不同激发方式对小鼠过敏性支气管哮喘模型的影响

目的 探讨不同激发方式对小鼠过敏性支气管哮喘(简称哮喘)模型的影响.方法 模型组用卵清蛋白致敏和激发BalB/c小鼠,第0天、第7天、第14天腹腔注射致敏,从第28天开始分别给予不同次数和方式的激发.根据激发方式的不同,随机分为5组,包括三次滴鼻激发组、二次雾化20 min激发组、三次雾化20 min激发组、三次雾化30 min激发组、四次雾化20 min激发组,每组12只.激发后48 h采用整体体积描记法检测小鼠气道反应性,结果 以增强的呼气间歇(enhanced pause,Penh)表示,测定肺功能后再用磷酸盐缓冲液对全肺进行支气管肺泡灌洗,支气管肺泡灌洗液(BALF)进行细胞学分析.结果 哮喘组气道反应性(Penh%)和BALF中嗜酸粒细胞比例(EOS%)与正常组相比差异均有统计学意义(P<0.05).三次滴鼻激发组EOS%和Penh%显著高于其他雾化激发组(P<0.05),其中BALF中EOS%三次滴鼻激发组(46.30±4.55)%,与二次雾化20 min激发组(31.19±12.84)%,三次雾化20 min激发组(29.00±12.33)%、四次雾化20 min激发组(37.08±8.44)%相比有显著差异.与三次雾化30 min激发组(41.17±8.78)%无显著差异.三次滴鼻激发组PCI00[(3.75±1.79)g/L]和三次雾化30 min激发组[(5.94±3.27)g/L],四次雾化20 min激发组[(5.19±1.88)g/L]有显著差异(P<0.05).三次滴鼻激发组激发过程中动物死亡2只,其余各组均无死亡.结论 滴鼻和雾化激发均能成功建立哮喘模型,其中滴鼻激发建立的哮喘模型气道炎症及气道反应性升高更为显著.     

不同激发方式对小鼠过敏性支气管哮喘模型的影响

目的探讨不同激发方式对小鼠过敏性支气管哮喘（简称哮喘）模型的影响。方法模型组用卵清蛋白致敏和激发BalB/c小鼠,第0天、第7天、第14天腹腔注射致敏,从第28天开始分别给予不同次数和方式的激发。根据激发方式的不同,随机分为5组,包括三次滴鼻激发组、二次雾化20min激发组、三次雾化20min激发组、三次雾化30min激发组、四次雾化20min激发组,每组12只。激发后48h采用整体体积描记法检测小鼠气道反应性,结果以增强的呼气间歇（enhanced pause,Penh）表示,测定肺功能后再用磷酸盐缓冲液对全肺进行支气管肺泡灌洗,支气管肺泡灌洗液（BALF）进行细胞学分析。结果哮喘组气道反应性（Penh%）和BALF中嗜酸粒细胞比例（EOS%）与正常组相比差异均有统计学意义（P〈0.05）。三次滴鼻激发组EOS%和Penh%显著高于其他雾化激发组（P〈0.05）,其中BALF中EOS%三次滴鼻激发组（46.30±4.55）%,与二次雾化20min激发组（31.19±12.84）%、三次雾化20min激发组（29.00±12.33）%、四次雾化20min激发组（37.08±8.44）%相比有显著差异,与三次雾化30min激发组（41.17±8.78）%无显著差异。三次滴鼻激发组PC100[（3.75±1.79）g/L]和三次雾化30min激发组[（5.94±3.27）g/L]、四次雾化20min激发组[（5.19±1.88）g/L]有显著差异（P〈0.05）。三次滴鼻激发组激发过程中动物死亡2只,其余各组均无死亡。结论滴鼻和雾化激发均能成功建立哮喘模型,其中滴鼻激发建立的哮喘模型气道炎症及气道反应性升高更为显著。     

Short-term cigarette smoke exposure enhances allergic airway inflammation in mice

RATIONALE: Epidemiologic studies suggest that tobacco smoke contributes to the prevalence and occurrence of exacerbations in asthma. The effect of active smoking in adolescents with atopy is poorly understood. OBJECTIVES: We developed an experimental model to investigate the influence of smoking on antigen-induced airway inflammation and airway responsiveness in mice that were previously sensitized. METHODS: Ovalbumin (OVA)-sensitized BALB/c mice were exposed to air or mainstream smoke (5 days/week) and to phosphate-buffered saline (PBS) or OVA aerosol (3 times/week) for 2 weeks (n = 8 for each group). RESULTS: Airway responsiveness to intravenously injected carbachol was increased (p < 0.05) in smoke- and OVA-exposed mice compared with all other groups. There was an additive effect of smoke and OVA exposure on total cell numbers, macrophages, and dendritic cells in bronchoalveolar lavage fluid and on CD4+ and CD8+ T lymphocytes and dendritic cells in lung tissue (p < 0.05 compared with mice exposed to smoke and PBS and to mice exposed to air and OVA). Concurrent smoke and OVA exposure augmented OVA-specific IgE in serum compared with air and OVA exposure. In lavage fluid supernatant, eotaxin was increased in air- and OVA-exposed mice. The further increase observed in the group exposed to both OVA and cigarette smoke came close to formal significance (p = 0.06). Thymus- and activation-regulated chemokine was augmented in mice exposed to either smoke or OVA, without additional effect. CONCLUSIONS: Our data indicate that acute concurrent exposure to allergen and mainstream cigarette smoke enhances airway inflammation and airway responsiveness in previously sensitized mice.     

Immunization with live influenza viruses in an experimental model of allergic bronchial asthma: infection and vaccination

Background Asthmatics in particular have a need for influenza vaccines because influenza infection is a frequent cause of hospitalization of patients with bronchial asthma. Currently, only inactivated influenza vaccines are recommended for influenza prevention in asthma sufferers. Objective The aim of our study was to analyze and compare the effects of influenza infection and vaccination with live attenuated influenza vaccine (LAIV) on different phases of experimental murine allergic bronchial asthma (acute asthma and remission phase) and on subsequent exposure to allergen in sensitized animals. Methods Ovalbumin (OVA)‐specific serum IgE levels, IL‐4 production by spleen and lung lymphocytes, and histological changes in the lungs of mice infected with pathogenic virus or LAIV were studied at two phases of OVA‐induced bronchial asthma (acute asthma and remission). Results Infection with pathogenic virus both in acute asthma and remission led to asthma exacerbation associated with the production of OVA‐specific IgE, IL‐4 and significant inflammatory infiltration in airways. Infection, even after complete virus clearance, induced the aggravation of lung inflammation and IgE production in asthmatic mice additionally exposed to OVA. Immunization with LAIV at remission did not enhance allergic inflammatory changes in the lung, OVA‐specific IgE or IL‐4 production. Then after additional OVA exposure, histological and immunological changes in these mice were the same as in the control group. Conclusions Influenza infection provokes asthma exacerbation regardless of the disease phase. Immunization with LAIV during the remission phase of bronchial asthma is safe and does not interfere upon subsequent contact of asthma sufferers with allergen.     

Sirtuin 1 activator SRT1720 suppresses inflammation in an ovalbumin‐induced mouse model of asthma

Background and objective: In asthma, reduced histone deacetylase activity and enhanced histone acetyltransferase activity in the lungs have been reported. However, the precise function of Sirtuin 1 (Sirt1), a class III histone deacetylase, and the effect of the Sirt1 activator SRT1720 on allergic inflammation have not been fully elucidated. Methods: The effect of SRT1720, a synthetic activator of Sirt1, in an ovalbumin (OVA)‐induced asthma mouse model was investigated. The effect of SRT1720 and resveratrol on OVA stimulation in splenocytes from OVA‐sensitized and challenged mice was also examined. Results: In OVA‐sensitized and challenged mice (OVA mice) compared with saline‐sensitized and challenged mice (control mice), Sirt1 messenger RNA expression in the lungs was decreased (P = 0.02), while cellular infiltration, airway eosinophilia and bronchoalveolar lavage (BAL) fluid levels of interleukin (IL)‐4, IL‐5 and IL‐13 were increased (P < 0.01). In OVA mice, SRT1720 treatment decreased total and eosinophil cell counts and IL‐5 and IL‐13 levels in the BAL fluid compared with the vehicle treatment (P < 0.05). In OVA mice, SRT1720 treatment also decreased inflammatory cell lung infiltrates histologically (P = 0.002). Both SRT1720 and resveratrol suppressed OVA‐induced cell proliferation and IL‐6 (P < 0.05) and tumour necrosis factor‐α (TNF‐α) (P < 0.05) production in splenocytes (P < 0.01). Conclusions: The Sirt1 activator SRT1720 suppressed inflammatory cell infiltration and cytokine production in an OVA‐induced mouse model of asthma. SRT1720 and resveratrol suppressed OVA‐induced splenocyte proliferation and TNF‐α and IL‐6 production. Sirt1 activators might have beneficial effects in asthmatics by suppressing inflammation.     

可溶性IL-13受体α2对支气管哮喘小鼠气道炎症的影响

目的 通过观察可溶性IL-13受体α2(sIL-13Rα2)对支气管哮喘(简称哮喘)小鼠气道炎症的影响,了解sIL-13Rα2对哮喘潜在的治疗价值.方法 24只BALB/c小鼠随机分成正常对照组、哮喘组及sIL-13Rα2治疗组,哮喘组和sIL-13Rα2治疗组以鸡卵白蛋白(OVA)致敏和激发,建立哮喘模型,对照组用生理盐水代替OVA.sIL-13Rα2治疗组每次激发前30 min腹腔注射sIL-13Rα2 100μg,正常对照组及哮喘组则用生理盐水替代.比较各组支气管肺泡灌洗液(BALF)细胞计数、肺组织学检查.结果 与正常对照组相比,哮喘组BALF中细胞总数及嗜酸粒细胞百分比显著增加(P值均＜0.001),血清及BALF中IL-13明显增多(P值均＜0.001),病理示肺组织损害明显.与哮喘组相比,sIL-13Rα2治疗组BALF中细胞总数及嗜酸粒细胞百分比显著降低(P值均＜0.001),血清及BALF中IL-13明显减少(P值均＜0.001),病理示肺组织损害明显减轻.结论 sIL-13Rα2可明显减轻哮喘小鼠气道炎症.     

Therapeutic Effect of Intratracheal Administration of Murine IL-4 Receptor Antagonist on Asthmatic Airway Inflammation

Objective. It is well known that IL-4 and IL-13 play critical roles in the pathogenesis of asthma. In this study, by overexpressing murine IL-4 receptor antagonist (mIL-4RA), a competitive antagonist for both IL-4 and IL-13, we investigated the therapeutic effects of mIL-4RA on mouse asthmatic airway inflammation. Material and methods. BALB/c mice were randomly divided into four groups: healthy control mice; ovalbumin (OVA) sensitized/challenged mice; OVA sensitized/challenged mice intratracheally administered with mIL-4RA plasmid (mIL-4RA group); and OVA sensitized/challenged mice intratracheally administered with control plasmid (control plasmid group). The airway inflammation was determined by histopathological examinations. Cytokines were measured by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to analyze CD4 and CD8 T-lymphocyte subsets. Results. Compared to the control plasmid-treated mice, intratracheal administration of mIL-4RA expressing plasmid on the sensitization phase protected the mice from the subsequent induction of asthmatic airway inflammation. The eosinophilic infiltration in bronchoalveolar lavage fluid (BALF) was significantly reduced compared to that of the control (p < 0.01). Interestingly, intratracheal administration of mIL-4RA regulated the Th1/Th2 cytokine imbalance in local airway with increased IL-13 levels and decreased IFN-γ levels compared to the control plasmid group. However, although we did see the decreased level of IL-4 and IL-13 in serum, the serum level of IFN-γ is not changed in the mIL-4RA group, suggesting that mIL-4RA could not correct the imbalance of Th1/Th2 cytokines in serum. In addition, intratracheal administration of mIL-4RA had no effect on the ratio of CD4/CD8 T-lymphocyte subsets in the peripheral blood, lung, or spleen. Conclusions. This study demonstrated that intratracheal administration of mIL-4RA attenuated the asthmatic inflammation and regulated the Th1/Th2 cytokine imbalance in local airway with minimal systemic effects. This method may serve as a potential therapeutic option for treating asthma.     

Transfer of T cells from intranasal ovalbumin-immunized mice ameliorates allergic response in ova-sensitized recipient mice.

Mucosal immunotherapy is suggested as a treatment strategy for tolerance induction in allergic diseases. The purpose of this study was to determine the effect of transferred splenic T cells from intranasal ovalbumin (OVA)-immunized mice to naive mice before sensitization on its impact of cytokine production and airway histopathology. BALB/c mice in group I received intranasal immunotherapy (days1-6), carboxylfluorescein succinyl ester (CFSE)-labeled splenocytes or splenic T cells were i.v. transferred to naive recipients (group II) before OVA sensitization. Acute murine asthma model was established by two i.p. OVA injections (days 21 and 28) and seven OVA nebulizations (days 42-48) in groups I, II and III. Groups III and IV served as asthma model and control, respectively. CFSE-labeled cells in splenocytes and lymph node lymphocytes, lung histopathology, IL-4, IL-10, and interferon (IFN) gamma cytokines of recipients were analyzed 24 hours after OVA nebulization challenge. CFSE-labeled T cells from group I were detected in spleen and regional lymph nodes of the OVA-sensitized recipients (group II). Smooth muscle and thickness of airways were less in intranasal OVA immunotherapy and OVA-sensitized recipients when compared with the asthma model (p < 0.05). Area of inflammation was significantly suppressed in OVA-sensitized recipients compared with the asthma model (p < 0.01). IL-10 and IFN-gamma levels in splenocyte supernatants were significantly increased in intranasal immunotherapy and OVA-sensitized recipients compared with asthma model and controls (p < 0.01). IL-4 levels were significantly less in intranasal immunotherapy group and the OVA-sensitized recipient group when compared with asthma the model group (p < 0.05). This study suggests that intranasal immunotherapy with allergens regulates T-cell responses and ameliorates airway histopathology in sensitized mice, hence, encouraging mucosal tolerance induction as a suitable treatment of allergic diseases.     

可溶性IL-13受体α2对支气管哮喘小鼠气道炎症的影响

目的通过观察可溶性IL-13受体α2（sIL-13Rα2）对支气管哮喘（简称哮喘）小鼠气道炎症的影响,了解sIL-13Rα2对哮喘潜在的治疗价值。方法 24只BALB/c小鼠随机分成正常对照组、哮喘组及sIL-13Rα2治疗组,哮喘组和sIL-13Rα2治疗组以鸡卵白蛋白（OVA）致敏和激发,建立哮喘模型,对照组用生理盐水代替OVA。sIL-13Rα2治疗组每次激发前30min腹腔注射sIL-13Rα2100μg,正常对照组及哮喘组则用生理盐水替代。比较各组支气管肺泡灌洗液（BALF）细胞计数、肺组织学检查。结果与正常对照组相比,哮喘组BALF中细胞总数及嗜酸粒细胞百分比显著增加（P值均〈0.001）,血清及BALF中IL-13明显增多（P值均〈0.001）,病理示肺组织损害明显。与哮喘组相比,sIL-13Rα2治疗组BALF中细胞总数及嗜酸粒细胞百分比显著降低（P值均〈0.001）,血清及BALF中IL-13明显减少（P值均〈0.001）,病理示肺组织损害明显减轻。结论 sIL-13Rα2可明显减轻哮喘小鼠气道炎症。     

哮喘小鼠肺组织T-bet的表达及意义

目的观察T-bet在OVA致敏小鼠、哮喘小鼠中表达并探讨其意义。方法雄性昆明小鼠随机分成致敏组、哮喘组和对照组。用OVA致敏和激发,建立哮喘模型。Western Blot法检测肺组织中T-bet的水平,ELISA法测定肺泡灌洗液中IFN-γ、IL-4的水平。结果1.致敏组T-bet表达较对照组明显下降,差异有统计学意义,哮喘组T-bet表达与致敏组比较,差异无统计学意义。2.T-bet的表达与IFN-γ/IL-4比值正相关。结论OVA致敏后T-bet表达明显减少,OVA激发至哮喘状态后T-bet表达没有进一步减少。     

Effect of diet-induced obesity on ovalbumin-specific immune response in a murine asthma model

Some epidemiologic surveys have demonstrated that asthma is more prevalent in obese children and adults. However, the mechanism of association between obesity and asthma has not been fully clarified. This report investigates a murine model for antigen-induced asthma and diet-induced obesity from an immunologic perspective. For the induction of obesity, C57BL/6J mice were fed a high-fat diet supplemented with lard or soybean oil. Mice were then sensitized and challenged with ovalbumin (OVA) to induce allergic lung inflammation. OVA-specific serum immunoglobulin levels were lower in obese mice compared with non-obese control mice. The decline of OVA-specific IgE in the soybean oil group was found to be especially pronounced. However, obese mice with OVA-induced asthma showed a higher sensitivity of antigen-induced T-cell responses, and increased gamma interferon (IFN-gamma) production of splenocytes with phytohemagglutinin (PHA) stimulation. Furthermore, mast cell numbers in the tracheal mucosa were increased in obese mice upon sensitization by OVA. These results suggest that obesity-induced changes in T-cell function may be partly involved in the pathophysiology of asthma in human obesity, rather than Ig E-mediated allergic responses.     

慢性哮喘患者肺组织 IL-21和转录激活因子3的表达

目的：研究慢性哮喘患者肺组织中 IL-21和转录激活因子3(p-STAT3)表达水平。方法选择30只小鼠随机分为实验组和对照组,实验组进行哮喘干预,检测 IL-21和 p-STAT3的表达水平。实验组小鼠分别在第1、14天皮下注射0.15 ml 卵清白蛋白(ovalbumin,OVA)混合试剂,在第20天将小鼠放置于实验箱中,用雾化的方法将 OVA 混合试剂喷向实验箱中,2次/d,每次20 min,观察小鼠出现的症状,对照组则在第1、14天皮下注射0.15 ml 无菌氯化钠注射液,其余处置同实验组小鼠。结果实验组小鼠的炎性细胞总数为(18.80±1.82)×105/L,嗜酸粒细胞数为(1.02±0.22)×105/L,单核细胞为(1.56±0.24)×105/L。与对照组比较,差异有统计学意义(t =2.449、2.656、2.361,P 值均<0.05)。实验组小鼠的 IL-21表达水平为(65.45±5.56)ng/L,IL-2表达水平为(55.48±12.11)ng/L,p-STAT3表达水平为(76.86±9.46)ng/L,与对照组比较,差异有统计学意义(t =13.057、12.694、3.982,P 值均<0.05)。结论慢性哮喘小鼠肺组织 IL-21和p-STAT3表达水平明显增加。     

Respiratory syncytial virus in allergic lung inflammation increases Muc5ac and gob-5

Respiratory syncytial virus (RSV) is associated with wheezing and childhood asthma. We previously reported that RSV infection prolongs methacholine-induced airway hyperresponsiveness in ovalbumin (OVA)-sensitized mice. In addition, allergically sensitized RSV-infected (OVA/RSV) mice had more abundant airway epithelial mucus production compared with OVA mice 14 days after infection, whereas there was almost no mucus in mice that were only RSV infected. We hypothesized that this increased mucus was associated with mucosal expression of Muc5ac, a mucus gene expression in airways, and gob-5, a member of the Ca(2)(+)-activated chloride channel family. By histochemical analysis, we found that there was significantly increased staining for gob-5 and Muc5ac in the airways of OVA/RSV mice compared with either OVA mice or allergically sensitized mice that were challenged with inactivated RSV, and virtually no detectable staining in the RSV group. These findings were confirmed by Western blot analysis. The increased mucus expression in the OVA/RSV group was associated with increased lung levels of interleukin-17, a factor known to stimulate airway mucin gene expression. The impact of virus infection combined with allergic inflammation on mucus production may partially explain the more severe disease and airway hyperresponsiveness associated with RSV in the setting of atopy.     

CD+4CD+25 T淋巴细胞对支气管哮喘小鼠气道炎症的影响及作用机制

目的探讨CD+4 CD+25 T淋巴细胞(Treg细胞)对支气管哮喘(简称哮喘)小鼠气道炎症的影响及作用机制.方法 60只小鼠按随机数字表法分为3组,每组20只.哮喘组(A组)小鼠于第1、13天以鸡卵白蛋白(OVA)0.1 ml腹腔注射致敏,第21～29天雾化吸入2% OVA生理盐水溶液10 ml激发 30 min后建立小鼠哮喘模型.生理盐水对照组(B组)以生理盐水10 ml替代OVA处理.去除T淋巴细胞哮喘组(C组)去除小鼠体内CD+25 T淋巴细胞后再按A组方法复制小鼠哮喘模型(用药剂量和方法同A组).分离A、B、C 3组小鼠脾脏淋巴细胞,用流式细胞仪(FACS)检测Treg细胞数量,计算其占CD+4 T淋巴细胞的百分比;分离CD+4 T淋巴细胞,用逆转录-聚合酶链反应(RT-PCR)法检测白细胞介素10(IL-10)、转化生长因子β1(TGF-β1)和细胞毒性T淋巴细胞抗原4 mRNA(CTLA-4 mRNA)的表达;同时对肺组织行苏木精-伊红 (HE)染色,观察小鼠肺组织的炎症改变. 结果经过OVA反复激发,A组小鼠脾脏Treg细胞占CD+4 T淋巴细胞的百分比为(3.10±0.03)%,B组为(9.60±0.04)%,A、B两组间及C组分别与A、B组比较差异均有统计学意义(P均<0.01); IL-10、TGF-β1和CTLA-4 mRNA的表达A组分别为0.250±0.040、0.29±0.03、0.28±0.06, B组分别为0.480±0.080、0.47±0.05、0.50±0.03、C组分别为0.080±0.020、0.11±0.04、0.12±0.05,A、B两组及C组分别与A、B组比较差异均有统计学意义(P均<0.01).与B组比较,A组肺部以嗜酸粒细胞浸润为主要表现的炎症改变明显增强,C组则较A、B组显著增强.结论 Treg细胞的数量减少和(或)功能障碍可能是哮喘气道炎症发生发展的重要机制.     

中性粒细胞性支气管哮喘小鼠模型建立的探索

目的利用不同剂量脂多糖（lipopolysaccharides,LPS）干预卵清蛋白（ovalbumin,OVA）致敏和激发的小鼠,探索中性粒细胞性哮喘（neutrophilic asthma,NA）小鼠模型的建立。方法 80只BALB/c小鼠随机分为正常对照组（A组）、肺损伤对照组（B组：B1～B4）、嗜酸细胞性哮喘模型对照组（C组）、NA模型探索组（D组：D1～D4）。分致敏和激发两阶段建模,致敏阶段：A组PBS腹腔注射及PBS滴鼻,B组PBS腹腔注射及LPS滴鼻,C组OVA腹腔注射,D组OVA腹腔注射及LPS滴鼻;激发阶段：A、B组生理盐水雾化,C、D组5%OVA雾化。通过观察小鼠雾化时的症状、肺组织病理改变,检测支气管肺泡灌洗液（bronchoalveolar lavage fluid,BALF）细胞总数及分类计数和血清OVA-sIgE等评价NA小鼠模型建立。结果①D3组小鼠出现类似C组小鼠呼吸急促、大小便失禁等表现。②D3组BALF炎症细胞总数较A组显著升高（P〈0.01）;D3组中性粒细胞（neutrophil,NEU）百分比（NEU%）较A、C、D1、D2组显著升高（P值均〈0.01）,嗜酸粒细胞（eosinophil,EOS）百分比（EOS%）较A组显著升高而较C组显著低下（P值均〈0.01）。③D3组支气管管壁及肺泡间隔增厚变形,部分断裂,气道黏膜下除了EOS浸润外还存在明显NEU浸润。④D3组血清OVA-sIgE水平显著高于A组而低于C组（P值均〈0.05）。⑤D3组IL-4水平显著高于A组（P〈0.05）,与C组无显著差异（P〉0.05）;D3组IFN-γ水平显著低于A组（P〈0.05）,与C组无显著差异（P〉0.05）。结论 10μg LPS滴鼻吸入＋50μg OVA腹腔注射三次与5%OVA连续激发两周即D3组可成功建立NA小鼠模型。     

Inhaled corticosteroid prevents the thickening of airway smooth muscle in murine model of chronic asthma

Airway smooth muscle growth contributes to the mechanism of airway hyperresponsiveness (AHR) in asthma. Although current steroid use demonstrates anti-inflammatory activity, there is little reported on the action of corticosteroid on smooth muscle of the asthmatic airway. The present study investigated the effect of inhaled corticosteroid on the thickening of airway smooth muscle in bronchial asthma. We developed a mouse model of airway remodeling including smooth muscle thickening in which ovalbumin (OVA)-sensitized female BALB/c-mice were repeatedly exposed to intranasal OVA administration twice a week for 3 months. Mice were treated intranasally with fluticasone during the OVA challenge. Mice chronically exposed to OVA developed sustained eosinophilic airway inflammation compared with control mice. In addition, the mice chronically exposed to OVA developed features of airway remodeling, including thickening of the peribronchial smooth muscle layer. Intranasal administration of fluticasone inhibited the development of eosinophilic inflammation, and importantly, thickening of the smooth muscle layer. Moreover, intranasal fluticasone treatment reduced the transforming growth factor (TGF)-beta 1 level in bronchoalveolar lavage fluid and regulated active TGF-beta 1 signaling with a reduction in the expression of phospho-Smad2/3 and the concomitant up-regulation of Smad7 in lung tissue sections. These results suggest that intranasal administration of fluticasone can modulate the remodeling of airway smooth muscle via regulation of TGF-beta 1 production and active TGF-beta 1 signaling.     

Different roles of interleukin-10 in onset and resolution of asthmatic responses in allergen-challenged mice

OBJECTIVE: Although interleukin (IL)-10 is an immunoregulatory cytokine produced by various cells including T cells, its precise role in asthma remains uncertain. The aim of this study was to investigate the role of IL-10 in experimental asthma using ovalbumin (OVA)-sensitized mice. METHODOLOGY: Mice were challenged with OVA aerosol, and airway responsiveness and inflammation were measured. OVA-specific IL-10-producing CD4+ T cells were counted from lung cells collected by enzymatic digestion and stimulated ex vivo with OVA. The effects of an anti-IL-10 antibody on airway responsiveness and inflammation were also evaluated. RESULTS: The OVA challenge caused airway hyperresponsiveness and eosinophilic inflammation. A significant increase in IL-10-producing CD4+ T cells was observed, mainly in the CD45RB(low) subset, for several days after the OVA challenge. Anti-IL-10 antibody treatment before the OVA challenge did not affect eosinophilic inflammation but significantly inhibited airway hyperresponsiveness 24 h after the OVA challenge. However, anti-IL-10 antibody treatment just before the last OVA challenge significantly attenuated the resolution of eosinophilic inflammation without affecting airway responsiveness 2 weeks after the OVA challenge. CONCLUSIONS: Intrinsic IL-10 may have a distinct role in the early and late phases of asthmatic responses. In the early phase, IL-10 induces airway hyperresponsiveness, while in the late phase IL-10 contributes to the resolution of eosinophilic inflammation.     

Evaluation of the anti-inflammatory effect of infliximab in a mouse model of acute asthma

Background and objective:   To evaluate the potential role of anti-tumour necrosis factor (TNF)-α mAb (infliximab) on the inflammatory response in a mouse model of acute asthma.
Methods:   BALB/c mice received intraperitoneal (i.p.) ovalbumin (OVA) on days 0 and 14, 100 μg of OVA intranasally on day 14 and 50 μg of OVA intranasally on days 25, 26 and 27. The low-dose (2.5 mg/kg) and high-dose (6.25 mg/kg) infliximab groups received i.p. infliximab before each i.p. sensitization and on challenge days 1, 6, 13, 20 and 27. The control group received i.p. injections of normal saline with alum on days 0 and 14 and normal saline without alum on days 14, 25, 26 and 27.
Results:   There were statistically significant decreases in the numbers of BAL fluid (BALF) neutrophils, eosinophils, as well as lung eosinophils in both the low- and high-dose infliximab groups when compared with the control OVA sensitized/challenged group. The lower dose of infliximab did not alter lung neutrophil counts, but a marked decrease was seen with the high dose of infliximab. After treatment with low and high doses of infliximab, BALF levels of regulated on activation normal T cell expressed and secreted (RANTES), granulocyte macrophage-colony stimulating factor (GM-CSF), TNF-α, IL-6, macrophage inflammatory protein (MIP)-2, and levels of RANTES, IL-4, GM-CSF, TNF-α, IL-6 and MIP-2 in lung tissue were significantly decreased when compared with the control OVA sensitized/challenged group. There was a significant decrease in BALF IL-4 only in the high-dose infliximab group.
Conclusions:   These results show that an anti-TNF-α mAb has a considerable anti-inflammatory effect on allergen-induced lung inflammation in an animal model of acute asthma.