Serine Protease Activity of Cur l 1 from <Emphasis Type="Italic">Curvularia lunata</Emphasis> Augments Th2 Response in Mice

Rationale  Studies with mite allergens demonstrated that proteolytic activity augments allergic airway inflammation. This knowledge is limited to few enzyme allergens. Objective  The objective of this study is to investigate the effect of serine protease Cur l 1 from Curvularia lunata in airway inflammation/hyper-responsiveness. Methods  Cur l 1 was purified and inactivated using a serine protease inhibitor. Balb/c mice were sensitized with enzymatically active Cur l 1 or C. lunata extract. Sensitized mice were given booster dose on day 14 with active or inactivated Cur l 1. Intranasal challenge was given on day 28, 29, and 30. Airway hyper-responsiveness was measured by plethysmography. Blood, bronchoalveolar lavage fluid (BALF), spleen, and lungs from mice were analyzed for cellular infiltration, immunoglobulins, and cytokine levels. Results  Mice challenged with enzymatically active Cur l 1 demonstrated significantly higher airway inflammation than inactive Cur l 1 group mice (p < 0.01). There was a significant difference in serum IgE and IgG1 levels among mice immunized with active Cur l 1 and inactive Cur l 1 (p < 0.01). IL-4 and IL-5 were higher in BALF and splenocyte culture supernatant of active Cur l 1 than inactive Cur l 1 mice. Lung histology revealed increased eosinophil infiltration, goblet cell hyperplasia and mucus secretion in active group. Conclusion  Proteolytic activity of Cur l 1 plays an important role in airway inflammation and the inactivated Cur l 1 has potential to be explored for immunotherapy.     

Therapeutic effects of DNA vaccine on allergen-induced allergic airway inflammation in mouse model

Vaccination with DNA encoding Dermatophagoides pteronyssinus group 2 （Der p 2） allergen previously showed its effects of immunologic protection on Der p 2 allergen-induced allergic airway inflammation in mice. In present study, we investigated whether DNA vaccine encoding Der p 2 could exert therapeutic role on allergen-induced allergic airway inflammation in mouse model and explored the mechanism of DNA vaccination in asthma specific-allergen immunotherapy. After sensitized and challenged by Der p 2, the BALB/c mice were immunized with DNA vaccine. The degrees of cellular infiltration were scored. IgE levels in serum and IL-4/IL-13 levels in BALF were determined by ELISA. The lung tissues were assessed by histological examinations. Expressions of STAT6 and NF-kB in lung were determined by immunohistochemistry staining. Vaccination of mice with DNA vaccine inhibited the development of airway inflammation and the production of mucin induced by allergen, and reduced the level of Der p 2-specific IgE level. Significant reductions of eosinophil infiltration and levels of IL-4 and IL-13 in BALF were observed after vaccination. Further more, DNA vaccination inhibited STAT6 and NF-kB expression in lung tissue in Der p 2-immunized mice. These results indicated that DNA vaccine encoding Der p 2 allergen could be used for therapy of allergen-induced allergic airway inflammation in our mouse model. Cellular ＆ Molecular Immunology.     

HSP70/CD80嵌合DNA疫苗对哮喘小鼠气道炎症和气道高反应性的作用

目的 研究HSP70/CD80嵌合DNA质粒对哮喘小鼠气道炎症和气道高反应性的作用,为安全可靠的新型免疫调节性疫苗奠定基础.方法 将40只雌性健康BALB/c小鼠随机分为4组:对照组、哮喘组、pcDNA3.1载体组、HSP70/CD80嵌合DNA疫苗组,每组10只.用HSP70/CD80嵌合疫苗免疫小鼠后,建立鸡卵清蛋白致敏的小鼠哮喘模型,观察其气道阻力变化,支气管肺泡灌洗液中IL-13、IFN-γ含量的变化.取肺组织进行病理组织学分析,观察肺内炎症情况.结果 HSP70/CD80嵌合DNA疫苗免疫小鼠后,能有效减轻气道炎症(P＜0.05),降低气道阻力(P＜0.05),肺泡灌洗液中IFNl的分泌增加(P＜0.05),IL-13降低.结论 HSP70/CD80嵌合DNA疫苗可促进免疫反应向Th1偏移并增加IFN-γ的生成,减轻气道炎症,降低气道阻力,这为过敏性哮喘新型免疫调节性疫苗的机制及应用研究提供了实验资料.     

金黄色葡萄球菌及其肠毒素B对慢性实验性哮喘小鼠的影响

目的探索金黄色葡萄球菌肠毒素B（SEB）对实验性支气管哮喘小鼠肺组织Th0细胞分化的在体调节和对气道炎症的作用。方法32只15～17dBALB／c小鼠，随机分为4组：对照组、模型组、金黄色葡萄球菌组、金黄色葡萄球菌肠毒素B（SEB）组。用卵蛋白（OVA）致敏和激发建立小鼠慢性哮喘模型，在致敏前14d对幼年鼠做金黄色葡萄球菌或SEB预防性腹腔注射。观察记录小鼠的耗氧量、肺组织切片、支气管肺泡灌洗液（BALF）中炎性细胞及相关细胞因子等的改变。结果金黄色葡萄球菌组与模型组相比，肺组织病理切片结构紊乱减轻、炎症细胞明显减少，小鼠耗氧量降低（5．24±0．12vs5．59±0．18），BALF中IL-4水平明显下降（44．94±4．51vs29．37±4．17），IFN-γ水平明显增加（19．61±3．83vs29．33±4．04），SEB组也有上述作用（耗氧量：5．09±0.20；细胞介素4：36．68±5．10；γ干扰素：24．27±3．46）。结论金黄色葡萄球菌能明显减轻实验性哮喘的气道炎症，纠正哮喘小鼠肺组织中Th1／Th2细胞因子的失衡，其作用可能是通过其分泌的SEB。     

转录因子GATA-3 mRNA在哮喘模型小鼠体内的表达

目的:探讨转录因子GATA-3 mRNA在哮喘模型小鼠体内的表达。 方法:建立卵白蛋白（OVA）致小鼠哮喘模型，计数支气管肺泡灌洗液（BALF）中炎症细胞总数和分类，评价肺组织炎症细胞浸润；ELISA检测BALF和脾细胞培养上清液中IL-4和IFN-γ浓度；RT-PCR检测脾细胞和肺组织GATA-3 mRNA表达水平。 结果:哮喘组BALF中炎症细胞总数及嗜酸粒细胞百分比明显高于对照组，支气管出现明显炎症细胞浸润、黏液分泌和支气管收缩，BALF和脾细胞培养上清液中IL-4明显高于对照组，肺组织和脾细胞GATA-3 mRNA表达水平均明显高于对照组。 结论:哮喘模型小鼠肺组织和脾细胞GATA-3 mRNA表达增加，可能在促进Th2细胞因子合成和介导气道炎症细胞浸润中具有重要作用。     

Serine protease inhibitors nafamostat mesilate and gabexate mesilate attenuate allergen-induced airway inflammation and eosinophilia in a murine model of asthma

BACKGROUND: Serine proteases such as mast cell tryptase and certain allergens are important in the pathogenesis of allergic inflammation of asthma. OBJECTIVE: We sought to investigate the effects of serine protease inhibitors nafamostat mesilate (FUT), gabexate mesilate (FOY), and ulinastatin (UTI) on airway inflammation in a mouse model of allergic asthma. METHODS: BALB/c mice were sensitized to Dermatophagoides pteronyssinus (Der p) and intratracheally challenged with Der p (0.5 mg/mL). Therapeutic doses of FUT (0.0625 mg/kg), FOY (20 mg/kg), and UTI (10,000 U/kg) were intra-peritoneally injected into 3 corresponding sensitized mice during the sensitization phase (protocol 1) or 24 hours after allergen challenge (protocol 2). RESULTS: Both FUT-treated and FOY-treated sensitized mice had reduced mast cells activation, airway hyperresponsiveness, attenuated eosinophils infiltrations, and decreased Der p-induced IL-4 and TNF-alpha, but increased IL-12 cytokine production in bronchoalveolar lavage fluid compared with nontreated mice. Furthermore, FUT treatment downregulated the expression of IL-1beta, TNF-alpha, IL-6, eotaxin, inducible NO synthase, CD86, and nuclear factor-kappaB activation, but enhanced the expression of IL-12 and IL-10 in Der p-stimulated alveolar macrophages. UTI-treated mice have no significant change of the aforementioned measurements compared with nontreated sensitized mice. CONCLUSION: Nafamostat mesilate and FOY exerting the therapeutic effect in allergen-induced airway inflammation was a result not only of their inhibitory action in the early phase of mast cells activation but also of immunoregulatory function in the late phase of allergic inflammation. Such properties of FUT and FOY might be a potential therapeutic approach for asthma. CLINICAL IMPLICATIONS: The clinical used of serine protease inhibitors FUT and FOY may also have implications for treating airway inflammation of asthma.     

Effects of alpha tocopherol and probucol supplements on allergen-induced airway inflammation and hyperresponsiveness in a mouse model of allergic asthma

OBJECTIVE: We investigated the role of antioxidants in airway hyperresponsiveness to acetylcholine using young asthma model mice, which were sensitized and stimulated with ovalbumin. METHODS: The mice had been fed either a normal diet, an alpha-tocopherol-supplemented diet or a probucol-supplemented diet 14 days before the first sensitization. They were immunized with antigen at intervals of 12 days and, starting from 10 days after the second immunization, they were exposed to antigen 3 times every 4th day using an ultrasonic nebulizer. Twenty-four hours after the last antigen inhalation, airway responsiveness to acetylcholine was measured and bronchoalveolar lavage fluid (BALF) was collected. A blood and lung tissue study was also carried out. RESULTS: Twenty-four hours after the last antigen challenge, both IL-4 and IL-5 in the BALF of alpha-tocopherol-supplemented mice were significantly decreased. The IL-5 level in probucol-supplemented mice was also decreased, but there was no difference in IL-4 levels. The serum IgE level was decreased in probucol-supplemented mice. Differential cell rates of the fluid revealed a significant decrease in eosinophils due to antioxidant supplementation. Airway hyperresponsiveness to acetylcholine was also repressed in antioxidant-supplemented mice. In histological sections of lung tissue, inflammatory cells and mucus secretion were markedly reduced in antioxidant-supplemented mice. We investigated the antioxidant effect on our model mice by examining 8-isoprostane in BALF and lung tissue, and acrolein in BALF; however, our experiment gave us no evidence of the antioxidant properties of either alpha-tocopherol or probucol contributing to the reduction of airway inflammation. CONCLUSION: These findings indicate that alpha-tocopherol and probucol suppress allergic responses in asthma model mice, although these two drugs cause suppression in different ways that are unrelated to antioxidation.     

Allergen-induced bronchial inflammation is associated with decreased levels of surfactant proteins A and D in a murine model of asthma

Background Increasing evidence suggests that pulmonary surfactant protein A (SP‐A) and D (SP‐D) participate in the lung defence against pathogens. However, the role of surfactant proteins in the pathogenesis of allergen‐induced airway inflammation has not been elucidated. In this study we examined the levels and distributions of SP‐A and SP‐D in a dust mite (Dermatophagoides pteronyssinus, Der p) allergen‐induced murine model of asthma. Methods The concentration of SP‐A and SP‐D in the bronchoalveolar lavage fluid (BALF) and the distribution of surfactant proteins in the lung were assayed by ELISA and immunohistochemistry methods, respectively. The effect of surfactant proteins on allergen‐induced pulmonary lymphocyte proliferation was also studied. Results We demonstrated that there were marked reductions of SP‐A and SP‐D levels in the BALF of Der p‐sensitized BALB/c mice at 48–72 h after allergen challenge (AC). Both purified SP‐A and SP‐D were able to suppress, in a dose dependent manner, Der p‐stimulated intrapulmonary lymphocyte proliferation of naïve mice with saline or allergen challenge, or of Der p‐sensitized mice with saline challenge. On the contrary, this suppressive effect was mild (< 9%) on lymphocytes from sensitized mice after AC. Conclusion These results indicated the involvement of pulmonary surfactant proteins in the allergic bronchial inflammation of sensitized mice.     

Interleukin-18-deficient mice exhibit diminished chronic inflammation and airway remodelling in ovalbumin-induced asthma model

Interleukin (IL)-18, which is produced by activated monocytes/macrophages and airway epithelial cells, is suggested to contribute to the pathophysiology of asthma by modulating airway inflammation. However, the involvement of IL-18 on modulating chronic airway inflammation and airway remodelling, which are characterized in a refractory asthma model exposed to long-term antigen, has not been investigated sufficiently. We examined the role of IL-18 in chronic airway inflammation and airway remodelling by long-term antigen exposure. IL-18-deficient and C57BL/6-wild-type mice were sensitized by ovalbumin (OVA) and were then exposed to aerosolized OVA twice a week for 12 weeks. We assessed airway inflammation by assessing the infiltration of cells into the airspace and lung tissues, and airway remodelling by airway mucus expression, peribronchial fibrosis and smooth muscle thickness. In IL-18-deficient mice, when exposed to OVA, the total cells and neutrophils of the bronchoalveolar lavage fluid (BALF) were diminished, as were the number of infiltrated cells in the lung tissues. IL-18-deficient mice exposed to OVA after 12 weeks showed significantly decreased levels of interferon (IFN)-gamma, IL-13 and transforming growth factor (TGF)-beta1 in the BALF. The airway hyperresponsiveness to acetyl-beta-methacholine chloride was inhibited in IL-18-deficient mice in comparison with wild-type mice. In addition, IL-18-deficient mice exposed to OVA had fewer significant features of airway remodelling. These findings suggest that IL-18 may enhance chronic airway inflammation and airway remodelling through the production of IFN-gamma, IL-13 and TGF-beta1 in the OVA-induced asthma mouse model.     

Involvement of the cysteinyl-leukotrienes in allergen-induced airway eosinophilia and hyperresponsiveness in the mouse

The leukotriene modifiers are a novel generation of therapeutic agents in the treatment of allergic asthma. However, the mechanisms by which the cysteinyl (cys) leukotrienes (LTs) participate in allergen-induced airway eosinophilia and airway hyperresponsiveness (AHR) are still unclear. In the present study, we have investigated the role of cys-LTs in ovalbumin (OVA)-induced airway responses in a murine model of asthma. Montelukast (3 or 10 mg/kg), a selective cys-LT1 receptor antagonist, reduced airway eosinophilia and AHR after OVA challenge. The levels of interleukin (IL)-5 and eotaxin in the bronchoalveolar lavage fluid (BALF) from montelukast-treated (3 mg/kg) mice were unaffected, although a decrease in IL-5 was observed with a dose of 10 mg/kg. LTD4 (50 ng) instilled intranasally to immunized mice augmented macrophages in the BALF, but in conjunction with OVA challenge it caused BALF eosinophilia and neutrophilia when given before challenge and BALF neutrophilia but not eosinophilia when given 2 h after challenge. However, there were no increases of IL-5 or eotaxin in BALF following LTD4 treatment. Repeated instillations of LTD4 to immunized mice, mimicking allergen challenge, did not induce AHR but in conjunction with OVA challenge LTD4 enhanced AHR. These results indicate that allergen-induced eosinophilia and AHR are in part mediated by the cys-LT1 receptor, and that, although LTD4 alone has no effect on airway eosinophilia, in conjunction with antigenic stimulation it potentiates the degree of airway inflammation and AHR.     

The effect of allergen-induced airway inflammation on airway remodeling in a murine model of allergic asthma

OBJECTIVE AND DESIGN: We examined the effect of airway inflammation on airway remodeling and bronchial responsiveness in a mouse model of allergic asthma. MATERIALS AND METHODS: BALB/c mice were sensitized to ovalbumin (OA), and exposed to aerosolized OA (0.01, 0.1 and 1%). Twenty-four hours after the final antigen challenge, bronchial responsiveness was measured, and bronchoalveolar lavage (BAL) and histological examinations were carried out. RESULTS: Repeated antigen exposure induced airway inflammation, IgE/IgG1 responses, epithelial changes, collagen deposition in the lungs, subepithelial fibrosis associated with increases in the amount of transforming growth factor (TGF)-beta1 in BAL fluid (BALF), and bronchial hyperresponsiveness to acetylcholine. The number of eosinophils in BALF was significantly correlated with TGF-beta1 production in BALF and the amount of hydroxyproline. Furthermore, significant correlations were found between these fibrogenic parameters and the bronchial responsiveness. CONCLUSION: These findings demonstrated that in this murine model airway eosinophilic inflammation is responsible for the development of airway remodeling as well as bronchial hyperresponsiveness in allergic bronchial asthma.     

Role of Glycoproteins Isolated from Epicoccum purpurascens in Host-Pathogen Interaction.

OBJECTIVE: Attachment to host matrix is an important provisory step for the institution of any fungal infection. The present study investigates the role of glycoproteins of Epicoccum purpurascens in host-fungal adherence. METHODS:Epicoccum spore-mycelial extract was fractionated on a concanavalin A-Sepharose column. Three glycoproteins of 12, 17 and 33 kDa (Epi p 1) were electroeluted and checked for hemagglutination and hemagglutination inhibition. The monosaccharide content of the highly potent protein Epi p 1 was determined by high-performance anion exchange chromatography and pulsed amperometric detection. The interaction of Epi p 1 with mannose-binding lectin (MBL) leading to the activation of the complement system was studied by immunoblot, ELISA and ELISA inhibition techniques. Immunoblot and immunoblot inhibition were carried out with culture filtrate to determine the nature of Epi p 1. RESULTS: 33 (Epi p 1)-, 17- and 12-kDa proteins were 58, 46 and 38 times more potent than crude extract in hemagglutination activity (HA). The HA of Epi p 1 was inhibited by N-acetyl glucosamine, glucose and laminin. Epi p 1 had a high mannose content, showed MBL binding in ion-dependent manner and caused complement activation. The protein was detected in culture filtrate and thus seems to play a significant role in fungal invasion. CONCLUSION: Epi p 1, an allergenic glycoprotein of E. purpurascens, is involved in host-fungal interactions through MBL.     

Early interleukin 4-dependent response can induce airway hyperreactivity before development of airway inflammation in a mouse model of asthma

In experimental models of bronchial asthma with mice, airway inflammation and increase in airway hyperreactivity (AHR) are induced by a combination of systemic sensitization and airway challenge with allergens. In this report, we present another possibility: that systemic antigen-specific sensitization alone can induce AHR before the development of inflammation in the airway. Male BALB/c mice were sensitized with ovalbumin (OVA) by a combination of intraperitoneal injection and aerosol inhalation, and various parameters for airway inflammation and hyperreactivity were sequentially analyzed. Bronchial response measured by a noninvasive method (enhanced pause) and the eosinophil count and interleukin (IL)-5 concentration in bronchoalveolar lavage fluid (BALF) gradually increased following the sensitization, and significant increase was achieved after repeated OVA aerosol inhalation along with development of histologic changes of the airway. In contrast, AHR was already significantly increased by systemic sensitization alone, although airway inflammation hardly developed at that time point. BALF IL-4 concentration and the expression of IL-4 mRNA in the lung reached maximal values after the systemic sensitization, then subsequently decreased. Treatment of mice with anti-IL-4 neutralizing antibody during systemic sensitization significantly suppressed this early increase in AHR. In addition, IL-4 gene-targeted mice did not reveal this early increase in AHR by systemic sensitization. These results suggest that an immune response in the lung in an early stage of sensitization can induce airway hyperreactivity before development of an eosinophilic airway inflammation in BALB/c mice and that IL-4 plays an essential role in this process. If this early increase in AHR does occur in sensitized human infants, it could be another therapeutic target for early prevention of the future onset of asthma.     

Apolipoprotein A-I attenuates ovalbumin-induced neutrophilic airway inflammation via a granulocyte colony-stimulating factor-dependent mechanism

Apolipoprotein A-I (apoA-I) is a key component of high-density lipoproteins that mediates reverse cholesterol transport from cells and reduces vascular inflammation. We investigated whether endogenous apoA-I modulates ovalbumin (OVA)-induced airway inflammation in mice. We found that apoA-I expression was significantly reduced in the lungs of OVA-challenged, compared with saline-challenged, wild-type (WT) mice. Next, to investigate the role of endogenous apoA-I in the pathogenesis of OVA-induced airway inflammation, WT and apoA-I(-/-) mice were sensitized by intraperitoneal injections of OVA and aluminum hydroxide, followed by multiple nasal OVA challenges for 4 weeks. OVA-challenged apoA-I(-/-) mice exhibited a phenotype of increased airway neutrophils compared with WT mice, which could be rescued by an administration of a 5A apoA-I mimetic peptide. Multiple pathways promoted neutrophilic inflammation in OVA-challenged apoA-I(-/-) mice, including the up-regulated expression of (1) proinflammatory cytokines (IL-17A and TNF-α), (2) CXC chemokines (CXCL5), (3) vascular adhesion molecules (i.e., vascular cell adhesion molecule-1), and (4) granulocyte colony-stimulating factors (G-CSF). Because concentrations of G-CSF in bronchoalveolar lavage fluid (BALF) were markedly increased in OVA-challenged apoA-I(-/-) mice, we hypothesized that enhanced G-CSF expression may represent the predominant pathway mediating increased neutrophilic inflammation. This was confirmed by the intranasal administration of a neutralizing anti-G-CSF antibody, which significantly reduced BALF neutrophilia by 72% in OVA-challenged apoA-I(-/-) mice, compared with mice that received a control antibody. We conclude that endogenous apoA-I negatively regulates OVA-induced neutrophilic airway inflammation, primarily via a G-CSF-dependent mechanism. Furthermore, these findings suggest that apoA-I may play an important role in modulating the severity of neutrophilic airway inflammation in asthma.     

活菌卡介苗对哮喘小鼠IL-17的调节作用

目的初步探讨活菌卡介苗（BCG）对哮喘小鼠IL-17的调节作用。方法 4周龄雌性Balb/c小鼠30只随机分为A组（对照组）、B组（哮喘组）和C组（BCG干预组）,每组各10只。B、C两组予OVA腹腔注射致敏、OVA雾化诱发哮喘,C组在致敏前14d接种BCG。HE染色观察小鼠肺部病理改变,计数支气管肺泡灌洗液（bronchoalveolar lavage fluid,BALF）中细胞总数并分类,酶联免疫吸附试验（ELISA）检测血清及BALF中白介素-17（IL-17）含量。结果肺组织病理观察显示A组气管周围基本无炎症细胞浸润,B组支气管周围大量炎症细胞浸润,杯状细胞增生,C组炎症较B组减轻。B、C组BALF中细胞总数和嗜酸性粒细胞、淋巴细胞百分率均显著高于对照组（P〈0.01）,而C组嗜酸性粒细胞比例则明显低于B组（P〈0.01）。B、C组小鼠血清、BALF中IL-17含量高于A组（P〈0.01）,而C组则明显低于B组（P〈0.01）。各组小鼠血清及BALF中IL-17水平与BALF中嗜酸性粒细胞呈正相关（P〈0.01）。结论 BCG接种可抑制IL-17的产生,减轻哮喘小鼠气道炎症反应。     

Endogenous interleukin-10 suppresses allergen-induced airway inflammation and nonspecific airway responsiveness

BACKGROUND: The airway inflammation observed in asthma is orchestrated by activated Th-2 lymphocytes relevant for the induction of altered airway responsiveness. An increasing body of evidence is accumulating that not only the pro-inflammatory cytokines interleukin (IL)-4 and IL-5 but also the immunomodulating cytokines IL-12 and possibly IL-10 are crucial for regulating the allergic airway inflammation. OBJECTIVE: Since IL-10 is capable of downregulating a broad spectrum of pro-inflammatory cytokines, we wanted to address the role of endogenously produced IL-10 in vivo in allergic asthma. METHODS: Knockout (IL-10(-/-)) mice (C57BL/6-IL10tm1Cgn) and wild-type (WT) counterparts were immunized (day 0) and exposed (day 14-21) to ovalbumin (OVA). Airway inflammation and reactivity (AR), serum allergen-specific IgE responses and cytokine profiles in the bronchoalveolar lavage fluid (BALF) were studied. RESULTS: The IL-10(-/-) mice had more eosinophilic airway inflammation but comparable levels of allergen-specific serum IgE compared to the WT mice after allergen challenge. The AR was comparably increased in the OVA challenged WT and IL-10(-/-) mice vs sham-exposed WT, but not vs sham-exposed IL-10(-/-)mice since these showed a higher baseline AR. IFN gamma, IL-4 and IL-13 were comparable and IL-5 was even lower in the BALF of the in IL-10(-/-) mice compared to the similarly exposed WT mice. CONCLUSION: These results indicate that IL-10 plays an important and possibly direct role in the control of airway inflammation and responsiveness in an in vivo mouse model of allergy.     

Blockade of macrophage migration inhibitory factor (MIF) prevents the antigen-induced response in a murine model of allergic airway inflammation

Objective and Design: The role of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, was tested using a mouse asthma model. Materials: One hundred and four male BALB/c mice were used in this study. Treatment: Mice were actively sensitized with an intraperitoneal injection of ovalbumin (OVA) and challenged with repeated nebulization of 1 w/v% OVA. Polyclonal anti-MIF antibody was intraperitoneally injected at 10 mg/kg during the antigen challenge period. Methods: Bronchoalveolar lavage (BAL) was performed 8 h after the last challenge. Airway hyperresponsiveness to inhaled methacholine was measured 24 h after the last challenge. Results: Antigen challenge to immunized mice induced increase in inflammatory cells and concentration of Th2 cytokines in BAL fluid (BALF), and caused the development of airway hyperresponsiveness. Anti-MIF antibody significantly decreased the numbers of inflammatory cells including macrophages, eosinophils, lymphocytes and neutrophils in BALF from OVA-challenged mice. Prednisolone decreased the numbers of eosinophils, lymphocytes and neutrophils but not macrophages. Anti-MIF antibody reduced airway hyperresponsiveness. Anti-MIF antibody affected neither the cytokine levels in BALF nor the IgE levels in serum. Conclusion: MIF was involved in the antigen-induced inflammatory cell accumulation in the lung and airway hyperresponsiveness without affecting immune responses. Received 17 November 2005; returned for revision 14 June 2006; accepted by M. Katori 25 July 2006     

Aspergillus fumigatus-induced allergic airway inflammation alters surfactant homeostasis and lung function in BALB/c mice

The differential regulation of pulmonary surfactant proteins (SPs) is demonstrated in a murine model of Aspergillus fumigatus (Af )-induced allergic airway inflammation and hyperresponsiveness. BALB/c mice were sensitized intraperitoneally and challenged intranasally with Af extract. Enzyme-linked immunosorbent assay analysis of serum immunoglobulin (Ig) levels in these mice showed markedly increased total IgE and Af-specific IgE and IgG1. This was associated with peribronchial/perivascular tissue inflammation, airway eosinophilia, and secretion of interleukin (IL)-4 and IL-5 into the bronchoalveolar lavage fluid (BALF). Functional analysis revealed that in comparison with nonsensitized mice, allergic sensitization and challenge resulted in significant increases in acetylcholine responsiveness. To analyze levels of SPs, the cell-free supernate of the BALF was further fractionated by high-speed (20,000 x g) centrifugation. After sensitization and challenges, the pellet (large-aggregate fraction) showed a selective downregulation of hydrophobic SPs SP-B and SP-C by 50%. This reduction was reflected by commensurate decreases in SP-B and SP-C messenger RNA (mRNA) expression of the lung tissue of these animals. In contrast, there was a 9-fold increase in SP-D protein levels in the 20,000 x g supernate without changes in SP-D mRNA. The increased levels of SP-D showed a significant positive correlation with serum IgE (r = 0.85, P < 0.001). Tissue mRNA and protein levels of SP-A in either the large- or the small-aggregate fractions were unaffected. Our data indicate that allergic airway inflammation induces selective inhibition of hydrophobic SP synthesis accompanied by marked increases in the lung collectin SP-D protein content of BALF. These changes may contribute significantly to the pathophysiology of Af-induced allergic airway hyperresponsiveness.     

Exposure to endotoxins during sensitization prevents further endotoxin-induced exacerbation of airway inflammation in a mouse model of allergic asthma

BACKGROUND: We have shown previously that lipopolysaccharides (LPS) inhibited airway inflammation in allergen-sensitized and challenged mice when administered during sensitization, while exacerbating the inflammation when given upon challenge. We have here investigated the effect of LPS administered during both sensitization and challenge on airway inflammation, as well as on the profile of the T-helper (Th) response to allergen. METHODS: Mice were sensitized and challenged with ovalbumin (OVA), in the presence or absence of effective doses of LPS, namely 1 mug during sensitization and 1 ng during challenge. Inflammation was assessed by measuring cell counts and cytokine levels in bronchoalveolar lavage fluid (BALF). The profile of the Th response was determined by quantifying OVA-specific IgE and IgG2a in serum and Th1/Th2 cytokines in the culture medium of splenocytes and in BALF. RESULTS: Allergen-induced airway eosinophilia was increased in mice exposed to LPS during challenge only when compared with controls, whereas it was similarly reduced in animals exposed during sensitization only and during both sensitization and challenge. Mice exposed to LPS during sensitization only or during both sensitization and challenge also displayed a decrease in IgE and an increase in IgG2a, suggesting a switch in the immune response toward the Th1 profile. This was confirmed by quantification of Th1/Th2 cytokines in culture medium of splenocytes and in BALF. CONCLUSIONS: Our data demonstrate that exposure to endotoxins during sensitization prevents allergen-induced airway inflammation, as well as its exacerbation triggered by further exposure to endotoxins during challenge, while switching the immune response to allergen from a Th2 to a Th1 profile.