哮喘小鼠气道上皮TSLP表达及激活DCs加重气道炎症的研究

目的 研究支气管哮喘小鼠气道上皮中胸腺间质淋巴细胞生成素(TSLP)表达,探讨其对哮喘小鼠肺部炎症的影响.方法 BALB/c小鼠分为生理盐水对照组、哮喘模型组和TSLP中和抗体干预组.通过气道反应性和肺组织病理学评价哮喘模型;酶联免疫吸附试验(ELISA)检测支气管肺泡灌洗液(BALF)上清中IL-4、IL-5和IL13的含量;实时荧光定量PCR(qRT-PCR)测定肺组织中TSLP mRNA的表达;免疫组化及Western blot法测定肺组织中TSLP蛋白的表达;流式细胞术检测BALF中树突状细胞(OCs)表面CD40、CD80、CD86的表达水平.结果 小鼠气道反应性增高和肺组织病理学检查结果均符合哮喘的典型表现证实造模成功;哮喘组BALF中IL-4、IL-5和IL-13的水平显著高于正常组(P<0.05),且TSLP与其成正相关;与正常对照组相比,哮喘组气道上皮TSLPmRNA和蛋白高表达,两组间差异有统计学意义(P<0.05);哮喘组BALF中DCs表面CD40、CD80、CD86表达明显高于正常组(P<0.05).TSLP中和抗体干预后,BALF中DCs表面CD40、CD80、CD86表达明显减低,并进一步减少IL-4、IL-5和IL-13的表达.结论 哮喘气道上皮中TSLP表达增高,TSLP通过上调DCs表面CD40、CD80、CD86的表达,激活DCs诱导CD4~+T细胞向Th2分化发育,与加重哮喘的气道炎症有关;TSLP抗体干预可阻断DCs的活化,减少Th2细胞因子的分泌,这些因素可能与减轻哮喘炎症反应有关,为哮喘治疗途径提供新的思路.     

呼吸道合胞病毒感染后期OVA刺激对小鼠气道炎症及AHR的影响

目的研究呼吸道合胞病毒(RSV)感染后期过敏原刺激对小鼠气道炎症及AHR的影响。方法 6~8周龄雌性Balb/c小鼠随机分为Mock组、RSV组、OVA组及R+O组。检测各组小鼠支气管肺泡灌洗液(BALF)中细胞总数及分类计数;苏木精-伊红(HE)染色观察肺部病理损伤;全身体积描述记法检测小鼠气道反应性;ELISA检测BALF中IL-4、IL-5、CXCL10、CCL5、CCL20的水平。结果 R+O组小鼠BALF中炎症细胞总数、巨噬细胞、中性粒细胞及嗜酸性粒细胞分类计数较其他3组均显著增高(P0.05);R+O组小鼠肺组织病理评分及AHR较其他3组亦显著增高(P0.05);BALF中各处理组IL-4、IL-5较Mock组明显增高(P0.05),但处理组之间无显著性差异;R+O组CXCL10水平较其他3组显著升高(P0.05)。结论 RSV感染后期接受OVA刺激可致CXCL10表达增加,进而促使巨噬细胞、中性粒细胞及嗜酸性粒细胞募集,加重小鼠气道炎症及AHR。     

玉屏风散对小鼠哮喘合并人偏肺病毒感染的干预机制探讨

目的:建立人偏肺病毒(Human metapneumovirus,hMPV)感染的哮喘小鼠模型,验证玉屏风散对hMPV诱导的哮喘小鼠气道高反应性和炎症的疗效并初步探讨其机理。方法:随机将48只雌性BALB/c小鼠分为对照组(A组)、OVA致敏激发哮喘组(B组)、偏肺病毒哮喘组(C组)、小剂量玉屏风组(D组)、中剂量玉屏风组(E组)、大剂量玉屏风组(F组),采用卵蛋白致敏和激发,hMPV滴鼻方法建立哮喘人偏肺病毒感染模型并给予玉屏风治疗,采用动物体描箱法测定气道反应性;采用支气管肺泡灌洗液(BALF)进行细胞分类计数;肺组织病理切片HE染色观察炎性细胞浸润;采用流式细胞术分别测定肺部细胞因子IFNγ-和IL-4、IL-17。结果:(1)随吸入乙酰甲胆碱浓度增加各组气道反应性明显增加,C组比B组气道反应性显著升高(P<0.05);F组气道反应性明显降低,低于C组(P<0.05);(2)各组BALF中白细胞总数及炎症细胞数都比对照组显著升高,C组BALF中白细胞总数、嗜酸性粒细胞与B组、F组相比显著升高(P<0.05);(3)各哮喘组的炎症评分都显著高于对照组。在细支气管周围炎、肺泡炎方面B组和F组比C组明显减轻(P<0.05)。(4)A、B组IFNγ-无差异(P>0.05),各剂量组IFNγ-,IFNγ-/IL-4均显著高于B、C组(P<0.05);哮喘组、治疗组IL-4显著高于正常组(P<0.01),但各组间无明显差异;与B组相比,C组IL-17水平明显升高(P<0.05);与C组相比,E、F组IL-17水平明显降低。结论:大剂量玉屏风散可以抑制感染hMPV哮喘小鼠的气道高反应性及气道炎症,且改善Th1/Th2失衡状态。     

气道应用T-bet重组腺病毒抑制哮喘小鼠过敏性气道炎症

目的探讨气道应用T-bet重组腺病毒(AdT-bet)对哮喘小鼠气道炎症反应的影响及机制。方法C57BL/6小鼠随机分为4组,实验组(A组)、对照病毒组(B组)、PBS对照组(C组)和正常对照组(D组),A、B、C组采用卵蛋白(OVA)、明矾建立哮喘模型,分别于第19天激发前气道内单次应用50μLAdT-bet(108pfu)、AdLacZ、PBS。26d取肺泡灌洗液(BALF)测定细胞成分、IL-4、IL-5、IFNγ浓度,取血测定血浆IgE水平,观察肺组织病理学变化及GATA-3表达。结果1)A组BALF中的嗜酸粒细胞(EOS)为(0.5±0.2)%明显低于B组(21.2±6.9)%和C组(20.9±6.8)%(P<0.01);2)A组BALF中的IL-4(6.7±3.8)pg/mL和IL-5(12.4±4.9)pg/mL的水平明显低于B组[IL-4(91.4±22.5)pg/mL和IL-5(55.6±10.6)pg/mL]和C组[IL-4(89.8±23.6)pg/mL和IL-5(56.7±11.5)pg/mL](P<0.01),而IFNγ的水平(710±45)pg/mL则明显高于B组(13.1±3.5...     

地塞米松减轻过敏性哮喘模型小鼠气道炎性反应

目的 观察地塞米松(DEX)对过敏性哮喘模型小鼠气道炎性的影响并探讨相关机制。方法 将小鼠随机分为对照组、哮喘组、地塞米松组。哮喘组小鼠于实验第0、7、14天皮下注射卵清蛋白(OVA)/氢氧化铝混合液,第21、22天1%OVA混悬液雾化吸入20 min;地塞米松组在哮喘组基础上于每次雾化吸入前3 h地塞米松(2 mg/kg)腹腔注射。末次雾化结束测定小鼠气道阻力,24 h后收集肺泡灌洗液(BALF),Wright-Giemsa染色后行细胞分类计数;ELISA测定BALF中IL-6、IL-18和IL-1β等浓度;免疫组织化学法(IHC)检测肺组织NLRP3、IL-1β蛋白表达,HE染色观察肺组织病理。结果 与对照组比较,哮喘组小鼠气道高反应性(AHR)明显增高;BALF中嗜酸性粒细胞、中性粒细胞等炎性细胞数量明显增加;IL-5、IL-6、IL-18和IL-1β表达均升高(P<0.01);肺组织NLRP3、IL-1β蛋白表达增强。与哮喘组比较,地塞米松组小鼠AHR显著降低,BALF中炎性细胞总数、嗜酸性粒细胞、中性粒细胞均明显减少(P<0.01),IL-5、IL-6、IL-18...     

呼吸道合胞病毒对致敏小鼠气道炎症和CD8+ T细胞功能的影响

目的观察呼吸道合胞病毒（RSV）对致敏小鼠气道炎症和CD8^＋T细胞功能的影响.方法BALB/c小鼠40只,随机分成4组,分别为磷酸盐缓冲液（PBS）对照组、鸡卵白蛋白（OVA）组、RSV组、OVA/RSV组;应用OVA腹腔注射致敏、OVA气道雾化结合RSV滴鼻激发哮喘;支气管肺泡灌洗液（BALF）作细胞分类计数;酶联免疫吸附试验（ELISA）测定BALF上清中白细胞介素（IL）-4、IL-5、干扰素（IFN）-γ含量;苏木精-依红（HE）染色观察肺病理变化;采用三色光流式细胞分析法测定气管旁淋巴结（PBLN）中CD4^＋、CD8^＋T细胞及细胞内细胞因子IFN-γ、IL-4、IL-5表达与TH2/TH1、Tc2/Tc1比值变化.结果（1）BALF中细胞总数及分类：与OVA组比较,OVA/RSV组细胞总数、嗜酸性粒细胞、淋巴细胞均明显增加（分别P＜0.01）;与RSV组比较,OVA/RSV组细胞总数、嗜酸性粒细胞明显增加（分别P＜0.01）.（2）BALF上清中细胞因子含量：与OVA组比较,OVA/RSV组IFN-γ、IL-4、IL-5含量均明显升高（分别P＜0.01）;与RSV组比较,OVA/RSV组IFN-γ无明显变化,而IL-4、IL-5显著上升（分别P＜0.01）.（3）肺组织病理：OVA/RSV组与其他各组比较气道黏膜增厚,管腔狭窄、收缩,上皮破坏,管壁周围炎症细胞浸润明显加重.（4）PBLN中CD4^＋（WN-γ^＋、IL-4^＋、IL-5^＋）、CD8^＋（IFN-γ^＋、IL-4^＋、IL-5^＋）T细胞各占CD3^＋T细胞百分比及TH2/TH1、Tc2/Tc1比值变化：与OVA组比较,OVA/RSV组CD8^＋（IFN-γ^＋、IL-4^＋、IL-05^＋）T细胞百分比、Tc2/Tc1比值增加（分别P＜0.01）,TH2/TH1比值无明显变化.与RSV组比较,OVA/RSV组CD4^＋（IL-4^＋、IL-5^＋）T细胞、TH2/TH1比值、CD8^＋（IL-4^＋、IL-5^＋）T细胞、Tc2/Tc1比值均明显上升（分别P＜0.01）.结论（1）OVA致敏小鼠RSV感染后可明显加重气道炎症,TH2、TH1型炎症均加强,且以TH2型炎症加重为主.（2）OVA致敏小鼠RSV感染后可引起CD8^＋T细胞数量及功能改变,即由产生IFN-γ^＋为特征的Tc1细胞向产生IL-4^＋、IL-5^＋为特征Tc2细胞转化,并可能与气道内IL-4、IL-5升高及嗜酸性粒细胞的大量募集有关.     

芝麻素通过AMPK/NLRP3信号通路缓解哮喘小鼠气道炎症的作用机制

目的 探讨芝麻素通过AMPK/NLRP3信号通路缓解卵清蛋白(ovalbumin, OVA)诱导的哮喘小鼠模型的气道炎症。方法 将40只雄性清洁级Balb/c小鼠,随机分为5组,分别为正常组(control)、OVA模型组、芝麻素低剂量组(50 mg/kg)、芝麻素高剂量组(100 mg/kg)、阳性对照地塞米松(dexamethasone, DEX)治疗组(1 mg/kg),每组8只。使用Diff-Quick染色法对每组小鼠肺泡灌洗液(BALF)中的各种炎症细胞进行分类、计数;小鼠BALF中IL-4、IL-5、IL-13、IFN-γ的含量使用ELISA法进行检测;流式细胞术测定小鼠肺组织CD4阳性细胞群中细胞因子的阳性百分率;对各组小鼠的肺组织进行HE、PAS染色,并观察其病理学改变;对小鼠肺组织进行免疫组织化学染色,观察NLRP3蛋白的表达分布情况;Western blot方法检测AMPK、p-AMPK、NLRP3、Caspase-1、ASC和IL-1β蛋白表达水平。结果 芝麻素能够减少OVA引起的哮喘小鼠BALF中各种炎症细胞数量,降低小鼠BALF中IL-4、IL-5、IL-13...     

IL-12~+重组卡介苗降低哮喘小鼠气道炎症的作用及其机制研究

目的探讨IL-12+重组卡介苗(recombinant balillus calmette-guerin secreting IL-12,rBCG)新生期接种对实验性哮喘小鼠气道炎症和气道高反应(airway hyperresponsiveness,AHR)的作用及其可能机制。方法新生Balb/c小鼠分4组:对照组(control组),卵白蛋白(OVA)组,rBCG干预(rBCG/OVA)组,rBCG/OVA/IFN-gamma中和抗体(rBCG/OVA/anti-IFN-gamma Ab)组。除对照组外,其余3组均给予OVA致敏和激发。最后一次激发后测24 h内AHR,观察支气管肺泡灌洗液(bronchoalveolarlavage fluid,BALF)中细胞总数及分类,评估肺部炎症变化程度,采用酶联免疫吸附双抗体夹心法(ELISA)检测BALF中IFN-gamma、IL-10水平。结果 1)OVA组BALF中细胞总数、嗜酸性粒细胞、中性粒细胞、淋巴细胞绝对计数和炎症病理评分均明显高于对照组,rBCG/OVA组上述内容均显著低于OVA组。2)新生期rBCG接种能显著降低哮喘小鼠模型的气道高反应性。3)rBCG/OVA组支气管肺泡灌洗液中IFN-gamma、IL-10水平明显高于OVA组。4)rBCG/OVA组与接种rBCG同时并使用anti-IFN-gamma Ab的哮喘小鼠相比气道炎症和AHR无显著差异。结论新生期rBCG接种能抑制哮喘小鼠气道炎症和AHR,促进IFN-gamma和IL-10的产生,其抗哮喘效应可能与其促进IL-10分泌有关。     

芝麻素通过AMPK/NLRP3信号通路缓解哮喘小鼠气道炎症的作用机制

目的 探讨芝麻素通过AMPK/NLRP3信号通路缓解卵清蛋白(ovalbumin, OVA)诱导的哮喘小鼠模型的气道炎症。方法 将40只雄性清洁级Balb/c小鼠,随机分为5组,分别为正常组(control)、OVA模型组、芝麻素低剂量组(50 mg/kg)、芝麻素高剂量组(100 mg/kg)、阳性对照地塞米松(dexamethasone, DEX)治疗组(1 mg/kg),每组8只。使用Diff-Quick染色法对每组小鼠肺泡灌洗液(BALF)中的各种炎症细胞进行分类、计数;小鼠BALF中IL-4、IL-5、IL-13、IFN-γ的含量使用ELISA法进行检测;流式细胞术测定小鼠肺组织CD4阳性细胞群中细胞因子的阳性百分率;对各组小鼠的肺组织进行HE、PAS染色,并观察其病理学改变;对小鼠肺组织进行免疫组织化学染色,观察NLRP3蛋白的表达分布情况;Western blot方法检测AMPK、p-AMPK、NLRP3、Caspase-1、ASC和IL-1β蛋白表达水平。结果 芝麻素能够减少OVA引起的哮喘小鼠BALF中各种炎症细胞数量,降低小鼠BALF中IL-4、IL-5、IL-13...     

IL-27对哮喘小鼠气道炎症的影响

目的研究IL-27对卵白蛋白(OVA)激发哮喘小鼠气道炎症的影响。方法 24只雌性BALB/c小鼠随机分为生理盐水组、哮喘组及IL-27组,每组8只。应用OVA建立哮喘模型,IL-27组小鼠应用1μgIL-27(溶于50μlPBS中)滴鼻给药,观察3组小鼠肺组织病理改变,计数支气管肺泡灌洗液(BALF)中嗜酸性粒细胞;ELISA法测定小鼠BALF中IL-4和IFN-γ浓度,RT-PCR测定肺组织T-bet mRNA的表达量。结果 IL-27组小鼠肺组织炎症反应明显轻于哮喘组小鼠;IL-27组小鼠BALF中嗜酸性粒细胞计数为(2.21±0.33)×107/L明显低于哮喘组的(12.82±2.17)×107/L(P0.01);IL-27组小鼠BALF中IL-4浓度为(20.4±3.2)μg/L,明显低于哮喘组的(61.3±13.1)μg/L(P0.05);IL-27组小鼠BALF中IFN-γ浓度为(50.3±6.3)μg/L,明显高于哮喘组的(11.1±3.3)μg/L(P0.05);IL-27组小鼠肺组织T-bet mRNA表达量(吸光度积分比值)为(0.268±0.048),明显高于哮喘组的(0.130±0.012)(P0.05)。结论 IL-27可能通过增强T-bet mRNA的表达增强Th1反应,减少BALF中嗜酸性粒细胞数量,进而减轻了哮喘小鼠肺组织炎症反应。     

Respiratory syncytial virus infection does not increase allergen-induced type 2 cytokine production, yet increases airway hyperresponsiveness in mice

Severe respiratory syncytial virus (RSV)-induced disease is associated with childhood asthma and atopy. We combined murine models of allergen-sensitization and RSV infection to explore the interaction of allergic and virus-induced airway inflammation and its impact on airway hyperresponsiveness (AHR). We found that RSV infection during ova-sensitization (OVA/RSV) increased and prolonged AHR compared to mice only RSV-infected (RSV) or ova-sensitized (OVA). AHR is known to be associated with an increase in Type 2 cytokines (IL-4, IL-5, and IL-13) in allergen-sensitized mice. Therefore, we hypothesized that RSV-induced enhancement of AHR was a result of potentiating the Type 2 cytokine profile promoted by ova-sensitization. Surprisingly, we found that Type 2 cytokines induced by ova-sensitization were not increased by RSV infection despite the increase in AHR, and in some cases were diminished. RNAse protection assay revealed no difference in IL-4 and IL-5 mRNA levels between the OVA and OVA/RSV groups, and IL-13 mRNA was significantly decreased in the OVA/RSV mice compared to the OVA group. Flow cytometric analysis of Type 2 cytokines demonstrated the same frequency of IL-4 and IL-5 production in lung-derived T lymphocytes from the OVA/RSV and OVA groups. Direct cytokine ELISA measurements of lung supernatant showed the level of IL-13 was significantly decreased in the OVA/RSV group compared to OVA mice, while there was no difference in either IL-4 or IL-5 between these two groups. These data indicate that the enhanced and prolonged AHR caused by the interaction of allergic airway inflammation and virus-induced immune responses is a complex process that can not be explained simply by augmented production of Type 2 cytokines.     

Respiratory syncytial virus infection prolongs methacholine-induced airway hyperresponsiveness in ovalbumin-sensitized mice

Severe respiratory syncytial virus (RSV)-induced disease is associated with childhood asthma and atopy. We combined models of allergen sensitization and RSV infection to begin exploring the immunologic interactions between allergic and virus-induced airway inflammation and its impact on airway hypersensitivity. Airway resistance was measured after methacholine challenge in tracheally intubated mice by whole body plethysmography. Lung inflammation was assessed by bronchoalveolar lavage (BAL) and histopathology. RSV infection alone did not cause significant airway hyperresponsiveness (AHR) to methacholine. Ovalbumin (OVA)-induced AHR lasted only a few days past the discontinuance of OVA aerosol in mice that were ovalbumin sensitized and mock infected. In contrast, OVA-sensitized mice infected with RSV during the OVA aerosol treatments (OVA/RSV) had AHR for more than 2 weeks after infection. However, 2 weeks after either RSV or mock infection, OVA/RSV mice had significantly more lymphocytes found during BAL than OVA mice, whereas the OVA and OVA/RSV groups had the same number of eosinophils. Histopathologic analysis confirmed an increased inflammation in the lungs of OVA/RSV mice compared with OVA mice. In addition, OVA/RSV mice had a more widespread distribution of mucus in their airways with increased amounts of intraluminal mucus pools compared with the other groups. Thus, prolonged AHR in RSV-infected mice during ovalbumin-sensitization correlates with increased numbers of lymphocytes in BAL fluid, increased lung inflammation, and mucus deposition in the airways, but not with airway eosinophilia. A further understanding of the immunologic consequences of combined allergic and virus-induced airway inflammation will impact the management of diseases associated with airway hyperreactivity. J. Med. Virol. 57:186–192, 1999. © 1999 Wiley-Liss, Inc.     

Influence of viral infection on the development of nasal hypersensitivity

BACKGROUND: The underlying relationship between viral infections and allergic diseases of the upper respiratory tract has not been well clarified. METHODS: In order to clarify the relationship between viral infection and nasal hypersensitivity, mice were sensitized with ovalbumin (OVA) and then infected intranasally with respiratory syncytial virus (RSV), after which their nasal sensitivity to histamine or antigen was examined. RESULTS: Non-sensitized mice showed transient mild nasal hypersensitivity following nasal administration of histamine after intranasal RSV inoculation. In mice sensitized with OVA, RSV infection significantly exaggerated their nasal hypersensitivity to histamine and OVA. Treatment of these mice with a neurokinin (NK)-1/NK-2 receptor antagonist, but not with anti-IL-5 antibodies, reduced their hypersensitivity. The infiltration of nasal mucosa with eosinophils was temporarily associated with accelerated rate of RSV elimination in these animals. CONCLUSION: RSV infection induced transient nasal hypersensitivity. Several mechanisms, including impairment of nasal epithelial cells are thought to mediate this effect. In allergen-sensitized mice, RSV inoculation strongly enhanced nasal hypersensitivity.     

Neonatal respiratory syncytial virus infection has an effect on lung inflammation and the CD4+CD25+ T cell subpopulation during ovalbumin sensitization in adult mice

In BALB/c adult mice, respiratory syncytial virus (RSV) infection enhances the degree of lung inflammation before and/or after ovalbumin (OVA) respiratory sensitization. However, it is unclear whether RSV infection in newborn mice has an effect on the immune response to OVA respiratory sensitization in adult mice. The aim of this study was to determine if RSV neonatal infection alters T CD4⁺ population and lung inflammation during OVA respiratory sensitization in adult mice. BALB/c mice were infected with RSV on the fourth day of life and challenged by OVA 4 weeks later. We found that in adult mice, RSV neonatal infection prior to OVA sensitization reduces the CD4⁺CD25⁺ and CD4⁺CD25⁺ forkhead protein 3 (FoxP3)⁺ cell populations in the lungs and bronchoalveolar lavage. Furthermore, it also attenuates the inflammatory infiltrate and cytokine/chemokine expression levels in the mouse airways. In conclusion, the magnitude of the immune response to a non‐viral respiratory perturbation in adult mice is not enhanced by a neonatal RSV infection.     

Respiratory syncytial virus enhances respiratory allergy in mice despite the inhibitory effect of virus-induced interferon-gamma

In mice, respiratory syncytial virus (RSV) infection during allergic provocation aggravates the allergic Th2 immune response, characterised by production of interleukin (IL)-4, IL-5, and IL-13, and eosinophilic inflammation. This enhancement of the Th2 response occurs simultaneously with a strong RSV-induced Th1 cytokine response (IL-12 and IFN-gamma). The present study investigated whether IFN-gamma and IL-12 are critically involved in this RSV-enhanced OVA allergy. Therefore, IFN-gammaR- and IL-12-deficient mice (both on a 129/Sv/Ev background) were sensitised and challenged with ovalbumin (OVA) and infected with RSV during the OVA challenge period. Neither gene deletion affected the development of ovalbumin-induced allergic inflammation in mice. However, when OVA-allergic IFN-gammaR deficient mice were infected with RSV, an increased pulmonary eosinophilic infiltrate and increased IL-4 and IL-13 mRNA expression in lung tissue were observed compared with identically treated wild-type mice. In contrast, deficiency of IL-12 did not aggravate the Th2 immune and inflammatory response in OVA/RSV-treated mice, compared with wild-type. In conclusion, the virus-induced IFN-gamma response diminishes the Th2 inflammatory response during OVA allergy but fails to prevent totally the enhancement of the OVA allergy by RSV. In contrast, IL-12 is not involved in inhibiting nor increasing the RSV-enhanced allergy in 129/Sv/Ev mice.     

Dual Effects of Respiratory Syncytial Virus Infections on Airway Inflammation by Regulation of Th17/Treg Responses in Ovalbumin-Challenged Mice

We investigated the effects of respiratory syncytial virus (RSV) infections on ovalbumin (OVA)-challenged mice via regulation of Th17/Treg cell responses. BALB/c mice were challenged with OVA, followed by RSV infections twice. In OVA-challenged mice, the secretion of Th2/Th17-type cytokines, airway hyperresponsiveness and inflammation were significantly inhibited by initial RSV infection. Moreover, the in vivo findings demonstrated that initial RSV infection reversed the imbalance of Th17/Treg responses. In contrast, RSV re-infection strengthened Th2/Th17-type cytokine secretion, airway hyperresponsiveness, and inflammation, especially for lymphocyte infiltration in OVA-challenged mice. Meanwhile, RSV re-infection enhanced the imbalanced Th17/Treg responses. Upon all results reveal that RSV-induced respiratory infections may lead to dual effects pertaining to allergic airway inflammation by regulation of Th17/Treg responses.     

Influence of respiratory syncytial virus infection on cytokine and inflammatory responses in allergic mice

BACKGROUND: Th2 lymphocyte responses are associated with inflammation and disease during allergic responses. Exposure to particular environmental factors during the expression of allergy could result in more pronounced Th2-like immune responses and more severe disease. One factor might be a respiratory virus infection. OBJECTIVE: The aim of our study was to investigate the influence of respiratory syncytial virus (RSV) infection on the expression of ovalbumin (OVA)-induced allergy in BALB/c mice. METHODS: We determined OVA-specific IgE in serum, cytokine profiles and histopathological lesions in lungs of OVA-allergic mice after RSV infection. RESULTS: OVA sensitization and challenge induced OVA-specific IgE in serum, Th2 cytokine mRNA expression, and mononuclear and eosinophilic inflammation in the lungs. RSV inoculation during the challenge period enhanced OVA-induced IL-4 and IL-5 mRNA expression in lung tissue. RSV further enhanced the OVA-induced hypertrophy of mucous cells and eosinophilic infiltration in lung tissue. Surprisingly, RSV infection decreased Th2 cytokine secretion and eosinophilic influx in bronchoalveolar lavage of OVA-allergic mice. Because inactivated RSV did not influence these responses, replication of RSV appeared essential for the modification of OVA-induced Th2 cytokine expression. RSV did not change OVA-specific IgE levels in serum. Furthermore, the RSV-induced IL-12 mRNA expression in lung tissue of OVA-allergic mice was diminished, but IFN-gamma mRNA expression was not affected. CONCLUSION: RSV infection enhanced particular OVA-induced Th2 cytokine mRNA responses and pulmonary lesions in allergic mice and thus aggravated allergic respiratory disease.     

右美托咪定通过抑制内质网应激反应减轻肺缺血/再灌注小鼠肾损伤

目的:评价右美托咪定(dexmedetomidine,DEX)通过抑制内质网应激反应减轻小鼠肺缺血/再灌注(I/R)诱发肾损伤的机制。方法:雄性健康SPF级C57BL/6J小鼠50只,体重20~24 g,8~10周龄,随机分为5组(n=10):假手术组(sham组)、I/R组、阿替美唑(atipamezole,Atip)组、DEX组和DEX+Atip组。采用小鼠在体左侧肺门夹闭30 min再灌注180 min方法制备肺缺血/再灌注损伤(I/R)模型。Atip组、DEX组和DEX+Atip组分别在肺门阻断前30 min腹腔注射Atip(250μg/kg)、DEX(20μg/kg)和DEX+Atip,其余处理同I/R组。再灌注结束后眼眶采血检测血肌酐与尿素氮浓度,取肾组织光镜下观察肾细胞的形态学改变,检测caspase-3的酶活性,TUNEL法检测肾细胞凋亡指数,Western blot和RT-PCR检测c-Jun氨基末端激酶(JNK)、caspase-12、CCAAT/增强子结合蛋白同源蛋白(CHOP)和葡萄糖调节蛋白78(GRP78)的蛋白及mRNA水平。结果:与假手术组相比,其余组光镜下肾组织有明显损伤,血肌酐与尿素氮、肾细胞凋亡指数、caspase-3酶活性、JNK、caspase-12、CHOP和GRP78的蛋白及mRNA水平均升高(P0.01)。与I/R、Atip组和DEX+Atip组相比,DEX组光镜下可见肾细胞损伤减轻,血肌酐与尿素氮、肾细胞凋亡指数、caspase-3酶活性、JNK、caspase-12和CHOP表达均有下降,GRP78表达升高,差异有统计学意义(P0.01)。结论:右美托咪定预先给药可减轻小鼠肺缺血/再灌注诱发的肾损伤,其机制可能与激动α2-肾上腺素能受体,抑制内质网过度应激有关。     

Respiratory syncytial virus protects against the subsequent development of ovalbumin‐induced allergic responses by inhibiting Th2‐type γδ T cells

Respiratory syncytial virus (RSV) infection has been hypothesized to be a risk factor for the development of allergy and asthma, but epidemiologic studies in humans still remain inconclusive. The association between RSV infection and allergic diseases may be dependent on an atopic background and previous history of RSV infection. It has been reported that RSV infection before sensitization to an allergen decreased the production of Th2‐like cytokines in the lung and the levels of allergen‐specific Th2‐type antibodies in the serum. However, the underlying mechanisms are largely unknown. In the present study, the role of pulmonary γδ T cells in RSV‐affected, allergen‐induced airway inflammation was investigated. BALB/c mice were sensitized to or challenged with ovalbumin (OVA) and infected with RSV either before or after the sensitization period. It became clear that sensitization and challenge of mice with OVA induced a large influx of γδ T cells to the lungs. However, prior RSV infection inhibited the infiltration of γδ T cells as well as activated γδ T cells, characterized by expression of CD40L or CD69 molecular in the cell surface. Moreover, prior RSV infection elevated the type 1 cytokine gene expression but suppressed type 2 cytokine expression in the lung γδ T cells. Adoptive transfer of γδ T cells from OVA‐sensitized and challenged mice increased airway inflammation, suggesting that γδ T cells may play a proinflammatory role in allergic responses. These results described here support the idea of an unknown γδ T cell‐dependent mechanism in the regulation of RSV‐affected, allergen‐induced allergic airway responses. J. Med. Virol. 85:149–156, 2012. © 2012 Wiley Periodicals, Inc.     

人参二醇组皂苷具有与地塞米松类似的改善LPS处理小鼠肾功能的作用*

 目的：研究人参二醇组皂苷（PDS）和地塞米松（DEX）是否具有类似的减轻LPS诱导的小鼠急性肾损伤（AKI）的作用,并探讨它们的作用机制。方法：C57BL/6小鼠随机分为4组,除对照组腹腔注射生理盐水外,其余3组均经腹腔注射LPS 10 mg/kg,PDS组和DEX组小鼠在LPS注射前1 h分别经腹腔注射PDS（25.0 mg/kg）或DEX（2.5 mg/kg）。12 h后麻醉下取血和肾脏组织备生物化学与免疫印迹检测。结果：LPS组小鼠血尿素氮和肌酐含量显著高于对照组（P<0.01）,而PDS组和DEX组则明显低于LPS组（P<0.05）;PDS和DEX上调 LPS处理的小鼠肾组织IκB蛋白的表达,抑制NF-κB信号通路的活化,进而减少TNF-α和IL-6的产生;PDS和DEX均能下调LPS处理的小鼠肾脏诱导型一氧化氮合酶（iNOS）的表达,上调肾组织锰过氧化物歧化酶的表达,减轻肾脏的氧化应激损伤。此外,PDS和DEX均明显上调LPS处理的小鼠肾脏组织细胞核糖皮质激素受体蛋白的含量。结论：人参二醇组皂苷具有与DEX相类似的减轻LPS诱导的小鼠AKI的作用,而且,它们的作用机制相似,但PDS的药效学是否也通过糖皮质受体介导还需进一步研究。