ovalbumin and Respiratory-Syncytial-Virus-Infections

Clarifying the pathogenesis of asthma and/or identifying the specific pathway underlying oral asthma tolerance (OT) would be of great significance. In our previous study, promyelocytic leukemia zinc finger (PLZF), which reportedly regulates memory phenotypes, was found to promote ovalbumin (OVA)-induced OT. Therefore, this study aimed to explore the regulatory effects of PLZF on memory phenotypes in asthma and OT mouse models. We found that Zbtb16 (encoding PLZF) and PLZF

Topics: Animals; Asthma; Hyaluronan Receptors; Lung; Lymphocytes; Mice; Ovalbumin; Phenotype; Promyelocytic Leukemia Zinc Finger Protein; Respiratory Syncytial Virus Infections

The susceptibility to respiratory syncytial virus (RSV) infection in early life has been associated with a deficient T-helper cell type 1 (Th1) response. Conversely, healthy adults generally do not exhibit severe illness from RSV infection. In the current study, we investigated whether Th1 cytokine IFN-γ is essential for protection against RSV and RSV-associated comorbidities in adult mice. We found that, distinct from influenza virus, prior RSV infection does not induce significant IFN-γ production and susceptibility to secondary

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Coinfection; Comorbidity; Female; Inflammation; Interferon-gamma; Lung; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Respiratory Syncytial Virus Infections; Th1 Cells; Th2 Cells

Infants with respiratory syncytial virus (RSV)-associated bronchiolitis are at increased risk of childhood asthma. Recent studies demonstrated that certain infections induce innate immune memory (also termed trained immunity), especially in macrophages, to respond more strongly to future stimuli with broad specificity, involving in human inflammatory diseases. Metabolic reprogramming increases the capacity of the innate immune cells to respond to a secondary stimulation, is a crucial step for the induction of trained immunity. We hypothesize that specific metabolic reprogramming of lung trained macrophages induced by neonatal respiratory infection is crucial for childhood allergic asthma.. To address the role of metabolic reprogramming in lung trained macrophages induced by respiratory virus infection in allergic asthma.. Neonatal mice were infected and sensitized by the natural rodent pathogen Pneumonia virus of mice (PVM), a mouse equivalent strain of human RSV, combined with ovalbumin (OVA). Lung CD11b. Proline metabolism reprogramming of trained macrophages induced by early respiratory infection combined with allergen sensitization contributes to development of allergic asthma in childhood. Proline metabolism could be a well target for prevention of allergic asthma in childhood.

Topics: Allergens; Animals; Asthma; Humans; Hypersensitivity; Macrophages; Mice; Mice, Inbred BALB C; Ovalbumin; Proline; Respiratory Syncytial Virus Infections; Respiratory Tract Infections

When the integrity of airway epithelium is destroyed, the ordered airway barrier no longer exists and increases sensitivity to viral infections and allergens, leading to the occurrence of airway inflammation such as asthma. Here, we found that galectin-7 transgenic(+) mice exhibited abnormal airway structures as embryos and after birth. These abnormalities included absent or substantially reduced pseudostratified columnar ciliated epithelium and increased monolayer cells with irregular arrangement and widening of intercellular spaces. Moreover, airway tissue from galectin-7 transgenic(+) mice showed evidence of impaired cell-cell junctions and decreased expression of zonula occludens-1(ZO-1) and E-cadherin. When treated with respiratory syncytial virus (RSV) or ovalbumin (OVA), galectin-7 transgenic(+) mice developed substantially increased bronchial epithelial detachment and apoptosis, airway smooth muscle and basement membrane thickening, and enhanced airway responsiveness. We found that Galectin-7 localized in the cytoplasm and nucleus of bronchial epithelial cells, and that increased apoptosis was mediated through mitochondrial release of cytochrome c and upregulated JNK1 activation and expression of caspase-3 in galectin-7 Tg(+) mice. These findings suggested that Galectin-7 causes airway structural defects and destroys airway epithelium barrier, which predispose the airways to RSV or OVA-induced epithelial apoptosis, injury, and other asthma responses.

Topics: Animals; Apoptosis; Asthma; Bronchi; Cadherins; Disease Models, Animal; Epithelial Cells; Galectins; Mice, Transgenic; Ovalbumin; Rats, Sprague-Dawley; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Tight Junctions

Bronchial asthma (BA) is a chronic disease of the airways. The great majority of BA exacerbations are associated with respiratory viral infections. Recent findings point out a possible role of proinflammatory cytokine interleukin-33 (IL-33) in the development of atopic diseases. Although, little is known about the role of IL-33 in virus-induced BA exacerbations.. We used mouse models of RSV (respiratory syncytial virus)-induced inflammation exacerbation in OVA-sensitized mice and RSV infection alone in adult animals to characterize expression of il33 in the mouse lungs. Moreover, we studied the influence of il33 knockdown with intranasally administrated siRNA on the development of RSV-induced inflammation exacerbation. In addition, we evaluated the expression of IL33 in the ex vivo stimulated PBMCs from allergic asthma patients and healthy subjects with and without confirmed acute respiratory viral infection.. Using mouse models, we found that infection with RSV drives enhanced il33 mRNA expression in the mouse lung. Treatment with anti-il33 siRNA diminishes airway inflammation in the lungs (we found a decrease in the number of inflammatory cells in the lungs and in the severity of histopathological alterations) of mice with RSV-induced inflammation exacerbation, but do not influence viral load. Elevated level of the IL33 mRNA was detected in ex vivo stimulated blood lymphocytes of allergic asthmatics infected with respiratory viruses. RSV and rhinovirus were the most detected viruses in volunteers with symptoms of respiratory infection.. The present study provides additional evidence of the crucial role of the IL-33 in pathogenesis of RSV infection and virus-induced allergic bronchial asthma exacerbations.

Topics: Adolescent; Adult; Aged; Animals; Asthma; Disease Models, Animal; Female; Humans; Hypersensitivity; Inflammation; Interleukin-33; Leukocytes, Mononuclear; Lung; Male; Mice; Mice, Inbred BALB C; Middle Aged; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Respiratory Syncytial Viruses; RNA, Messenger; RNA, Small Interfering; Up-Regulation; Young Adult

Respiratory viral infections are one of the leading causes of need for emergency care and hospitalizations in asthmatic individuals, and airway-secreted cytokines are released within hours of viral infection to initiate these exacerbations. IL-33, specifically, contributes to these allergic exacerbations by amplifying type 2 inflammation. We hypothesized that blocking IL-33 in RSV-induced exacerbation would significantly reduce allergic inflammation.. Sensitized BALB/c mice were challenged with aerosolized ovalbumin (OVA) to establish allergic inflammation, followed by RSV-A2 infection to yield four treatment groups: saline only (Saline), RSV-infected alone (RSV), OVA alone (OVA), and OVA-treated with RSV infection (OVA-RSV). Lung outcomes included lung mRNA and protein markers of allergic inflammation, histology for mucus cell metaplasia and lung immune cell influx by cytospin and flow cytometry.. While thymic stromal lymphopoietin (TSLP) and IL-33 were detected 6 h after RSV infection in the OVA-RSV mice, IL-23 protein was uniquely upregulated in RSV-infected mice alone. OVA-RSV animals varied from RSV- or OVA-treated mice as they had increased lung eosinophils, neutrophils, group 2 innate lymphoid cells (ILC2) and group 3 innate lymphoid cells (ILC3) detectable as early as 6 h after RSV infection. Neutralized IL-33 significantly reduced ILC2 and eosinophils, and the prototypical allergic proteins, IL-5, IL-13, CCL17 and CCL22 in OVA-RSV mice. Numbers of neutrophils and ILC3 were also reduced with anti-IL-33 treatment in both RSV and OVA-RSV treated animals as well.. Taken together, our findings indicate a broad reduction in allergic-proinflammatory events mediated by IL-33 neutralization in RSV-induced asthma exacerbation.

Topics: Animals; Asthma; Female; Interleukin-33; Lymphocytes; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

Topics: Adaptive Immunity; Allergens; Animals; Cells, Cultured; Dendritic Cells; Disease Models, Animal; Humans; Hypersensitivity; Immunoglobulin E; Lung; Lymph Nodes; Mice; Mice, Inbred BALB C; Ovalbumin; OX40 Ligand; Peptides; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; STAT6 Transcription Factor; Th2 Cells

How respiratory syncytial virus (RSV) influences the development of ovalbumin (OVA)-induced asthma remains elusive. As potent T helper (Th)2 cytokine producers, group 2 innate lymphoid cells (ILC2s) are known to serve important functions in the pathogenesis of allergic inflammation. However, how RSV infection affects innate immunity, especially with regard to the function of ILC2s in OVA-induced allergic airway inflammation, is largely unknown.. RSV was used to infect adult BALB/c mice intranasally prior to sensitization and subsequent challenge with OVA. ILC2 frequencies and Th2 cytokine production by ILC2s were assessed by flow cytometry. Cytokine levels were detected both by real-time PCR and ELISA.. Previous infection with RSV attenuated airway inflammation and decreased Th2 cytokine production in mice sensitized and challenged with OVA. Furthermore, previous infection with RSV inhibited the influx of ILC2s into the lung, and constrained their Th2 cytokine production. Adoptive transfer of ILC2s increased asthma-associated airway inflammation in mice previously infected with RSV. These results indicate that previous infection with RSV prevents OVA-induced asthma development via inhibition of ILC2s. Previous infection with RSV attenuated IL-33 production in lung tissue and reduced relative ST2L expression in lung ILC2s, meaning that previous infection with RSV may alter ILC2 function via the IL-33/ST2 signaling pathway.. These results demonstrate that previous infection with RSV attenuates OVA-induced airway inflammation by inhibiting the recruitment and Th2 cytokine production of ILC2s via the IL-33/ST2 pathway.

Topics: Allergens; Animals; Cells, Cultured; Disease Models, Animal; Female; Humans; Hypersensitivity; Immunity, Innate; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Lung; Lymphocytes; Mice; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Signal Transduction; Th2 Cells

Asthma tolerance can be induced by breast-feeding or oral feeding with ovalbumin (OVA). Anergy or deletion of specific T cells and generation of T regulatory cells might contribute to this process. However, whether respiratory syncytial virus (RSV) infection would affect asthma tolerance is not very clear. Here, we first established asthma and oral tolerance mouse models and then analyzed airway hypersensitivity and asthma-related genes in the lung, CCR6-expressing IL-17A

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; CD3 Complex; CD4 Antigens; Cell Line, Tumor; Chemokine CCL20; Chloride Channels; Female; Immune Tolerance; Immunoglobulin E; Interleukin-17; Lung; Mice; Mice, Inbred BALB C; Mucoproteins; Ovalbumin; Receptors, CCR6; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

Respiratory viral infections have frequently been reported to closely correlate with asthma exacerbations. Distinctive expression of cytokine/chemokine and anomalous responses of innate immunity induced by respiratory viral infections were suggested to play a key role. This study further evaluates the effects of airway sensitization on innate immunity in response to different viruses.. Murine sensitization was established using an ovalbumin (OVA) sensitization model. Mice were subsequently infected with either respiratory syncytial virus (RSV) or human metapneumovirus (hMPV). Type I interferon (IFN), cytokines, and chemokines were measured in bronchoalveolar lavage (BAL) fluid. Pulmonary tissue samples were collected for the analysis of viral titers and type I IFN signal transcriptors.. Distinct expressions of cytokine/chemokine responses after viral infection were also found in mice with OVA sensitization. A significant increase of virus replication was found in lungs of RSV-infected sensitized mice. The increment of RSV titer was associated with the decreased levels of type I IFN. Although Toll-like receptor 3 (TLR3) expression was significantly increased in the lungs, the key signal transcriptor, IFN regulatory factor 3, was significantly suppressed in the RSV-infected sensitized mice.. A defective antiviral innate response was observed in the murine respiratory allergy model. Suppressed expression of IFN signal transcriptor contributes to decreased production of type I IFN. The defective innate immune response might result in acute viral exacerbations of allergic airway diseases.

Topics: Allergens; Animals; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Disease Susceptibility; Female; Hypersensitivity; Immunity, Innate; Lung; Mice, Inbred BALB C; Ovalbumin; Paramyxoviridae Infections; Respiratory Syncytial Virus Infections

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

Topics: Animals; Animals, Newborn; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; Cytokines; Disease Models, Animal; Forkhead Transcription Factors; Immunization; Interleukin-2 Receptor alpha Subunit; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

Viral respiratory infections trigger severe exacerbations of asthma, worsen disease symptoms, and impair lung function. To investigate the mechanisms underlying viral exacerbation, we established a mouse model of respiratory syncytial virus (RSV)-induced exacerbation after allergen sensitization and challenge. RSV infection of OVA-sensitized/challenged BALB/c mice resulted in significantly increased airway hyperresponsiveness (AHR) and macrophage and neutrophil lung infiltration. Exacerbation was accompanied by increased levels of inflammatory cytokines (including TNF-α, MCP-1, and keratinocyte-derived protein chemokine [KC]) compared with uninfected OVA-treated mice or OVA-treated mice exposed to UV-inactivated RSV. Dexamethasone treatment completely inhibited all features of allergic disease, including AHR and eosinophil infiltration, in uninfected OVA-sensitized/challenged mice. Conversely, dexamethasone treatment following RSV-induced exacerbation only partially suppressed AHR and failed to dampen macrophage and neutrophil infiltration or inflammatory cytokine production (TNF-α, MCP-1, and KC). This mimics clinical observations in patients with exacerbations, which is associated with increased neutrophils and often poorly responds to corticosteroid therapy. Interestingly, we also observed increased TNF-α levels in sputum samples from patients with neutrophilic asthma. Although RSV-induced exacerbation was resistant to steroid treatment, inhibition of TNF-α and MCP-1 function or depletion of macrophages suppressed features of disease, including AHR and macrophage and neutrophil infiltration. Our findings highlight critical roles for macrophages and inflammatory cytokines (including TNF-α and MCP-1) in viral-induced exacerbation of asthma and suggest examination of these pathways as novel therapeutic approaches for disease management.

Topics: Allergens; Animals; Asthma; Chemokine CCL2; Cytokines; Dexamethasone; Disease Models, Animal; Disease Progression; Humans; Inflammation; Lung; Macrophages; Mice; Mice, Inbred BALB C; Neutrophils; Ovalbumin; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Saliva; Tumor Necrosis Factor-alpha; Ultraviolet Rays

In recent years, asthma has increased dramatically in prevalence with a considerable economic burden all over the world. Long-term remission should be regarded as the promising and meaningful therapeutic goal in asthma management. However, the precise definition criteria and rational therapies for asthma remission have not been well-established. In academia, there is a consensus that even in those who develop asymptomatic remission of asthma, persistent airway inflammation is ubiquitous. Gubenfangxiao decoction (GBFXD) has been widely used in treating asthma remission stage for decades in the Jiangsu Province Hospital of Chinese Medicine, China. We previously demonstrated that GBFXD could downregulate the asthma susceptibility gene ORMDL3, a trigger of Endoplasmic reticulum (ER) stress and unfolded protein response (UPR).. To investigate the involvement of ER stress and UPR in the anti-inflammatory effects of GBFXD in Respiratory Syncytial Virus (RSV)-OVA-induced asthma remission mice.. Mice were orally administered GBFXD at three doses for 30 days after an RSV-OVA challenge. The levels of inflammation mediators in serum were measured using a Luminex assay and the amount of IFN-γ in lung homogenates was detected using ELISA. The splenic CD4+ and CD8+ T lymphocytes were counted using flow cytometric analysis. The mRNA and protein levels of asthma susceptibility gene ORMDL3, ER stress markers (BIP, CHOP), and three canonical UPR branches (PERK-eIF2a-ATF4, IRE1α-XBP1/IRE1α-JNK-AP1 and ATF6-SERCA2b signal pathways) were detected using real-time RT-PCR and western blot.. Histopathological analysis showed that the model group mice still exhibited a sustained airway inflammation even after suspending the OVA-challenge and RSV infections for 30 days. H&E staining results indicated that GBFXD could attenuate sustained airway inflammation. Decreased serum CXCL1 level and increased IFN-γ level in lung homogenate were observed after GBFXD treatment. Reductions in the number of splenic CD4+/CD8+ T lymphocytes were found after DEX treatment. We further confirmed the previous finding that GBFXD could downregulate the expression of ORMDL3. As a result of suppressed UPR, decreased ER stress markers and inhibited UPR branches (PERK and IRE1α signal pathway) were also observed through the significant reduction of signature mRNA and protein expressions after GBFXD treatment.. GBFXD can significantly attenuate RSV-OVA-induced persistent airway inflammation in murine asthma remission model. These effects may be mediated, at least partially, by inhibiting the activation of ER stress responses.

Topics: Animals; Anti-Asthmatic Agents; Anti-Inflammatory Agents; Asthma; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Chromatography, High Pressure Liquid; Cytokines; Disease Models, Animal; Drugs, Chinese Herbal; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Female; Gene Expression Regulation; Heat-Shock Proteins; Inflammation Mediators; Lung; Membrane Proteins; Mice, Inbred BALB C; Ovalbumin; Remission Induction; Respiratory Syncytial Virus Infections; RNA, Messenger; Signal Transduction; Spleen; Transcription Factor CHOP; Unfolded Protein Response

Exposure to dogs in early infancy has been shown to reduce the risk of childhood allergic disease development, and dog ownership is associated with a distinct house dust microbial exposure. Here, we demonstrate, using murine models, that exposure of mice to dog-associated house dust protects against ovalbumin or cockroach allergen-mediated airway pathology. Protected animals exhibited significant reduction in the total number of airway T cells, down-regulation of Th2-related airway responses, as well as mucin secretion. Following dog-associated dust exposure, the cecal microbiome of protected animals was extensively restructured with significant enrichment of, amongst others, Lactobacillus johnsonii. Supplementation of wild-type animals with L. johnsonii protected them against both airway allergen challenge or infection with respiratory syncytial virus. L. johnsonii-mediated protection was associated with significant reductions in the total number and proportion of activated CD11c(+)/CD11b(+) and CD11c(+)/CD8(+) cells, as well as significantly reduced airway Th2 cytokine expression. Our results reveal that exposure to dog-associated household dust results in protection against airway allergen challenge and a distinct gastrointestinal microbiome composition. Moreover, the study identifies L. johnsonii as a pivotal species within the gastrointestinal tract capable of influencing adaptive immunity at remote mucosal surfaces in a manner that is protective against a variety of respiratory insults.

Topics: Animals; Bronchial Hyperreactivity; Dogs; Dust; Environmental Exposure; Flow Cytometry; Fluorescence; Gastrointestinal Tract; Lactobacillus; Lung; Mice; Mice, Inbred BALB C; Microbiota; Ovalbumin; Respiratory Syncytial Virus Infections; Reverse Transcriptase Polymerase Chain Reaction; Th2 Cells

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

Topics: Allergens; Analysis of Variance; Animals; Apoptosis; Cytokines; Disease Models, Animal; Fas Ligand Protein; Female; Immunization; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia; Random Allocation; Reference Values; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Risk Assessment; Sensitivity and Specificity; Th2 Cells

The prevalence of allergic asthma has been increased rapidly in recent years. About 20% of all these sufferers have experienced asthma exacerbation. Although corticosteroids and β-agonists therapy improves serious asthma symptoms, they can׳t completely cure these allergic diseases. BuShenYiQi Formula (BSYQF) has been widely used to treat bronchial asthma and its exacerbation for decades in Huashan Hospital of Fudan University, China. Nevertheless, the mechanisms of BSYQF' anti-asthmatic effects haven׳t been fully elucidated. In this study, we evaluated the involvement of Th1, Th2 and Th17 cells in the anti-asthmatic effects of BSYQF in Respiratory Syncytial Virus (RSV)-induced asthma exacerbated mice.. BALB/c mice were challenged with ovalbumin (OVA), followed by RSV infections for establishment of asthma exacerbated model. Airway hyperresponsiveness (AHR) was examined by direct airway resistance analysis. Bronchoalveolar lavage fluid (BALF) was assessed for inflammatory cell counts and secreted levels of cytokines. Lung tissues were detected for inflammatory cell infiltration and mucus hypersecretion. Subsequently, CD4(+)T cells and alveolar macrophages were sorted and purified from mice lungs in different groups. CD4(+)T cell subpopulations including the expression levels of important transcription factors in T lymphocyte polarization were examined. In asthma exacerbation group, the purified CD4(+)T cells and macrophages were co-cultured, and the changes of co-cultured cells with BSYQF treatment were further analyzed in vitro.. BSYQF significantly attenuated airway hyperresponsiveness and inhibited inflammatory cell infiltration, especially for excessive infiltration of eosinophils and neutrophils. Histopathological analysis showed that BSYQF could suppress airway inflammation and RSV replication. The decreases of antigen-specific IgE, IL-4, IL-5, IL-6, IL-17a and increases of IFN-γ, IL-12 were observed in BALF, lung homogenate or serum after BSYQF treatment. We further confirmed that BSYQF could down-regulate Th2-Th17 cell proportions with lower expressions of GATA3, STAT6 and RORγT, and up-regulate Th1 cell proportion with higher expression of T-bet. And as a result of strengthened Th1-response, activated macrophages were also observed by remarkable enhancement of signature gene expressions and phagocytosis.. BSYQF can significantly attenuate RSV-induced asthma exacerbation. These effects may be mediated at least partially by regulating the balance between Th1 and Th2-Th17 responses.

Topics: Allergens; Animals; Anti-Asthmatic Agents; Anti-Inflammatory Agents; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Drugs, Chinese Herbal; Female; Immunoglobulin E; Lung; Macrophages, Alveolar; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; T-Lymphocytes, Helper-Inducer; Viral Load; Virus Replication

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

Topics: Animals; Dose-Response Relationship, Drug; Female; Hep G2 Cells; Humans; Inflammation; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Random Allocation; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; T-Lymphocytes, Regulatory; Th17 Cells

Respiratory syncytial virus (RSV) infection is associated with both the development and exacerbation of bronchial asthma. We examined eosinophil infiltration and the cytokine profiles of both airway and peripheral blood in antigen-sensitized mice infected with RSV to investigate the pathogenesis of exacerbations of asthma due to RSV infection.. Ovalbumin (OVA)-sensitized mice were challenged by OVA inhalation 3 times and then infected with RSV [10(5) TCID50 (50% of tissue culture infectious dose)/25 g body weight] or mock infection immediately after the last challenge. Animals from each group, namely, the control (PBS instead of OVA inhalation plus mock infection), RSV (PBS plus RSV), OVA (OVA plus mock) and OVA/RSV (OVA plus RSV) were analyzed. Analysis included evaluation of airway responsiveness to methacholine, pathological findings in the airway by hematoxylin and eosin (HE) and Luna staining, bronchoalveolar fluid (BALF) and peripheral leukocytes counts, and concentrations of multiple cytokines/chemokines in both BALF and serum.. Airway responsiveness was significantly enhanced in the OVA and OVA/RSV groups compared with the control group. Levels of tissue and BALF eosinophils were higher in the OVA and OVA/RSV groups than in the RSV or control group. Significantly higher levels of macrophage inflammatory protein (MIP)-1α in BALF were observed in the OVA/RSV group compared with the 3 other groups. Production of serum IL-17 was also significantly elevated in the OVA/RSV group compared with the control or OVA group.. These findings suggest that MIP-1α and IL-17 may play important roles in acute exacerbation of asthma induced by RSV in an animal model.

Topics: Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cell Line; Chemokine CCL3; Cytokines; Immunoglobulin E; Interleukin-17; Lung; Male; Mice; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

Mucous cell metaplasia is a hallmark of asthma, and may be mediated by signal transducers and activators of transcription (STAT)-6 signaling. IL-17A is increased in the bronchoalveolar lavage fluid of patients with severe asthma, and IL-17A also increases mucus production in airway epithelial cells. Asthma therapeutics are being developed that inhibit STAT6 signaling, but the role of IL-17A in inducing mucus production in the absence of STAT6 remains unknown. We hypothesized that IL-17A induces mucous cell metaplasia independent of STAT6, and we tested this hypothesis in two murine models in which increased IL-17A protein expression is evident. In the first model, ovalbumin (OVA)-specific D011.10 Th17 cells were adoptively transferred into wild-type (WT) or STAT6 knockout (KO) mice, and the mice were challenged with OVA or PBS. WT-OVA and STAT6 KO-OVA mice demonstrated increased airway IL-17A and IL-13 protein expression and mucous cell metaplasia, compared with WT-PBS or STAT6 KO-PBS mice. In the second model, WT, STAT1 KO, STAT1/STAT6 double KO (DKO), or STAT1/STAT6/IL-17 receptor A (RA) triple KO (TKO) mice were challenged with respiratory syncytial virus (RSV) or mock viral preparation, and the mucous cells were assessed. STAT1 KO-RSV mice demonstrated increased airway mucous cell metaplasia compared with WT-RSV mice. STAT1 KO-RSV and STAT1/STAT6 DKO-RSV mice also demonstrated increased mucous cell metaplasia, compared with STAT1/STAT6/IL17RA TKO-RSV mice. We also treated primary murine tracheal epithelial cells (mTECs) from WT and STAT6 KO mice. STAT6 KO mTECs showed increased periodic acid-Schiff staining with IL-17A but not with IL-13. Thus, asthma therapies targeting STAT6 may increase IL-17A protein expression, without preventing IL-17A-induced mucus production.

Topics: Adoptive Transfer; Animals; Bronchoalveolar Lavage Fluid; Female; Interleukin-13; Interleukin-17; Lung; Metaplasia; Mice; Mice, Inbred BALB C; Mice, Knockout; Mucus; Neutrophils; Ovalbumin; Peptide Fragments; Receptors, Interleukin-17; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; STAT1 Transcription Factor; STAT6 Transcription Factor; Th17 Cells; Transcriptional Activation

Allergic conjunctivitis is characterized by itchy, watery and swollen eyes which occur in response to exposure to seasonal or environmental allergens. The early phase reaction of allergic conjunctivitis is primarily mediated by mast cell degranulation while the late phase reaction is driven by Th2 cells and eosinophils. Prostaglandin D(2) (PGD(2)), released from mast cells, is present in allergic conjunctival tears and may elicit classical allergic responses via interaction with the high-affinity DP2 receptor (chemoattractant receptor-homologous molecule expressed on Th2 cells, CRTh2). Furthermore, antagonism of this receptor is well known to inhibit eosinophil chemotaxis, basophil activation and Th2 cytokine production. PGD(2), therefore, may be involved in both early and late phase reactions in response to allergen challenge.. Thus, we explored whether our novel and selective DP2 antagonist AM156 would be efficacious in animal models of allergic conjunctivitis. Furthermore, as respiratory syncytial virus (RSV) has been implicated in the pathogenesis of allergic conjunctivitis, we examined the effects of DP2 antagonism in a murine model of RSV ocular infection.. Utilizing a guinea pig ovalbumin model and a murine ragweed model we demonstrated that AM156 reduces redness, discharge and swelling in response to allergen challenge. These effects were equal to or greater than those of current clinical treatment options for allergic conjunctivitis including topical corticosteroids and a dual-mechanism antihistamine and decongestant. AM156 significantly reduced RSV-induced ocular inflammation and IL-4 production.. These results suggest that a topical DP2 antagonist such as AM156 may represent a novel therapeutic for allergic conjunctivitis.

Topics: Administration, Topical; Allergens; Ambrosia; Animals; Anti-Allergic Agents; Benzylamines; Conjunctivitis, Allergic; Conjunctivitis, Viral; Disease Models, Animal; Female; Guinea Pigs; Interleukin-4; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Receptors, Immunologic; Receptors, Prostaglandin; Respiratory Syncytial Virus Infections

Immune tolerance is instituted early in life, during which time regulatory T (T(reg)) cells have an important role. Recurrent infections with respiratory syncytial virus (RSV) in early life increase the risk for asthma in adult life. Repeated infection of infant mice tolerized to ovalbumin (OVA) through their mother's milk with RSV induced allergic airway disease in response to OVA sensitization and challenge, including airway inflammation, hyper-reactivity and higher OVA-specific IgE, as compared to uninfected tolerized control mice. Virus infection induced GATA-3 expression and T helper type 2 (T(H)2) cytokine production in forkhead box P3 (FOXP3)(+) T(reg) cells and compromised the suppressive function of pulmonary T(reg) cells in a manner that was dependent on interleukin-4 receptor α (IL-4Rα) expression in the host. Thus, by promoting a T(H)2-type inflammatory response in the lung, RSV induced a T(H)2-like effector phenotype in T(reg) cells and attenuated tolerance to an unrelated antigen (allergen). Our findings highlight a mechanism by which viral infection targets a host-protective mechanism in early life and increases susceptibility to allergic disease.

Topics: Animals; Asthma; Forkhead Transcription Factors; GATA3 Transcription Factor; Immune Tolerance; Immunoglobulin E; Interleukin-4 Receptor alpha Subunit; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; T-Lymphocytes, Regulatory

Much evidence suggests that respiratory syncytial virus (RSV) infection prolongs airway hyperresponsiveness (AHR) and exacerbates asthma by enhancing airway inflammation. However, the characteristic of airway inflammation and kinetics of airway dysfunction occurred in the central and peripheral airways were not fully delineated. The objective of this study was to investigate the effect of RSV on the allergic airway inflammation in different size airways and to elucidate its possible mechanism. Using a murine model of prior ovalbumin (OVA) sensitization and subsequent RSV challenge, lung resistance (R(L)), and dynamic compliance (Cdyn) was conducted by barometric whole-body plethysmography. Histological examinations were carried out. Differential cells count in bronchoalveolar lavage (BAL) fluid, serum anti-OVA IgE, and IgG1 were measured. Cytokine mRNA expression in lung tissue were determined. RSV triggered a significant increase in R(L) and reduction in Cdyn, as well as greatly prolonged the recovery of Cdyn more than that of R(L) in OVA-sensitized mice. Also, RSV resulted in more severe peripheral airway inflammation which exhibit as globe cell hyperplasia and CD8+ T cell infiltration. Furthermore, the number of lymphocytes, neutrophils and macrophages in BAL fluid, serum anti-OVA IgE and IgG1 were remarkably increased. Additionally, mice increased relative expression of cytokines IL-4, IL-13, and IFN-γ, but not IL-5, IL-17, and IL-17F. These findings demonstrated that RSV could selectively affect pathologic processes that contribute to altered airway function in the central and peripheral airways in OVA-sensitized mice. These processes may be involved in goblet cell hyperplasia and CD8+ T cell infiltration in peripheral airways.

Topics: Acetylcholine; Animals; Asthma; Bronchi; Cell Line, Tumor; Female; Humans; Immunoglobulin E; Immunoglobulin G; Interferon-gamma; Interleukins; Lung; Lung Compliance; Mice; Mice, Inbred BALB C; Ovalbumin; Periodic Acid-Schiff Reaction; Respiratory Syncytial Virus Infections; RNA, Messenger

Each year, approximately 20% of asthmatics in the United States experience acute symptom exacerbations, which commonly result from pulmonary viral infections. The majority of asthma exacerbations in very young children follow infection with respiratory syncytial virus (RSV). However, pathogenic mechanisms underlying induction of asthma exacerbations by RSV are not well understood. We therefore investigated the effect of post-sensitization RSV infection on lung function in ovalbumin (OVA)-sensitized BALB/c mice as a model of RSV asthma exacerbations. OVA sensitization of uninfected female BALB/c mice increased bronchoalveolar lavage fluid (BALF) eosinophil levels and induced airway hyperresponsiveness to the muscarinic agonist methacholine, as measured by the forced-oscillation technique. In contrast, intranasal infection with replication-competent RSV strain A2 for 2-8 days reduced BALF eosinophil counts and reversed airway hyperresponsiveness in a pertussis toxin-sensitive manner. BALF levels of the chemokine keratinocyte cytokine (KC; a murine homolog of interleukin-8) were elevated in OVA-sensitized, RSV-infected mice and reversal of methacholine hyperresponsiveness in these animals was rapidly inhibited by KC neutralization. Hyporesponsiveness could be induced in OVA-sensitized, uninfected mice by recombinant KC or the Gαi agonist melittin. These data suggest that respiratory syncytial virus induces KC-mediated activation of Gαi, resulting in cross-inhibition of Gαq-mediated M(3)-muscarinic receptor signaling and reversal of airway hyperresponsiveness. As in unsensitized mice, KC therefore appears to play a significant role in induction of airway dysfunction by respiratory syncytial virus. Hence, interleukin-8 may be a promising therapeutic target to normalize lung function in both asthmatics and non-asthmatics with bronchiolitis. However, the OVA-sensitized, RSV-infected mouse may not be an appropriate model for investigating the pathogenesis of viral asthma exacerbations.

Topics: Animals; Asthma; Bronchoalveolar Lavage Fluid; Female; Melitten; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Receptor, Muscarinic M3; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

To assess IgE response and cytokine gene expressions in pulmonary lymph collected from bovine respiratory syncytial virus (BRSV)-infected calves after ovalbumin inhalation.. Thirteen 7- to 8-week-old calves.. The efferent lymphatic duct of the caudal mediastinal lymph node of each calf was cannulated 3 or 4 days before experiment commencement. Calves were inoculated (day 0) with BRSV (n = 7) or BRSV-free tissue culture medium (mock exposure; 6) via aerosolization and exposed to aerosolized ovalbumin on days 1 through 6 and day 15. An efferent lymph sample was collected daily from each calf on days -1 through 16; CD4+ and CD8+ T lymphocyte subsets in lymph samples were enumerated with a fluorescence-activated cell scanner. Expressions of several cytokines by efferent lymphocytes and lymph ovalbumin-specific IgE concentration were measured. Each calf was euthanized on day 16 and then necropsied for evaluation of lungs.. Mean fold increase in ovalbumin-specific IgE concentration was greater in BRSV-infected calves than in mock-infected calves. At various time points from days 4 through 10, percentages of T lymphocyte subsets and CD4+:CD8+ T lymphocyte ratios differed between BRSV-infected calves and day -1 values or from values in mock-infected calves. On days 3 through 5, IL-4 and IL-13 gene expressions in BRSV-infected calves were increased, compared with expressions in mock-infected calves. Lung lesions were consistent with antigen exposure.. In response to the inhalation of aerosolized ovalbumin, BRSV infection in calves appeared to facilitate induction of a T helper 2 cell response and ovalbumin-specific IgE production.

Topics: Animals; Antibodies, Viral; Cattle; Cytokines; Gene Expression Regulation; Immunoglobulin E; Lung; Lymph; Lymphocyte Subsets; Male; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Bovine

To investigate the inflammatory changes and the airway hyper-responsiveness in the asthma mouse model infected by respiratory syncytial virus and elucidate the relationship between the infection and the effect of glucocorticoid.. 60 BALB/c mice were randomly divided into 6 groups. One of these is the control group; the others are the OVA/sham group, the OVA/sham +Dex group, the PBS/RSV group, the OVA/RSV group and the OVA/RSV+Dex group. The airway resistance was measured using a sealed body plethysmograph. Pathological slides were stained with hematoxylin-eosin, and the peribronchial inflammation was observed microscopically. The concentrations of IL-4, IFN-gamma, TGF-beta1 in lung tissues were detected by ELISA.. Compared with the control group, the degree of the airway inflammation and hyperresponsiveness and the concentrations of IL-4/IFN-gamma, TGF-beta1 in all four OVA groups increased significantly. And there was a statistically significant difference between the OVA/sham group and the OVA/sham+Dex group, and between the OVA/RSV group and the OVA/RSV+Dex group respectively. Compared with the OVA/RSV group, there was an obvious aggravation of airway inflammation and hyper-responsiveness in the OVA/RSV+Dex group.. Glucocorticoid significantly reduces airway inflammation and hyper-responsiveness induced by repetitive OVA challenge in the mouse model of asthma. However, the significant decrease in Th1 and increase in Th2 inflammation and aggravation of airway hyper-responsiveness in the mice in OVA/RSV group show that they are not sensitive to glucocorticoid. The effects of infection with RSV on the mouse model of asthma could be the cause of the glucocorticoid resistance during the therapy.

Topics: Allergens; Animals; Asthma; Bronchial Hyperreactivity; Cell Line; Dexamethasone; Disease Models, Animal; Disease Progression; Female; Humans; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Plethysmography; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Th1-Th2 Balance

To study the relation between Respiratory Syncytial Virus infection and asthma development by measuring airway responsiveness (AR) and M2R function.. Guinea pigs (n = 34) were randomly divided into 4 groups: Hep-2/NS group (group A, n = 9), RSV/NS group (group B, n =9), Hep-2/OVA group (group C, n = 8) and RSV/OVA group(group D, n = 8). On day 21 after infection we tested AR and M2R. Then counted eosinophils in BALF and observed pathological change.. Intraairway pressure(IP mmH20) of group B had no significant difference with group A(P > 0.01), and the extent of IP decrease also had no difference between groups A and B (P > 0. 05), but IP of C group were much higher than group A (P<0.05), with extent of IP decrease lower than group A (P < 0.05). And IP of group D were higher than group C (P < 0.01), with the extent of IP decrease much lower than group C (P < 0.05).. RSV infection could enhance OVA-induced M2R dysfunction, then develop AHR.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Female; Guinea Pigs; Male; Ovalbumin; Random Allocation; Receptor, Muscarinic M2; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

The mechanisms underlying exacerbation of asthma induced by respiratory syncytial virus (RSV) infection have been extensively studied in human and animal models. However, most of these studies focused on acute inflammation and little is known of its long-term consequences on remodelling of the airway tissue.. The aim of the study was to use a murine model of prolonged allergen-induced airway inflammation to investigate the effect of RSV infection on allergic airway inflammation and tissue remodelling.. We subjected mice to RSV infection before or during the chronic phase of airway challenges with OVA and compared parameters of airway inflammation and remodelling at the end-point of the prolonged allergen-induced airway inflammation protocol.. RSV infection did not affect the severity of airway inflammation in any of the groups studied. However, RSV infection provoked airway remodelling in non-sensitized, allergen-challenged mice that did not otherwise develop any of the features of allergic airways disease. Increased collagen synthesis in the lung and thickening of the bronchial basal membrane was observed in non-sensitized allergen-challenged mice only after prior RSV infection. In addition, fibroblast growth factor (FGF)-2 but not TGF-beta(1) was increased in this group following RSV infection.. Our data show for the first time that RSV infection can prime the lung of mice that are not previously systemically sensitized, to develop airway remodelling in response to allergen upon sole exposure via the airways. Moreover, our results implicate RSV-induced FGF-2 in the remodelling process in vivo.

Topics: Alum Compounds; Analysis of Variance; Animals; Asthma; Bronchoalveolar Lavage Fluid; Collagen; Cytokines; Extracellular Matrix; Female; Fibroblast Growth Factor 2; Immunohistochemistry; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Statistics, Nonparametric; Transforming Growth Factor beta

Respiratory syncytial virus (RSV) infection is the major cause of bronchiolitis in infants and is a risk factor for the development of asthma. Allergic asthmatics are more susceptible to RSV infection and viral exacerbation.. Since the effectiveness of corticosteroids in treating RSV infection has been controversial, we tested fluticasone propionate (FP) and salmeterol (Sal) alone versus FP plus Sal (FPS) on RSV-induced airway inflammation. Mice were sensitized and challenged with ovalbumin (OVA) and infected with RSV. Following infection they were treated with FP, Sal, or FPS intranasally and airway hyperreactivity (AHR), inflammation and RSV titers were examined.. The group treated with FPS showed significantly lower AHR compared to the group treated with FP or Sal alone. The group treated with FP alone showed slightly decreased (non-significant) AHR compared to controls. Treatment with FPS resulted in significant decreases in the percentage of eosinophils and neutrophils in bronchoalveolar lavage fluid and in lung pathology compared to FP or Sal. FP alone decreased eosinophils but not neutrophils or lymphocytes, while Sal alone decreased eosinophils and neutrophils but not lymphocytes. FPS treatment of mice infected with RSV in the absence of allergen sensitization resulted in a 50% decrease of RSV titer in the lung and a reduction in neutrophils compared to FP or Sal.. Together, these results indicate that fluticasone in combination with salmeterol is a more effective treatment for decreasing airway hyperreactivity and inflammation than either of them alone in allergen-sensitized, RSV-infected mice.

Topics: Albuterol; Allergens; Androstadienes; Animals; Anti-Allergic Agents; Asthma; Bronchoalveolar Lavage; Bronchodilator Agents; Drug Combinations; Female; Fluticasone; Fluticasone-Salmeterol Drug Combination; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Salmeterol Xinafoate

Neonatal Bacillus Calmette-Guerin (BCG) vaccination could decrease asthma prevalence in human according to "hygiene hypothesis". The authors proposed a hypothesis that effect of BCG vaccination on inhibiting asthma in human might be reversed by respiratory virus infection. The objective of this study was to observe combined effects of neonatal BCG vaccination and respiratory syncytial virus (RSV) infection on experimental asthma in mice.. Neonatal BALB/c mice were divided into five groups. Control and ovalbumin (OVA) groups were mock-vaccinated at birth and mock-infected at 3 weeks of age. BCG + OVA group was BCG-vaccinated and mock-infected. RSV + OVA group was mock-vaccinated and RSV-infected. BCG + RSV + OVA group was BCG-vaccinated and RSV-infected. Except for control group, all the other groups underwent ovalbumin (OVA) sensitization and challenge. Airway responsiveness to inhaled methacholine was measured and bronchoalveolar lavage (BAL) was performed after the last challege. Cells in BAL fluid (BALF) were counted. Cytokines in BALF and serum OVA-specific IgE were detected by ELISA and inflammatory characteristics of lungs was scored by staining with hematoxylin and eosin.. (1) The numbers of total white cells, lymphocytes, monocytes, neutrophils, and eosinophils in the BALF from all OVA-sensitized/challenged groups were significantly greater than those in control (P < 0.01), and BCG + OVA group had significantly lower total white cells, lymphocytes and eosinophils as compared with other OVA-sensitized/challenged groups (P < 0.05 or 0.01). (2) All OVA-sensitized/challenged groups had significantly lower IFNgamma (P < 0.05) and higher IL-4 (P < 0.05) level in BALF as compared with control, but there was no significant difference among all OVA sensitized/challenged groups. There was no significant difference in IL-10 level between all experimental groups. (3) All OVA-sensitized/challenged groups showed significantly higher serum OVA-specific IgE titers than control (P < 0.05 or 0.01), but no significant difference was found among all OVA sensitized/challenged groups. (4) RSV + OVA and BCG + RSV + OVA groups displayed the highest airway resistance and subsequently in order as follows: OVA group, BCG + OVA group and control group in severity of airway hyperreactivity (AHR), but no significant difference was found between RSV + OVA and BCG + RSV + OVA groups. (5) Histological score of peribronchiolitis, perivasculitis, alveolitis, and peribronchial eosinophilia in all OVA-sensitized/challenged groups was significantly higher than that in control. BCG + OVA group had significantly milder peribronchiolitis and peribronchial eosinophilia than the other OVA-sensitized/challenged groups (P < 0.05) and significantly milder alveolitis than OVA and BCG + RSV + OVA groups (P < 0.05).. Neonatal BCG vaccination decreased asthmatic inflammation and AHR and RSV infection could reverse anti-asthma effect of neonatal BCG vaccination in OVA-sensitized/challenged mouse model.

Topics: Animals; Animals, Newborn; Asthma; BCG Vaccine; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Eosinophils; Immunoglobulin E; Interferon-gamma; Interleukin-10; Interleukin-4; Leukocytes; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Treatment Outcome

Heat, oxidation and exposure to aldehydes create reactive carbonyl groups on proteins, targeting antigens to scavenger receptors. Formaldehyde is widely used in making vaccines, but has been associated with atypical enhanced disease during subsequent infection with paramyxoviruses. We show that carbonyl groups on formaldehyde-treated vaccine antigens boost T helper type 2 (T(H)2) responses and enhance respiratory syncytial virus (RSV) disease in mice, an effect partially reversible by chemical reduction of carbonyl groups.

Topics: Animals; Antigens, Viral; Bronchoalveolar Lavage Fluid; Eosinophilia; Formaldehyde; Immunization; Interferon-gamma; Interleukin-5; Lung; Mice; Mice, Inbred BALB C; Neutralization Tests; Ovalbumin; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus Vaccines; Respiratory Syncytial Viruses; Th2 Cells; Time Factors; Vaccines, Inactivated

To reproduce a severe asthma model in ovalbumin (OVA)-sensitized Balb/C mice by induction with respiratory syncytial virus (RSV).. Thirty Balb/C mice were randomly divided into phosphate buffer solution (PBS) control group, OVA group and OVA/RSV group. The severe asthma model was reproduced by sensitization with intraperitoneal injection of OVA, followed by repeated inhalation of OVA combined with repeated intranasal instillation of RSV (1.0x10(9) pfu/L in 50 microl). Asthmatic symptoms were observed. The changes in airway responsiveness represented by lung resistance (R(L)) stimulated by acetylcholine (Ach) and function of lung in terms of peak expiratory flow (PEF) and the ratio of forced expiratory volume in 0.4 second (FEV 0.4) /forced vital capacity (FVC) were determined. Lung tissue sections with hematoxylin and eosin (HE) staining for general pathology, periodic acid Schiff (PAS) staining for identification of goblet cells mucus secretion and Masson staining for pathologic changes in lung tissue and remodeling were examined. The ratio of inner diameter to outer diameter of the airway, and the thickness of smooth muscle and basement membrane were determined.. (1) The differences in R(L), PEF and ratio of FEV 0.4 /FVC both in OVA/RSV group and OVA group were significant when compared with those in PBS control group when stimulated by Ach (5.0, 15.0 and 45.0 g/L) (respectively P<0.01). Asthma symptoms were more severe in OVA/RSV group, compared with those of OVA group. Total R(L) was increased and PEF and ratio of FEV 0.4 /FVC were decreased in OVA/RSV group compared with those of OVA group (respectively P<0.01). There were more severe bronchoconstriction and more extensive inflammatory cells (eosinophils, lymphocytes, neutrophils) infiltration around the bronchi in the OVA/RSV group. A marked and extensive airway goblet cell hyperplasia and mucus excretion in airway lumen and deposition of collagen in subepithelial basement membrane were found in the OVA/RSV group. (2) The ratio of inner diameter to outer diameter and that of the thickness of smooth muscle and basement membrane were 0.56+/-0.03, (45.12+/-2.08) microm and (36.15+/-1.88) microm, respectively, in OVA/RSV group, and the differences were significant (respectively P<0.01), as compared with OVA group [0.75+/-0.06, (24.63+/-0.94) microm and (21.68+/-1.13) microm, respectively].. An animal model of severe asthma is successfully reproduced by nasal inoculation with RSV in OVA-sensitized Balb/C mice.

Topics: Animals; Asthma; Disease Models, Animal; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

Experimental respiratory syncytial virus (RSV) infection of guinea pigs is associated with enhanced allergic sensitisation to inhaled ovalbumin (OA) and low-level viral persistence in the lungs. Based on the T-helper (Th)1/Th2 paradigm, in which a Th2 shift is characteristic of an allergic response and less effective anti-viral immunity, the effects of immunotherapy with synthetic cytosine phosphate-guanine-oligodeoxynucleotides (CpG-ODN), which are potent Th1 stimuli, on OA sensitisation with and without RSV infection were evaluated. Measurements included quantitative histology for airway inflammation by T-cells and eosinophils, semiquantitative RT-PCR for lung Th1/Th2 balance (interferon (IFN)-gamma/interleukin (IL)-5 mRNA ratios), and serology for circulating titres of OA-specific immunoglobulin (Ig)G1 antibodies. RSV antigens were identified in lung tissue sections by immunohistochemistry. CpG-ODN immunotherapy did not prevent OA sensitisation of guinea pigs; however, in RSV-infected, OA-sensitised animals, CpG-ODN administration was associated with significant reductions of airway T-cells and eosinophils, increased lung IFN-gamma/IL-5 ratios, and decreased OA-specific IgG1 antibody titres to levels observed in uninfected, OA-sensitised animals. Viral antigens were identified in a similar proportion of the lungs of RSV-infected animals, irrespective of CpG-ODN immunisation status. In conclusion, cytosine phosphate-guanine-oligodeoxynucleotides immunotherapy protects guinea pigs against respiratory syncytial virus-enhanced ovalbumin sensitisation and might be a relevant intervention in the context of post-bronchiolitis allergic sensitisation in children.

Topics: Analysis of Variance; Animals; CpG Islands; Female; Guinea Pigs; Immunoglobulin G; Immunohistochemistry; Inflammation; Interferon-gamma; Interleukin-5; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Reverse Transcriptase Polymerase Chain Reaction

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

Topics: Administration, Intranasal; Animals; Antibodies; Eosinophils; Histamine; Interleukin-5; Male; Mice; Mice, Inbred C57BL; Nasal Mucosa; Neurokinin-1 Receptor Antagonists; Nose; Ovalbumin; Receptors, Neurokinin-1; Receptors, Neurokinin-2; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections; Virus Replication

Severe respiratory syncytial virus infection (RSV) during infancy has been shown to be a major risk factor for the development of subsequent wheeze. However, the reasons for this link remain unclear. The objective of this research was to determine the consequences of early exposure to RSV and allergen in the development of subsequent airway hyperreactivity (AHR) using a developmental time point in the mouse that parallels that of the human neonate.. Weanling mice were sensitized and challenged with ovalbumin (Ova) and/or infected with RSV. Eight days after the last allergen challenge, various pathophysiological endpoints were examined.. AHR in response to methacholine was enhanced only in weanling mice exposed to Ova and subsequently infected with RSV. The increase in AHR appeared to be unrelated to pulmonary RSV titer. Total bronchoalveolar lavage cellularity in these mice increased approximately two-fold relative to Ova alone and was attributable to increases in eosinophil and lymphocyte numbers. Enhanced pulmonary pathologies including persistent mucus production and subepithelial fibrosis were observed. Interestingly, these data correlated with transient increases in TNF-alpha, IFN-gamma, IL-5, and IL-2.. The observed changes in pulmonary structure may provide an explanation for epidemiological data suggesting that early exposure to allergens and RSV have long-term physiological consequences. Furthermore, the data presented here highlight the importance of preventative strategies against RSV infection of atopic individuals during neonatal development.

Topics: Animals; Bronchial Provocation Tests; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

Respiratory syncytial virus (RSV) may play an important role in allergic diathesis by creating a Th2-type immune response. Mycobacterium bovis bacillus Calmette-Guérin (BCG) is known to induce a Th1-type immune response, but the association of BCG vaccination and the suppression of allergy development remain controversial. We investigated the influence of BCG vaccination on the immune response to RSV in a mouse model. Balb/c mice were BCG vaccinated, RSV infected and ovalbumin (OVA) challenged. Mice were sacrificed one, two and four weeks after allergen exposure. Bronchoalveolar lavage was performed. Alveolar macrophages and lymphocytes from spleens and lung-associated lymph nodes were investigated for cytokine production and cell proliferation. Serum was tested for allergen-specific immunoglobulin-E (IgE). Lung eosinophilia was diminished by BCG immunisation. OVA-specific serum IgE was increased regardless of prior BCG vaccination. Interleukin-4 secretion of spleen lymphocytes increased in BCG-vaccinated mice only one week after allergen exposure but was comparable to non-vaccinated mice at four weeks. The reactivity of spleen lymphocytes towards concanavalin-A to secrete interferon-gamma was increased in the vaccinated group at the end of the observation period. Interleukin-6 and tumour necrosis factor-alpha secretion of alveolar macrophages as well as proliferation of stimulated thoracic lymph node cells were increased and prolonged in vaccinated mice. BCG immunisation led to a local suppression of the allergic reaction within the lung. No reduction of systemic IgE production was observed. Further studies are necessary to determine a possible time dependence of BCG immunisation.

Topics: Allergens; Animals; BCG Vaccine; Bronchoalveolar Lavage Fluid; Cells, Cultured; Female; Immunoglobulin E; Inhalation Exposure; Lymph Nodes; Lymphocytes; Macrophages, Alveolar; Mice; Mice, Inbred BALB C; Mycobacterium bovis; Organ Size; Ovalbumin; Respiratory Syncytial Virus Infections; Spleen

Respiratory viral infections in early childhood may interact with the immune system and modify allergen sensitization and/or allergic manifestations. In mice, respiratory syncytial virus (RSV) infection during allergic provocation aggravates the allergic T helper (Th) 2 immune response, characterized by the production of IL-4, IL-5, and IL-13, and inflammatory infiltrates. However, it is unclear whether the RSV-enhanced respiratory allergic response is a result of non-specific virus-induced damage of the lung, or virus-specific immune responses.. In the present study we investigated whether RSV, pneumonia virus of mice (PVM) and influenza A virus similarly affect the allergic response.. BALB/c mice were sensitized and challenged with ovalbumin (OVA), and inoculated with virus during the challenge period. Pulmonary inflammation, lung cytokine mRNA responses, and IgE production in serum were assessed after the last OVA-challenge.. Like RSV, PVM enhanced the OVA-induced pulmonary IL-4, IL-5, and IL-13 mRNA expression, which was associated with enhanced perivascular inflammation. In addition, PVM increased the influx of eosinophils in lung tissue. In contrast, influenza virus decreased the Th2 cytokine mRNA expression in the lungs. However, like PVM, influenza virus enhanced the pulmonary eosinophilic infiltration in OVA-allergic mice.. The Paramyxoviruses RSV and PVM both are able to enhance the allergic Th2 cytokine response and perivascular inflammation in BALB/c mice, while the Orthomyxovirus influenza A is not.

Topics: Animals; Female; Hypersensitivity; Immunoglobulin E; Influenza A virus; Interleukin-13; Interleukin-4; Interleukin-5; Lung; Mice; Mice, Inbred BALB C; Murine pneumonia virus; Orthomyxoviridae Infections; Ovalbumin; Pneumovirus Infections; Pulmonary Eosinophilia; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; RNA, Messenger; Virus Diseases

Respiratory syncytial virus (RSV) infection has been shown to be a risk factor for the development of allergy in humans and mice. The allergy-enhancing properties of RSV may be dependent on atopic background and an individual's history of RSV infection. We examined the influence of the timing of infection and prior inoculation with RSV in a mouse model of allergic asthma. Mice were sensitized to and challenged with ovalbumin (OVA) and were inoculated with RSV either before or during the sensitization or challenge period. One group of mice was inoculated with RSV both before sensitization to OVA and during challenge with OVA. Increased pulmonary expression of interleukin (IL)-4, IL-5, and IL-13 mRNA and aggravated alveolitis and hypertrophy of mucus-producing cells were observed only when OVA-sensitized mice were inoculated with RSV shortly before or during challenge with OVA. Despite protection against viral replication, prior inoculation with RSV did not abrogate RSV-enhanced, OVA-induced expression of T helper 2 (Th2) cytokines in the lung. In conclusion, inoculation with RSV enhances allergic disease only when the immune system has already been Th2-primed by the allergen (i.e., OVA). This RSV-enhanced allergy is not completely abrogated by prior inoculation with RSV.

Topics: Animals; Asthma; Female; Histocytochemistry; Hypersensitivity; Immunoglobulin E; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Specific Pathogen-Free Organisms; Statistics, Nonparametric

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.

Topics: Animals; Chloride Channels; Cytokines; Disease Models, Animal; Female; Interleukin-17; Lung; Mice; Mice, Inbred BALB C; Mucin 5AC; Mucins; Mucoproteins; Ovalbumin; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

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

Topics: Animals; Cytokines; Disease Models, Animal; Female; Hypersensitivity; Immunization; Immunoglobulin E; Interferon-gamma; Mice; Mice, Knockout; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; RNA, Messenger

Respiratory syncytial virus (RSV) bronchiolitis in early life can lead to changes in airway function, but there are likely additional predisposing factors, such as prior allergen exposure, determining which children develop wheezing and asthma.. To define the effects of prior airway exposure to sensitizing allergen on the development of airway inflammation and hyperresponsiveness (AHR) to subsequent RSV infection.. BALB/c mice were exposed to ovalbumin or PBS exclusively through the airways and subsequently infected with RSV or sham-inoculated. AHR, lung inflammation, and the frequency of cytokine-producing T lymphocytes in the lung were determined.. In PBS-exposed mice, RSV infection induced AHR and an increased proportion of TH1-type (IFN-gamma and IL-12) cytokine-producing cells in the lungs. However, in mice previously exposed to ovalbumin through the airways and subsequently infected with RSV, the degree of AHR was significantly increased and was associated with an increased proportion of TH2 (IL-4, IL-5) cytokine-producing T lymphocytes. This response was also associated with an increased accumulation of eosinophils, neutrophils, and CD8+ T cells in the lungs.. These data suggest that prior airway exposure to allergen may predispose sensitized hosts to a greater degree of altered airway function upon subsequent respiratory viral infection.

Topics: Administration, Inhalation; Animals; Bronchial Hyperreactivity; Cytokines; Female; Lung; Lymphocytes; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia, Viral; Respiratory Syncytial Virus Infections; Respiratory System

IL-13 is a central mediator of allergen-induced airway hyperresponsiveness (AHR), but its role in respiratory syncytial virus (RSV)-induced AHR is not defined. The combination of allergen exposure and RSV infection is known to increase AHR and lung inflammation, but whether IL-13 regulates this increase is similarly not known.. Our objective was to determine the role of RSV infection and IL-13 on airway responsiveness and lung inflammation on sensitized and challenged mice.. Using a murine model of RSV infection and allergen exposure, we examined the role of IL-13 in the development of AHR and lung inflammation in IL-13 knockout mice, as well as using a potent IL-13 inhibitor (IL-13i). Mice were sensitized and challenged to allergen, and 6 days after the last challenge, they were infected with RSV. IL-13 was inhibited using an IL-13 receptor alpha(2)-human IgG fusion protein. AHR to inhaled methacholine was measured 6 days after infection, as was bronchoalveolar lavage fluid and lung inflammatory and cytokine responses.. RSV-induced AHR was unaffected by the IL-13i, despite prevention of goblet cell hyperplasia. Similar results were seen in IL-13-deficient mice. In sensitized and challenged mice, RSV infection significantly increased AHR, and after IL-13i treatment, AHR was significantly reduced, but to the levels seen in RSV-infected mice alone.. These results indicate that despite some similarities, the mechanisms leading to AHR induced by RSV are different from those that follow allergen sensitization and challenge. Because IL-13 inhibition is effective in preventing the increases in AHR and mucus production in sensitized and challenged mice infected with RSV, IL-13i could play an important role in preventing the consequences of viral infection in patients with allergic asthma.

Topics: Allergens; Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Female; Humans; Interleukin-13; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human

To determine the effects of RSV infection on the development of lung inflammation and the expressions of T-helper cell related cytokines in Balb/c mice pre-sensitized with ovalbumin.. Forty mice were randomly divided into four groups: (1) the control group: nonsensitized, noninfected; (2) the RSV group: nonsensitized, infected; (3) the OVA group: sensitized, noninfected; and (4) the OVA + RSV group: sensitized, infected (RSV 6.5 x 10(6) PFU nasal drip). Bronchoalveolar lavage (BAL) was performed in six mice from each group five days after RSV nasal inoculation. Cells in the BAL were counted and classified and the supernatants of the BALF were used for detection of IL-4 and IFN-gamma. Four mice in each group were sacrificed for lung RNA extraction, and IL-4, IL-5 and IFN-gamma mRNA levels were determined by RT-PCR.. (1) Total BAL cells from the RSV group [(14.5 +/- 5.4) x 10(6)/ml] and the OVA + RSV group [(16.8 +/- 4.9) x 10(6)/ml] were significantly higher than those in the control group [(7.7 +/- 2.4) x 10(6)/ml] and the OVA group [(9.0 +/- 2.5) x 10(6)/ml] (all P < 0.05), with more lymphocytes in the RSV group (0.63 +/- 0.05) and the OVA + RSV group (0.77 +/- 0.09) than the control group (0.28 +/- 0.05) (P < 0.05) and the OVA group (0.36 +/- 0.03) (P < 0.05). More eosinophils were found in the OVA + RSV group (0.0690 +/- 0.0100) than in the RSV group (0.0090 +/- 0.0050), the OVA group (0.0100 +/- 0.0040) and the control (0.0030 +/- 0.0010) (all P < 0.05). (2) Pulmonary inflammation in the OVA + RSV group and the RSV group was more severe than that in the OVA group and the control group. More lymphocyte infiltration was found in the OVA + RSV and the RSV groups. More eosinophils were found in the OVA + RSV group, but not in the other groups. (3) Expression of IL-4, IL-5, and IFN-gamma mRNA: IFN-gamma mRNA expression (1.05 +/- 0.12) was higher in the RSV group, than in the control (0.00 +/- 0.00). There were only minimal expression of IL-5 mRNA and no expression of IL-4 mRNA, indicating a Th1-like cytokine response. Expressions of IL-4 mRNA and IL-5 mRNA were significantly higher in the OVA + RSV group than in the other groups, but the IFN-gamma mRNA expression was less than that in the RSV group, indicating a Th2-like cytokine response. (4) IFN-gamma activation in BALF from the RSV group [(33.8 +/- 1.1) pg/ml] was significantly higher than that in the other groups (P < 0.05), while IL-4 showed no significant change as compared to the control group. The level of IL-4 in the OVA + RSV group [(24.0 +/- 1.5) pg/ml] was significantly higher than that in all the other groups (P < 0.05).. RSV infection in OVA-sensitized Balb/c mice caused a different immune response from that caused by RSV infection in nonsensitized mice. RSV infection alone resulted in a Th1-like cytokine response, while infection after OVA sensitization resulted in a Th2-like response.

Topics: Animals; Bronchoalveolar Lavage Fluid; Female; Interferon-gamma; Interleukin-4; Interleukin-5; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; RNA, Messenger; Th2 Cells

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

Topics: Animals; Antibody Specificity; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Female; Hypersensitivity; Immunoglobulin E; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Pneumonia; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; RNA, Messenger; Severity of Illness Index; Time Factors; Ultraviolet Rays

Smooth muscle contraction is one of the hallmarks of asthma. A recently developed pyridine derivative, Y-27632, a selective Rho kinase inhibitor, has been reported to inhibit the smooth muscle contraction of human and animal trachea in ex vivo systems but its effect in animal models of airway hyperresponsiveness (AHR) has not been examined. The purpose of this study was to evaluate the effect of Y-27632 in a murine model of allergic and virally induced AHR.. Baseline lung resistance and methacholine induced AHR were measured in mice sensitised to ovalbumin (OVA) and also in mice infected with respiratory syncytial virus (RSV) following ovalbumin sensitisation (OVA/RSV).. Time course and dose ranging experiments indicated that 30 mg/kg Y-27632 given by gavage 2 hours before methacholine challenge significantly reduced baseline lung resistance and prevented AHR in OVA sensitised mice. Y-27632 also suppressed AHR induced by the bronchospastic agent serotonin in OVA sensitised mice and prevented methacholine induced AHR in OVA/RSV mice.. These results suggest that the signalling pathway mediated through Rho kinase may have an important role in bronchial smooth muscle tone in allergen induced and virus induced AHR and should be considered as a novel target for asthma treatment.

Topics: Airway Resistance; Animals; Antihypertensive Agents; Asthma; Benzopyrans; Bronchial Hyperreactivity; Dose-Response Relationship, Drug; Female; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections

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

Topics: Allergens; Animals; Cytokines; Disease Models, Animal; Female; Flow Cytometry; Hypersensitivity; Immunization; Interleukin-13; Interleukin-4; Interleukin-5; Lung; Lymphocytes; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; RNA, Messenger; Specific Pathogen-Free Organisms

Severe respiratory syncytial virus (RSV) infection has been hypothesized to be a risk factor for the development of allergy and asthma, but epidemiologic studies in humans have been inconclusive. By use of a well-characterized murine model of RSV infection and allergic sensitization with ovalbumin, the effect of a preceding severe RSV infection on the development of the pulmonary allergic inflammatory response and airway hyperresponsiveness (AHR) was tested. The impact of prior allergic sensitization on RSV-induced illness, as measured by weight loss, also was evaluated. RSV infection before allergic sensitization decreased allergen-induced AHR, production of interleukin-13 in lung tissue, and lung eosinophilia. In contrast, allergic sensitization before RSV infection increased AHR and decreased RSV-related weight loss and lung levels of interferon-gamma but did not alter viral clearance. These data provide evidence that RSV-associated AHR occurs in hosts with allergic responses and that allergic inflammation is diminished when preceded by RSV infection.

Topics: Allergens; Animals; Bronchial Hyperreactivity; Bronchoconstrictor Agents; Female; Hypersensitivity; Interferon-gamma; Interleukin-13; Lung; Lymphocyte Count; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Pulmonary Eosinophilia; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Time Factors; Virus Replication; Weight Loss

In mice, respiratory syncytial virus (RSV) infection can enhance the consequences of allergic airway sensitization, resulting in lung eosinophilia and the development of airway hyperresponsiveness (AHR) to inhaled methacholine (MCh). To delineate a role for interleukin-5 (IL-5), interleukin-4 (IL-4), and interferon gamma (IFN-gamma) in mediating the effects of RSV infection on subsequent allergic sensitization, we treated BALB/c mice with anti-IL-5 during acute RSV infection but not during subsequent exposure to ovalbumin (OVA). IL-5-deficient and IL-4-deficient mice were also treated with IL-5 either during acute RSV infection or during the sensitization period. Airway responsiveness to inhaled MCh was assessed and numbers of lung eosinophils were monitored. Anti-IL-5 treatment during RSV infection reduced AHR and lung eosinophilia after subsequent exposure to allergen. In IL-5-deficient or IL-4-deficient mice lung eosinophilia and AHR after RSV infection and allergen exposure were also markedly reduced. IL-5 administration during RSV infection restored the responses to allergen in both IL-5- and IL-4-deficient mice. However, IL-5 administration only during sensitization restored these responses in IL-4-deficient but not in IL-5-deficient animals. IFN-gamma-deficient mice developed AHR and some lung eosinophilia after allergen exposure alone and when RSV infection preceded allergen, these responses were enhanced. We conclude that both IL-5, particularly during acute infection, and IL-4 are critical in mediating the effects of RSV infection on allergic airway sensitization, resulting in the development of AHR and lung eosinophilia.

Topics: Animals; Female; Immunization; Interferon-gamma; Interleukin-4; Interleukin-5; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Pulmonary Eosinophilia; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections

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

Topics: Animals; Body Weight; Bronchial Provocation Tests; Eosinophils; Female; Inflammation; Lung; Lymphocytes; Macrophages; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Hypersensitivity; Respiratory Syncytial Virus Infections; Specific Pathogen-Free Organisms; Time Factors; Viral Plaque Assay

Children with acute respiratory syncytial virus (RSV) bronchiolitis often develop recurrent wheezing, asthma and allergic sensitization, but the role of RSV in the pathogenesis of these sequelae is unclear. This study examined whether RSV infection potentiates subsequent allergic sensitization, airway hyperresponsiveness (AHR) and airway inflammation induced by repeated exposures to aerosolized ovalbumin (OA) in guinea-pigs. Guinea-pigs received either RSV or sham inoculum, followed by exposures to OA- or saline-containing aerosols to form the following groups: 1) noninfected, nonsensitized controls (sham/saline group); 2) RSV-infected, nonsensitized animals (RSV/ saline group); 3) noninfected, OA-sensitized animals (sham/OA group); 4) RSV infection and first OA exposure on the same day (RSV/OA group), and 5) RSV infection six days prior to first OA exposure (RSV6/OA group). Three days after the final aerosol exposure, circulating OA-specific immunoglobulin (Ig)G1 antibody titres and AHR to inhalation acetylcholine challenge were measured and morphometry performed to evaluate allergic inflammation of the airways. OA-exposed animals developed OA-specific IgG1 antibodies, AHR and airway eosinophilia (sham/OA, RSV/OA and RSV6/OA groups. RSV infection alone induced significant AHR and airway eosinophilia (RSV/saline group). RSV infection, and concomitant exposure to OA (RSV/OA group) enhanced OA-specific IgG1 antibodies, but not airway eosinophilia or AHR. Such increases were not observed in the RSV6/OA group. In conclusion, respiratory syncytial virus potentiates the production of ovalbumin-specific immunoglobulin G1 antibodies in guinea-pigs, but circulating titres of these antibodies do not reflect the extent of airway hyperresponsiveness or airway inflammation. In addition, respiratory syncytial virus infection alone can produce slight increases in airway hyperresponsiveness that are associated with increased numbers of eosinophils in the airways.

Topics: Allergens; Animals; Asthma; Bronchial Hyperreactivity; Eosinophils; Female; Guinea Pigs; Immunoglobulin G; Ovalbumin; Random Allocation; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses

We recently described a murine model of atopic asthma in which a marked, extensive hyperplasia of airway goblet cells is induced by repeated challenge of ovalbumin (OA)-sensitized mice with intratracheally administered allergen (Am. J. Respir. Cell Mol. Biol. 1996;14:425-438). We report here the time course of the duration of this feature and of its spontaneous resolution in the absence of further allergen exposure. Induction of severe neutrophilic inflammation in the airways by repeated intratracheal administration of lipopolysaccharide failed to induce goblet cell hyperplasia (GCH) to as great a degree as that induced by allergen, suggesting that nonallergic inflammation is a relatively poor inducer of this phenotype change in mice. When a "subclinical" infection of the lungs with the human A2 strain of respiratory syncytial virus was superimposed on the model of atopic asthma, recruitment of monocytes and lymphocytes to the airways was enhanced and a discharge of goblet cell mucin contents was observed. This may partly explain the respiratory difficulty that typifies virally induced exacerbations of asthma in humans. Daily systemic treatment of sensitized mice with dexamethasone during the period of allergen challenge produced a dose-related suppression of developing GCH, while similar treatment during the period following the establishment of extensive hyperplasia induced an accelerated resolution toward a normal epithelial phenotype. These results confirm and extend the relevance of this model as a representation of the human disease.

Topics: Allergens; Animals; Anti-Inflammatory Agents; Asthma; Bronchoalveolar Lavage Fluid; Dexamethasone; Eosinophils; Epithelial Cells; Hyperplasia; Leukocyte Count; Lipopolysaccharides; Lung; Lymphocytes; Macrophages; Male; Mice; Mice, Inbred BALB C; Neutrophils; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Tract Infections

Virus infections frequently exacerbate asthma, and in some cases may even precipitate its onset. Although this association is well known, experimental investigation has been hampered by the lack of adequate models.. The effects of acute respiratory virus infection on sensitization to aereoallergen were investigated in this study.. Nebulized ovalbumin was used as an aeroantigen in normal mice, and in those infected with respiratory syncytial virus or influenza A.. Both viruses caused transient illness. Ovalbumin inhalation did not induce specific serum antibodies unless the mice were infected at the time of nebulization. In exposed uninfected mice cutaneous challenge with ovalbumin caused no response, but caused acute systemic illness and collapse if previous pulmonary exposure had occurred during respiratory infection. Mice that collapsed in response to cutaneous ovalbumin were found to have IgG1 specific to ovalbumin that was not found in the other mice. Intracellular cytokine staining of splenocyte cultures showed ovalbumin-specific production of IL-4 was enhanced by virus infection during exposure. In CD8+ T cells, ovalbumin-specific interferon-gamma production was also enhanced by co-infection with influenza. Both viruses were equally associated with the induction of anaphylaxis.. These results show that infection with respiratory viruses powerfully augments cellular and humoral immune responses to aeroantigen and provide an experimental model that allows such effects to be investigated.

Topics: Administration, Inhalation; Allergens; Anaphylaxis; Animals; Bronchial Hyperreactivity; Female; Flow Cytometry; Immunoglobulin E; Immunoglobulin G; Influenza A virus; Injections, Intradermal; Mice; Orthomyxoviridae Infections; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Spleen; Weight Loss

Viral respiratory infections can predispose to the development of asthma by mechanisms that are presently undetermined. Using a murine model of respiratory syncytial virus (RSV) infection, acute infection is associated with airway hyperresponsiveness as well as enhanced responses to subsequent sensitization to allergen. We demonstrate that acute viral infection results in increased airway responsiveness to inhaled methacholine and pulmonary neutrophilic and eosinophilic inflammation. This response is associated with predominant production of Th-1-type cytokines in peribronchial lymph node cells in vitro. Mice sensitized to ovalbumin via the airways after RSV infection developed increased airway responsiveness to methacholine and pulmonary eosinophilic and neutrophilic inflammation, associated with the predominant production of Th-2-type cytokines. Treatment of the mice with anti-IL-5 antibody abolished airway hyperresponsiveness and eosinophilic but not neutrophilic inflammation in both acutely infected mice and mice sensitized after infection. We conclude that RSV infection results in airway hyperresponsiveness in the acute phase and leads to changes in immune function that can enhance the effects of airway sensitization to antigen after infection. In both situations, airway hyperresponsiveness is closely associated with pulmonary eosinophilic inflammation. This model provides a means for further analyzing the influence of viral respiratory infections on airway sensitization and the development of altered airway responsiveness.

Topics: Allergens; Animals; Bronchoconstrictor Agents; Cytokines; Eosinophils; Female; Humans; Hypersensitivity; Inflammation; Interferon-gamma; Interleukin-4; Interleukin-5; Methacholine Chloride; Mice; Mice, Inbred BALB C; Neutrophils; Ovalbumin; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Th2 Cells; Time Factors; Tumor Cells, Cultured

Respiratory syncytial virus (RSV) causes acute bronchiolitis in children and has been implicated in the pathogenesis of recurrent wheezing and asthma. However, few children exposed to RSV experience acute bronchiolitis or its sequelae, suggesting a subgroup of susceptible children. An allergic diathesis may predispose children to subsequent airway disease.. This study was carried out to determine whether a preexisting allergic state, induced by repeated inhalational exposures to ovalbumin, potentiates nonspecific airway responsiveness to acetylcholine and increases airway inflammation during acute RSV bronchiolitis in guinea pigs.. Forty guinea pigs were randomized into four groups: nonsensitized, noninfected (ovalbumin-, RSV-); sensitized, noninfected (ovalbumin+, RSV-); nonsensitized, infected (ovalbumin-, RSV+); sensitized, infected (ovalbumin+, RSV+). Depending on grouping, animals were exposed to either repeated aerosols of ovalbumin or saline solution and were subsequently inoculated with either human RSV or uninfected culture medium. Six days after inoculation, animals underwent acetylcholine challenge, and lung specimens were prepared for histologic scoring of airway inflammation.. Maximal increases in pulmonary resistance (centimeters of water per milliliter per second) to acetylcholine were greater for RSV alone (12.4 +/- 3.9) and ovalbumin alone (13.7 +/- 3.9) compared with controls (4.3 +/- 1.1), but significantly greater increases occurred in ovalbumin+, RSV+ animals (34.0 +/- 11.0). These ovalbumin+, RSV+ animals demonstrated the combined histologic changes noted with RSV alone and ovalbumin alone including airway epithelial necrosis, mononuclear and granulocyte infiltrates, airway wall edema, hyperplasia of bronchus-associated lymphoid tissue, and goblet cell metaplasia.. Prior allergic sensitization potentiates the physiologic and structural changes induced by acute RSV bronchiolitis. These results suggest that an allergic diathesis may increase the severity of RSV infections in children.

Topics: Acetylcholine; Administration, Inhalation; Animals; Bronchial Hyperreactivity; Bronchiolitis, Viral; Guinea Pigs; Humans; Hypersensitivity; Immunization; Ovalbumin; Respiratory Syncytial Virus Infections

In pediatric patients with bronchial asthma and/or atopic dermatitis, peripheral lymphocytes are activated if they are stimulated with the responsible antigen, resulting in induction of responsiveness to IL-2. Because some nursing infants experience recurrent wheezing after respiratory syncytial virus (RSV) infection, attention is being directed to progression of the disease to bronchial asthma.. The study was designed to elucidate the mechanism of the onset of allergic diseases after RSV infection.. We examined allergen-specific IL-2 responsiveness induced in lymphocytes in the peripheral blood of infants after infection by RSV. The relationship between the onset of recurrent wheezing and antigen-specific IL-2 responsiveness was analyzed in 25 pediatric patients who could be followed up for 3 years after RSV infection.. Stimulation of lymphocytes with ovalbumin, alpha-casein, and mite (Dermatophagoides farinae) antigens induced significantly higher responsiveness to IL-2 in the RSV-infected infant group than in the healthy infant and disease control groups of the same age. There was no clear correlation between the IgE RAST scores for D. farinae, ovalbumin, and alpha-casein and IL-2 responsiveness. The families of RSV-infected infants had a high incidence of history of allergy (67%), but there was no significant difference in the incidence of patients with positive test results for IL-2 responsiveness between the groups with and without a familial history of allergy. The D. farinae-specific IL-2 responsiveness was significantly increased in the group with the symptom (16 patients) for a value of 1.64 +/- 0.13 (mean +/- SEM) compared with the value of 1.31 +/- 0.21 in the asymptomatic group (9 patients). The incidence of patients with positive test results for IL-2 responsiveness was 68.8% in the symptomatic group and 44.4% in the asymptomatic group. Similarly, the ovalbumin-specific IL-2 responsiveness was significantly increased in the symptomatic group (1.63 +/- 0.17) compared with the asymptomatic group (1.12 +/- 0.26). The incidence of patients with positive test results was 62.5% and 22.2%, respectively. alpha-Casein-specific IL-2 responsiveness was also higher in the symptomatic group than in the asymptomatic group, but the difference was not statistically significant. In the patient groups without RSV infection, on the other hand, the D. farinae-, ovalbumin-, and alpha-casein-specific IL-2 responsiveness in the symptomatic group were all similar to that in the asymptomatic group; no significant increases were detected.. The results indicated that after RSV infection, lymphocytes acquire specific susceptibility to D. farinae, a mite antigen, and food antigens, particularly ovalbumin. Hence, it is thought that positive IL-2 responsiveness specific for D. farinae and/or ovalbumin, detected several months after RSV infection, can be a prediction factor for the onset of allergic diseases, such as recurrent wheezing and bronchial asthma.

Topics: Allergens; Animals; Antigens, Bacterial; Asthma; Caseins; Child, Preschool; Humans; Immunity, Cellular; Immunoglobulin E; Infant; Infant, Newborn; Interleukin-2; Lymphocyte Activation; Lymphocytes; Mites; Ovalbumin; Radioallergosorbent Test; Recurrence; Respiratory Sounds; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Tuberculin