口服潘生丁对呼吸道合胞病毒肺炎肺组织分泌细胞功能的影响

口服潘生丁（ＤＰＭ）对呼吸道合胞病毒（ＲＳＶ）肺炎小鼠肺组织分泌细胞的影响。４０只ＲＳＶ肺炎小鼠随机分组,ＤＰＭ组用ＤＰＭ５０ｍｇ·ｋｇ－１·ｄ－１灌胃三天。感染后第５、７、９、１２天通过ＡＮＡＥ组织化学染色和透射电镜检查Ｃｌａｒａ细胞与Ⅱ型肺泡细胞。结果显示下呼吸道上皮肿胀、脱落,尤其以呼吸性细支气管持续时间长。感染后５～７天,肺炎组Ｃｌａｒａ细胞与Ⅱ型肺泡细胞内出现许多分泌小泡,可能为炎性细胞因子。ＤＰＭ组二种分泌细胞中分泌小泡少,出现短暂,有较多磷脂被持续释入血液,其磷脂可能与抑制脾淋巴细胞增生有关     

H5N1型禽流感病毒感染非人灵长类动物的观察

目的观察H5N1型禽流感病毒对中国非人灵长类动物的易感性并建立动物模型。方法将病毒通过滴鼻接种实验猴,观察感染后动物的临床症状,采血、咽拭子及各器官组织进行血清学、病原学及病理学检查,记录抗体变化、病毒分离情况及病理学改变。结果感染后动物表现轻度食欲下降、一过性体温升高及外周血白细胞减少,肺组织病毒分离及RT-PCR阳性,病理检查感染急性期动物肺组织表现为间质性肺炎,肺泡间隔增宽,充血出血明显,肺泡受压变形,间质及肺泡内有大量炎细胞浸润,符合病毒性肺炎的改变,感染后14 d动物血清IgG抗体水平较感染前升高4倍。结论H5N1病毒可感染非人灵长类动物,可以作为感染模型进行H5N1病毒的发病机制、疫苗评价、药物筛选等研究。     

裸鼠呼吸道合胞病毒感染的动物模型

呼吸道合胞病毒(RSV)是全世界婴幼儿下呼吸道感染的首位病毒病原体,免疫缺陷个体容易发生严重感染,目前尚无理想RSV感染动物模型用于研究。我们用细胞免疫缺陷裸鼠感染RSV,旨在建立理想的动物模型,为RSV感染的防治研究奠定基础。裸鼠滴鼻感染RSV后肺组织分离到病毒,直接免疫荧光检测到支气管肺泡灌洗液RSV抗原阳性,空斑形成实验检测肺组织病毒滴度在感染后第3天达高峰,并持续到第9天仍能检测到病毒。免疫组化检测RSV抗原主要分布在细支气管、毛细支气管和肺泡上皮细胞胞浆内。肺组织病理学显示RSV感染导致裸鼠淋巴细胞浸润为主的肺间质性炎症,电镜分析超微结构可见到细胞内病毒颗粒和气血屏障的破坏。支气管肺泡灌洗液白细胞计数显示裸鼠RSV感染炎症高峰在感染后第9天。裸鼠RSV感染的病毒复制和病理改变特点与人相似,病毒持续高水平复制,是客观而实用的评价抗RSV制剂效果的小鼠模型。     

裸鼠呼吸道合胞病毒感染的动物模型

呼吸道合胞病毒(RSV)是全世界婴幼儿下呼吸道感染的首位病毒病原体,免疫缺陷个体容易发生严重感染,目前尚无理想RSV感染动物模型用于研究.我们用细胞免疫缺陷裸鼠感染RSV,旨在建立理想的动物模型,为RSV感染的防治研究奠定基础.裸鼠滴鼻感染RSV后肺组织分离到病毒,直接免疫荧光检测到支气管肺泡灌洗液RSV抗原阳性,空斑形成实验检测肺组织病毒滴度在感染后第3天达高峰,并持续到第9天仍能检测到病毒.免疫组化检测RSV抗原主要分布在细支气管、毛细支气管和肺泡上皮细胞胞浆内.肺组织病理学显示RSV感染导致裸鼠淋巴细胞浸润为主的肺间质性炎症,电镜分析超微结构可见到细胞内病毒颗粒和气血屏障的破坏.支气管肺泡灌洗液白细胞计数显示裸鼠RSV感染炎症高峰在感染后第9天.裸鼠RSV感染的病毒复制和病理改变特点与人相似,病毒持续高水平复制,是客观而实用的评价抗RSV制剂效果的小鼠模型.     

汉滩病毒S基因免疫小鼠的细胞免疫应答的初步观察

将汉滩病毒Ｓ片段编码区基因插入到含ＣＭＶ启动了／增强子（ｐｒｏｍｏｔｅｒ／ｅｎｈａｎｃｅｒ）的真核表达载体ｐＶＲ１０１２中,构建成真核表达质粒ｐＶＲＳ２２。质粒ＤＮＡ经纯化后,注射经布比卡因预处理的Ｂａｌｂ／ｃ小鼠的股四头肌,多次免疫后,免疫小鼠淋巴细胞增殖功能的检测结果显示：免疫鼠的脾细胞能够对体处抗原刺激产生增殖反应;ＣＴＬ活性检测结果表明：靶细胞＾５１Ｃｒ的释放是疚细胞依赖性的,并且与病毒感     

BALB/c小鼠和雪貂感染H7N9禽流感病毒后的肺组织动态病理学变化

目的了解用H7N9禽流感病毒分别感染BALB/c小鼠和雪貂后,其肺部动态病理改变,为临床诊断、治疗、预防及机制研究提供帮助。方法 BALB/c小鼠经鼻腔接种106EID50(50μL)H7N9禽流感病毒后第1、2、3、5、7、14、28天分别安乐死2~3只小鼠;雪貂经鼻腔吸入接种106EID50(500μL)H7N9禽流感病毒后第3、7、14、28天分别安乐死1只雪貂,分别观察动物的临床特征改变,肺组织的大体组织形态学变化,HE染色观察动态病理改变,免疫组化染色观察病毒分布及肺组织各种炎细胞的浸润情况。结果感染病毒后的小鼠出现竖毛、嗜睡、死亡等表现,雪貂表现为打喷嚏、鼻腔分泌物、稀便、嗜睡等;大体观察小鼠与雪貂肺组织均可见到暗红色病灶;光镜观察小鼠与雪貂的肺组织均呈现坏死性支气管炎和渗出性间质性肺炎、肺泡炎。感染第2天开始出现炎性病变,7~9 d炎症病变最严重,14 d后逐渐修复吸收,28 d基本完全吸收;T、B淋巴细胞,巨噬细胞不同程度的表达增多,以T细胞增多为主,尤其是CD8+T细胞两种动物均大量表达。结论 H7N9禽流感病毒感染可引起BALB/c小鼠和雪貂肺组织急性支气管炎和肺炎,感染后7~9 d肺部炎症的组织病理学变化最严重,CD8+T细胞明显增多,14d后病灶逐渐吸收。该研究可为临床诊断、治疗、预防该病及进行疾病机制研究提供帮助。     

利用脊髓灰质炎病毒5‘NCR和RNA聚合酶基因可提高外源基因表达

将含脊髓灰质炎病毒（ＰＶ）ＲＮＡ聚合酶的不同长度基因片段克隆到载体ｐＳＧ５质粒上,分别构建了４个表达ＲＮＡ聚合酶的质粒。体外转录实验证明,ｐＳＧ５－ＰＯＬ１．９９和ｐＳＧ５－ＰＯＬ２．０３质粒转染细胞的提取物促进了特异的ＲＮＡ转录,表明两质闰可表达ＲＮＡ聚合酶。将ＰＶ的５’ＮＣＲ序列插在载体ｐＧＲＥＥＮ ＬＡＮＴＥＲＮ－１的ＣＭＶ启动子下游,构建了ｐＧＲＥＥＮ ＬＡＮＴＥＲＮ－１－５’ＮＣＲ质粒;     

病毒性心肌炎发病机理的实验研究：—T细胞亚群和抗心肌抗体检测

以柯萨奇Ｂ＿３病毒（ＣＶＢ＿３）感染Ｂａｌｂ／ｃ小鼠建立心肌炎模型,检测了小鼠脾脏中Ｔ细胞亚群和血清中的抗心肌抗体,并进行了心脏病毒分离及组织病理学检查。结果显示,病毒感染后５天,脾脏中Ｔｈｙ１,２￣＋（Ｔ＿总）增高,７一１５天降低,第２１天恢复正常。Ｌ３Ｔ４￣＋（Ｔｃ／Ｔｓ）于病毒感染后５一２１天均明显高于对照组。Ｌ３Ｔ４＋（Ｔｈ／ｉ）于病毒感染后７天开始增高,直到２１天均明显高于对照组。病毒感染后１５天,抗心脏肌球蛋白抗休开始增高,第２１天继续增高。病毒感染后３一５天,心脏病毒分离均为阳性;第７天部分小鼠心脏中仍可分离出病毒;第１５天心脏病毒分离为阴性。病毒感染后７一２１天,心肌坏死、间质炎细胞浸润等病理变化进行性加重。上述结果提示,病毒感染本身和免疫因素都可能参与心肌炎的发病。     

非洲猪瘟病毒j5R膜蛋白的电脑预测和实验证实

蛋白多肽二级结构的电脑预测表明,非洲猪瘟病毒（ Ａｆｒｉｃａｎ ｓｗｉｎｅ ｆｅｖｅｒ ｖｉｒｕｓ , Ａ Ｓ Ｆ Ｖ）ｊ５ Ｒ阅读框编码１２ ．９ ｋ Ｄａ 膜蛋白。该蛋白的 Ｃ 末端含有一个潜在抗原决定簇,针对其合成肽的抗体能在 Ａ Ｓ Ｆ Ｖ 感染细胞和病毒颗粒中检测到２３ 或２５ ｋ Ｄａ（ 取决于不同毒株） 特异蛋白。免疫荧光试验显示,ｊ５ Ｒ 蛋白主要位于感染细胞的病毒复制部位。油水两相分离和细胞分级分离试验结果证明ｊ５ Ｒ 蛋白是膜相关蛋白     

EB病毒转化Hu—TLC—SCID小鼠脾细胞的实验研究

利用ＥＢ病毒转化可产生较高水平人ＩｇＧ和特异性抗２型登革病毒人抗体的Ｈｕ－ＴＬＣ－ＳＣＩＤ小鼠脾细胞,通过免疫组化、免疫荧光和ＰＣＲ法检测转化细胞的人Ｂ细胞表面标志、ＥＢ病毒抗原和ＥＢ病毒基因。结果表明,被团体的Ｈｕ－ＴＬＣ－ＳＣＩＤ小鼠脾细胞能继续产生抗２型登革病毒的特异性人抗体,并具有人Ｂ细胞的ＣＤ２０＾＋、ＳｍＩｇＧ标志及ＥＢ病毒潜伏膜蛋白－１（ＬＭＰ－１）基因,可表达ＬＭＰ－１和ＥＢ病毒核     

双哌达莫促肺泡巨噬细胞抗病毒作用

观察双哌达莫 （ＤＰＭ） 对呼吸道合胞病毒 （ＲＳＶ） 肺炎小鼠肺泡巨噬细胞 （Ａｍ ） 的作用。采用组织化学和电镜等方法, 对肺炎组与肺炎＋ ＤＰＭ 处理组进行了对比观察。结果显示肺炎组Ａｍ 超微结构发育不良, 吞噬与分泌能力弱; ＤＰＭ 处理组比肺炎组Ａｍ 数量轻度增加, 细胞内溶酶体、滑面内质网与线粒体丰富,吞噬消化、分泌能力增强,病毒滴度与ＲＮＡ阳性细胞明显减少（Ｐ＜ ００１ 与Ｐ＜ ００５）。ＤＰＭ 提高Ａｍ非特异性免疫功能     

Local IL-17A Potentiates Early Neutrophil Recruitment to the Respiratory Tract during Severe RSV Infection

Respiratory syncytial virus (RSV) bronchiolitis triggers a strong innate immune response characterized by excessive neutrophil infiltration which contributes to RSV induced pathology. The cytokine IL-17A enhances neutrophil infiltration into virus infected lungs. IL-17A is however best known as an effector of adaptive immune responses. The role of IL-17A in early immune modulation in RSV infection is unknown. We aimed to elucidate whether local IL-17A facilitates the innate neutrophil infiltration into RSV infected lungs prior to adaptive immunity. To this end, we studied IL-17A production in newborns that were hospitalized for severe RSV bronchiolitis. In tracheal aspirates we measured IL-17A concentration and neutrophil counts. We utilized cultured human epithelial cells to test if IL-17A regulates RSV infection-induced IL-8 release as mediator of neutrophil recruitment. In mice we investigated the cell types that are responsible for early innate IL-17A production during RSV infection. Using IL-17A neutralizing antibodies we tested if IL-17A is responsible for innate neutrophil infiltration in mice. Our data show that increased IL-17A production in newborn RSV patient lungs correlates with subsequent neutrophil counts recruited to the lungs. IL-17A potentiates RSV-induced production of the neutrophil-attracting chemokine IL-8 by airway epithelial cells in vitro. Various lung-resident lymphocytes produced IL-17A during early RSV infection in Balb/c mice, of which a local population of CD4 T cells stood out as the predominant RSV-induced cell type. By removing IL-17A during early RSV infection in mice we showed that IL-17A is responsible for enhanced innate neutrophil infiltration in vivo. Using patient material, in vitro studies, and an animal model of RSV infection, we thus show that early local IL-17A production in the airways during RSV bronchiolitis facilitates neutrophil recruitment with pathologic consequences to infant lungs.     

小鼠感染合胞病毒与鼠流感病毒后肺脏病理学比较研究

目的与方法用合胞病毒(RSV)和鼠肺流感病毒(IVP)感染SPF级BALB/c小鼠,复制两种不同的小鼠病毒性肺炎动物模型,观察其临床症状,并对两种模型各自的肺部组织病理学特点进行研究。结果与结论IVP模型组与RSV模型组小鼠感染病毒后,分别在试验的2天和3天发病,临床症状均表现为精神沉郁、耸毛、卷缩、毛无光泽、活动减少、呼吸急促、咳嗽。但IVP感染模型组小鼠在发病后出现死亡,第7天其死亡率达到40%,而RSV感染模型组小鼠7日试验内无死亡病例发生。病理组织学诊断,RSV模型组小鼠为急性渗出性间质性肺炎,IVP模型组小鼠为出血性间质性肺炎。     

Alternative mechanisms of respiratory syncytial virus clearance in perforin knockout mice lead to enhanced disease

Virus-specific cytotoxic T lymphocytes are key effectors for the clearance of virus-infected cells and are required for the normal clearance of respiratory syncytial virus (RSV) in mice. Although perforin/granzyme-mediated lysis of infected cells is thought to be the major molecular mechanism used by CD8(+) cytotoxic T lymphocytes for elimination of virus, its role in RSV has not been reported. Here, we show that viral clearance in perforin knockout (PKO) mice is slightly delayed but that both PKO and wild-type mice clear virus by day 10, suggesting an alternative mechanism of RSV clearance. Effector T cells from the lungs of both groups of mice were shown to lyse Fas (CD95)-overexpressing target cells in greater numbers than target cells expressing low levels of Fas, suggesting that Fas ligand (CD95L)-mediated target cell lysis was occurring in vivo. This cell lysis was associated with a delay in RSV-induced disease in PKO mice compared to the time of disease onset for wild-type controls, which correlated with increased and prolonged production of gamma interferon and tumor necrosis factor alpha levels in PKO mice. We conclude that while perforin is not necessary for the clearance of primary RSV infection, the use of alternative CTL target cell killing mechanisms is less efficient and can lead to enhanced disease.     

Mice transgenic for human angiotensin-converting enzyme 2 provide a model for SARS coronavirus infection

To establish a small animal model of severe acute respiratory syndrome (SARS), we developed a mouse model of human severe acute respiratory syndrome coronavirus (SARS-CoV) infection by introducing the human gene for angiotensin-converting enzyme 2 (hACE2) (the cellular receptor of SARS-CoV), driven by the mouse ACE2 promoter, into the mouse genome. The hACE2 gene was expressed in lung, heart, kidney, and intestine. We also evaluated the responses of wild-type and transgenic mice to SARS-CoV inoculation. At days 3 and 7 postinoculation, SARS-CoV replicated more efficiently in the lungs of transgenic mice than in those of wild-type mice. In addition, transgenic mice had more severe pulmonary lesions, including interstitial hyperemia and hemorrhage, monocytic and lymphocytic infiltration, protein exudation, and alveolar epithelial cell proliferation and desquamation. Other pathologic changes, including vasculitis, degeneration, and necrosis, were found in the extrapulmonary organs of transgenic mice, and viral antigen was found in brain. Therefore, transgenic mice were more susceptible to SARS-CoV than were wild-type mice, and susceptibility was associated with severe pathologic changes that resembled human SARS infection. These mice will be valuable for testing potential vaccine and antiviral drug therapies and for furthering our understanding of SARS pathogenesis.     

Scanning electron microscope study of the lung epithelium of the rabbit during ontogenesis

The development of the bronchial and alveolar epithelium was observed in rabbits from the 15th day post conception until the time of birth with the scanning electron microscope. In the pseudoglandular phase, primitive bronchi proliferate in the mesenchyme. The epithelial cells are not differentiated and have single cilia. After retraction of these single cilia cell differentiation begins. Flat cells densely populated with cytopodia can be recognized on the 22nd day, ciliated cells on the 23rd day post conception. Both are located in the bronchi near the hilus. In the canalicular phase of development, the differentiation of the mucoid cells and the Clara-cells begins. The interstitial connective tissue develops more and more capillaries. The alveolar phase begins around the 26th day p. c. The lung capillaries reach the alveolar epithelial cells and arrange themselves directly beneath the epithelial basement membrane. This "alveolarization" of the lung tissue starts in the centre of the lung lobules and proceeds to the periphery. After the 26th day post conception the alveolar epithelial cells retract their single cilium and at the same time become type I or type II pneumocytes. The undifferentiated entodermal stem cell of the alveolar epithelium is the pneumoblast.     

Virus-specific memory and effector T lymphocytes exhibit different cytokine responses to antigens during experimental murine respiratory syncytial virus infection.

Mice sensitized to the G (attachment) or F (fusion) glycoproteins of respiratory syncytial virus (RSV) expressed different patterns of cytokine production and lung pathology when challenged by intranasal infection with RSV. Five days after challenge, mice sensitized to G glycoprotein produced high levels of interleukin-4 (IL-4) and IL-5 in the lungs and spleens and developed extensive pulmonary eosinophilia, while mice sensitized to F glycoprotein produced IL-2 and developed a mononuclear cell infiltration. Memory lymphocytes isolated 2 weeks after intranasal challenge of mice primed to the G or F glycoprotein secreted only IL-2 and gamma interferon (IFN-gamma) when stimulated with RSV. IL-4 and IL-5 production characteristic of Th2-type effectors in the lung was observed only after multiple rounds of in vitro stimulation of RSV G-specific memory T lymphocytes with antigen. Also IFN-gamma production appeared to play only a minor role in the expression of pulmonary pathology characteristic of Th1 or Th2 T-lymphocyte responses, because mice genetically deficient in IFN-gamma production by gene disruption displayed the same pattern of pulmonary inflammation to RSV infection after priming to RSV F or G as conventional mice. These results suggest that effector T lymphocytes exhibit a different pattern of cytokine production than memory T-lymphocyte precursors precommitted to a Th1 or Th2 pattern of differentiation. Furthermore, these observations raise the possibility that the cytokine response of human memory T lymphocytes after a single exposure to antigen in vitro may not accurately reflect the cytokine response of differentiated effector T lymphocytes at the site of infection in vivo.     

IL-10 regulates viral lung immunopathology during acute respiratory syncytial virus infection in mice

Interleukin (IL-) 10 is a pleiotropic cytokine with broad immunosuppressive functions, particularly at mucosal sites such as the intestine and lung. Here we demonstrate that infection of BALB/c mice with respiratory syncytial virus (RSV) induced IL-10 production by CD4(+) and CD8(+) T cells in the airways at later time points (e.g. day 8); a proportion of these cells also co-produced IFN-γ. Furthermore, RSV infection of IL-10(-/-) mice resulted in more severe disease with enhanced weight loss, delayed recovery and greater cell infiltration of the respiratory tract without affecting viral load. In addition, IL-10(-/-) mice had a pronounced airway neutrophilia and heightened levels of pro-inflammatory cytokines and chemokines in the bronchoalveolar lavage fluid. Notably, the proportion of lung T cells producing IFN-γ was enhanced, suggesting that IL-10 may act in an autocrine manner to dampen effector T cell responses. Similar findings were made in mice treated with anti-IL-10R antibody and infected with RSV. Therefore, IL-10 inhibits disease and inflammation in mice infected with RSV, especially during recovery from infection.     

Respiratory Syncytial Virus (RSV) RNA loads in peripheral blood correlates with disease severity in mice

Background

Respiratory Syncytial Virus (RSV) infection is usually restricted to the respiratory epithelium. Few studies have documented the presence of RSV in the systemic circulation, however there is no consistent information whether virus detection in the blood correlates with disease severity.

Methods

Balb/c mice were inoculated with live RSV, heat-inactivated RSV or medium. A subset of RSV-infected mice was treated with anti-RSV antibody 72 h post-inoculation. RSV RNA loads were measured by PCR in peripheral blood from day 1-21 post-inoculation and were correlated with upper and lower respiratory tract viral loads, the systemic cytokine response, lung inflammation and pulmonary function. Immunohistochemical staining was used to define the localization of RSV antigens in the respiratory tract and peripheral blood.

Results

RSV RNA loads were detected in peripheral blood from day 1 to 14 post-inoculation, peaked on day 5 and significantly correlated with nasal and lung RSV loads, airway obstruction, and blood CCL2 and CXCL1 expression. Treatment with anti-RSV antibody reduced blood RSV RNA loads and improved airway obstruction. Immunostaining identified RSV antigens in alveolar macrophages and peripheral blood monocytes.

Conclusions

RSV RNA was detected in peripheral blood upon infection with live RSV, followed a time-course parallel to viral loads assessed in the respiratory tract and was significantly correlated with RSV-induced airway disease.