浸潤。而感染后期C3H小鼠肺組織PMN活性降低,不足以吞噬清除病原體,導(dǎo)致C3H小鼠持續(xù)的疾病過程及加重的肺組織病理,可能是C3H小鼠對衣原體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.
【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2008
【分類號】：R392
本文編號：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.
【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2008
【分類號】：R392
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相關(guān)期刊論文 前2條
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