transforming-growth-factor-beta and Bronchial-Hyperreactivity

Asthma is a chronic disease of the airways affecting around 10% of the population. The majority of cases are well controlled with current therapies, however in approximately 20% of severe asthmatics the available therapeutic strategies are inadequate. Structural changes in the asthmatic airway, including an increase in smooth muscle mass and an increased deposition of extracellular matrix proteins, which correlate with airway hyperresponsivenes, reduced lung function and an increase in fibroblast/myofibroblast numbers, are not specifically targetted by current therapeutic agents and therefore represent an area of unmet need. The mechanisms involved in the development of airway remodelling are incompletely understood but are thought to involve one or more isoforms of transforming growth factor-beta (TGF-beta). The TGF-betas are pleiotropic mediators which have important roles in the regulation of inflammation, cell growth, differentiation and wound healing. All three mammalian isoforms of TGF-beta are present in the airways and at least TGF-beta1 and TGF-beta2 have been shown to be increased in asthmatic airways and cells, together with evidence of increased TGF-beta signalling. In addition, evidence from animal models suggests that airway remodelling may be prevented or reversed using agents which target TGF-beta. Therefore modulation of TGF-betas or their activity represent a potential therapeutic target for asthma. This review focuses on the current knowledge of TGF-beta1-3, their their role in normal and asthmatic airways, as well as the potential for modulating the TGF-betas and their effects as a therapeutic approach to asthma.

Topics: Animals; Asthma; Bronchi; Bronchial Hyperreactivity; Fibroblasts; Fibrosis; Humans; Myocytes, Smooth Muscle; Protein Isoforms; Receptors, Transforming Growth Factor beta; Signal Transduction; Transforming Growth Factor beta

It is well known that supplemental oxygen used to treat preterm infants in respiratory distress is associated with permanently disrupting lung development and the host response to influenza A virus (IAV). However, many infants who go home with normally functioning lungs are also at risk for hyperreactivity after a respiratory viral infection. We recently reported a new, low-dose hyperoxia mouse model (40% for 8 days; 40×8) that causes a transient change in lung function that resolves, rendering 40×8 adult animals functionally indistinguishable from room air controls. Here we report that when infected with IAV, 40×8 mice display an early transient activation of TGFβ signaling and later airway hyperreactivity associated with peribronchial inflammation (profibrotic macrophages) and fibrosis compared with infected room air controls, suggesting neonatal oxygen induced hidden molecular changes that prime the lung for hyperreactive airways disease. Although searching for potential activators of TGFβ signaling, we discovered that thrombospondin-1 (TSP-1) is elevated in naïve 40×8 mice compared with controls and localized to lung megakaryocytes and platelets before and during IAV infection. Elevated TSP-1 was also identified in human autopsy samples of former preterm infants with bronchopulmonary dysplasia. These findings reveal how low doses of oxygen that do not durably change lung function may prime it for hyperreactive airways disease by changing expression of genes, such as TSP-1, thus helping to explain why former preterm infants who have normal lung function are susceptible to airway obstruction and increased morbidity after viral infection.

Topics: Animals; Bronchial Hyperreactivity; Bronchopulmonary Dysplasia; Cell Line; Disease Models, Animal; Dogs; Female; Humans; Hyperoxia; Influenza A virus; Influenza, Human; Madin Darby Canine Kidney Cells; Male; Mice; Mice, Inbred C57BL; Orthomyxoviridae Infections; Pulmonary Fibrosis; Thrombospondin 1; Transforming Growth Factor beta

Sphingosine-1-phosphate (S1P) has been widely associated with inflammation-based lung pathologies. Because B cells play a critical role as antigen-presenting and/or Ig-producing cells during asthmatic conditions, we wanted to dissect the role of these cells in S1P-dependent airway hyperreactivity and inflammation. Mice were sensitized to ovalbumin or exposed to S1P. Ovalbumin sensitization caused airway hyperreactivity coupled to an increased lung infiltration of B cells, which was significantly reduced after the inhibition of sphingosine kinases I/II. Similarly, the sole administration of S1P increased bronchial reactivity compared with vehicle and was accompanied by a higher influx of B cells in a time-dependent manner. This effect was associated with higher levels of IL-13, transforming growth factor-β, IL-10, and T regulatory cells. In addition, isolated S1P-derived lung B cells increased CD4(+) and CD8(+) T cell proliferation in vitro, and their suppressive nature at Day 14 was associated with the higher release of transforming growth factor-β and IL-10 when they were cocultured. Therefore, to prove the role of B cells in S1P-mediated airway inflammation, and because CD20 expression, contrary to major hystocompatibility complex I and major hystocompatibility complex II, was up-regulated at Day 14, CD20(+) B cells were depleted by means of a specific monoclonal antibody. The absence of CD20(+) B cells increased airway reactivity and inflammation in S1P-treated mice compared with control mice. These data imply that sphingosine kinase/S1P-mediated airway inflammation is countered by B cells via the induction of an immune-suppressive environment to reduce asthma-like outcomes in mice.

Topics: Animals; Antibodies, Monoclonal; Antigens, CD20; B-Lymphocytes; Bronchial Hyperreactivity; Bronchoconstriction; Cell Proliferation; Chemotaxis, Leukocyte; Disease Models, Animal; Female; Inflammation Mediators; Interleukin-10; Interleukin-13; Lung; Lymphocyte Activation; Lysophospholipids; Mice, Inbred BALB C; Ovalbumin; Phosphotransferases (Alcohol Group Acceptor); Pneumonia; Protein Kinase Inhibitors; Sphingosine; T-Lymphocytes, Regulatory; Time Factors; Transforming Growth Factor beta

Fudosteine is a cysteine derivative that is used as an expectorant in chronic bronchial inflammatory disorders. It has been shown to decrease the number of goblet cells in an animal model. This study examined the effects of fudosteine on airway inflammation and remodeling in a murine model of chronic asthma.. BALB/c mice were sensitized by an intraperitoneal injection of ovalbumin (OVA), and subsequently challenged with nebulized ovalbumin three days a week for four weeks. Seventy-two hours after the fourth challenge, airway hyperresponsiveness (AHR) and the cell composition of bronchoalveolar lavage (BAL) fluid were assessed. Fudosteine was administered orally at 10mg/kg or 100mg/kg body weight from the first to the fourth challenge.. We investigated the effects of fudosteine on the development of allergic airway inflammation and airway hyperresponsiveness after chronic allergen challenges. The administration of fudosteine during the challenge with ovalbumin prevented the development of airway hyperresponsiveness and accumulation of lymphocytes in the airways. Eotaxin, IL-4, and TGF-β levels and the relative intensity of matrix metalloproteinase-2 and matrix metalloproteinase-9 (MMP-2 and MMP-9) in BAL fluid were reduced by the fudosteine treatment; however, the number of eosinophils in BAL fluid and serum IgE levels did not change. The expression of TGF-β, the development of goblet cell hyperplasia, subepithelial collagenization, and basement membrane thickening were also reduced by the fudosteine treatment.. These results indicate that fudosteine is effective in reducing airway hyperresponsiveness, airway inflammation, and airway remodeling in a murine model of chronic asthma.

Topics: Allergens; Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cystine; Female; Lung; Mice; Mice, Inbred BALB C; Real-Time Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta

Airway inflammation and airway remodeling are the key contributors to airway hyperresponsiveness (AHR), a characteristic feature of asthma. Both processes are regulated by Transforming Growth Factor (TGF)-β. Caveolin 1 (Cav1) is a membrane bound protein that binds to a variety of receptor and signaling proteins, including the TGF-β receptors. We hypothesized that caveolin-1 deficiency promotes structural alterations of the airways that develop with age will predispose to an increased response to allergen challenge.. AHR was measured in Cav1-deficient and wild-type (WT) mice 1 to 12 months of age to examine the role of Cav1 in AHR and the relative contribution of inflammation and airway remodeling. AHR was then measured in Cav1-/- and WT mice after an ovalbumin-allergen challenge performed at either 2 months of age, when remodeling in Cav1-/- and WT mice was equivalent, and at 6 months of age, when the Cav1-/- mice had established airway remodeling.. Cav1-/- mice developed increased thickness of the subepithelial layer and a correspondingly increased AHR as they aged. In addition, allergen-challenged Cav1-/- mice had an increase in AHR greater than WT mice that was largely independent of inflammation. Cav1-/- mice challenged at 6 months of age have decreased AHR compared to those challenged at 2 months with correspondingly decreased BAL IL-4 and IL-5 levels, inflammatory cell counts and percentage of eosinophils. In addition, in response to OVA challenge, the number of goblet cells and α-SMA positive cells in the airways were reduced with age in response to OVA challenge in contrast to an increased collagen deposition further enhanced in absence of Cav1.. A lack of Cav1 contributed to the thickness of the subepithelial layer in mice as they aged resulting in an increase in AHR independent of inflammation, demonstrating the important contribution of airway structural changes to AHR. In addition, age in the Cav1-/- mice is a contributing factor to airway remodeling in the response to allergen challenge.

Topics: Actins; Aging; Airway Remodeling; Animals; Asthma; Bronchial Hyperreactivity; Caveolin 1; Collagen; Disease Models, Animal; Female; Interleukin-4; Interleukin-5; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Pneumonia; Transforming Growth Factor beta

Asthma is defined as a chronic inflammatory disease of the airways; however, the underlying physiologic and immunologic processes are not fully understood.. The aim of this study was to determine whether TH9 cells develop in vivo in a model of chronic airway hyperreactivity (AHR) and what factors control this development.. We have developed a novel chronic allergen exposure model using the clinically relevant antigen Aspergillus fumigatus to determine the time kinetics of TH9 development in vivo.. TH9 cells were detectable in the lungs after chronic allergen exposure. The number of TH9 cells directly correlated with the severity of AHR, and anti-IL-9 treatment decreased airway inflammation. Moreover, we have identified programmed cell death ligand (PD-L) 2 as a negative regulator of TH9 cell differentiation. Lack of PD-L2 was associated with significantly increased TGF-β and IL-1α levels in the lungs, enhanced pulmonary TH9 differentiation, and higher morbidity in the sensitized mice.. Our findings suggest that PD-L2 plays a pivotal role in the regulation of TH9 cell development in chronic AHR, providing novel strategies for modulating adaptive immunity during chronic allergic responses.

Topics: Adaptive Immunity; Allergens; Animals; Antibodies; Aspergillus fumigatus; Bronchial Hyperreactivity; Cell Differentiation; Chronic Disease; Disease Models, Animal; Female; Gene Expression Regulation; Interleukin-1alpha; Interleukin-9; Lung; Lymphocyte Count; Mice; Mice, Inbred BALB C; Programmed Cell Death 1 Ligand 2 Protein; Severity of Illness Index; T-Lymphocyte Subsets; Transforming Growth Factor beta

The pathophysiology of asthma involves allergic inflammation and remodelling in the airway and airway hyperresponsiveness (AHR) to cholinergic stimuli, but many details of the specific underlying cellular and molecular mechanisms remain unknown. Periostin is a matricellular protein with roles in tissue repair following injury in both the skin and heart. It has recently been shown to be up-regulated in the airway epithelium of asthmatics and to increase active TGF-β. Though one might expect periostin to play a deleterious role in asthma pathogenesis, to date its biological role in the airway is unknown.. To determine the effect of periostin deficiency on airway responses to inhaled allergen.. In vivo measures of airway responsiveness, inflammation, and remodelling were made in periostin deficient mice and wild-type controls following repeated intranasal challenge with Aspergillus fumigatus antigen. In vitro studies of the effects of epithelial cell-derived periostin on murine T cells were also performed.. Surprisingly, compared with wild-type controls, periostin deficient mice developed increased AHR and serum IgE levels following allergen challenge without differences in two outcomes of airway remodelling (mucus metaplasia and peribronchial fibrosis). These changes were associated with decreased expression of TGF-β1 and Foxp3 in the lungs of periostin deficient mice. Airway epithelial cell-derived periostin-induced conversion of CD4(+) CD25(-) cells into CD25(+) , Foxp3(+) T cells in vitro in a TGF-β dependent manner.. Allergen-induced increases in serum IgE and bronchial hyperresponsiveness are exaggerated in periostin deficient mice challenged with inhaled aeroallergen. The mechanism of periostin's effect as a brake on allergen-induced responses may involve augmentation of TGF-β-induced T regulatory cell differentiation.

Topics: Airway Remodeling; Animals; Antigens, Fungal; Aspergillus fumigatus; Asthma; Bronchial Hyperreactivity; Cell Adhesion Molecules; Disease Models, Animal; Hypersensitivity; Immunoglobulin E; Inflammation; Lung; Mice; Mice, Inbred C57BL; Transforming Growth Factor beta

Allergic asthma is the most common form of asthma, affecting more than 10 million Americans. Although it is clear that mast cells have a key role in the pathogenesis of allergic asthma, the mechanisms by which they regulate airway narrowing in vivo remain to be elucidated. Here we report that mice lacking αvβ6 integrin are protected from exaggerated airway narrowing in a model of allergic asthma. Expression microarrays of the airway epithelium revealed mast cell proteases among the most prominent differentially expressed genes, with expression of mouse mast cell protease 1 (mMCP-1) induced by allergen challenge in WT mice and expression of mMCP-4, -5, and -6 increased at baseline in β6-deficient mice. These findings were most likely explained by loss of TGF-β activation, since the epithelial integrin αvβ6 is a critical activator of latent TGF-β, and in vitro-differentiated mast cells showed TGF-β-dependent expression of mMCP-1 and suppression of mMCP-4 and -6. In vitro, mMCP-1 increased contractility of murine tracheal rings, an effect that depended on intact airway epithelium, whereas mMCP-4 inhibited IL-13-induced epithelial-independent enhancement of contractility. These results suggest that intraepithelial activation of TGF-β by the αvβ6 integrin regulates airway responsiveness by modulating mast cell protease expression and that these proteases and their proteolytic substrates could be novel targets for improved treatment of allergic asthma.

Topics: Animals; Antigens, Neoplasm; Bone Marrow Cells; Bronchial Hyperreactivity; Cells, Cultured; Chymases; Epithelium; Gene Expression Profiling; Humans; Integrins; Interleukin-13; Lung; Mast Cells; Mice; Mice, Knockout; Microarray Analysis; Muscle Contraction; Muscle, Smooth; Serine Endopeptidases; Trachea; Transforming Growth Factor beta

Although a similar prevalence of smoking is evident among patients with asthma and the general population, little is known about the impact of cigarette smoke on the immune inflammatory processes elicited by common environmental allergens. We investigated the impact of exposure to cigarette smoke on house dust mite (HDM)-induced allergic airway inflammation and its consequences for tissue remodeling and lung physiology in mice. BALB/c mice received intranasal HDMs daily, 5 days per week, for 3 weeks to establish chronic airway inflammation. Subsequently, mice were concurrently exposed to HDMs plus cigarette smoke, 5 days per week, for 2 weeks (HDMs + smoke). We observed significantly attenuated eosinophilia in the bronchoalveolar lavage of mice exposed to HDMs + smoke, compared with animals exposed only to HDMs. A similar activation of CD4 T cells and expression of IL-5, IL-13, and transforming growth factor-β was observed between HDM-treated and HDM + smoke-treated animals. Consistent with an effect on eosinophil trafficking, HDMs + smoke exposure attenuated the HDM-induced expression of eotaxin-1 and vascular cell adhesion molecule-1, whereas the survival of eosinophils and the numbers of blood eosinophils were not affected. Exposure to cigarette smoke also reduced the activation of B cells and the concentrations of serum IgE. Although the production of mucus decreased, collagen deposition significantly increased in animals exposed to HDMs + smoke, compared with animals exposed only to HDMs. Although airway resistance was unaffected, tissue resistance was significantly decreased in mice exposed to HDMs + smoke. Our findings demonstrate that cigarette smoke affects eosinophil migration without affecting airway resistance or modifying Th2 cell adaptive immunity in a murine model of HDM-induced asthma.

Topics: Airway Remodeling; Airway Resistance; Allergens; Animals; Asthma; B-Lymphocytes; Bronchial Hyperreactivity; Chemokine CCL11; Dendritic Cells; Disease Models, Animal; Female; Interleukin-13; Interleukin-5; Lung; Mice; Mice, Inbred BALB C; Pulmonary Eosinophilia; Pyroglyphidae; Smoking; T-Lymphocytes; Time Factors; Transforming Growth Factor beta; Vascular Cell Adhesion Molecule-1

Many studies have found that smoking reduces lung function, but the relationship between cigarette smoke and allergic asthma has not been clearly elucidated, particularly the role of mast cells. This study aimed to investigate the effects of smoke exposure on allergic asthma and its association with mast cells.. BALB/c mice were sensitized and challenged by OVA to induce asthma, and bone marrow-derived mast cells (BMMCs) were stimulated with antigen/antibody reaction. Mice or BMMCs were exposed to cigarette smoke or CSE solution for 1 mo or 6 h, respectively. The recruitment of inflammatory cells into BAL fluid or lung tissues was determined by Diff-Quik or H&E staining, collagen deposition by Sircol assay, penh values by a whole-body plethysmography, co-localization of tryptase and Smad3 by immunohistochemistry, IgE and TGF-β level by ELISA, expressions of Smads proteins, activities of signaling molecules, or TGF-β mRNA by immunoblotting and RT-PCR.. Cigarette smoke enhanced OVA-specific IgE levels, penh values, recruitment of inflammatory cells including mast cells, expressions of smad family, TGF-β mRNA and proteins, and cytokines, phosphorylations of Smad2 and 3, and MAP kinases, co-localization of tryptase and Smad3, and collagen deposition more than those of BAL cells and lung tissues of OVA-induced allergic mice. CSE solution pretreatment enhanced expressions of TGF-β, Smad3, activities of MAP kinases, NF-κB/AP-1 or PAI-1 more than those of activated-BMMCs.. The data suggest that smoke exposure enhances antigen-induced mast cell activation via TGF-β/Smad signaling pathways in mouse allergic asthma, and that it exacerbates airway inflammation and remodeling.

Topics: Animals; Antigen-Antibody Reactions; Asthma; Blotting, Western; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Cells, Cultured; Collagen; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Immunoglobulin E; Immunohistochemistry; Lung; Mast Cells; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; NF-kappa B; Ovalbumin; Phosphorylation; Plasminogen Activator Inhibitor 1; Plethysmography, Whole Body; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA, Messenger; Signal Transduction; Smad Proteins; Smad2 Protein; Smad3 Protein; Smoking; Time Factors; Transcription Factor AP-1; Transforming Growth Factor beta; Tryptases

IL-13 and IL-4 are hallmark cytokines of Th2-associated diseases including asthma. Recent studies revealed that IL-13Rα1 regulates asthma pathogenesis by mediating both IL-4- and IL-13-mediated responses. Nonetheless, the relative contribution of each cytokine in response to aeroallergen challenge and the degree of functional dichotomy between IL-4 and IL-13 in asthma remains unclear. Consistent with prior publications, we demonstrate that IL-13Rα1 regulates aeroallergen-induced airway resistance and mucus production but not IgE and Th2 cytokine production. We demonstrate that aeroallergen-induced eosinophil recruitment and chemokine production were largely dependent on IL-13Rα1 after Aspergillus but not house dust mite (HDM) challenges. Notably, Aspergillus-challenged mice displayed increased IL-13Rα1-dependent accumulation of dendritic cell subsets into lung-draining lymph nodes in comparison with HDM-challenged mice. Comparison of IL-4 and IL-13 levels in the different experimental models revealed increased IL-4/IL-13 ratios after HDM challenge, likely explaining the IL-13Rα1-independent eosinophilia and chemokine production. Consistently, eosinophil adoptive transfer experiments revealed near ablation of lung eosinophilia in response to Aspergillus in Il13ra1(-/-) mice, suggesting that Aspergillus-induced lung eosinophil recruitment is regulated by IL-13-induced chemokine production rather than altered IL-13 signaling in eosinophils. Furthermore, the near complete protection observed in Il13ra1(-/-) mice in response to Aspergillus challenge was dependent on mucosal sensitization, as alum/Aspergillus-sensitized mice that were rechallenged with Aspergillus developed IL-13Rα1-independent eosinophilia although other asthma parameters remained IL-13Rα1 dependent. These results establish that IL-13Rα1 is required for aeroallergen-induced airway resistance and that allergen-induced chemokine production and consequent eosinophilia is dictated by the balance between IL-4 and IL-13 production in situ.

Topics: Air Pollutants; Allergens; Animals; Bronchial Hyperreactivity; Interleukin-13 Receptor alpha1 Subunit; Lung; Mice; Mice, Inbred BALB C; Mice, Knockout; Mucus; Respiratory Hypersensitivity; Transforming Growth Factor beta

In the present study the effects of bradykinin receptor antagonists were investigated in a murine model of asthma using BALB/c mice immunized with ovalbumin/alum and challenged twice with aerosolized ovalbumin. Twenty four hours later eosinophil proliferation in the bone marrow, activation (lipid bodies formation), migration to lung parenchyma and airways and the contents of the pro-angiogenic and pro-fibrotic cytokines TGF-beta and VEGF were determined. The antagonists of the constitutive B(2) (HOE 140) and inducible B(1) (R954) receptors were administered intraperitoneally 30min before each challenge. In sensitized mice, the antigen challenge induced eosinophil proliferation in the bone marrow, their migration into the lungs and increased the number of lipid bodies in these cells. These events were reduced by treatment of the mice with the B(1) receptor antagonist. The B(2) antagonist increased the number of eosinophils and lipid bodies in the airways without affecting eosinophil counts in the other compartments. After challenge the airway levels of VEGF and TGF-beta significantly increased and the B(1) receptor antagonist caused a further increase. By immunohistochemistry techniques TGF-beta was found to be expressed in the muscular layer of small blood vessels and VEGF in bronchial epithelial cells. The B(1) receptors were expressed in the endothelial cells. These results showed that in a murine model of asthma the B(1) receptor antagonist has an inhibitory effect on eosinophils in selected compartments and increases the production of cytokines involved in tissue repair. It remains to be determined whether this effects of the B(1) antagonist would modify the progression of the allergic inflammation towards resolution or rather towards fibrosis.

Topics: Analysis of Variance; Animals; Asthma; Bradykinin B1 Receptor Antagonists; Bradykinin B2 Receptor Antagonists; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cell Count; Cell Movement; Cell Proliferation; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Eosinophils; Immunohistochemistry; Lung; Mice; Receptor, Bradykinin B1; Receptor, Bradykinin B2; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

In this study, we explored whether prolonged ovalbumin (OVA) exposure in sensitized mice created an environment suitable for Th17 differentiation.. BALB/c and C57BL/6 mice (n = 36), after intraperitoneal OVA sensitization on days 0 and 12, received prolonged OVA aerosol challenges up to day 55. Airway inflammatory cell levels, cytokine profiles, and Th17 cell infiltration were evaluated after sacrifice.. Prolonged OVA challenge caused inflammation that was characterized by raised influxes of airway macrophages and neutrophils. Following long-term exposure, Th17 cytokines and Th17 cell numbers progressively increased in the lung (P < 0.05) along with increased production of Th17 polarization-related factors, including TGF-beta, IL-6, and IL-23. The lineage-specific transcription factor for Th17 subsets, RORgammat, displayed similar upregulation throughout the OVA challenge (P < 0.05).. Prolonged OVA challenge induces an environment that facilitates Th17 polarization.

Topics: Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cell Differentiation; Cell Polarity; Cytokines; Interleukin-23; Interleukin-6; Lung; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Nuclear Receptor Subfamily 1, Group F, Member 3; Ovalbumin; T-Lymphocyte Subsets; T-Lymphocytes, Helper-Inducer; Transforming Growth Factor beta

Genetic and epigenetic programming of T helper (Th) cell subsets during their polarization from naive Th cells establishes long-lived memory Th cells that stably maintain their lineage signatures. However, whether memory Th cells can be redifferentiated into another Th lineage is unclear. In this study, we show that Ag-specific memory Th cells were redifferentiated into Foxp3(+) T cells by TGF-beta when stimulated in the presence of all-trans retinoic acid and rapamycin. The "converted" Foxp3(+) T cells that were derived from Th2 memory cells down-regulated GATA-3 and IRF4 and produced little IL-4, IL-5, and IL-13. Instead, the converted Foxp3(+) T cells suppressed the proliferation and cytokine production of Th2 memory cells. More importantly, the converted Foxp3(+) T cells efficiently accumulated in the airways and significantly suppressed Th2 memory cell-mediated airway hyperreactivity, eosinophilia, and allergen-specific IgE production. Our findings reveal the plasticity of Th2 memory cells and provide a strategy for adoptive immunotherapy for the treatment of allergic diseases.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Cytokines; Eosinophils; Epitopes; Female; Forkhead Transcription Factors; GATA3 Transcription Factor; Immunologic Memory; Inflammation; Mice; Mice, Inbred BALB C; Neutralization Tests; Sirolimus; T-Lymphocytes, Regulatory; Th2 Cells; Transforming Growth Factor beta; Tretinoin

Chronic allergic asthma is the result of a T-helper type 2 (Th2)-biased immune status. Current asthma therapies control symptoms in some patients, but a long-lasting therapy has not been established. Anti-Asthma Simplified Herbal Medicine Intervention (ASHMI™), a Chinese herbal formula, improved symptoms and lung function, and reduced Th2 responses in a controlled trial of patients with persistent moderate to severe asthma.. We evaluated the persistence of ASHMI™ beneficial effects following therapy in a murine model of chronic asthma and the immunological mechanisms underlying such effects. Methods BALB/c mice sensitized intraperitoneally with ovalbumin (OVA) received 3 weekly intratracheal OVA challenges to induce airway hyper-reactivity (AHR) and inflammation (OVA mice). Additionally, OVA mice were treated with ASHMI™ (OVA/ASHMI™) or water (OVA/sham) for 4 weeks, and then challenged immediately and 8 weeks post-therapy. In other experiments, OVA mice received ASHMI™ treatment with concomitant neutralization of IFN-γ or TGF-β. Effects on airway responses, cytokine- and OVA-specific IgE levels were determined 8 weeks post-therapy.. Before treatment, OVA mice exhibited AHR and pulmonary eosinophilic inflammation following OVA challenge, which was almost completely resolved immediately after completing treatment with ASHMI™ and did not re-occur following OVA re-challenge up to 8 weeks post-therapy. Decreased allergen-specific IgE and Th2 cytokine levels, and increased IFN-γ levels also persisted at least 8 weeks post-therapy. ASHMI™ effects were eliminated by the neutralization of IFN-γ, but not TGF-β, during therapy.. ASHMI™ induced long-lasting post-therapy tolerance to antigen-induced inflammation and AHR. IFN-γ is a critical factor in ASHMI™ effects.

Topics: Animals; Anti-Asthmatic Agents; Antibodies; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Cells, Cultured; Disease Models, Animal; Drugs, Chinese Herbal; Female; Immunoglobulin E; Interferon-gamma; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia; Pulmonary Eosinophilia; Th2 Cells; Time Factors; Transforming Growth Factor beta

There is evidence that sex and sex hormones influence the severity of asthma. Airway and lung parenchyma remodeling and the relationship of ultrastructural changes to airway responsiveness and inflammation in male, female, and oophorectomized mice (OVX) were analyzed in experimental chronic allergic asthma. Seventy-two BALB/c mice were randomly divided into three groups (n=24/each): male, female, and OVX mice, whose ovaries were removed 7 days before the start of sensitization. Each group was further randomized to be sensitized and challenged with ovalbumin (OVA) or saline. Twenty-four hours after the last challenge, collagen fiber content in airways and lung parenchyma, the volume proportion of smooth muscle-specific actin in alveolar ducts and terminal bronchiole, the amount of matrix metalloproteinase (MMP)-2 and MMP-9, and the number of eosinophils and interleukin (IL)-4, IL-5, and transforming growth factor (TGF)-β levels in bronchoalveolar lavage fluid were higher in female than male OVA mice. The response of OVX mice was similar to that of males, except that IL-5 remained higher. Nevertheless, after OVA provocation, airway responsiveness to methacholine was higher in males compared with females and OVX mice. In conclusion, sex influenced the remodeling process, but the mechanisms responsible for airway hyperresponsiveness seemed to differ from those related to remodeling.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchodilator Agents; Chronic Disease; Collagen; Disease Models, Animal; Dose-Response Relationship, Drug; Extracellular Matrix; Female; Inflammation Mediators; Interleukin-4; Interleukin-5; Lung; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Ovariectomy; Pneumonia; Sex Factors; Time Factors; Transforming Growth Factor beta

Topics: Animals; Anti-Asthmatic Agents; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Drugs, Chinese Herbal; Humans; Immunoglobulin E; Interferon-gamma; Lung; Pneumonia; Pulmonary Eosinophilia; Tea; Th2 Cells; Transforming Growth Factor beta

The interactions between airway responsiveness, structural remodelling and inflammation in allergic asthma remain poorly understood. Prolonged challenge with inhaled allergen is necessary to replicate many of the features of airway wall remodelling in mice. In both mice and humans, genetic differences can have a profound influence on allergy, inflammation, airway responsiveness and structural changes.. The aim of this study was to provide a comparative analysis of allergen-induced airway changes in sensitized BALB/c and C57BL/6 mice that were exposed to inhaled allergen for 2 ('acute'), 6 or 9 weeks ('chronic'). Inflammation, remodelling and responsiveness were analyzed.. Both strains developed a Th-2-driven airway inflammation with allergen-specific IgE, airway eosinophilia and goblet cell hyperplasia upon 2 weeks of allergen inhalation. This was accompanied by a significant increase in airway smooth muscle mass and hyperresponsiveness in BALB/c but not in C57BL/6 mice. However, airway eosinophilia was more pronounced in the C57BL/6 strain. Chronic allergen exposure (6 or 9 weeks) resulted in an increase in airway smooth muscle mass as well as subepithelial collagen and fibronectin deposition in both strains. The emergence of these structural changes paralleled the disappearance of inflammation in both C57BL/6 and BALB/c mice and loss of hyperresponsiveness in the BALB/c strain. TGF-beta(1 )was accordingly elevated in both strains.. Airway inflammation, remodelling and hyperresponsiveness are closely intertwined processes. Genetic background influences several aspects of the acute allergic phenotype. Chronic allergen exposure induces a marked airway remodelling that parallels a decreased inflammation, which was largely comparable between the two strains.

Topics: Acute Disease; Administration, Inhalation; Allergens; Animals; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Chronic Disease; Disease Models, Animal; Eosinophilia; Eosinophils; Extracellular Matrix Proteins; Goblet Cells; Immunoglobulin E; Inflammation; Lung; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Muscle, Smooth; Ovalbumin; Transforming Growth Factor beta

Treatment of patients with allergic asthma using low doses of peptides containing T cell epitopes from Fel d 1, the major cat allergen, reduces allergic sensitization and improves surrogate markers of disease. Here, we demonstrate a key immunological mechanism, linked epitope suppression, associated with this therapeutic effect. Treatment with selected epitopes from a single allergen resulted in suppression of responses to other ("linked") epitopes within the same molecule. This phenomenon was induced after peptide immunotherapy in human asthmatic subjects and in a novel HLA-DR1 transgenic mouse model of asthma. Tracking of allergen-specific T cells using DR1 tetramers determined that suppression was associated with the induction of interleukin (IL)-10(+) T cells that were more abundant than T cells specific for the single-treatment peptide and was reversed by anti-IL-10 receptor administration. Resolution of airway pathophysiology in this model was associated with reduced recruitment, proliferation, and effector function of allergen-specific Th2 cells. Our results provide, for the first time, in vivo evidence of linked epitope suppression and IL-10 induction in both human allergic disease and a mouse model designed to closely mimic peptide therapy in humans.

Topics: Allergens; Animals; Asthma; Bronchial Hyperreactivity; Cats; Desensitization, Immunologic; Disease Models, Animal; Double-Blind Method; Epitopes; Forkhead Transcription Factors; Genes, MHC Class II; Glycoproteins; HLA-DR1 Antigen; Humans; Immune Tolerance; Interleukin-10; Lung; Mice; Mice, Inbred C57BL; Mice, Transgenic; Peptides; Placebos; Randomized Controlled Trials as Topic; Receptors, Interleukin-10; Th2 Cells; Transforming Growth Factor beta

To clarify whether growth factors play critical roles in the development of airway hyperresponsiveness (AHR) and airway inflammation in the early stages of asthma, the relationship between growth factors and AHR and airway inflammation were analyzed in a mouse model of asthma.. Following ovalbumin (OVA) sensitization and challenge, airway function, inflammation, cytokine and growth factor levels were monitored.. AHR to inhaled methacholine increased at 6 h, peaked at 48 h, and remained elevated for 14 days. IL-4 and IL-5 levels in bronchoalveolar lavage (BAL) fluid were increased at 6 h, peaked at 24 h, but returned to baseline quickly. IL-13 levels increased up to 14 days, peaking at 48 h. Increases in BAL fluid transforming growth factor-beta(1) and platelet-derived growth factor were observed at 12 h, and remained elevated at 14 days. Nerve growth factor levels were increased at 24-28 days. BAL fluid hepatocyte growth factor (HGF) was detected at 12 h, peaked at 24 h, and returned to baseline by 72 h. c-Met/HGF receptor was detected in the airways at 6 h, before HGF in the BAL, and continued to be observed 96 h after the last OVA challenge.. These data identify a temporal association between growth factor production and Th2 cytokine production and the kinetics of AHR. Growth factors may play important roles in the development of allergic airway inflammation and AHR even in the early stages of asthma, before remodeling is initiated.

Topics: Allergens; Animals; Bronchial Hyperreactivity; Female; Hepatocyte Growth Factor; Inflammation Mediators; Intercellular Signaling Peptides and Proteins; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Time Factors; Transforming Growth Factor beta

It is now believed that both chronic airway inflammation and remodeling contribute significantly to airway dysfunction and clinical symptoms in allergic asthma. Transforming growth factor (TGF)-beta is a powerful regulator of both the tissue repair and inflammatory responses, and numerous experimental and clinical studies suggest that it may play an integral role in the pathogenesis of asthma.. We investigated the role of TGF-beta in the regulation of allergic airway inflammation and remodeling using a mouse model of house dust mite (HDM)-induced chronic allergic airway disease.. We have previously shown that intranasal administration of an HDM extract (5 d/wk for 5 wk) elicits robust Th2-polarized airway inflammation and remodeling that is associated with increased airway hyperreactivity. Here, Balb/c mice were similarly exposed to HDM and concurrently treated with a pan-specific TGF-beta neutralizing antibody.. We observed that anti-TGF-beta treatment in the context of either continuous or intermittent HDM exposure had no effect on the development of HDM-induced airway remodeling. To further confirm these findings, we also subjected SMAD3 knockout mice to 5 weeks of HDM and observed that knockout mice developed airway remodeling to the same extent as HDM-exposed littermate controls. Notably, TGF-beta neutralization exacerbated the eosinophilic infiltrate and led to increased airway hyperreactivity.. Collectively, these data suggest that TGF-beta regulates HDM-induced chronic airway inflammation but not remodeling, and furthermore, caution against the use of therapeutic strategies aimed at interfering with TGF-beta activity in the treatment of this disease.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Eosinophils; Female; Hypersensitivity; Lung; Mice; Mice, Inbred BALB C; Mice, Knockout; Pyroglyphidae; Smad3 Protein; Transforming Growth Factor beta

Eosinophils contribute to the early features of allergic lung inflammation through the generation and release of a plethora of mediators. Eosinophil peroxidase (EPO) is one of the eosinophil granule proteins involved in the early response, but its participation in airway remodeling is not established. The present study addressed this question comparing an EPO-deficient mouse strain (NZW) with BALB/c and C57Bl/c strains.. Mice were immunized with ovalbumin/alum, challenged twice with ovalbumin aerosol, and lung responses were measured at day 22 or 28. Collagen, mucus and eosinophils were determined in lung sections stained with picrosirius, periodic acid-Schiff or hematoxylin-eosin; transforming growth factor-beta and vascular endothelial growth factor were determined by ELISA, lipid bodies by enumeration in osmium-stained eosinophils, and airway reactivity to methacholine in isolated lung preparations.. NZW mice showed significantly less collagen around bronchi and blood vessels, less mucus and less eosinophils around bronchi. Eosinophil lipid body formation and airway hyperreactivity were comparable among strains. Levels of transforming growth factor-beta were also comparable; however, the NZW mice showed much higher levels of vascular endothelial growth factor, even under basal conditions.. In allergic lung inflammation, the combination of EPO deficiency and overexpression of VEGF found in NZW mice is associated with less collagen deposition, less mucus and reduced tissue eosinophilia. Eosinophil activation and airway hyperreactivity in NZW mice were similar to the other strains.

Topics: Animals; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Collagen; Eosinophil Peroxidase; Eosinophilia; Male; Methacholine Chloride; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Ovalbumin; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Pirfenidone was administered to sensitized Brown Norway rats prior to a series of ovalbumin challenges. Airway hyperresponsiveness, inflammatory cell infiltration, mucin and collagen content, and the degree of epithelium and smooth muscle staining for TGF-beta were examined in control, sensitized, and sensitized/challenged rats fed a normal diet or pirfenidone diet. Pirfenidone had no effect on airway hyperresponsiveness, but reduced distal bronchiolar cell infiltration and proximal and distal mucin content. Statistical analysis showed that the control group and sensitized/challenged pirfenidone diet group TGF-beta staining intensity scores were not significantly different from isotype controls, but that the staining intensity scores for the sensitized/challenged normal diet group was significantly different from isotype controls. These results suggest that pirfenidone treatment is effective in reducing some of the components of acute inflammation induced by allergen challenge.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchial Provocation Tests; Collagen; Disease Models, Animal; Inflammation; Lung; Male; Mucins; Muscle, Smooth; Ovalbumin; Pyridones; Random Allocation; Rats; Rats, Inbred BN; Respiratory Mucosa; Transforming Growth Factor beta

Microbial intestinal colonization in early in life is regarded to play a major role for the maturation of the immune system. Application of non-pathogenic probiotic bacteria during early infancy might protect from allergic disorders but underlying mechanisms have not been analysed so far.. The aim of the current study was to investigate the immune effects of oral application of probiotic bacteria on allergen-induced sensitization and development of airway inflammation and airway hyper-reactivity, cardinal features of bronchial asthma.. Newborn Balb/c mice received orally 10(9) CFU every second day either Lactobacillus rhamnosus GG or Bifidobacterium lactis (Bb-12) starting from birth for consecutive 8 weeks, during systemic sensitization (six intraperitoneal injections, days 29-40) and airway challenge (days 54-56) with ovalbumin.. The administration of either Bb-12 or LGG suppressed all aspects of the asthmatic phenotype: airway reactivity, antigen-specific immunoglobulin E production and pulmonary eosinophilia (mean: 137 vs. 17 and 13 cellsx10(3)/mL, respectively). Antigen-specific recall proliferation by spleen cells and T-helper type 2 cytokine production (IL-4, IL-5 and IL-10) by mesenteric lymph node cells also showed significant reduction, while TGF production remained unchanged. Oral LGG administration particularly suppressed allergen-induced proliferative responses and was associated with an increase in numbers of TGF-beta-secreting CD4+/CD3+ T cells in mesenteric lymph nodes (6.5, 16.7%) as well as nearly 2-fold up-regulation of Foxp3-expressing cells in peribronchial lymph nodes.. Neonatal application of probiotic bacteria inhibits subsequent allergic sensitization and airway disease in a murine model of asthma by induction of T regulatory cells associated with increased TGF-beta production.

Topics: Allergens; Animals; Asthma; Bifidobacterium; Bronchial Hyperreactivity; Cell Proliferation; Cytokines; Disease Models, Animal; Eosinophilia; Female; Forkhead Transcription Factors; Immunoglobulin E; Immunoglobulin G; Lacticaseibacillus rhamnosus; Lymph Nodes; Mice; Mice, Inbred BALB C; Ovalbumin; Probiotics; Reverse Transcriptase Polymerase Chain Reaction; Spleen; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Up-Regulation

Although eosinophils play an essential role in allergic inflammation, their role has recently been under controversy. Epidemic studies suggest that hypereosinophilia induced by parasite infection could suppress subsequent Ag sensitization, although the mechanism has not been fully clarified. In this study, we investigated whether eosinophils could suppress the Ag-specific immune response in the airway. BALB/c mice were sensitized and airway challenged with OVA. Systemic hypereosinophilia was induced by delivery of an IL-5-producing plasmid. IL-5 gene delivery suppressed the Ag-specific proliferation and cytokine production of CD4+ T cells in the spleen. IL-5 gene delivery before OVA sensitization significantly suppressed airway eosinophilia and hyperresponsiveness provoked by subsequent OVA airway challenge, while delivery during the OVA challenge did not suppress them. This IL-5-induced immune suppression was abolished in eosinophil-ablated mice, suggesting an essential role of eosinophils. IL-5 treatment increased the production of TGF-beta1 in the spleen, and we demonstrated that the main cellular source of TGF-beta1 production was eosinophils, using eosinophil-ablated mice and depletion study. TGF-beta1, but not IL-5 itself, suppressed the Ag-specific immune response of CD4+ T cells in vitro. Furthermore, IL-5 treatment enhanced phosphorylation of Smad2 in CD4+ T cells. Finally, a TGF-beta type I receptor kinase inhibitor restored this IL-5-induced immune suppression both in vitro and in vivo. These results suggest that IL-5-induced hypereosinophilia could suppress sensitization to Ag via a TGF-beta-dependent mechanism, thus suppressed allergic airway inflammation. Therefore, hypereosinophilia could reveal an immunosuppressive effect in the early stage of Ag-induced immune response.

Topics: Animals; Antigens; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; Cells, Cultured; Eosinophils; Gene Transfer Techniques; Growth Inhibitors; Hypereosinophilic Syndrome; Immunosuppressive Agents; Interleukin-5; Male; Mice; Mice, Inbred BALB C; Mice, Transgenic; Mucus; Ovalbumin; Plasmids; Spleen; Transforming Growth Factor beta

Asthma is a chronic airway inflammatory disease that encompasses three cardinal processes: T helper (Th) cell type 2 (Th2)-polarized inflammation, bronchial hyperreactivity, and airway wall remodeling. However, the link between the immune-inflammatory phenotype and the structural-functional phenotype remains to be fully defined. The objective of these studies was to evaluate the relationship between the immunologic nature of chronic airway inflammation and the development of abnormal airway structure and function in a mouse model of chronic asthma. Using IL-4-competent and IL-4-deficient mice, we created divergent immune-inflammatory responses to chronic aeroallergen challenge. Immune-inflammatory, structural, and physiological parameters of chronic allergic airway disease were evaluated in both strains of mice. Although both strains developed airway inflammation, the profiles of the immune-inflammatory responses were markedly different: IL-4-competent mice elicited a Th2-polarized response and IL-4-deficient mice developed a Th1-polarized response. Importantly, this chronic Th1-polarized immune response was not associated with airway remodeling or bronchial hyperresponsiveness. Transient reconstitution of IL-4 in IL-4-deficient mice via an airway gene transfer approach led to partial Th2 repolarization and increased bronchial hyperresponsiveness, along with full reconstitution of airway remodeling. These data show that distinct structural-functional phenotypes associated with chronic airway inflammation are strictly dependent on the nature of the immune-inflammatory response.

Topics: Adenoviridae; Administration, Intranasal; Allergens; Animals; Antigens, Dermatophagoides; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage; Cytokines; Dermatophagoides pteronyssinus; Female; Immunoglobulins; Inflammation; Interleukin-4; Lung; Mice; Mice, Inbred BALB C; Mice, Knockout; Spleen; Transforming Growth Factor beta

We investigated the therapeutic potential of a newly developed antifibrotic agent, pirfenidone, to regulate airway remodeling and the development of allergic airway inflammation and airway hyperresponsiveness after chronic allergen challenge. Administration of pirfenidone after sensitization but during the period of ovalbumin challenge significantly prevented the development of airway hyperresponsiveness and prevented eosinophil and lymphocyte accumulation in the airways. IL-4, IL-5, and IL-13 levels in bronchoalveolar lavage fluid and ovalbumin-specific serum IgE antibody levels were also significantly reduced. Treatment with pirfenidone significantly reduced transforming growth factor-beta1 and platelet-derived growth factor levels in bronchoalveolar lavage fluid. Pirfenidone reduced the expression of transforming growth factor-beta1, the development of goblet cell hyperplasia and subepithelial collagenization, and the increases in contractile elements in the lung. These data indicate that pirfenidone may play an important role in the treatment of asthma and has the potential reduce or prevent airway remodeling.

Topics: Allergens; Animals; Anti-Inflammatory Agents, Non-Steroidal; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cell Proliferation; Cytokines; Eosinophils; Goblet Cells; Hyperplasia; Immunoglobulin E; Interleukin-13; Interleukin-4; Interleukin-5; Leukocytes, Mononuclear; Lymphocytes; Mice; Mice, Inbred BALB C; Ovalbumin; Platelet-Derived Growth Factor; Pyridones; Transforming Growth Factor beta; Transforming Growth Factor beta1

An increasing prevalence of allergic diseases, such as atopic dermatitis, allergic rhinitis and bronchial asthma, has been noted worldwide. Allergic asthma strongly correlates with airway inflammation caused by the unregulated production of cytokines secreted by allergen-specific type-2 T helper (Th2) cells. This study aims to explore the therapeutic effect of the airway gene transfer of IL-12, IL-10 and TGF-beta on airway inflammation in a mouse model of allergic asthma.. BALB/c mice were sensitized to ovalbumin (OVA) by intraperitoneal injections with OVA and challenged by nebulized OVA. Different cytokine gene plasmids or non-coding vector plasmids were instilled daily into the trachea up to one day before the inhalatory OVA challenge phase.. Intratracheal administration of IL-10, IL-12 or TGF-beta can efficiently inhibit antigen-induced airway hyper-responsiveness and is able to largely significantly lower the number of eosinophils and neutrophils in bronchoalveolar lavage fluid of ovalbumin (OVA) sensitized and challenged mice during the effector phase. Furthermore, the effect of IL-10 plasmids is more remarkable than any other cytokine gene plasmid. On the other hand, local administration of IL-4 gene plasmids before antigen challenge can induce severe airway hyper-responsiveness (AHR) and airway eosinophilia.. Our data demonstrated that anti-inflammatory cytokines, particularly IL-10, have the therapeutic potential for the alleviation of airway inflammation in murine model of asthma.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Chemokine CCL11; Chemokines, CC; Disease Models, Animal; Female; Gene Transfer Techniques; Interleukin-10; Interleukin-12; Interleukin-4; Leukotriene B4; Mice; Mice, Inbred BALB C; Ovalbumin; Pulmonary Eosinophilia; Transforming Growth Factor beta

Japanese hop (Hop J) pollen has been considered as one of the major causative pollen allergens in the autumn season. We developed a new Hop J immunotherapy extract in collaboration with Allergopharma (Reinbeck, Germany) and investigated immunologic mechanisms during 3 yr immunotherapy. Twenty patients (13 asthma with rhinitis and 7 hay fever) were enrolled from Ajou University Hospital. Sera were collected before, 1 yr, and 3 yr after the immunotherapy. Changes of serum specific IgE, IgG1, and IgG4 levels to Hop J pollen extracts and serum IL-10, IL-12, TGF-beta1 and soluble CD23 levels were monitored by ELISA. Skin reactivity and airway hyper-responsiveness to methacholine were improved during the study period. Specific IgG1 increased at 1 yr then decreased again at 3 yr, and specific IgG4 levels increased progressively (p<0.05, respectively), whereas total and specific IgE levels showed variable responses with no statistical significance. IL-10, TGF-beta1 and soluble CD23 level began to decrease during first year and then further decreased during next two years with statistical significances. (p<0.05, respectively). In conclusion, these findings suggested the favorable effect of long term immunotherapy with Hop J pollen extracts can be explained by lowered IgE affinity and generation of specific IgG4, which may be mediated by IL-10 and TGF-beta1.

Topics: Bronchial Hyperreactivity; Cytokines; Desensitization, Immunologic; Humans; Immunoglobulin E; Immunoglobulin G; Interleukin-10; Poaceae; Pollen; Receptors, IgE; Transforming Growth Factor beta

Airway remodeling, including subepithelial fibrosis, is a characteristic feature of asthma and likely contributes to the pathogenesis of airway hyperresponsiveness. We examined expression of genes related to airway wall fibrosis in a model of chronic allergen-induced airway dysfunction using laser capture microdissection and quantitative real-time PCR. BALB/c mice were sensitized and subjected to chronic ovalbumin exposure over a 12-wk period, after which they were rested and then harvested 2 and 8 wk after the last exposure. Chronic allergen-exposed mice had significantly increased indices of airway remodeling and airway hyperreactivity at all time points, although no difference in expression of fibrosis-related genes was found when mRNA extracted from whole lung was examined. In contrast, fibrosis-related gene expression was significantly upregulated in mRNA obtained from microdissected bronchial wall at 2 wk after chronic allergen exposure. In addition, when bronchial wall epithelium and smooth muscle were separately microdissected, gene expression of transforming growth factor-beta1 and plasminogen activating inhibitor-1 were significantly upregulated only in the airway epithelium. These data suggest that transforming growth factor-beta1 and other profibrotic mediators produced by airway wall, and specifically, airway epithelium, play an important role in the pathophysiology of airway remodeling.

Topics: Allergens; Animals; Biomarkers; Bronchi; Bronchial Hyperreactivity; Epithelium; Female; Fibrosis; Gene Expression Regulation; Mice; Mice, Inbred BALB C; Muscle, Smooth; Ovalbumin; Plasminogen Activator Inhibitor 1; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

Hepatocyte growth factor (HGF) is known to influence a number of cell types and their production of regulatory cytokines. We investigated the potential of recombinant HGF to regulate not only the development of allergic airway inflammation and airway hyperresponsiveness (AHR), but also airway remodeling in a murine model. Administration of exogenous HGF after sensitization but during ovalbumin challenge significantly prevented AHR, as well as eosinophil and lymphocyte accumulation in the airways; interleukin (IL)-4, IL-5, and IL-13 levels in bronchoalveolar lavage (BAL) fluid were also significantly reduced. Further, treatment with HGF significantly suppressed transforming growth factor-beta (TGF-beta), platelet-derived growth factor, and nerve growth factor levels in BAL fluid. The expression of TGF-beta, the development of goblet cell hyperplasia and subepithelial collagenization, and the increases in contractile elements in the lung were also reduced by recombinant HGF. Neutralization of endogenous HGF resulted in increased AHR as well as the number of eosinophils, levels of Th2 cytokines (IL-4, IL-5, and IL-13) and TGF-beta in BAL fluid. These data indicate that HGF may play an important role in the regulation of allergic airway inflammation, hyperresponsiveness, and remodeling.

Topics: Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cytokines; Eosinophils; Female; Hepatocyte Growth Factor; Humans; Immunoglobulin E; Inflammation; Interferon-gamma; Mice; Mice, Inbred BALB C; Mice, Knockout; Ovalbumin; Recombinant Proteins; Respiratory System; Transforming Growth Factor beta

Airway inflammation and remodelling are important pathophysiologic features of chronic asthma. Although current steroid use demonstrates anti-inflammatory activity, there are limited effects on the structural changes in the lung tissue.. We have used a mouse model of prolonged allergen challenge that exhibits many of the salient features of airway remodelling in order to investigate the anti-remodelling effects of Budesonide.. Treatment was administered therapeutically, with dosing starting after the onset of established eosinophilic airway inflammation and hyper-reactivity.. Budesonide administration reduced airway hyper-reactivity and leukocyte infiltration in association with a decrease in production of the Th2 mediators, IL-4, IL-13 and eotaxin-1. A reduction in peribronchiolar collagen deposition and mucus production was observed. Moreover, our data show for the first time that, Budesonide treatment regulated active transforming growth factor (TGF)-beta signalling with a reduction in the expression of pSmad 2 and the concomitant up-regulation of Smad 7 in lung tissue sections.. Therefore, we have determined that administration of Budesonide modulates the progression of airway remodelling following prolonged allergen challenge via regulation of inflammation and active TGF-beta signalling.

Topics: Allergens; Animals; Anti-Asthmatic Agents; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Budesonide; Chemokine CCL11; Chemokines, CC; Collagen; Extracellular Matrix; Female; Image Processing, Computer-Assisted; Interleukin-13; Interleukin-4; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Models, Animal; Mucus; Signal Transduction; Time Factors; Transforming Growth Factor beta

Bronchial asthma is characterized by chronic airway inflammation and airway remodelling which occurs in both proximal and distal airways. These changes are associated with development of airway hyper-responsiveness and airflow limitation.. This study was aimed to analyse whether chronic inhalative allergen challenges in mice lead to morphological and physiological changes comparable with this phenotype.. For this purpose, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed by aerosol allergen challenges on 2 consecutive days per week for 12 weeks.. In chronically challenged mice, tissue inflammation in proximal as well as distal airways was observed with a predominance of lymphocytes within the cellular infiltrate. In contrast, inflammation in the airway lumen decreased over time. These changes were associated by a shift in bronchoalveolar lavage-cytokine levels from IL-4, IL-5 and TNF-alpha production (during the acute phase) towards markedly increased levels of TGF-beta during the chronic phase. Goblet cell hyperplasia and subepithelial fibrosis occurred throughout the airway tree. In terms of lung function, chronically challenged mice developed persistent bronchial hyper-responsiveness and progressive airflow limitation. Six weeks after OVA aerosol discontinuation, airway inflammation still persisted although lung function was normalized.. These data indicate that our model of chronic aerosol allergen challenges leads to a phenotype of experimental asthma with participation of distal airways and persistence of inflammation thereby resembling many morphological and physiological aspects of human bronchial asthma.

Topics: Administration, Inhalation; Allergens; Animals; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Chronic Disease; Cytokines; Disease Models, Animal; Disease Progression; Female; Mice; Mice, Inbred BALB C; Mucous Membrane; Ovalbumin; Transforming Growth Factor beta

Immunostimulatory sequences of DNA (ISS) inhibit eosinophilic airway inflammation, Th2 responses, and airway hyperreactivity (AHR) in mouse models of acute ovalbumin (OVA)-induced airway inflammation. To determine whether ISS inhibits airway remodeling, we developed a mouse model of airway remodeling in which OVA-sensitized mice were repeatedly exposed to intranasal OVA administration for 1-6 mo. Mice chronically exposed to OVA developed sustained eosinophilic airway inflammation and sustained AHR to methacholine 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, peribronchial myofibroblast accumulation, expression of the profibrotic growth factor transforming growth factor-beta, and subepithelial collagen deposition (assessed by quantitation of the area of peribronchial trichrome staining using image analysis, and immunostaining with anti-collagen V antibodies). Administration of ISS systemically every other week significantly inhibited the development of AHR, eosinophilic inflammation, airway mucus production, and importantly, airway remodeling in mice chronically exposed to OVA for 3-6 mo. In addition, ISS significantly reduced bronchoalveolar lavage and lung levels of the profibrotic cytokine transforming growth factor-beta. These studies demonstrate that ISS prevents not only Th2-mediated airway inflammation in response to acute allergen challenge, but also airway remodeling associated with chronic allergen challenge.

Topics: Animals; Bronchi; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Bronchoconstrictor Agents; DNA; Female; Humans; Inflammation; Interferon-gamma; Interleukin-5; Methacholine Chloride; Mice; Mice, Inbred BALB C; Muscle, Smooth; Ovalbumin; Respiratory System; Th2 Cells; Transforming Growth Factor beta

Allergic asthma is characterized by airway hyperreactivity, inflammation, and a Th2-type cytokine profile favoring IgE production. Beneficial effects of TGF-beta and conflicting results regarding the role of Th1 cytokines have been reported from murine asthma models. In this study, we examined the T cell as a target cell of TGF-beta-mediated immune regulation in a mouse model of asthma. We demonstrate that impairment of TGF-beta signaling in T cells of transgenic mice expressing a dominant-negative TGF-beta type II receptor leads to a decrease in airway reactivity in a non-Ag-dependent model. Increased serum levels of IFN-gamma can be detected in these animals. In contrast, after injection of OVA adsorbed to alum and challenge with OVA aerosol, transgenic animals show an increased airway reactivity and inflammation compared with those of wild-type animals. IL-13 levels in bronchoalveolar lavage fluid and serum as well as the number of inducible NO synthase-expressing cells in lung infiltrates were increased in transgenic animals. These results demonstrate an important role for TGF-beta signaling in T cells in the regulation of airway responses and suggest that the beneficial effects observed for TGF-beta in airway hyperreactivity and inflammation may be due to its regulatory effects on T cells.

Topics: Administration, Inhalation; Aerosols; Alum Compounds; Animals; Antibody Specificity; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; CD2 Antigens; Cell Movement; Epitopes, T-Lymphocyte; Humans; Immunoglobulin E; Immunohistochemistry; Inflammation; Interferon-gamma; Interleukin-13; Lung; Mice; Mice, Inbred Strains; Mice, Transgenic; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Ovalbumin; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; T-Lymphocyte Subsets; Th1 Cells; Transforming Growth Factor beta

Tissue eosinophilia probably plays important roles in the pathophysiology of bronchial asthma and allergic disorders; however, this concept was challenged recently by controversial results in mouse models of bronchial asthma treated with anti-IL-5 Ab and the failure of anti-IL-5 therapy in humans. We have now used a unique model, IL-5 transgenic (TG) mice, to address a fundamental question: is airway eosinophilia beneficial or detrimental in the allergic response? After sensitization and challenge with OVA, IL-5 TG mice showed a marked airway eosinophilia. Surprisingly, these IL-5 TG mice showed lower airway reactivity to methacholine. Immunohistochemical analysis of the lungs revealed a marked peribronchial infiltration of eosinophils, but no eosinophil degranulation. In vitro, mouse eosinophils from peritoneal lavage fluids did not produce superoxide anion, but did produce an anti-inflammatory and fibrotic cytokine, TGF-beta 1. Indeed, the TGF-beta 1 levels in bronchoalveolar lavage fluid specimens from IL-5 TG mice directly correlated with airway eosinophilia (r = 0.755). Furthermore, anti-IL-5 treatment of IL-5 TG mice decreased both airway eosinophilia and TGF-beta 1 levels in bronchoalveolar lavage fluids and increased airway reactivity. Thus, in mice, marked eosinophilia prevents the development of airway hyper-reactivity during an allergic response. Overall, the roles of eosinophils in asthma and in animal models need to be addressed carefully for their potentially detrimental and beneficial effects.

Topics: Allergens; Animals; Antibodies, Monoclonal; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Eosinophils; Humans; Inflammation; Interleukin-5; Male; Mice; Mice, Inbred C3H; Mice, Transgenic; Ovalbumin; Pulmonary Eosinophilia; Respiratory Hypersensitivity; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transgenes

We have previously demonstrated that CpG oligodeoxynucleotides (CpG-ODNs) protect against eosinophilia and airway hyperresponsiveness in murine models of allergen-induced asthma. Acute inflammation is hypothesized to induce chronic airway responses, but no previous studies have evaluated the effects of CpG-ODNs on allergen-induced airway remodeling. Because remodeling is thought to be responsible for many of the long-term adverse effects on asthmatic patients, we evaluated whether CpG-ODNs might similarly prevent these changes using a murine model of recurrent allergen exposure.. The purpose of this study was to evaluate the effect of CpG-ODNs on chronic inflammatory changes and airway remodeling by using a murine model of chronic allergen-induced asthma.. C57BL/6 mice were sensitized to ovalbumin (OVA) and subsequently exposed to nebulized OVA by means of inhalation 3 times weekly for 6 weeks. Some mice received CpG-ODNs by means of intraperitoneal injection at the time of sensitization. At the end of the exposure period, mice were evaluated for the development of airway inflammation, airway hyperresponsiveness, and airway remodeling.. OVA-sensitized mice exposed to recurrent airway challenge with OVA have chronic inflammation, persistent airway hyperresponsiveness, and evidence of airway remodeling, including subepithelial collagen deposition and goblet cell hyperplasia-metaplasia. These changes are significantly reduced in mice treated with CpG-ODNs. Interestingly, mice treated with CpG-ODNs exhibit increased levels of bronchoalveolar lavage transforming growth factor beta, suggesting that regulatory T cells might be responsible for some of these protective effects.. CpG-ODNs are effective not only in preventing acute inflammation but also appear to reduce markers of airway remodeling that develop after chronic allergen exposure.

Topics: Animals; Asthma; Bronchi; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Chronic Disease; Collagen; Disease Models, Animal; Eosinophilia; Female; Fibrosis; Immunoglobulin E; Mice; Mice, Inbred C57BL; Oligodeoxyribonucleotides; Transforming Growth Factor beta

Smad7 is an intracellular antagonist of transforming growth factor beta (TGF-beta) signaling, which could determine the intensity or duration of the TGF-beta signal. Because TGF-beta has been implicated in the development of airway remodeling in asthma on the basis of its strong capacity to induce extracellular matrix production, it is possible that Smad7 also plays some roles in the regulation of the process.. We sought to determine the relationships between Smad7 expression in bronchial biopsy samples from asthmatic subjects and clinicopathologic features.. Bronchial biopsy specimens were obtained from 40 asthmatic subjects and 6 healthy control subjects. Expression levels of Smad7 on a histologic section were estimated by immunohistochemical staining. In addition, the roles of Smad7 in TGF-beta-mediated transcriptional responses were studied by in vitro studies.. Smad7 immunoreactivity was detected mainly in bronchial epithelial cells in control and asthmatic subjects. Interestingly, asthmatic subjects exhibited less Smad7 immunoreactivity in bronchial epithelial cells than normal subjects. Expression levels of Smad7 in bronchial epithelial cells were inversely correlated with basement membrane thickness and airway hyperresponsiveness in asthmatic subjects. In addition, abrogation of endogenous Smad7 expression through use of an antisense oligonucleotide enhanced transcriptional responses to TGF-beta, whereas overexpression of Smad7 inhibited TGF-beta-induced plasminogen activator inhibitor 1production in a human bronchial epithelial cell line, BEAS2B cells.. These findings suggest that Smad7 is a key molecule that defines the susceptibility of bronchial epithelial cells to TGF-beta action and that regulation of Smad7 expression in bronchial epithelial cells might be related to the development of airway remodeling and airway hyperresponsiveness in asthma.

Topics: Adult; Asthma; Basement Membrane; Bronchi; Bronchial Hyperreactivity; DNA-Binding Proteins; Epithelial Cells; Female; Humans; Immunohistochemistry; Male; Middle Aged; Plasminogen Activator Inhibitor 1; Smad7 Protein; Trans-Activators; Transcription, Genetic; Transforming Growth Factor beta

Because chronic Mycoplasma pneumoniae respiratory infection is hypothesized to play a role in asthma, the potential of M. pneumoniae to establish chronic respiratory infection with associated pulmonary disease was investigated in a murine model. BALB/c mice were intranasally inoculated once with M. pneumoniae and examined at 109, 150, 245, 368, and 530 days postinoculation. M. pneumoniae was detected in bronchoalveolar lavage fluid by culture or PCR in 70 and 22% of mice at 109 and 530 days postinoculation, respectively. Lung histopathology was normal up to 368 days postinoculation. At 530 days, however, 78% of the mice inoculated with M. pneumoniae demonstrated abnormal histopathology characterized by peribronchial and perivascular mononuclear infiltrates. A mean histopathologic score (HPS) at 530 days of 5.1 was significantly greater (P < 0.01) than that for controls (HPS score of 0). Serum anti-M. pneumoniae immunoglobulin G was detectable in all of the mice inoculated with M. pneumoniae and was inversely correlated with HPS (r = -0.95, P = 0.01) at 530 days postinoculation. Unrestrained whole-body plethysmography measurement of enhanced pause revealed significantly elevated airway methacholine reactivity in M. pneumoniae-inoculated mice compared with that in controls at 245 days (P = 0.03) and increased airway obstruction at 530 days (P = 0.01). Murine M. pneumoniae respiratory infection can lead to chronic pulmonary disease characterized by airway hyperreactivity, airway obstruction, and histologic inflammation.

Topics: Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Chronic Disease; Female; Interleukin-4; Interleukin-6; Mice; Mice, Inbred BALB C; Mycoplasma pneumoniae; Plethysmography; Pneumonia, Mycoplasma; Respiratory Tract Infections; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

CTLA-4 (CD152) expression is restricted to subsets of activated T lymphocytes and shares homology with CD28. CTLA-4 and CD28 molecules both bind to B7 molecules on antigen-presenting cells. Whereas CD28-B7 interaction enhances T cell activation, cytokine production and survival, CTLA-4 signaling down-regulates T cell responses. Here, we studied the involvement of CTLA-4 triggering in the pathogenesis of allergen-induced airway inflammation in mice. Anti-CTLA-4 mAb were injected during i.p. sensitization with ovalbumin (OVA). This treatment favored OVA-specific IgE production and augmented blood eosinophilia in BALB/c mice. In BALB/c mice, enhanced Th2 sensitization after anti-CTLA-4 mAb injections resulted in more severe airway inflammation, and increased airway hyperresponsiveness to metacholine, bronchial eosinophilia and IL-4 and IL-5 levels in broncho-alveolar lavage (BAL) fluid following repeated allergen inhalations. Importantly, aggravation of airway inflammation and enhancement of Th2 responses were accompanied by a significant reduction of pulmonary TGF-beta levels at protein level in BAL fluid as well as on mRNA level in inflamed lung tissue. In contrast to BALB/c mice, blockade of CTLA-4 did not alter IgE production nor the phenotype of airway inflammation or TGF-beta production in C57BL/6 mice. Our data suggest that CTLA-4 triggering represents an important regulatory mechanism for Th2 sensitization in genetically predisposed mice by modulating TGF-beta production.

Topics: Abatacept; Animals; Antibodies, Monoclonal; Antigens, CD; Antigens, Differentiation; Asthma; Bronchial Hyperreactivity; CTLA-4 Antigen; Disease Models, Animal; Eosinophilia; Immunization; Immunoconjugates; Immunoglobulin E; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Ovalbumin; RNA, Messenger; Signal Transduction; Species Specificity; T-Lymphocytes; Th2 Cells; Transforming Growth Factor beta

Signal transducer and activator of transcription 6 (Stat6) is critical for Th2-mediated responses during allergic airway disease. To investigate the role of Stat6 in fungus-induced airway hyperresponsiveness and remodeling, Stat6-deficient (Stat6-/-) and Stat6-wildtype (Stat6+/+) mice were sensitized to Aspergillus fumigatus and airway disease was subsequently assessed in both groups at days 21, 30, 38, and 44 after an intratracheal challenge with live A. fumigatus conidia. At all times after conidia, histological analysis revealed an absence of goblet cell hyperplasia and markedly diminished peribronchial inflammation in Stat6-/- mice in contrast to Stat6+/+ mice. Airway hyperresponsiveness and peribronchial fibrosis in Stat6-/- mice were significantly reduced at day 21 after conidia compared with Stat6+/+ mice, but both groups exhibited significant, similar increases in these parameters at all subsequent times after conidia. In separate experiments, IL-13-responsive cells in Stat6-/- mice were targeted via the daily intranasal administration of 200 ng of IL-13-PE38QQR (IL13-PE), comprised of human IL-13 and a derivative of Pseudomonas exotoxin, from days 38 to 44 after the conidia challenge. IL13-PE treatment abolished airway hyperresponsiveness, but not peribronchial fibrosis in Stat6-/- mice. Taken together, these data demonstrate that the chronic development of airway hyperresponsiveness during fungal asthma is IL-13-dependent but Stat6-independent.

Topics: Animals; Aspergillosis, Allergic Bronchopulmonary; Aspergillus fumigatus; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Chemokine CCL11; Chemokine CCL2; Chemokine CCL5; Chemokines, CC; Chronic Disease; Collagen; Humans; Immunoglobulin E; Interleukin-13; Interleukin-4; Leukocytes; Lung; Mice; Mice, Inbred BALB C; Mice, Transgenic; Pulmonary Fibrosis; STAT6 Transcription Factor; T-Lymphocytes; Trans-Activators; Transforming Growth Factor beta

Diesel exhaust particles (DEP) are known to modulate the production of cytokines associated with acute and chronic respiratory symptoms and allergic respiratory disease. Tolerance is an important mechanism through which the immune system can maintain nonresponsiveness to common environmental antigens. We examined the effect of DEP on IL-10 and TGF-beta, cytokines produced by macrophages and repressor (Tr-like) lymphocytes which influence tolerance. Human PBMCs (n = 22) were incubated with 1-100 ng/ml of DEP, and suboptimally primed with LPS. IL-10 gene expression was assessed by the S1 nuclease protection assay, and production of IL-10, TGF-beta, TNF-alpha, IL-1 beta and IL-4 stimulated CD23 was evaluated by ELISA after 24 and 48 h. The effect of the order of exposure to DEP and LPS was evaluated on IL-10 protein and mRNA in cells (1) preincubated with LPS followed by DEP, or (2) exposed first to DEP followed by LPS. IL-10 was further evaluated using benzo[a]pyrene and [alpha]naphthoflavone as a surrogate for the polyaromatic hydrocarbons (PAHs) adsorbed to DEP. Control cells were incubated with carbon black, without PAHs. In PBMCs exposed to DEP with LPS, or preincubated with LPS before DEP, IL-10 production and mRNA fall significantly. TGF-beta is similarly suppressed, IL-1 beta secretion is significantly stimulated, and IL-4 stimulated CD23 release rises in the atopic subjects. In contrast, when DEP is added prior to LPS, IL-10 production rises, and IL-1 beta falls to zero. These effects on IL-10 are reproduced with benzo[a]pyrene and reversed by the coaddition of [alpha]naphthoflavone, its known antagonist. The carbon black fraction has no effect on IL-10 production. The effect of DEP on IL-10 can be inhibitory or stimulatory, depending on the order of exposure to DEP and LPS. Pro-inflammatory cytokines and factors rise when IL-10 is inhibited, and are suppressed when IL-10 is stimulated. These results are duplicated with benzo[a]pyrene, suggesting that the PAH portion of the DEP is the active agent.

Topics: Adult; Benzo(a)pyrene; Benzoflavones; Bronchial Hyperreactivity; Carbon; Gene Expression; Humans; Hypersensitivity; In Vitro Techniques; Interleukin-1; Interleukin-10; Interleukin-4; Leukocytes, Mononuclear; Lipopolysaccharides; Lymphocytes; Macrophages; Middle Aged; Receptors, IgE; RNA, Messenger; Transforming Growth Factor beta; Vehicle Emissions

We examined the effect of airway inflammation on airway remodeling and bronchial responsiveness in a mouse model of allergic asthma.. 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.. 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.. 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.

Topics: Acetylcholine; Allergens; Animals; Asthma; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Collagen; Cytokines; Epithelial Cells; Female; Hydroxyproline; Hypersensitivity; Immunoglobulin E; Immunoglobulin G; Immunoglobulins; Lung; Mice; Mice, Inbred BALB C; Respiratory System; Transforming Growth Factor beta

T helper 2 (Th2) cells play a critical role in the pathogenesis of asthma, but the precise immunological mechanisms that inhibit Th2 cell function in vivo are not well understood. Using gene therapy, we demonstrated that ovalbumin-specific (OVA-specific) Th cells engineered to express latent TGF-beta abolished airway hyperreactivity and airway inflammation induced by OVA-specific Th2 effector cells in SCID and BALB/c mice. These effects correlated with increased concentrations of active TGF-beta in the bronchoalveolar lavage (BAL) fluid, demonstrating that latent TGF-beta was activated in the inflammatory environment. In contrast, OVA-specific Th1 cells failed to inhibit airway hyperreactivity and inflammation in this system. The inhibitory effect of TGF-beta-secreting Th cells was antigen-specific and was reversed by neutralization of TGF-beta. Our results demonstrate that T cells secreting TGF-beta in the respiratory mucosa can indeed regulate Th2-induced airway hyperreactivity and inflammation and suggest that TGF-beta-producing T cells play an important regulatory role in asthma.

Topics: Allergens; Animals; Bronchial Hyperreactivity; CD4-Positive T-Lymphocytes; Cell Line; Eosinophilia; Genetic Therapy; Interferon-gamma; Mice; Mice, Inbred BALB C; Mice, SCID; Ovalbumin; Pneumonia; Transforming Growth Factor beta

Transforming growth factor (TGF)-beta has been implicated in immunosuppression. However, it remains obscure whether regulation of T cells by TGF-beta contributes to the immunosuppression in vivo. To address this issue, we developed transgenic mice expressing Smad7, an intracellular antagonist of TGF-beta/Smad signaling, selectively in mature T cells using a plasmid construct coding a promoter element (the distal lck promoter) that directs high expression in peripheral T cells. Peripheral T cells were not growth inhibited by TGF-beta in Smad7 transgenic mice. Although Smad7 transgenic mice did not spontaneously show a specific phenotype, antigen-induced airway inflammation and airway reactivity were enhanced in Smad7 transgenic mice associated with high production of both T helper cell type 1 (Th1) and Th2 cytokines. Thus, blockade of TGF-beta/Smad signaling in mature T cells by expression of Smad7 enhanced airway inflammation and airway reactivity, suggesting that regulation of T cells by TGF-beta was crucial for negative regulation of the inflammatory (immune) response. Our findings also implicated TGF-beta/Smad signaling in mature T cells as a regulatory component of allergic asthma.

Topics: Animals; Asthma; B-Lymphocytes; Bronchial Hyperreactivity; Cytokines; DNA-Binding Proteins; Lymphocyte Activation; Mice; Mice, Transgenic; Ovalbumin; Smad7 Protein; T-Lymphocytes; Trachea; Trans-Activators; Transforming Growth Factor beta

Parainfluenza type 1 (Sendai) virus infection in young rats induces airway growth abnormalities associated with persistent pulmonary dysfunction and hyperresponsiveness. The objectives of this study were to compare virus-susceptible brown Norway (BN) rats and virus-resistant F344 rats and to determine which of several virus-induced structural abnormalities, including bronchiolar hypoplasia, alveolar dysplasia, bronchiolar mural fibrosis, and increases in bronchiolar mast cells, were associated with virus-induced increases in pulmonary resistance and hyperresponsiveness to methacholine. We also determined whether bronchiolar mural thickening and fibrosis may be caused by increased bronchiolar expression of cytokines such as TGF-beta 1 into airways. BN rats infected with virus developed increases in respiratory resistance and hyperresponsiveness that persisted for 28 to 65 d after inoculation. Functional abnormalities were most strongly associated with bronchiolar mural thickening and fibrosis as well as with recruitment of inflammatory cells, including macrophages, mast cells, lymphocytes, and eosinophils, into the bronchiolar wall. F344 rats were resistant to significant virus-induced alterations in bronchiolar airway wall thickness and mast cell increases as well as to pulmonary function abnormalities. BN rats had increase pulmonary mRNA levels of TGF-beta 1 at 10 and 14 d after viral inoculation as compared with F344 rats. BN rats also had greater numbers of bronchiolar macrophages expressing TGF-beta 1 protein that were localized in bronchiolar walls at 10, 14, and 30 d after inoculation. We conclude that recruitment and persistence of airway inflammatory cells and airway wall fibrosis may be important alterations induced by viral lower respiratory disease during early life that can lead to long-term airway dysfunction and hyperresponsiveness. Virus-induced airway fibrosis may be mediated in part by increased TGF-beta 1 gene expression by bronchiolar macrophages in genetically susceptible individuals.

Topics: Airway Resistance; Animals; Animals, Newborn; Bronchi; Bronchial Hyperreactivity; Bronchial Provocation Tests; Disease Susceptibility; Fibrosis; Immunohistochemistry; In Situ Hybridization; Inflammation; Lung; Lung Compliance; Macrophages; Mast Cells; Methacholine Chloride; Parainfluenza Virus 1, Human; Rats; Rats, Inbred BN; Rats, Inbred F344; Respiratory Mechanics; Respiratory Tract Infections; Respirovirus Infections; Transforming Growth Factor beta