T-helper 1 cells induce alveolitis but do not lead to pulmonary fibrosis in mice.

T-helper (Th)1 cells have a pivotal role in the pathogenesis of hypersensitivity pneumonitis. Continued low-level exposure to the antigens may induce chronic hypersensitivity pneumonitis with lung fibrosis. Although such exposure may activate Th1 cells in the lung, it is not known whether activation of Th1 cells per se can lead to pulmonary fibrosis. To determine this, the lung pathology induced by Th1 clones was investigated. Mice (BALB/c) were injected intraperitoneally with Th1 clones 1-4 times. Each injection was performed 4 days apart and was followed by repeated exposure to aerosolised ovalbumin (OVA) once a day for 5 days. The number of macrophages and lymphocytes in bronchoalveolar lavage fluids (BALF) increased as the number of Th1 transfers increased. The number of neutrophils also increased but peaked in the second transfer and then decreased following further transfers. Increased cell infiltration, thickness of alveolar walls and number of type II cells in the lung occurred. However, histological findings showed no evidence of fibrosis and hydroxyproline levels did not increase. Findings of histology and BALF were ameliorated 2 weeks after the discontinuation of OVA exposure, indicating the reversibility of the Th1-induced pathology. In conclusion, adoptive transfer of T-helper 1 cells results in reversible alveolitis but does not lead to pulmonary fibrosis.     

Anti-interleukin 5 but not anti-IgE prevents airway inflammation and airway hyperresponsiveness.

The role of IL-5 and allergen-specific IgE in the development of eosinophilic airway inflammation and airway hyperresponsiveness (AHR) was investigated in a murine model. BALB/c mice were sensitized to ovalbumin (OVA) by intraperitoneal injection on Days 1 and 14, followed by airway challenge with OVA on Days 28 and 29. Anti-IL-5 (TRFK-5) or anti-IgE (antibody 1-5) was administered before each airway challenge. Sensitized and challenged mice developed increased OVA-specific IgE serum levels, Th2 cytokine production by peribronchial lymph node (PBLN) cells, increased numbers of eosinophils (predominantly located in the peribronchial regions of the lungs), and increased airway responsiveness to methacholine (MCh). Anti-IgE treatment significantly decreased serum anti-OVA IgE levels and prevented the development of anaphylaxis but failed to affect T cell function, eosinophil airway infiltration, and AHR in sensitized and challenged mice. In contrast, treatment with anti-IL-5 antibody did not affect B cell (Ig serum levels), T cell (cytokine production), or mast cell function (immediate cutaneous reactivity) but completely inhibited development of eosinophilic lung inflammation and AHR. These data identify IL-5-mediated eosinophilia as a major target for development of AHR in this model, with little effect resulting from neutralization of IgE.     

Nitric oxide and protein nitration are eosinophil dependent in allergen-challenged mice

To explore the possible role of eosinophils in NO-mediated tissue injury, we studied a murine model of allergic asthma. Male A/J mice were sensitized and challenged intranasally with ovalbumin (OVA). Following challenge, the number of eosinophils in bronchoalveolar lavage fluid (BALF) increased from 0.4% of total cells at baseline (0.02 x 10(4) cells/ml) to 60.2% at 48 h after the challenge (9.34 x 10(4) cells/ml). The rise in eosinophil count was accompanied by a 40.3% increase in total NO(2-) plus NO(3-) (NO(x)) in BALF. This in turn was accompanied by expression of inducible NO synthase (NOS II) in airway epithelial and inflammatory cells, as well as by evidence of staining for 3-nitrotyrosine (3NT) in peribronchial inflammatory cells and at the epithelial surface. Both NO(x) production and 3NT were significantly reduced by pretreatment of the challenged mice with the highly specific NOS II inhibitor N-3-aminomethyl-benzyl-acetamidine-dihydrochloride (1400W), as well as by the nonselective NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME). L-NAME and 1400W also reduced the number of BALF eosinophils (37.2% and 61.5%, respectively, as compared with the control value), suggesting that NO production by NOS II contributes to eosinophil recruitment. To further examine the role of eosinophils, we pretreated additional mice with an anti-interleukin (IL)-5 antibody, which reduced BALF eosinophilia following OVA challenge by 90.1%. In concert with the decrease in eosinophils, the anti-IL-5 antibody reduced NO(x) in BALF almost to the baseline value, and decreased the number of 3NT-positive cells in the peribronchial region by 74.4%. Western blot analysis of protein extracted from whole lung confirmed the reduction in tyrosine nitration by anti-IL-5 antibody. These findings indicate that NO and eosinophilic inflammation are closely coupled, and suggest that eosinophils are an important source of tyrosine nitration.     

外源性间充质干细胞减轻支气管哮喘小鼠气道炎症的研究

目的 观察鸡卵清蛋白诱导小鼠支气管哮喘(简称哮喘)模型中外源性间充质干细胞(mesenchymal stem cells,MSC)在哮喘小鼠肺组织气道炎症中的作用.方法 45只雌性SPF级C57BL/6小鼠,体质量18～22 g.随机分为对照组(P:P:P)、哮喘组(O:P:O)和MSC治疗组(O:M:O).哮喘组与MSC治疗组第1天和第8天致敏,第15天、第16天和第17天使用OVA气道内滴入激发哮喘.MSC治疗组于哮喘造模第14天移植外源性MSC.对照组小鼠予PBS处理.三组小鼠于末次激发结束后24 h(第18天)处死,取支气管肺泡灌洗液上清,ELISA检测IL-5、IL-9及β-氨基己糖苷酶;支气管肺泡灌洗液细胞计数总细胞数、嗜酸粒细胞数;取肺组织行病理切片苏木精-伊红染色观察肺部气道炎症情况.结果 ①MSC下调了哮喘小鼠气道局部炎症;②MSC减轻了哮喘小鼠肺组织中的炎细胞浸润;③MSC减轻了哮喘小鼠气道中的肥大细胞脱颗粒现象;④MSC抑制了哮喘小鼠过度的Th2变态反应.结论 外源性MSC通过抑制Th2变态反应,减轻哮喘肺组织的气道炎症.     

The effects of antisense interleukin-4 gene transferred by recombinant adeno-associated virus vector on the airway remodeling in allergic rats

Background: Th2-derived cytokines, including interleukin-4 (IL-4), are considered to play an important role in the development of airway remodeling of asthma. Objectives: Our previous study has demonstrated that a recombinant adeno-associated virus containing antisense against IL-4 gene (rAAV-asIL4) vector could significantly suppress the expression of IL-4 protein and airway inflammation in the rat models of allergic asthma. In this study, we applied the rAAV-asIL4 vector to allergic rats to investigate the effects of anti-IL4 therapy on airway remodeling in allergic asthma. Methods: rAAV-asIL4 was used to infect the ovalbumin (OVA)-sensitized and challenged rats by tail-vein injection. IL-4 protein in bronchoalveolar lavage fluid (BALF) was detected by enzyme-linked immunosorbent assay. The number of eosinophils in BALF was counted. Transforming growth factor-beta1 (TGF-beta1) and TGF-beta2-positive cells in the peribronchial space were detected by immunohistochemical staining, and collagen deposition beneath the basement membrane was detected by Sirius red stain. The lung tissues were collected for histologic analysis of total bronchial wall area (W_At) and airway smooth muscle area (W_Am). Results: rAAV-asIL4 significantly decreased IL-4 protein in BALF of OVA-sensitized and challenged rats. The number of eosinophils in BALF, the TGF-beta1 and TGF-beta2-positive cells in the peribronchial space were also suppressed. Moreover, the rAAV-asIL4 treatment inhibited the area of Sirius red staining in airways and the increase in W_At and W_Am. Conclusion: These results suggest that rAAV-asIL4 may attenuate the airway remodeling process relevant to the inhibition of airway inflammation. This study provides elementary evidence for the potential utility of rAAV-asIL4 as an approach to gene therapy for asthmatic airway remodeling.     

外源性间充质干细胞减轻支气管哮喘小鼠气道炎症的研究

目的观察鸡卵清蛋白诱导小鼠支气管哮喘（简称哮喘）模型中外源性间充质干细胞（mesenehymal stem cells,MSC）在哮喘小鼠肺组织气道炎症中的作用。方法45只雌性SPF级C57BL／6小鼠,体质量18-22g。随机分为对照组（P：P：P）、哮喘组（O：P：O）和MSC治疗组（O：M：O）。哮喘组与MSC治疗组第1天和第8天致敏,第15天、第16天和第17天使用OVA气道内滴入激发哮喘。MSC治疗组于哮喘造模第14天移植外源性MSC。对照组小鼠予PBS处理。三组小鼠于末次激发结束后24h（第18天）处死,取支气管肺泡灌洗液上清,ELISA检测IL-5、IL-9及β-氨基己糖苷酶;支气管肺泡灌洗液细胞计数总细胞数、嗜酸粒细胞数;取肺组织行病理切片苏木精-伊红染色观察肺部气道炎症情况。结果①MSC下调了哮喘小鼠气道局部炎症;②MSC减轻了哮喘小鼠肺组织中的炎细胞浸润;③MSC减轻了哮喘小鼠气道中的肥大细胞脱颗粒现象;④MSC抑制了哮喘小鼠过度的Th2变态反应。结论外源性MSC通过抑制Th2变态反应,减轻哮喘肺组织的气道炎症。     

Effect of choline chloride in allergen-induced mouse model of airway inflammation.

The incidence of asthma has increased the world over, and current therapies for the disease suffer from potential side-effects. This has created an opportunity to develop novel therapeutic approaches. Here, the anti-inflammatory activity of choline was investigated in a mouse model of allergic airway inflammation. Choline (1 mg.kg(-1)) was administered via oral gavage or intranasally before and after ovalbumin (OVA) challenge in sensitised mice. Airway hyperresponsiveness (AHR) to methacholine was measured in the mice by whole-body plethysmography. Type-2 T-helper cell cytokine and leukotriene levels were estimated in bronchoalveolar lavage fluid (BALF) and spleen culture supernatant by ELISA. Eosinophil peroxidase activity was also determined in the BALF supernatant. Choline treatment in sensitised mice before OVA challenge via oral/intranasal routes significantly inhibited eosinophilic airway inflammation and eosinophil peroxidase activity. It also reduced immunoglobulin E and G1 production and inhibited the release of type-2 T-helper cell cytokines and leukotrienes. However, the development of AHR was prevented effectively by intranasal choline treatment. Most importantly, choline treatment after OVA challenge by both routes could reverse established asthmatic conditions in mice by inhibiting AHR, eosinophilic airway inflammation and other inflammatory parameters. This study provides a new therapeutic approach for controlling as well as preventing asthma exacerbations.     

T helper 1 cells stimulated with ovalbumin and IL-18 induce airway hyperresponsiveness and lung fibrosis by IFN-gamma and IL-13 production

We previously reported that ovalbumin (OVA) and IL-18 nasally administered act on memory type T helper (Th)1 cells to induce airway hyperresponsiveness (AHR) and inflammation, which is characterized by peribronchial infiltration with neutrophils and eosinophils. Here, we report this administration also induces lung fibrosis in an IL-13-dependent manner. Th1 cells secrete several cytokines, including IFN-gamma and bronchogenic cytokine IL-13, when stimulated with antigen (Ag) and IL-18. However, IL-13 blockade failed to attenuate AHR, although this treatment inhibited eosinophilic infiltration. To understand the mechanism by which Th1 cells induce AHR after Ag plus IL-18 challenge, we established "passive" and "active" Th1 mice by transferring OVA-specific Th1 cells into na?ve BALB/c mice or by immunizing na?ve BALB/c mice with OVA/complete Freund's adjuvant, respectively. Administration of Ag and IL-18 induced both types of Th1 mice to develop AHR, airway inflammation, and lung fibrosis. Furthermore, this treatment induced deposition of periostin, a novel component of lung fibrosis. Neutralization of IL-13 or IFN-gamma during Ag plus IL-18 challenges inhibited the combination of eosinophilic infiltration, lung fibrosis, and periostin deposition or the combination of neutrophilic infiltration and AHR, respectively. We also found that coadministration of OVA and LPS into Th1 mice induced AHR and airway inflammation via endogenous IL-18. Thus, IL-18 becomes a key target molecule for the development of a therapeutic regimen for the treatment of Th1-cell-induced bronchial asthma.     

γ干扰素质粒基因转染对支气管哮喘小鼠气道炎症的影响

目的观察气道内γ干扰素(IFNγ)基因转染对支气管哮喘(简称哮喘)小鼠气道炎症的影响。方法健康6周龄SPF级C57BL/6小鼠40只,按随机数字表法分为4组。正常对照组(A组)、哮喘模型组(B组)、模型空质粒干预组(C组)、模型IFNγ质粒干预组(D组),每组10只。B组、C组及D组以0.1%卵白蛋白(OVA)0.1ml腹腔注射致敏,以1%的OVA50μl滴鼻激发建立哮喘模型;A组用等量生理盐水分别代替0.1%的OVA0.1ml和1%OVA50μl;C组和D组分别经鼻滴入空质粒pcDNA3.1()和Lipofentamine2000混合液50μl或重组IFNγ质粒和Lipofentamine2000混合液50μl。观察各组小鼠支气管肺泡灌洗液(BALF)中的细胞成分、白细胞介素4(IL4)、IL5、IFNγ和肺组织病理学变化。结果B组小鼠BALF中炎性细胞总数、嗜酸粒细胞(EOS)、中性粒细胞和淋巴细胞计数分别为(0.102±0.020)×109/L、(0.0193±0.0047)×109/L、(0.0107±0.0039)×109/L、(0.0255±0.0042)×109/L,A组分别为(0.082±0.012)×109/L、(0.0041±0.0009)×109/L、(0.0051±0.0016)×109/L、(0.0201±0.0019)×109/L,A、B两组比较差异有统计学意义(P<0.05);D组小鼠BALF中炎性细胞总数、EOS、中性粒细胞和淋巴细胞计数分别为(0.086±0.016)×109/L、(0.0116±0.0031)×109/L、(0.0062±0.0018)×109/L、(0.0182±0.0041)×109/L,与B组比较差异有统计学意义(P<0.05)。B组小鼠BALF中IL4、IL5、IFNγ水平分别为[(39.2±5.1)pg/ml、(83.7±4.7)pg/ml、(15.7±2.7)pg/ml],A组小鼠分别为[(13.3±1.9)pg/ml、(12.1±2.3)pg/ml、(31.8±7.9)pg/ml],A、B两组比较差异有统计学意义(P<0.05);D组小鼠BALF中IL4、IL5、IFNγ水平分别为[(16.4±3.2)pg/ml、(26.3±3.4)pg/ml、(65.4±10.4)pg/ml],与B组比较差异有统计学意义(P<0.05)。A组小鼠气道无明显炎症变化,B和C组小鼠小支气管、血管黏膜下和周围肺组织有明显的炎症细胞浸润,血管壁明显水肿;D组小鼠气道炎症明显减轻。结论气道内转染干扰素质粒能有效改善哮喘小鼠细胞因子IL4、IL5和IFNγ异常,同时对EOS、中性粒细胞数和淋巴细胞肺内募集、肺组织炎症改变有一定抑制作用。     

Airway epithelium expresses interleukin-18.

Interleukin (IL)-18 is an interferon (IFN)-gamma-inducing cytokine suggested to be important in regulating inflammatory responses. This study investigated the pulmonary expression of IL-18 under conditions characterized by T-helper (Th)1 (lipopolysaccharide (LPS) treatment/sarcoidosis) and Th2 (ovalbumin (OVA) challenge/asthma) cytokine production. In situ hybridization and immunocytochemistry were used to determine the number of cells expressing IL-18, IFN-gamma, IL-5 and major basic protein (MBP) within lung tissue from Balb/c mice stimulated with LPS, OVA and in normal control mice. Bronchial biopsies from patients with sarcoidosis, asthma and control individuals were also examined. IL-18 was localized primarily to airway epithelium and mononuclear cells. Constitutive expression was observed within the lungs of control mice. Animals challenged with LPS exhibited more IL-18 messenger ribonucleic acid (mRNA)-positive and IFN-gamma immunoreactive cells, compared to control mice (p<0.01). OVA-challenged mice had fewer IL-18 mRNA positive and more IL-5 and MBP immunoreactive cells, compared to control mice (p<0.01). Similarly, constitutive expression of IL-18 protein was observed within the airway epithelium of control individuals, with more positive cells found within sarcoidosis tissue (p<0.01) and fewer within asthmatic tissue (p<0.01), compared to controls. These results demonstrate the expression of interleukin-18 within airway epithelium and the regulation of this cytokine under conditions of both T-helper1 and T-helper2 cytokine production.     

粉尘螨Ⅲ类重组变应原致敏的小鼠哮喘模型致敏效果分析

目的 探讨粉尘螨Ⅲ类重组变应原（Der f3）诱导的小鼠哮喘模型的致敏效果。方法 30只6~8周龄雌性SPF级BALB/c小鼠随机分为PBS组（阴性对照组）、卵清蛋白（OVA）组（阳性对照组）和Der f3组（实验组）,OVA组和Der f3组分别使用OVA和纯化Der f3蛋白于第0、7、14天进行腹腔注射致敏,于第21d开始雾化吸入,连续7d,PBS组则换成PBS进行腹腔注射和雾化吸入。最后一次雾化吸入24h后,分别观察肺组织病理变化、支气管肺泡灌洗液（BALF）中的白细胞计数,酶联免疫吸附试验（ELISA）测定BALF和脾细胞培养上清中IL-4、IL-2、IL-17和IFN-γ的含量及血清中IgG1、IgE抗体水平变化;结果OVA组和Der f3组小鼠肺部支气管、血管粘膜下及周围肺组织有明显的炎性细胞浸润、支气管上皮细胞部分断裂及脱落,血管壁明显水肿等,而PBS组未见明显病理改变;Der f3组的BALF中白细胞总数[(19.99±1.03)×106个/ml]及嗜酸性粒细胞（EOS）[(1.81±0.07)×106个/ml]计数均明显高于PBS组（P<0.01）;与PBS组相比：BALF中IL-4 [(80.99±9.06) pg/ml]、IL-17 [(209.69±31.86) pg/ml]呈高水平表达（P<0.01）,而IL-2 [(8.29±1.27) pg/ml]和IFN-γ [(55.04±18.85) pg/ml]含量则显著下降（P<0.01）;上述指标在脾细胞培养上清中出现类似的变化。Der f3组血清中IgE [(31.92±2.68) U/ml]、IgG1 [(16.46±4.32) μg/ml]的含量表现为Th2型反应增强趋势;但OVA组和Der f3组间所有指标差异均无统计学意义（P>0.05）;结论 粉尘螨重组Der f3蛋白可成功建立小鼠变态反应性气道及肺部炎症动物模型。     

Lipopolysaccharides promote a shift from Th2-derived airway eosinophilic inflammation to Th17-derived neutrophilic inflammation in an ovalbumin-sensitized murine asthma model

Introduction: The currently available treatments for severe asthma are insufficient. Infiltration of neutrophils rather than eosinophils into the airways is an important inflammatory characteristic of severe asthma. However, the mechanism of the phenotypic change from eosinophilic to neutrophilic inflammation has not yet been fully elucidated. Methods: In the current study, we examined the effect of lipopolysaccharides (LPS) on eosinophilic asthmatic mice sensitized with ovalbumin (OVA), as well as the roles of interleukin (IL)-17A/T helper (Th) 17 cells on the change in the airway inflammatory phenotype from eosinophilic to neutrophilic inflammation in asthmatic lungs of IL-17A-deficient mice. Results: Following exposure of OVA-induced asthmatic mice to LPS, neutrophil-predominant airway inflammation rather than eosinophil-predominant inflammation was observed, with increases in airway hyperresponsiveness (AHR), the IL-17A level in bronchoalveolar lavage fluid (BALF) and Th17 cells in the spleen and in the pulmonary hilar lymph nodes. Moreover, the neutrophilic asthmatic mice showed decreased mucus production and Th2 cytokine levels (IL-4 and IL-5). In contrast, IL-17A knockout (KO) mice exhibited eosinophil-predominant lung inflammation, decreased AHR, mucus overproduction and increased Th2 cytokine levels and Th2 cells. Conclusion: These findings suggest that the eosinophilic inflammatory phenotype of asthmatic lungs switches to the neutrophilic phenotype following exposure to LPS. The change in the inflammatory phenotype is strongly correlated with the increases in IL-17A and Th17 cells.     

灵芝孢子对支气管哮喘豚鼠引喘潜伏期及类胰蛋白酶释放的影响

目的 研究灵芝孢子对支气管哮喘(简称哮喘)豚鼠引喘潜伏期及肥大细胞类胰蛋白释放的影响.方法 10%卵蛋白腹腔注射致敏,雾化吸入1%卵蛋白方式诱导复制哮喘动物模型.30只健康豚鼠随机分为对照组(A)、哮喘组(B)、灵芝组(C)3组,每组10只,分别用生理盐水,灵芝孢子灌胃15 d.测定哮喘豚鼠的引喘潜伏期及呼气相气道阻力(Re),计数支气管肺泡灌洗液(BALF)细胞总数及分类,肺组织HE染色和免疫组织化学观察肺组织病理变化及肥大细胞类胰蛋白酶分布情况.结果 ①灵芝组的引喘潜伏期明显较哮喘模型组延长,Re显著降低(P＜0.05).②哮喘BALF白细胞总数及嗜酸粒细胞比例较生理盐水组增高(P＜0.05),肺组织炎性病变明显;灵芝组BALF细胞总数、嗜酸粒细胞比例及肺组织炎性病变明显较哮喘组降低或减轻(P＜0.05).③哮喘组类胰蛋白酶染色阳性的肥大细胞计数明显较生理盐水组增多(P＜0.05),主要分布在气道黏膜下,肺泡间隔及血管周围;灵芝组类胰蛋白酶染色阳性的肥大细胞计数较哮喘组显著减少.结论 灵芝孢子有延长哮喘豚鼠引喘潜伏期,降低气道阻力,减轻肺组织炎性病变,抑制肥大细胞释放类胰蛋白酶的作用.     

Effects and Mechanism of Arsenic Trioxide on Reversing the Asthma Pathologies Including Th17-IL-17 Axis in a Mouse Model

In traditional Chinese medicine, arsenous compounds, including arsenic trioxide (ATO), are often used to treat many diseases, which are safe and effective. Recently, studies have indicated that Th17- IL-17 involved in the pathogenesis and development of asthma. The goal of this study was to investigate the effect and mechanism of ATO on asthma, especially the Th17- IL-17 axis.We used oval bumin (OVA)-immunized mice as a model for asthma and treated mice with ATO or dexamethasone. The mice were then monitored airway responsiveness, airway inflammation, mucus production, IL-17 levels in BALF and the positive rate of Th17 cells. In vitro, CD4+ T cells from splenic cell suspensions were separated and purified. We measured the expression of IL-17 and caspase-12 protein in purified CD4+ T cells, and detected IL-17 levels in CD4+ T lymphocyte culture solution with or without ATO. Moreover, apoptosis, mitochondrial membrane potential, cytosolic calcium were analyzed. We found that ATO could reduce airway responsiveness, airway inflammation, mucus hyperplasia, the expression of IL-17 in BALF and the positive rate of Th17 cells at a level comparable to treatment with DXM. In vitro data suggested that ATO can induce CD4+ T cells apoptosis, cause mitochondrial dysfunction, Ca2+ overload and promote caspase-12 activation. Our study suggested that ATO had potential medical value for the treatment of human asthma..     

Dual Role of Interleukin-23 in Epicutaneously-Sensitized Asthma in Mice

BackgroundInterleukin (IL)-23/Th17 axis plays an important role in the pathophysiology of asthma and eczema, however, there are some conflicting data about the effects of this system on allergic airway inflammation. In the present study, we aim to dissect the spatiotemporal differences in the roles of IL-23 in an epicutaneously-sensitized asthma model of mice.MethodsC57BL/6 mice were sensitized to ovalbumin (OVA) by patch application on the skin, followed by airway exposure to aerosolized OVA. During sensitization and/or challenge phase, either a specific neutralizing antibody (Ab) against IL-23 or control IgG was injected intraperitoneally. On days 1 and 8 after the final OVA exposure, airway inflammation and responsiveness to methacholine, immunoglobulin levels in serum, and cytokine release from splenocytes were evaluated. Skin Il23a mRNA levels were evaluated with quantitative RT-PCR.ResultsPatch application time-dependently increased the expression of Il23a mRNA expression in the skin. Treatment with the anti-IL-23 Ab during sensitization phase alone significantly reduced the number of eosinophils in bronchoalveolar lavage fluids and peribronchial spaces after allergen challenge compared with treatment with control IgG. Anti-IL-23 Ab also reduced serum levels of OVA-specific IgG1. In contrast, treatment with the anti-IL-23 Ab during the challenge phase alone rather exacerbated airway hyperresponsiveness to methacholine with little effects on airway eosinophilia or serum IgG₁ levels.ConclusionsIL-23 expressed in the skin during the sensitization phase plays an essential role in the development of allergic phenotypes, whereas IL-23 in the airways during the challenge phase suppresses airway hy- perresponsiveness.     

Infection with respiratory syncytial virus influences FasL-mediated apoptosis of pulmonary γδ T cells in a murine model of allergen sensitization

Background: It has been reported that adoptive transfer of γδ T cells increases the cellular infiltration, especially eosinophils, in the lungs of allergic mice, suggesting that γδ T cells may play a proinflammatory role in allergic airway inflammation. Respiratory syncytial virus (RSV) infection can decrease the number of Th2-type γδ T cells. However, the underlying mechanisms remain unknown. Methods: BALB/c mice were inoculated intranasally with RSV before or after sensitization to OVA. The amounts of Th1/Th2 cytokines as well as the levels of specific antibodies were determined by ELISA. The apoptotic death of pulmonary γδ T cells was analyzed by flow cytometry. Results: Adoptive transfer of γδ T cells increased the production of Th2 cytokines in the lungs and allergy-related antibodies in the serum, further confirming that γδ T cells act as pro-inflammatory cells or a promoter for the development of allergic asthma. RSV infection before sensitization to OVA enhanced apoptotic death of pulmonary γδ T cells. The percentage and absolute number of FasL-expressing γδ T cells in the lungs of allergic mice were elicited significantly by prior RSV infection. Blocking FasL with monoclonal antibody diminished apoptotic death of γδ T cells, suggesting that FasL is important for RSV-induced apoptosis of pulmonary γδ T cells. Conclusions: This work provides evidence that RSV infection suppresses the subsequent development of OVA-induced allergic responses partly by enhancing FasL-mediated apoptosis of pulmonary γδ T cells.     

内毒素诱导致敏小鼠建立支气管哮喘动物模型的实验研究

目的 评价用内毒素(LPS)诱导卵清白蛋白(OVA)激发、OVA致敏的小鼠,建立支气管哮喘(简称哮喘)模型的方法.方法 采用随机数字表法将120只BALB/c小鼠分为PBS对照组(A组,PBS致敏PBS激发)、OVA组(B组,OVA敛敏OVA激发)、LPS/LPS小剂量组(C1组,50 μg内毒素致敏50 μg内毒素激发)、LPS/LPS大剂量组(C2组,100μg内毒素敛敏100 μg内毒素激发)、OVA/LPS小剂量组(D1组,OVA致敏、OVA雾化吸入激发结合50 μg内毒素滴鼻诱导)、OVA/LPS大剂量组(D2组,OVA致敏、OVA雾化吸入激发结合100 μg内毒素滴鼻诱导).观察小鼠哮喘急性发作症状,检测BALF细胞分类计数,测定乙酰胆碱激发条件下气道反应性(以肺阻力R_L表示);HE染色观察肺组织病理变化.结果 (1)D1组与D2组小鼠喘息症状加重其中D2组更严重.(2)D1组与D2组BALF中细胞总数、巨噬细胞、淋巴细胞、嗜酸粒细胞、中性粒细胞均明显高于A组(均P<0.05).D1组的白细胞总数、淋巴细胞、嗜酸粒细胞、中性粒细胞均明最高于B组(均P<0.01),D2组的白细胞总数、巨噬细胞、淋巴细胞、中性粒细胞均明显高于B组(均P<0.05).(3)以5 g/L乙酰胆碱激发时,D1组RL[(9.32 4±1.51)cm H_2O·ml~(-1)·s~(-1)(1 cm H_2O=0.098 kPa)]和D2组R_L[(44.21±2.88)cm H_2O·ml~(-1)·s~(-1)]明显高于A组RL[(2.41±0.35)cm H_2O·ml~(-1)·s~(-1)]和B组R_L[(5.96±1.83)cm H_2O·ml~(-1)·s~(-1)],均P<0.01.(4)D1组与D2组呈现较为严重的支气管哮喘病变,其中D2组病变程度明显加重.结论 用内毒素诱导OVA致敏小鼠建立支气管哮喘模型的方法可产牛更严重支气管炎症改变以及明显的气道高反应性.     

Allergen-induced peribronchial fibrosis and mucus production mediated by IkappaB kinase beta-dependent genes in airway epithelium

In response to inflammation or injury, airway epithelial cells express inducible genes that may contribute to allergen-induced airway remodeling. To determine the contribution of epithelial cell NF-kappaB activation to the remodeling response, we generated CC10-Cre(tg)/Ikkbeta(delta/delta) mice in which NF-kappaB signaling through IkappaB kinase beta (IKKbeta) is selectively ablated in the airway epithelium by conditional Cre-recombinase expression from the Clara cell (CC10) promoter. Repetitive ovalbumin challenge of mice deficient in airway epithelial IKKbeta prevented nuclear translocation of the RelA NF-kappaB subunit only in airway epithelial cells, resulting in significantly lower peribronchial fibrosis in CC10-Cre(tg)/Ikkbeta(delta/delta) mice compared with littermate controls as assessed by peribronchial trichrome staining and total lung collagen content. Levels of airway mucus, airway eosinophils, and peribronchial CD4+ cells in ovalbumin-challenged mice were also reduced significantly upon airway epithelial Ikkbeta ablation. The diminished inflammatory response was associated with reduced expression of NF-kappaB-regulated chemokines, including eotaxin-1 and thymus- and activation-regulated chemokine, which attract eosinophils and Th2 cells, respectively, into the airway. The number of peribronchial cells expressing TGF-beta1, as well as TGF-beta1 amounts in bronchoalveolar lavage, were also significantly reduced in mice deficient in airway epithelium IKKbeta. Overall, these studies show an important role for NF-kappaB regulated genes in airway epithelium in allergen-induced airway remodeling, including peribronchial fibrosis and mucus production.     

不同内型哮喘小鼠模型中的小气道功能研究及其机制初探

目的 探讨不同内型哮喘小鼠模型中,小气道功能是否存在异常及其相关机制.方法 卵清蛋白(OVA)致敏、激发建立T2型哮喘模型,OVA联合臭氧暴露(OVA+ozone)建立非T2型哮喘模型.模拟强迫振荡系统检测小鼠小气道功能,激发试验检测气道反应性.酶联免疫吸附试验法检测支气管肺泡灌洗液(BALF)中的细胞因子;苏木精-伊...