Budesonide and formoterol inhibit inflammatory mediator production by bronchial epithelial cells infected with rhinovirus

Rhinovirus induces airway remodeling: what are the physiological consequences?

BACKGROUND

Rhinovirus infections commonly evoke asthma exacerbations in children and adults. Recurrent asthma exacerbations are associated with injury-repair responses in the airways that collectively contribute to airway remodeling. The physiological consequences of airway remodeling can manifest as irreversible airway obstruction and diminished responsiveness to bronchodilators. Structural cells of the airway, including epithelial cells, smooth muscle, fibroblasts, myofibroblasts, and adjacent lung vascular endothelial cells represent an understudied and emerging source of cellular and extracellular soluble mediators and matrix components that contribute to airway remodeling in a rhinovirus-evoked inflammatory environment.

MAIN BODY

While mechanistic pathways associated with rhinovirus-induced airway remodeling are still not fully characterized, infected airway epithelial cells robustly produce type 2 cytokines and chemokines, as well as pro-angiogenic and fibroblast activating factors that act in a paracrine manner on neighboring airway cells to stimulate remodeling responses. Morphological transformation of structural cells in response to rhinovirus promotes remodeling phenotypes including induction of mucus hypersecretion, epithelial-to-mesenchymal transition, and fibroblast-to-myofibroblast transdifferentiation. Rhinovirus exposure elicits airway hyperresponsiveness contributing to irreversible airway obstruction. This obstruction can occur as a consequence of sub-epithelial thickening mediated by smooth muscle migration and myofibroblast activity, or through independent mechanisms mediated by modulation of the β2 agonist receptor activation and its responsiveness to bronchodilators. Differential cellular responses emerge in response to rhinovirus infection that predispose asthmatic individuals to persistent signatures of airway remodeling, including exaggerated type 2 inflammation, enhanced extracellular matrix deposition, and robust production of pro-angiogenic mediators.

CONCLUSIONS

Few therapies address symptoms of rhinovirus-induced airway remodeling, though understanding the contribution of structural cells to these processes may elucidate future translational targets to alleviate symptoms of rhinovirus-induced exacerbations.

Airway Epithelial-Derived Immune Mediators in COVID-19

The airway epithelium, which lines the conducting airways, is central to the defense of the lungs against inhaled particulate matter and pathogens such as SARS-CoV-2, the virus that causes COVID-19. Recognition of pathogens results in the activation of an innate and intermediate immune response which involves the release of cytokines and chemokines by the airway epithelium. This response can inhibit further viral invasion and influence adaptive immunity. However, severe COVID-19 is characterized by a hyper-inflammatory response which can give rise to clinical presentations including lung injury and lead to acute respiratory distress syndrome, viral pneumonia, coagulopathy, and multi-system organ failure. In response to SARS-CoV-2 infection, the airway epithelium can mount a maladaptive immune response which can delay viral clearance, perpetuate excessive inflammation, and contribute to the pathogenesis of severe COVID-19. In this article, we will review the barrier and immune functions of the airway epithelium, how SARS-CoV-2 can interact with the epithelium, and epithelial-derived cytokines and chemokines and their roles in COVID-19 and as biomarkers. Finally, we will discuss these immune mediators and their potential as therapeutic targets in COVID-19.

The Role of Eosinophil-Derived Neurotoxin and Vascular Endothelial Growth Factor in the Pathogenesis of Eosinophilic Asthma

Asthma is a chronic complex pulmonary disease characterized by airway inflammation, remodeling, and hyperresponsiveness. Vascular endothelial growth factor (VEGF) and eosinophil-derived neurotoxin (EDN) are two significant mediators involved in the pathophysiology of asthma. In asthma, VEGF and EDN levels are elevated and correlate with disease severity and airway hyperresponsiveness. Diversity in VEGF polymorphisms results in the variability of responses to glucocorticosteroids and leukotriene antagonist treatment. Targeting VEGF and eosinophils is a promising therapeutic approach for asthma. We identified lichochalcone A, bevacizumab, azithromycin (AZT), vitamin D, diosmetin, epigallocatechin gallate, IGFBP-3, Neovastat (AE-941), endostatin, PEDF, and melatonin as putative add-on drugs in asthma with anti-VEGF properties. Further studies and clinical trials are needed to evaluate the efficacy of those drugs. AZT reduces the exacerbation rate and may be considered in adults with persistent symptomatic asthma. However, the long-term effects of AZT on community microbial resistance require further investigation. Vitamin D supplementation may enhance corticosteroid responsiveness. Herein, anti-eosinophil drugs are reviewed. Among them are, e.g., anti-IL-5 (mepolizumab, reslizumab, and benralizumab), anti-IL-13 (lebrikizumab and tralokinumab), anti-IL-4 and anti-IL-13 (dupilumab), and anti-IgE (omalizumab) drugs. EDN over peripheral blood eosinophil count is recommended to monitor the asthma control status and to assess the efficacy of anti-IL-5 therapy in asthma.

Anti-inflammatory effects of medications used for viral infection-induced respiratory diseases

Respiratory viruses like rhinovirus, influenza virus, respiratory syncytial virus, and coronavirus cause several respiratory diseases, such as bronchitis, pneumonia, pulmonary fibrosis, and coronavirus disease 2019, and exacerbate bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, and diffuse panbronchiolitis. The production of inflammatory mediators and mucin and the accumulation of inflammatory cells have been reported in patients with viral infection-induced respiratory diseases. Interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, granulocyte-macrophage colony-stimulating factor, and regulated on activation normal T-cell expressed and secreted are produced in the cells, including human airway and alveolar epithelial cells, partly through the activation of toll-like receptors, nuclear factor kappa B and p44/42 mitogen-activated protein kinase. These mediators are associated with the development of viral infection-induced respiratory diseases through the induction of inflammation and injury in the airway and lung, airway remodeling and hyperresponsiveness, and mucus secretion. Medications used to treat respiratory diseases, including corticosteroids, long-acting β2-agonists, long-acting muscarinic antagonists, mucolytic agents, antiviral drugs for severe acute respiratory syndrome coronavirus 2 and influenza virus, macrolides, and Kampo medicines, reduce the production of viral infection-induced mediators, including cytokines and mucin, as determined in clinical, in vivo, or in vitro studies. These results suggest that the anti-inflammatory effects of these medications on viral infection-induced respiratory diseases may be associated with clinical benefits, such as improvements in symptoms, quality of life, and mortality rate, and can prevent hospitalization and the exacerbation of chronic obstructive pulmonary disease, bronchial asthma, bronchiectasis, and diffuse panbronchiolitis.

Inhaled corticosteroids for the treatment of COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has caused severe illness and mortality for millions worldwide. Despite the development, approval and rollout of vaccination programmes globally to prevent infection by SARS-CoV-2 and the development of coronavirus disease 2019 (COVID-19), treatments are still urgently needed to improve outcomes. Early in the pandemic it was observed that patients with pre-existing asthma or COPD were underrepresented among those with COVID-19. Evidence from clinical studies indicates that the inhaled corticosteroids (ICS) routinely taken for asthma and COPD could have had a protective role in preventing severe COVID-19 and, therefore, may be a promising treatment for COVID-19. This review summarises the evidence supporting the beneficial effects of ICS on outcomes in patients with COVID-19 and explores the potential protective mechanisms.

An Overview on the Primary Factors That Contribute to Non-Allergic Asthma in Children

The prevalence of non-allergic asthma in childhood is low, peaking in late adulthood. It is triggered by factors other than allergens, like cold and dry air, respiratory infections, hormonal changes, smoke and air pollution. In the literature, there are few studies that describe non-allergic asthma in pediatric age. Even though it is a less common disorder in kids, it is crucial to identify the causes in order to keep asthma under control, particularly in patients not responding to conventional treatments. In this review, we discuss non-IgE-mediated forms of asthma, collecting the latest research on etiopathogenesis and treatment.

Asthma with Fixed Airflow Obstruction: From Fixed to Personalized Approach

Asthma is generally characterized by variable symptoms such as dyspnea and wheezing and variable airflow obstruction. This review focuses on a subset of patients suffering from asthma with persistent airflow limitation that is not fully reversible (asthma with fixed airflow obstruction, FAO). The pathophysiology, the risk factors and the clinical outcomes associated with FAO are presented, as well as the distinct clinical entity of severe asthma and its inflammatory subtypes (T2 and non-T2). The current strategies for the treatment of these endotypes and treatment of the distinct Asthma/COPD overlap (ACO) phenotype are described. Management and medical interventions in FAO and/or ACO patients demand a holistic approach, which is not yet clearly established in guidelines worldwide. Finally, a treatment algorithm that includes FAO/ACO management based on pharmacological and non-pharmacological treatment, guideline-based management for specific co-morbidities, and modification of the risk factors is proposed.

Susceptibility to rhinovirus-induced early wheezing as a risk factor for subsequent asthma development

Abstract:

Rhinovirus is one of the two most common viral agents that cause bronchiolitis in young children. During the first 12 months, it is second to the respiratory syncytial virus, but after 12 months, it begins dominating the statistics. Wheezing and dry cough are typical clinical symptoms indicative of rhinovirus-induced bronchiolitis, although overlap of symptoms with other virus infections is common. Several studies have shown that atopic predisposition and reduced interferon responses increase susceptibility to rhinovirus-induced wheezing. More recent studies have found that certain genetic variations at strong asthma loci also increase susceptibility. Rhinovirus-induced wheezing in the early years of life is known to increase the risk of subsequent asthma development and may be associated with airway remodeling. This risk is increased by aeroallergen sensitization. Currently, there are no clinically approved preventive treatments for asthma. However, studies show promising results indicating that children with rhinovirus-affected first-time wheezing respond to bronchodilators in terms of less short-term symptoms and that controlling airway inflammatory responses with anti-inflammatory medication may markedly decrease asthma development. Also, enhancing resistance to respiratory viruses has been a topic of discussion. Primary and secondary prevention strategies are being developed with the aim of decreasing the incidence of asthma. Here, we review the current knowledge on rhinovirus-induced early wheezing as a risk factor for subsequent asthma development and related asthma-prevention strategies.

In Vitro Effects of 5-Lipoxygenase Pathway Inhibition on Rhinovirus-Associated Bronchial Epithelial Inflammation

Introduction

The leukotriene pathway may be implicated in the induction of virus-induced inflammation. Respiratory epithelial cells may express low levels of 5-lipoxygenase (5-LO) and release leukotrienes (LTs) C4, D4, and E4, upon exposure to viruses or other stimuli. Enhanced expression of 5-LO pathway proteins after rhinovirus (RV) infection has previously been described. We hypothesized that anti-leukotriene treatment of epithelial cells, with or without exposure to RV-infected peripheral blood mononuclear cells (PBMCs)-conditioned media, may inhibit RV-induced up-regulation of inflammatory cytokines.

Methods

PBMCs from a healthy donor were exposed to RV1B and supernatants were harvested at 48 h post infection. BEAS-2B cells were infected with RV, with or without conditioning with the PBMC supernatant. Treatment with anti-LT agents was performed either on both PBMCs and BEAS-2B or at the bronchial epithelial level only, with varying concentrations of montelukast (CysLT receptor antagonist) or MK-886 [FLAP(5-lipoxygenase-activating-protein) inhibitor]. Evaluation of the inflammatory cytokines IL-8, RANTES, IL-11, IL-6, and IP-10 was performed using ELISA.

Results

Our results show that anti-LT treatment of RV-infected bronchial epithelial cells suppresses epithelial RV-mediated cytokine production, independent of conditioning.

Conclusions

This observation may represent an indirect mode of action of the anti-leukotrienes in virus-induced asthma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00152-x.

Global Initiative for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease. The 2020 GOLD Science Committee Report on COVID-19 and Chronic Obstructive Pulmonary Disease

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has raised many questions about the management of patients with chronic obstructive pulmonary disease (COPD) and whether modifications of their therapy are required. It has raised questions about recognizing and differentiating coronavirus disease (COVID-19) from COPD given the similarity of the symptoms. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) Science Committee used established methods for literature review to present an overview of the management of patients with COPD during the COVID-19 pandemic. It is unclear whether patients with COPD are at increased risk of becoming infected with SARS-CoV-2. During periods of high community prevalence of COVID-19, spirometry should only be used when it is essential for COPD diagnosis and/or to assess lung function status for interventional procedures or surgery. Patients with COPD should follow basic infection control measures, including social distancing, hand washing, and wearing a mask or face covering. Patients should remain up to date with appropriate vaccinations, particularly annual influenza vaccination. Although data are limited, inhaled corticosteroids, long-acting bronchodilators, roflumilast, or chronic macrolides should continue to be used as indicated for stable COPD management. Systemic steroids and antibiotics should be used in COPD exacerbations according to the usual indications. Differentiating symptoms of COVID-19 infection from chronic underlying symptoms or those of an acute COPD exacerbation may be challenging. If there is suspicion for COVID-19, testing for SARS-CoV-2 should be considered. Patients who developed moderate-to-severe COVID-19, including hospitalization and pneumonia, should be treated with evolving pharmacotherapeutic approaches as appropriate, including remdesivir, dexamethasone, and anticoagulation. Managing acute respiratory failure should include appropriate oxygen supplementation, prone positioning, noninvasive ventilation, and protective lung strategy in patients with COPD and severe acute respiratory distress syndrome. Patients who developed asymptomatic or mild COVID-19 should be followed with the usual COPD protocols. Patients who developed moderate or worse COVID-19 should be monitored more frequently and accurately than the usual patients with COPD, with particular attention to the need for oxygen therapy.

COVID-19 and COPD: a narrative review of the basic science and clinical outcomes

The 2019 coronavirus disease (COVID-19) pandemic is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Clinical outcomes, including mortality, are worse in males, older individuals and patients with comorbidities. COPD patients are included in shielding strategies due to their susceptibility to virus-induced exacerbations, compromised pulmonary function and high prevalence of associated comorbidities. Using evidence from basic science and cohort studies, this review addresses key questions concerning COVID-19 and COPD. First, are there mechanisms by which COPD patients are more susceptible to SARS-CoV-2 infection? Secondly, do inhaled corticosteroids offer protection against COVID-19? And, thirdly, what is the evidence regarding clinical outcomes from COVID-19 in COPD patients? This up-to-date review tackles some of the key issues which have significant impact on the long-term outlook for COPD patients in the context of COVID-19.

Inhibition of Virus-Induced Cytokine Production from Airway Epithelial Cells by the Late Addition of Budesonide

Background and objectives: Viral infection is the main cause of asthma and COPD (chronic obstructive pulmonary disease) exacerbation and accumulate inflammatory cells to airway tissue. We have reported poly I:C, a mimic product of the virus and ligand of toll-like receptor 3 (TLR3), induced inflammatory chemokines from airway epithelial cells and found prior incubation with corticosteroids diminishes the effect of TLR3 activation. In clinical practice, mild asthma is recommended as-needed budesonide (BUD) when symptoms occur following a viral infection, etc. However, many questions still surround BUD’s usefulness if taken after a virus has already infected airway tissue. The aim of this study was to investigate the inhibitory effects of BUD on inflammatory cytokines induced by viral infection. Materials and Methods: Normal human bronchial epithelial (NHBE) cells were stimulated with poly I:C or infected with human rhinovirus-16 (HRV16) and BUD was added after the initial stimulation. Expression of both thymic stromal lymphopoietin (TSLP) and CCL26/eotaxin-3 was quantified by real-time RT-PCR and enzyme-linked immunosorbent assay (ELISA), respectively. Knockdown study was performed. Results: Pre-or post-incubation with BUD inhibited both poly I:C- and HRV16-induced mRNAs and proteins of both thymic stromal lymphopoietin (TSLP) and CCL26 with significance. Knockdown of the glucocorticoid receptor diminished these effects of BUD. Under the same conditions of BUD’s experiment, post-incubation with neither fluticasone propionate nor dexamethasone suppressed expression of both TSLP and CCL26, which induced by poly I:C. Conclusion: Post-addition of BUD inhibited the virus-induced TSLP and CCL26 from the airway epithelial cells. These results suggest that inhalation of BUD after viral infection has beneficial effects on asthma. Conclusion: Late addition of BUD may benefit among patient with viral infection and type 2 allergic airway disease such as asthma.

Corticosteroid suppression of antiviral immunity increases bacterial loads and mucus production in COPD exacerbations

Inhaled corticosteroids (ICS) have limited efficacy in reducing chronic obstructive pulmonary disease (COPD) exacerbations and increase pneumonia risk, through unknown mechanisms. Rhinoviruses precipitate most exacerbations and increase susceptibility to secondary bacterial infections. Here, we show that the ICS fluticasone propionate (FP) impairs innate and acquired antiviral immune responses leading to delayed virus clearance and previously unrecognised adverse effects of enhanced mucus, impaired antimicrobial peptide secretion and increased pulmonary bacterial load during virus-induced exacerbations. Exogenous interferon-β reverses these effects. FP suppression of interferon may occur through inhibition of TLR3- and RIG-I virus-sensing pathways. Mice deficient in the type I interferon-α/β receptor (IFNAR1-/-) have suppressed antimicrobial peptide and enhanced mucin responses to rhinovirus infection. This study identifies type I interferon as a central regulator of antibacterial immunity and mucus production. Suppression of interferon by ICS during virus-induced COPD exacerbations likely mediates pneumonia risk and raises suggestion that inhaled interferon-β therapy may protect.

Antiviral and anti-inflammatory activity of budesonide against human rhinovirus infection mediated via autophagy activation

Human rhinovirus (HRV) infection causes more than 80% of all common colds and is associated with severe complications in patients with asthma and chronic obstructive pulmonary disease. To identify antiviral drug against HRV infection, we screened 800 FDA-approved drugs and found budesonide as one of the possible drug candidates. Budesonide is a corticosteroid, which is commonly used to prevent exacerbation of asthma and symptoms of common cold. Budesonide specifically protects host cells from cytotoxicity following HRV infection, which depend on the expression of glucocorticoid receptor. Intranasal administration of budesonide lowered the pulmonary HRV load and the levels of IL-1β cytokine leading to decreased lung inflammation. Budesonide regulates IL-1β production following HRV infection independent of inflammasome activation. Instead, budesonide induces mitochondrial reactive oxygen species followed by activation of autophagy. Further, the inhibition of autophagy following chloroquine or bafilomycin A1 treatment reduced the anti-viral effect of budesonide against HRV, suggesting that the antiviral activity of budesonide was mediated via autophagy. The results suggest that budesonide represents a promising antiviral and anti-inflammatory drug candidate for the treatment of human rhinovirus infection.

The effects of CXCL10 polymorphisms on COPD susceptibility

The polymorphisms of cytokine genes has been reported to modulate the individual's susceptibility to environmental stimuli in COPD development. C-X-C motif chemokine 10 (CXCL10) mediates recruitment inflammatory cells such as monocytes. Therefore, it may play a key role in COPD. Here, a case-control study was conducted to evaluate the association between CXCL10 tag-SNPs and COPD risk. Four tag-SNPs including rs4256246, rs4508917, rs56061981, and rs56316945 were identified based on the linkage disequilibrium (LD) analysis in 30 healthy controls. The associations between these four tag-SNPs and COPD risk were further evaluated in 480 COPD cases and 488 controls. We found that the "T" allele of rs56061981 was significantly associated with reducing risk of COPD, while "G" allele of rs56316945 was significantly associated with increasing risk of COPD. SNP rs56316945 was significantly associated with increasing risk of COPD under different models except recessive model after adjusting the sex, age, pack year, and biomass. SNP rs56061981 was significantly associated with decreasing COPD risk under different models except recessive model after adjusting the sex, age, pack year, and biomass. Stratified analysis of smoking status and biomass with SNPs supported rs56061981 may interact with biomass and smoking thus modulate COPD susceptibility and rs56216945 was apparently associated with the severity of pulmonary function of COPD patients. This study suggests that rs56061981 and rs56216945 in CXCL10 gene promoter contribute COPD susceptibility.

Routine Use of Budesonide/Formoterol Fixed Dose Combination in Elderly Asthmatic Patients: Practical Considerations

Asthma has been demonstrated to be as common in the elderly as in younger age groups. Although no specific recommendations exist to manage the disease differently in older individuals, functional features and clinical presentations may be affected by age per se, and by age-related conditions, such as comorbidities and polypharmacy. In this review article, we aimed to explore the efficacy and safety in elderly asthmatic patients of one of the most currently used inhaled treatments for asthma, that is, the fixed-dose combination of budesonide/formoterol. We attempted to address some practical questions that are relevant to the daily practice of clinicians. We focused on the efficacy and real-world effectiveness of inhaled corticosteroids and long-acting β-adrenergic bronchodilators (ICS/LABA) as treatment in the elderly population, since data are extrapolated from younger populations. We investigated whether a maintenance and reliever therapy approach is more effective in the elderly as opposed to maintenance regimens, from both the general practitioner's and the pulmonologist's perspective. To address these questions, we scanned electronic databases (PubMed, MEDLINE, Embase, Scopus and Google Scholar) from the date of inception up to October 2016 with a cross-search using the following keywords: 'asthma', 'elderly', 'SMART therapy', 'MART therapy', 'Turbuhaler', and 'budesonide/formoterol'. The available literature on the topic confirms that when the age-associated changes are properly managed in clinical practice, asthma in older populations can be optimally controlled with inhaled treatment including ICS/LABA. This also applies for the budesonide/formoterol fixed combination, thus allowing for the maintenance and reliever therapy approach.

Allergic environment enhances airway epithelial pro-inflammatory responses to rhinovirus infection

Airway epithelial cells (AEC) exhibit a pro-inflammatory phenotype in patients with allergic asthma. We examined the effect of an allergic cytokine environment on the response of AEC to rhinovirus (RV), the most common trigger of acute exacerbations of asthma. Calu-3 cells, a well-differentiated human AEC line, were cultured with or without the T-helper type 2 cytokines interleukin (IL)-4 and IL-13, then stimulated with a toll-like receptor (TLR) 3 agonist (poly I:C, dsRNA) or a TLR7 agonist (imiquimod), or infected with RV 16. Expression of pro-inflammatory and antiviral mediators, and of viral pattern-recognition molecules, was assessed using nCounter assays, quantitative real-time PCR (qRT-PCR) and protein immunoassays. Both dsRNA and imiquimod stimulated expression of mRNA for IL6 and IL8 whereas expression of several chemokines and antiviral response genes was induced only by dsRNA. Conversely, expression of other cytokines and growth factors was induced only by imiquimod. RV infection not only stimulated expression of the inflammation-related genes induced by dsRNA, but also of complement factor B and the novel pro-inflammatory cytokine IL-32. In the T helper type 2 (Th2) cytokine environment, several mediators exhibited significantly enhanced expression, whereas expression of interferons was either unchanged or enhanced. The allergic environment also increased expression of pattern-recognition receptors and of intercellular adhesion molecule 1, the cell surface receptor for RV. We conclude that Th2 cytokines promote increased production of pro-inflammatory mediators by AEC following infection with RV. Increased viral entry or enhanced signalling via pattern-recognition receptors could also contribute to the exaggerated inflammatory response to RV observed in allergic asthmatics.

Understanding how long-acting β2 -adrenoceptor agonists enhance the clinical efficacy of inhaled corticosteroids in asthma - an update

In moderate-to-severe asthma, adding an inhaled long-acting β₂ -adenoceptor agonist (LABA) to an inhaled corticosteroid (ICS) provides better disease control than simply increasing the dose of ICS. Acting on the glucocorticoid receptor (GR, gene NR3C1), ICSs promote anti-inflammatory/anti-asthma gene expression. In vitro, LABAs synergistically enhance the maximal expression of many glucocorticoid-induced genes. Other genes, including dual-specificity phosphatase 1(DUSP1) in human airways smooth muscle (ASM) and epithelial cells, are up-regulated additively by both drug classes. Synergy may also occur for LABA-induced genes, as illustrated by the bronchoprotective gene, regulator of G-protein signalling 2 (RGS2) in ASM. Such effects cannot be produced by either drug alone and may explain the therapeutic efficacy of ICS/LABA combination therapies. While the molecular basis of synergy remains unclear, mechanistic interpretations must accommodate gene-specific regulation. We explore the concept that each glucocorticoid-induced gene is an independent signal transducer optimally activated by a specific, ligand-directed, GR conformation. In addition to explaining partial agonism, this realization provides opportunities to identify novel GR ligands that exhibit gene expression bias. Translating this into improved therapeutic ratios requires consideration of GR density in target tissues and further understanding of gene function. Similarly, the ability of a LABA to interact with a glucocorticoid may be suboptimal due to low β₂ -adrenoceptor density or biased β₂ -adrenoceptor signalling. Strategies to overcome these limitations include adding-on a phosphodiesterase inhibitor and using agonists of other Gs-coupled receptors. In all cases, the rational design of ICS/LABA, and derivative, combination therapies requires functional knowledge of induced (and repressed) genes for therapeutic benefit to be maximized.

Advances in the treatment of virus-induced asthma

Viral exacerbations continue to represent the major burden in terms of morbidity, mortality and health care costs associated with asthma. Those at greatest risk for acute asthma are those with more severe airways disease and poor asthma control. It is this group with established asthma in whom acute exacerbations triggered by virus infections remain a serious cause of increased morbidity. A range of novel therapies are emerging to treat asthma and in particular target this group with poor disease control, and in most cases their efficacy is now being judged by their ability to reduce the frequency of acute exacerbations. Critical for the development of new treatment approaches is an improved understanding of virus-host interaction in the context of the asthmatic airway. This requires research into the virology of the disease in physiological models in conjunction with detailed phenotypic characterisation of asthma patients to identify targets amenable to therapeutic intervention.

Anti-inflammatory effects of the novel inhaled phosphodiesterase type 4 inhibitor CHF6001 on virus-inducible cytokines

Respiratory virus infections precipitate asthma and chronic obstructive pulmonary disease (COPD) exacerbations, with most exacerbations due to rhinovirus infection. Both asthma and COPD exacerbations are not well controlled by steroid therapies, and there is a much research interest in finding improved therapies or combinations of therapies for controlling exacerbations. CHF6001 is a new, inhaled highly potent and selective phosphodiesterase type 4 (PDE4) inhibitor. Using in vitro human bronchial epithelial cells (BEAS‐2B), we investigated the potential anti‐inflammatory effects of CHF6001 on rhinovirus (RV1B)‐induced cytokines. Cytokine mRNA was measured by real‐time PCR, while protein release was measured by ELISA. CHF6001 was used in a 7‐point dose–response curve (1000–0.001 nmol/L) as a 1.5‐h pretreatment prior to infection in comparison with roflumilast. Both roflumilast and CHF6001 reduced RV1B‐induced IL‐8, IL‐29, IP‐10, and RANTES mRNA and protein in a concentration‐dependent manner. Generally, CHF6001 was 13‐ to 16‐fold more potent (subnanomolar EC₅₀ values) than roflumilast at reducing IL‐8, IL‐29, IP‐10, and RANTES mRNA and protein release, but had similar efficacies. In combination with the steroid fluticasone propionate (1 nmol/L), CHF6001 had additive effects, significantly reducing RV‐induced cytokines when compared with steroid or CHF6001 alone. Combined low‐dose steroid and low‐dose CHF6001 had a similar efficacy as high‐dose steroid or CHF6001 alone, indicating the combination had steroid and PDE4 inhibitor sparing effects. Overall results indicate that PDE4 inhibitors have anti‐inflammatory activity against virus‐induced inflammatory mediators and that CHF6001 is more potent than roflumilast.

Long-acting Inhaled Bronchodilator and Risk of Vascular Events in Patients With Chronic Obstructive Pulmonary Disease in Taiwan Population

A combination of long-acting anticholinergic agents (LAACs) and long-acting β2-adrenergic receptor agonist (LABA) is effective in improving lung function in chronic obstructive pulmonary disease (COPD) compared with monotherapy. However, evidence on whether this combination increases the incidence of stroke or other cardiac events remains sparse. The objective of the present study was to investigate the incidence of stroke and other cardiovascular diseases in COPD patients treated with LAAC, LABA, or a combination of the 2.We conducted this population-based study using the Taiwan National Health Insurance Research Database (1997-2008), identifying COPD patients and their prescribed medication from the International Classification of Disease, Ninth Revision codes 490-492 or 496. A multivariate Cox proportional-hazards model was used to compare the risk of stroke and other cardiovascular diseases over the 11-year period after treatment with LAAC or LABA only or in combination.Of the 596 COPD patients (mean age 70 y), 196 were treated with LAAC, 318 with LABA, and 82 were treated with a combination. The overall incidence of stroke (8.53%) significantly increased in the combination group compared with LAAC (2.04%) or LABA (1.26%) only. In the Cox regression analysis, the adjusted hazard ratio over the 11-year survey period for stroke in patients treated with the combination compared with LABA only was 1.04 (95% confidence interval, 1.06-2.99) and for LAAC, it was 0.31 (95% confidence interval, 0.02-2.32).This cohort study using a large health insurance database showed that treating patients with COPD, with a combination of LAAC and LABA, may be associated with an increased hazard of stroke compared with treatment with either agent alone. We should be particularly cautious about comedication of LAAC and LABA in patients with COPD.

The association between seasonal asthma exacerbations and viral respiratory infections in a pediatric population receiving inhaled corticosteroid therapy with or without long-acting beta-adrenoceptor agonist: a randomized study

BACKGROUND

A seasonal peak in asthma exacerbations in the fall has previously been reported. The association between fall exacerbations and viral respiratory tract infections (RTI) remains uncertain.

OBJECTIVE

To investigate the number of fall exacerbations and the incidence of RTIs in a pediatric asthmatic population using an at-home mucus collection methodology.

METHODS

This was a 16-week, multicenter, randomized, double-blind, parallel-group exploratory study. Children, 4-11 years of age with a clinical diagnosis of asthma requiring use of an inhaled corticosteroid, a morning peak expiratory flow ≥70% predicted and a history of ≥1 asthma exacerbation during the previous respiratory viral season were eligible for enrollment. Subjects were randomized (1:1) to receive fluticasone propionate/salmeterol (FP/SAL) 100/50 mcg or FP 100 mcg prior to starting school. Subjects collected mucus samples using an at-home kit when they experienced respiratory symptoms. Mucus samples obtained during symptomatic periods were analyzed for common respiratory viruses by multiplex polymerase chain reaction. The number of exacerbations requiring systemic corticosteroids was recorded.

RESULTS

In total, 339 (FP/SAL, n = 171; FP, n = 168) subjects were randomized and included in the intent-to-treat population; 292 (86%) completed the study. Of the 537 mucus samples collected, 64% tested positive for viruses, but only 6% of positive samples were associated with an asthma exacerbation. Exacerbations were infrequent, with only 41 subjects reporting 49 exacerbations in total. Adverse events were reported in 66% of subjects.

CONCLUSIONS

In a susceptible population, the fall asthma exacerbation rates in children were low despite frequent detection of viral RTIs. NCT01192178; GSK ID: ADA113872.

Why use long acting bronchodilators in chronic obstructive lung diseases? An extensive review on formoterol and salmeterol

Long-acting β2-adrenoceptor agonists, formoterol and salmeterol, represent a milestone in the treatments of chronic obstructive lung diseases. Although no specific indications concerning the choice of one molecule rather than another are provided by asthma and COPD guidelines, they present different pharmacological properties resulting in distinct clinical employment possibilities. In particular, salmeterol has a low intrinsic efficacy working as a partial receptor agonist, while formoterol is a full agonist with high intrinsic efficacy. From a clinical perspective, in the presence of low β2-adrenoceptors availability, like in inflamed airways, a full agonist can maintain its bronchodilatory and non-smooth muscle activities while a partial agonist may be less effective. Furthermore, formoterol presents a faster onset of action than salmeterol. This phenomenon, combined with the molecule safety profile, leads to a prompt amelioration of the symptoms, and allows using this drug in asthma as an "as needed" treatment in patients already on regular treatment. The fast onset of action and the full agonism of formoterol need to be considered in order to select the best pharmacological treatment of asthma and COPD.

Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon

Glucocorticosteroids (GCS) are used on a daily basis to reduce airway inflammation in asthma and chronic obstructive pulmonary disease (COPD). This treatment is usually escalated during acute disease exacerbations, events often associated with virus infections. We examined the impact of GCS on anti-viral defences and virus replication and assessed supplementary interferon (IFN) treatment. Here, we report that treatment of primary human airway cells in vitro with GCS prior to rhinovirus (RV) or influenza A virus (IAV) infection significantly reduces the expression of innate anti-viral genes and increases viral replication. Mice given intranasal treatment with GCS prior to IAV infection developed more severe disease associated with amplified virus replication and elevated inflammation in the airways. Adjuvant IFN treatment markedly reduced GCS-amplified infections in human airway cells and in mouse lung. This study demonstrates that GCS cause an extrinsic compromise in anti-viral defences, enhancing respiratory virus infections and provides a rationale for adjuvant IFN treatment.

Exacerbation of asthma and airway infection: is the virus the villain?

Objetivo

Rever a literatura disponível sobre a relação entre infecção viral aguda do trato respiratório e o desencadeamento de exacerbações da asma, identificando os vírus mais prevalentes, os métodos de detecção, bem como os aspectos preventivos e terapêuticos.

Fonte dos dados

Foi realizada uma busca nas bases de dados PubMed, SciELO e Lilacs utilizando os descritores: asma, exacerbação, vírus, criança e infecção respiratória aguda, entre os anos de 2002 e 2013.

Síntese dos dados

Foram selecionados 42 artigos originais que tratavam da identificação de vírus respiratórios durante episódios de exacerbação da asma, em sua maioria estudos transversais. Houve ampla variação na metodologia dos trabalhos avaliados, principalmente em relação à idade das crianças e métodos de coleta e detecção viral. Os resultados apontam que, em até 92,2% das exacerbações, um agente viral foi potencialmente o principal fator desencadeante, sendo o rinovírus humano o mais identificado. O padrão de circulação viral pode ter sido responsável pela sazonalidade das exacerbações. A associação entre infecção viral e inflamação alérgica parece ser determinante para levar ao descontrole clínico‐funcional da asma, porém poucos estudos avaliaram outros fatores desencadeantes em associação com a infecção viral.

Conclusões

Os vírus respiratórios estão presentes na maioria das crianças asmáticas durante os episódios de exacerbação. Os mecanismos fisiopatológicos envolvidos ainda não estão totalmente estabelecidos e o sinergismo entre a inflamação alérgica e infecção viral parece determinar o descontrole da doença. O papel dos outros agentes desencadeantes e protetores não estão claramente determinados.

Exacerbation of asthma and airway infection: is the virus the villain?

OBJECTIVE

To review the available literature on the association between acute viral respiratory tract infection and the onset of asthma exacerbations, identifying the most prevalent viruses, detection methods, as well as preventive and therapeutic aspects.

SOURCES

A search was conducted in PubMed, Lilacs, and SciELO databases, between the years 2002 and 2013, using the following descriptors: asthma exacerbation, virus, child, and acute respiratory infection.

SUMMARY OF THE FINDINGS

A total of 42 original articles addressing the identification of respiratory viruses during episodes of asthma exacerbation were selected, mostly cross-sectional studies. There was a wide variation in the methodology of the assessed studies, particularly in relation to the children's age and methods of collection and viral detection. The results indicate that, in up to 92.2% of exacerbations, a viral agent was potentially the main triggering factor, and human rhinovirus was the most frequently identified factor. The pattern of viral circulation may have been responsible for the seasonality of exacerbations. The association between viral infections and allergic inflammation appears to be crucial for the clinical and functional uncontrolled asthma, but few studies have evaluated other triggering factors in association with viral infection.

CONCLUSIONS

Respiratory viruses are present in the majority of asthmatic children during episodes of exacerbation. The involved physiopathological mechanisms are yet to be fully established, and the synergism between allergic inflammation and viral infection appears to determine uncontrolled disease. The role of other triggering and protective agents is yet to be clearly determined.

Viral infections and asthma: an inflammatory interface?

Asthma is a chronic inflammatory disease of the airways in which the majority of patients respond to treatment with corticosteroids and β₂-adrenoceptor agonists. Acute exacerbations of asthma substantially contribute to disease morbidity, mortality and healthcare costs, and are not restricted to patients who are not compliant with their treatment regimens. Given that respiratory viral infections are the principal cause of asthma exacerbations, this review article will explore the relationship between viral infections and asthma, and will put forward hypotheses as to why virus-induced exacerbations occur. Potential mechanisms that may explain why current therapeutics do not fully inhibit virus-induced exacerbations, for example, β₂-adrenergic desensitisation and corticosteroid insensitivity, are explored, as well as which aspects of virus-induced inflammation are likely to be attenuated by current therapy.

Response of airway epithelial cells to double-stranded RNA in an allergic environment

Background

Respiratory viral infections are the most common trigger of acute exacerbations in patients with allergic asthma. The anti-viral response of airway epithelial cells (AEC) may be impaired in asthmatics, while cytokines produced by AEC may drive the inflammatory response. We investigated whether AEC cultured in the presence of Th2 cytokines associated with an allergic environment exhibited altered responses to double-stranded RNA, a virus-like stimulus.

Methods

We undertook preliminary studies using the MLE-12 cell line derived from mouse distal respiratory epithelial cells, then confirmed and extended our findings using low-passage human AEC. Cells were cultured in the absence or presence of the Th2 cytokines IL-4 and IL-13 for 48 hours, then stimulated with poly I:C for 4 hours. Expression of relevant anti-viral response and cytokine genes was assessed by quantitative real-time PCR. Secretion of cytokine proteins was assessed by immunoassay.

Results

Following stimulation with poly I:C, MLE-12 cells pre-treated with Th2 cytokines exhibited significantly higher levels of expression of mRNA for the cytokine genes Cxcl10 and Cxcl11, as well as a trend towards increased expression of Cxcl9 and Il6. Expression of anti-viral response genes was mostly unchanged, although Stat1, Ifit1 and Ifitm3 were significantly increased in Th2 cytokine pre-treated cells. Human AEC pre-treated with IL-4 and IL-13, then stimulated with poly I:C, similarly exhibited significantly higher expression of IL8, CXCL9, CXCL10, CXCL11 and CCL5 genes. In parallel, there was significantly increased secretion of CXCL8 and CCL5, as well as a trend towards increased secretion of CXCL10 and IL-6. Again, expression of anti-viral response genes was not decreased. Rather, there was significantly enhanced expression of mRNA for type III interferons, RNA helicases and other interferon-stimulated genes.

Conclusion

The Th2 cytokine environment appears to promote increased production of pro-inflammatory chemokines by AEC in response to double-stranded RNA, which could help explain the exaggerated inflammatory response to respiratory viral infection in allergic asthmatics. However, any impairment of anti-viral host defences in asthmatics appears unlikely to be a consequence of Th2 cytokine-induced downregulation of the expression of viral response genes by AEC.

Electronic supplementary material

The online version of this article (doi:10.1186/s40247-014-0011-6) contains supplementary material, which is available to authorized users.

Respiratory syncytial virus induces leukotriene C4 synthase expression in bronchial epithelial cells

BACKGROUND AND OBJECTIVE

Respiratory syncytial virus (RSV) results in acute wheezing in infants and is frequently associated with recurrent wheezing. Although RSV-induced wheezing clinically resembles that of asthma, corticosteroids are not equivalently effective in RSV-associated wheezing. The study sought to determine the mechanisms of RSV-induced wheezing by establishing an in vitro model of RSV-infected human bronchial epithelial cells (16-HBEC).

METHODS

Leukotriene C4 synthase (LTC4 S) messenger RNA (mRNA) expression in 16-HBEC was detected using fluorescence quantitative polymerase chain reaction, and the relative level of LTC4 S mRNA was expressed as quotient cycle threshold (qCt) based on the threshold cycle number value compared with that of β-actin. Cysteinyl leukotrienes (CysLT) in culture supernatant were measured by enzyme-linked immunosorbent assay. RSV-infected 16-HBEC was incubated with gradient concentration of budesonide (BUD) to assess its effects on LTC4 S expression and CysLT secretion.

RESULTS

RSV infection resulted in increased LTC4 S mRNA expression between 48 and 96 h post-infection. High level of CysLT was detected in the supernatant of RSV-infected 16-HBEC. BUD at concentrations of 10(-10) to 10(-5) mol/L did not significantly alter LTC4 S mRNA expression.

CONCLUSIONS

RSV infection upregulated LTC4 S expression in HBEC leading to increased CysLT secretion. Such induction was not attenuated by BUD, suggesting that CysLT might contribute to the pathogenesis of RSV-induced wheezing.

Inhaled corticosteroids and systemic inflammatory response in community-acquired pneumonia: a prospective clinical study

BACKGROUND AND OBJECTIVE

The previous use of inhaled corticosteroids (ICS) may reduce the inflammatory response and mortality in patients with community-acquired pneumonia (CAP).

METHODS

We measured serum levels of several inflammatory biomarkers, as well as mortality at various time-points, in 663 consecutive patients hospitalized for CAP; 128 (19%) were receiving chronic outpatient treatment with ICS. Patients on previous oral corticosteroids were excluded from the analysis.

RESULTS

On admission, patients treated with ICS were older; had been diagnosed with chronic obstructive pulmonary disease (COPD), asthma and pneumonia in the previous year more often; and had higher CAP severity risk classes and lower tumour necrosis factor (TNF)-alpha (P < 0.001) and interleukin (IL)-6 (P = 0.015) serum levels. After adjusting for potential confounders, this association persisted for TNF-alpha (P < 0.001), but not for IL-6. Mortality at 30 and 90 days tended to be lower in patients treated with ICS (P = 0.062 and 0.050, respectively), but mortality was similar after 1 year in both groups (16, 13% vs 81, 15% for patients treated and not treated with ICS, respectively). Hospital readmission rate after 1 year was higher in patients treated with ICS (49, 38% vs 109, 20%, P < 0.001). The association of ICS treatment with a previous diagnosis of pneumonia, lower levels of TNF-alpha and IL-6 on admission and higher readmission rates during follow up persisted in the subpopulation of 210 patients with COPD.

CONCLUSIONS

Previous use of ICS in patients hospitalized for CAP is associated with a reduced systemic inflammatory response without any impact on long-term mortality.

Formoterol and budesonide inhibit rhinovirus infection and cytokine production in primary cultures of human tracheal epithelial cells

BACKGROUND

Long-acting β(2) agonists (LABAs) and inhaled corticosteroids (ICSs) reduce the frequency of exacerbations of chronic obstructive pulmonary disease and bronchial asthma. However, inhibitory effects of LABAs and ICSs on the replication of rhinovirus (RV), the major cause of exacerbations, have not been demonstrated.

METHODS

Primary cultures of human tracheal epithelial cells were infected with a major group RV, type 14 rhinovirus (RV14), to examine the effects of formoterol and budesonide on RV infection and infection-induced airway inflammation.

RESULTS

Treatment with formoterol and budesonide 72 h before and after RV14 infection reduced RV14 titers and cytokine concentrations, including interleukin (IL)-1β, IL-6 and IL-8, in supernatants and viral RNA within cells. Formoterol and budesonide reduced mRNA expression and protein concentration of intercellular adhesion molecule-1 (ICAM-1), the receptor for RV14. Formoterol reduced the number and fluorescence intensity of acidic endosomes through which RV RNA enters the cytoplasm. Formoterol and budesonide reduced the activation of the nuclear factor kappa-B protein p65 in nuclear extracts. The effects of formoterol plus budesonide were additive with respect to RV14 replication, cytokine production, ICAM-1 expression, acidic endosome fluorescence intensity, and p65 activation. The selective β(2)-adrenergic receptor antagonist, ICI 118551 [erythro-dl-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol], reversed the inhibitory effects of formoterol on RV14 titers and RNA levels, the susceptibility of cells to RV14 infection, cytokine production, acidic endosomes, ICAM-1 expression, and p65 activation.

CONCLUSIONS

Formoterol and budesonide may inhibit RV infection by reducing the ICAM-1 levels and/or acidic endosomes and modulate airway inflammation associated with RV infections.

Rhinovirus-16 induced release of IP-10 and IL-8 is augmented by Th2 cytokines in a pediatric bronchial epithelial cell model

Background

In response to viral infection, bronchial epithelial cells increase inflammatory cytokine release to activate the immune response and curtail viral replication. In atopic asthma, enhanced expression of Th2 cytokines is observed and we postulated that Th2 cytokines may augment the effects of rhinovirus-induced inflammation.

Methods

Primary bronchial epithelial cell cultures from pediatric subjects were treated with Th2 cytokines for 24 h before infection with RV16. Release of IL-8, IP-10 and GM-CSF was measured by ELISA. Infection was quantified using RTqPCR and TCID₅₀. Phosphatidyl inositol 3-kinase (PI3K) and P38 mitogen activated protein kinase (MAPK) inhibitors and dexamethasone were used to investigate differences in signaling pathways.

Results

The presence of Th2 cytokines did not affect RV replication or viral titre, yet there was a synergistic increase in IP-10 release from virally infected cells in the presence of Th2 cytokines. Release of IL-8 and GM-CSF was also augmented. IP-10 release was blocked by a PI3K inhibitor and IL-8 by dexamethasone.

Conclusion

Th2 cytokines increase release of inflammatory cytokines in the presence of rhinovirus infection. This increase is independent of effects of virus replication. Inhibition of the PI3K pathway inhibits IP-10 expression.

Fixed airflow obstruction in asthma: a descriptive study of patient profiles and effect on treatment responses

Background

The role of fixed airflow obstruction (FAO) in asthma is unclear. Objective: To assess the relationship between FAO and clinical features of asthma and the effect of FAO on treatment response. Methods: Post hoc descriptive analysis of data stratified by FAO category (screening post-albuterol FEV₁/FVC <lower limit of normal [LLN] [FAO+] or ≥LLN [FAO−]) from two 12-week, randomized, placebo-controlled studies of budesonide/formoterol or the monocomponents in mild−moderate (study I; aged ≥6 years; NCT00651651; placebo run-in) or moderate−severe (study II; ≥12 years; NCT00652002; budesonide run-in) asthma patients. Results: At baseline, FAO+ versus FAO− patients were more likely male and had longer asthma duration and worse pulmonary function. During the treatment period, lung function and asthma control measures with placebo were generally worse in FAO+ versus FAO− patients. Budesonide was effective on most end points in both FAO+ and FAO− patients. In contrast to FAO− patients, FAO+ patients were unresponsive to formoterol monotherapy in both study populations. Consistently greater improvements in most end points (including worsening of asthma as predefined by specific lung function parameters or clinical symptoms) were observed moving from formoterol to budesonide to budesonide/formoterol in both FAO+ and FAO− patients, with generally greater than additive effects on lung function with budesonide/formoterol in FAO+ patients. Conclusions: FAO+ patients tended to be more impaired and at greater risk for an asthma event versus FAO− patients. While FAO+ patients were non-responsive to formoterol monotherapy, they retained responsiveness to budesonide and had the greatest lung function and control responses to budesonide/formoterol that were similar to or greater than responses of FAO− patients.

Simvastatin attenuates rhinovirus-induced interferon and CXCL10 secretion from monocytic cells in vitro

RV infections frequently trigger exacerbations of respiratory diseases, such as asthma, yet treatment and intervention options remain limited. Statin drugs are the treatment of choice for dyslipidemia and can also modulate immune cell function. To determine whether statin drugs modify antiviral responses of human monocytic cells, we obtained blood monocytes from donors with allergies and/or asthma and treated the cells with sim prior to challenge with RV. RV-induced secretion of CXCL10 was attenuated significantly, irrespective of RV type (RV-16, -14, or -1A), which corresponded with decreases in IFN-α secretion and pSTAT1. Sim pretreatment also reduced RV-induced CXCL10 secretion from human alveolar macrophages. The addition of mev and GGPP-two intermediates of the cholesterol biosynthesis pathway-was able to rescue CXCL10 release fully, demonstrating that effects of sim were related to inhibition of cholesterol biosynthesis and not to an off-target effect. In addition, sim pretreatment attenuated IFN-α-induced pSTAT1 and CXCL10 secretion, providing evidence that sim additionally can affect type I IFNR signaling. SOCS1 and 3 mRNA are both induced with RV stimulation, but sim did not elevate SOCS1 or SOCS3 mRNA expression basally or in the presence of RV. Our findings suggest that sim inhibition of the cholesterol biosynthesis pathway leads to decreased RV-induced chemokine secretion in monocytes and macrophages. These findings suggest that statin drugs have the potential to curb the inflammatory response to RV infection.

Budesonide and formoterol effects on rhinovirus replication and epithelial cell cytokine responses

Background

Combination therapy with budesonide and formoterol reduces exacerbations of asthma, which are closely associated with human rhinovirus (RV) infections in both children and adults. These data suggest that budesonide and formoterol inhibit virus-induced inflammatory responses of airway epithelial cells.

Methods

To test this hypothesis, bronchial epithelial (BE) cells were obtained from airway brushings of 8 subjects with moderate-to-severe allergic asthma and 9 with neither asthma nor respiratory allergies. Cultured BE cells were incubated for 24 hours with budesonide (1.77 μM), formoterol (0.1 μM), both, or neither, and then inoculated with RV-16 (5×10⁶ plaque forming units [PFU]/mL). After 24 hours, viral replication (RV RNA), cytokine secretion (CXCL8, CXCL10, TNFα, IFN-β, IL-28) and mRNA expression (CXCL8, CXCL10, TNF, IFNB1, IL28A&B) were analyzed.

Results

RV infection induced CXCL10 protein secretion and IFNB1 and IL28 mRNA expression. Drug treatments significantly inhibited secretion of CXCL10 in mock-infected, but not RV-infected, BE cells, and inhibited secretion of TNFα under both conditions. Neither budesonide nor formoterol, alone or in combination, significantly affected viral replication, nor did they inhibit RV-induced upregulation of IFNB1 and IL28 mRNA. Overall, RV replication was positively related to CXCL10 secretion and induction of IFNB1 and IL28 mRNA, but the positive relationship between RV RNA and CXCL10 secretion was stronger in normal subjects than in subjects with asthma.

Conclusions

Budesonide and formoterol can inhibit BE cell inflammatory responses in vitro without interfering with viral replication or production of interferons. These effects could potentially contribute to beneficial effects of budesonide/formoterol combination therapy in preventing RV-induced asthma exacerbations.

Tulobuterol inhibits rhinovirus infection in primary cultures of human tracheal epithelial cells

A transdermal patch preparation of the β2 agonist tulobuterol has been designed to yield sustained β2 agonistic effects and has been used as a long-acting β2 agonist (LABA) in Japan. LABAs reduce the frequency of exacerbations of chronic obstructive pulmonary disease and bronchial asthma. However, inhibitory effects of LABAs on the replication of rhinovirus (RV), the major cause of exacerbations, have not been demonstrated. To examine the effects of tulobuterol on RV replication and on the production of the replication-induced pro-inflammatory cytokines, human tracheal epithelial cells were infected with a major group RV, type 14 rhinovirus (RV14). Tulobuterol reduced the RV14 titers and RNA levels; the concentrations of cytokines, including interleukin (IL)-1β, IL-6, and IL-8, in the supernatants; and susceptibility to RV14 infection. Tulobuterol reduced the expression of intercellular adhesion molecule-1 (ICAM-1), the receptor for RV14, and the number of acidic endosomes in the cells in which RV14 RNA enters the cytoplasm. Tulobuterol inhibited the activation of nuclear factor kappa B (NF-κB) proteins in nuclear extracts. A selective β2-adrenergic receptor antagonist, ICI 118551 [erythro-dl-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol], reversed the inhibitory effects of tulobuterol on the RV14 titers and RNA levels, the susceptibility to RV14 infection, cytokine production, and ICAM-1 expression. Tulobuterol may inhibit RV replication by reducing ICAM-1 expression and acidic endosomes and modulate airway inflammation during RV replication.

Interaction between allergy and innate immunity: model for eosinophil regulation of epithelial cell interferon expression

BACKGROUND

Eosinophils in asthmatic airways are associated with risk of exacerbations. The most common cause of asthma exacerbations is viral respiratory infections, particularly human rhinovirus (HRV).

OBJECTIVE

To determine the mechanism by which eosinophils may influence virus-induced responses.

METHODS

We used an in vitro coculture model of primary human eosinophils and the BEAS-2B epithelial cell line either stimulated with HRV1A infection or polyinosinic-polycytidylic acid (poly[I:C]). The messenger RNA (mRNA) expression of interferon (IFN) β1 and IFN-λ1 was assessed by quantitative reverse-transcriptase polymerase chain reaction and the protein level of IFN- λ1 by enzyme-linked immunosorbent assay.

RESULTS

Both poly(I:C) and HRV1A infection induced BEAS-2B expression of IFN-β1 and IFN-λ1 mRNA. Coculture of eosinophils resulted in suppression of poly(I:C)-stimulated IFN-β1 and IFN-λ1 mRNA expression (2.5-fold and 3.6-fold less, respectively). Separation of cells did not block eosinophil regulatory activity. Coculture of eosinophils with HRV1A-infected BEAS-2B cells also suppressed IFN-β1 and IFN-λ1 mRNA (5.7-fold and 5.0-fold less, respectively) and reduced IFN-λ1 protein secretion (1.6-fold decrease). This corresponded to a 34% increase in the quantity of HRV1A virus RNA on coculture with eosinophils. Recombinant transforming growth factor β suppressed IFN-λ1 from HRV1A-infected BEAS-2B cells. Coculture of eosinophils and BEAS-2B cells induced transforming growth factor β secretion, which may mediate suppression of HRV-induced interferon expression.

CONCLUSION

Eosinophils suppressed HRV-induced expression of interferons from epithelial cells, resulting in increased quantity of HRV. This represents one mechanism for interaction between allergic inflammation and innate immunity.

Basic research on virus-induced asthma exacerbation: inhibition of inflammatory chemokine expression by fluticasone propionate

BACKGROUND

Viral infection can exacerbate asthma by inducing the accumulation of inflammatory cells in the airway. We have previously reported that double-stranded RNA (dsRNA), a viral product and ligand of the Toll-like receptor-3 (TLR3), activates the transcription factors NF-κB and IRF-3 and upregulates the expression of inflammatory chemokines in airway epithelial cells. Here, we examined the effects of the glucocorticoid fluticasone propionate (FP) on the expression of the inflammatory chemokines CCL5, CXCL8 and CXCL10.

METHODS

The airway epithelial cell line BEAS-2B was used for this study. Expression of CCL5, CXCL8 and CXCL10 mRNA and protein was quantified by real-time PCR and ELISA assay, respectively. To examine the association of FP with the physiology of chemokine production, we included several methods. Nuclear translocation of transcription factors was determined by performing Western blot analysis. Histone deacetylase (HDAC) activity in nuclear extracts was measured using a colorimetric assay. Stability of the chemokine mRNAs was examined in cells incubated with actinomycin D. The activities of the CCL5 promoter and the transcription factors NF-κB and IRF-3 were assessed using luciferase reporter assays.

RESULTS

Treatment of BEAS-2B cells with FP significantly and dose-dependently (10(-9) to 10(-6)M) inhibited dsRNA-induced expression of CCL5, CXCL8 and CXCL10 protein and mRNA, but did not affect mRNA stability. FP also significantly inhibited dsRNA-stimulated CCL5 promoter activity. However, FP had no effect on the activity of HDAC or the nuclear translocation of NF-κB and IRF-3.

CONCLUSIONS

FP inhibits the dsRNA-stimulated expression of inflammatory chemokines in airway epithelial cells. FP may act by inhibiting chemokine transcription through an as yet unidentified mechanism.

Acute asthma exacerbations in childhood: risk factors, prevention and treatment

Asthma is a heterogeneous disease more appropriately seen as a syndrome rather than a single pathologic entity. Although it can remain quiescent for extended time periods, the inflammatory and remodeling processes affect the bronchial milieu and predispose to acute and occasionally severe clinical manifestations. The complexity underlying these episodes is enhanced during childhood, an era of ongoing alterations and maturation of key biological systems. In this review, the authors focus on such sudden-onset events, emphasizing on their diversity on the basis of the numerous asthma phenotypes.

Modulation of transcriptional responses by poly(I:C) and human rhinovirus: effect of long-acting β₂-adrenoceptor agonists

Exacerbations of asthma, a chronic inflammatory respiratory disease, are associated with viral upper respiratory tract infections involving human rhinovirus. Although glucocorticoids (corticosteroids) effectively control airways inflammation in many asthmatics, human rhinovirus-associated exacerbations show reduced glucocorticoid responsiveness. Using human bronchial epithelial BEAS-2B cells, we show that human rhinovirus reduced glucocorticoid-inducible activation of glucocorticoid response element (GRE) reporter systems in a time- and concentration-dependent manner. The synthetic double-stranded viral RNA mimetic, polyinosinic:polycytidylic acid (poly(I:C)), also reduced activation of GRE reporter systems in BEAS-2B and pulmonary A549 cells. In addition, poly(I:C) decreased transcription from cAMP response element (CRE)-, TATA-, simian virus 40- and nuclear factor-kappa B (NF-κB)-dependent reporter systems. The effects of poly(I:C) on GRE-reporter activation were countered by the long-acting β2-adrenoceptor agonists, formoterol and salmeterol. Likewise, increased expression of the gene cyclin-dependent kinase inhibitor 1C (CDKN1C; p57(KIP2)) by dexamethasone was reduced by poly(I:C), but was substantially enhanced by the addition of formoterol. Poly(I:C) induced the expression of interleukin-8 (IL8; CXCL8) and this was significantly decreased by dexamethasone, formoterol or their combination. This confirms that not all transcriptional responses were attenuated by poly(I:C) and that decreased glucocorticoid-dependent transcription can be counteracted by the addition of long-acting β2-adrenoceptor agonists. These data show how human rhinovirus may attenuate glucocorticoid-induced transcription to reduce anti-inflammatory activity. However, addition of long-acting β2-adrenoceptor agonist to the glucocorticoid functionally restored this response and shows how glucocorticoid plus long-acting β2-adrenoceptor agonist combinations may prove beneficial during virus-induced exacerbations of asthma.

Corticosteroid insensitivity is reversed by formoterol via phosphoinositide-3-kinase inhibition

BACKGROUND AND PURPOSE

Patients with chronic obstructive pulmonary disease (COPD) show a poor response to corticosteroids, which has been linked to oxidative stress. Here we show that the long-acting β(2) -agonist formoterol (FM) reversed corticosteroid insensitivity under oxidative stress via inhibition of phosphoinositide-3-kinase (PI3K) signalling.

EXPERIMENTAL APPROACH

Responsiveness to corticosteroids dexamethasone (Dex), budesonide (Bud) and fluticasone propionate (FP) was determined, as IC(50) values on TNF-α-induced interleukin 8 release, in U937 monocytic cell line treated with hydrogen peroxide (H(2) O(2) ) or peripheral blood mononuclear cells (PBMCs) from patients with COPD or severe asthma.

KEY RESULTS

PBMCs from severe asthma and COPD were less sensitive to Dex compared with those from healthy subjects. Both FM (10(-9)  M) and salmeterol (SM, 10(-8)  M) reversed Dex insensitivity in severe asthma, but only FM restored Dex sensitivity in COPD. Although H(2) O(2) exposure decreased steroid sensitivity in U937 cells, FM restored responsiveness to Bud and FP while the effects of SM were weaker. Additionally, FM, but not SM, partially inhibited H(2) O(2) -induced PI3Kδ-dependent (PKB) phosphorylation. H(2) O(2) decreased SM-induced cAMP production in U937 cells, but did not significantly affect the response to FM. The reduction of SM effects by H(2) O(2) was reversed by pretreatment with LY294002, a PI3K inhibitor, or IC87114, a PI3Kδ inhibitor.

CONCLUSION AND IMPLICATIONS

FM reversed oxidative stress-induced corticosteroid insensitivity and decreased β(2) adrenoceptor-dependent cAMP production via inhibition of PI3Kδ signalling. FM will be more effective than SM, when combined with corticosteroids, for the treatment of respiratory diseases under conditions of high oxidative stress, such as in COPD.

Inflammation in COPD: implications for management

Chronic obstructive pulmonary disease (COPD) is recognized by the Global Initiative for Chronic Obstructive Lung Disease guidelines as an inflammatory disease state, and treatment rationales are provided accordingly. However, not all physicians follow or are even aware of these guidelines. Research has shown that COPD inflammation involves multiple inflammatory cells and mediators and the underlying pathology differs from asthma inflammation. For these reasons, therapeutic agents that are effective in asthma patients may not be optimal in COPD patients. COPD exacerbations are intensified inflammatory events compared with stable COPD. The clinical and systemic consequences believed to result from the chronic inflammation observed in COPD suggest that inflammation intensity is a key factor in COPD and exacerbation severity and frequency. Although inhaled corticosteroids are commonly used and are essential in asthma management, their efficacy in COPD is limited, with only a modest effect at reducing exacerbations. The importance of inflammation in COPD needs to be better understood by clinicians, and the differences in inflammation in COPD versus asthma should be considered carefully to optimize the use of anti-inflammatory agents.

Virus infection-induced bronchial asthma exacerbation

Infection with respiratory viruses, including rhinoviruses, influenza virus, and respiratory syncytial virus, exacerbates asthma, which is associated with processes such as airway inflammation, airway hyperresponsiveness, and mucus hypersecretion. In patients with viral infections and with infection-induced asthma exacerbation, inflammatory mediators and substances, including interleukins (ILs), leukotrienes and histamine, have been identified in the airway secretions, serum, plasma, and urine. Viral infections induce an accumulation of inflammatory cells in the airway mucosa and submucosa, including neutrophils, lymphocytes and eosinophils. Viral infections also enhance the production of inflammatory mediators and substances in airway epithelial cells, mast cells, and other inflammatory cells, such as IL-1, IL-6, IL-8, GM-CSF, RANTES, histamine, and intercellular adhesion molecule-1. Viral infections affect the barrier function of the airway epithelial cells and vascular endothelial cells. Recent reports have demonstrated augmented viral production mediated by an impaired interferon response in the airway epithelial cells of asthma patients. Several drugs used for the treatment of bronchial asthma reduce viral and pro-inflammatory cytokine release from airway epithelial cells infected with viruses. Here, I review the literature on the pathogenesis of the viral infection-induced exacerbation of asthma and on the modulation of viral infection-induced airway inflammation.

Asthma exacerbations: origin, effect, and prevention

Asthma is the most common chronic respiratory disease, affecting up to 10% of adults and 30% of children in the Western world. Despite advances in asthma management, acute exacerbations continue to occur and impose considerable morbidity on patients and constitute a major burden on health care resources. Respiratory tract viruses have emerged as the most frequent triggers for exacerbations in both children and adults; however, the mechanisms underlying these remain poorly understood. More recently, it has become increasingly clear that interactions might exist between viruses and other triggers, increasing the likelihood of an exacerbation. In this article we begin with an overview of the health, economic, and social burden that exacerbations of asthma carry with them. This is followed by a review of the pathogenesis of asthma exacerbations, highlighting the various triggers responsible and multiple interactions that exist between them. The final section first addresses what preventative measures are currently available for asthma exacerbations and subsequently examines which of the new treatments in development might lessen the burden of exacerbations in the future.

Budesonide and formoterol reduce early innate anti-viral immune responses in vitro

Asthma is a chronic inflammatory airways disease in which respiratory viral infections frequently trigger exacerbations. Current treatment of asthma with combinations of inhaled corticosteroids and long acting beta2 agonists improves asthma control and reduces exacerbations but what impact this might have on innate anti-viral immunity is unclear. We investigated the in vitro effects of asthma drugs on innate anti-viral immunity. Peripheral blood mononuclear cells (PBMC) from healthy and asthmatic donors were cultured for 24 hours with the Toll-like receptor 7 agonist, imiquimod, or rhinovirus 16 (RV16) in the presence of budesonide and/or formoterol. Production of proinflammatory cytokines and expression of anti-viral intracellular signalling molecules were measured by ELISA and RT-PCR respectively. In PBMC from healthy donors, budesonide alone inhibited IP-10 and IL-6 production induced by imiquimod in a concentration-dependent manner and the degree of inhibition was amplified when budesonide and formoterol were used in combination. Formoterol alone had little effect on these parameters, except at high concentrations (10⁻⁶ M) when IL-6 production increased. In RV16 stimulated PBMC, the combination of budesonide and formoterol inhibited IFNα and IP-10 production in asthmatic as well as healthy donors. Combination of budesonide and formoterol also inhibited RV16-stimulated expression of the type I IFN induced genes myxovirus protein A and 2′, 5′ oligoadenylate synthetise. Notably, RV16 stimulated lower levels of type Myxovirus A and oligoadenylate synthase in PBMC of asthmatics than control donors. These in vitro studies demonstrate that combinations of drugs commonly used in asthma therapy inhibit both early pro-inflammatory cytokines and key aspects of the type I IFN pathway. These findings suggest that budesonide and formoterol curtail excessive inflammation induced by rhinovirus infections in patients with asthma, but whether this inhibits viral clearance in vivo remains to be determined.

Can β2-adrenoceptor agonists, anticholinergic drugs, and theophylline contribute to the control of pulmonary inflammation and emphysema in COPD?

Chronic obstructive pulmonary disease (COPD) has become a global epidemic disease with an increased morbidity and mortality in the world. Inflammatory process progresses and contributes to irreversible airflow limitation. However, there is no available therapy to better control the inflammatory progression and therefore to reduce the exacerbations and mortality. Thus, the development of efficient anti-inflammatory therapies is a priority for patients with COPD. β(2) -Adrenoceptor agonists and anticholinergic agents are widely used as first line drugs in management of COPD because of their efficient bronchodilator properties. At present, many studies in vitro and some data obtained in laboratory animals reveal the potential anti-inflammatory effects of these bronchodilators but their protective role against chronic inflammation and the development of emphysema in patients with COPD remains to be investigated. The anti-inflammatory effects of theophylline at low doses have also been identified. Beneficial interactions between glucocorticoids and bronchodilators have been reported, and signaling pathways explaining these synergistic effects begin to be understood, especially for theophylline. Recent data demonstrating interactions between anticholinergics with β(2) -adrenoceptor agonists aiming to better control the pulmonary inflammation and the development of emphysema in animal models of COPD justify the priority to investigate the interactive effects of a tritherapy associating corticoids with the two main categories of bronchodilators.

Epithelial cells and airway diseases

The airway epithelial cell is the initial cell type impacted both by inhaled environmental factors, such as pathogens, allergens, and pollutants, and inhaled medications for airway diseases. As such, epithelial cells are now recognized to play a central role in the regulation of airway inflammatory status, structure, and function in normal and diseased airways. This article reviews our current knowledge regarding the roles of the epithelial cell in airway inflammation and host defense. The interactions of inhaled environmental factors and pathogens with epithelial cells are also discussed, with an emphasis on epithelial innate immune responses and contributions of epithelial cells to immune regulation. Recent evidence suggesting that epithelial cells play an active role in inducing several of the structural changes, collectively referred to airway remodeling, seen in the airways of asthmatic subjects is reviewed. Finally, the concept that the epithelium is a major target for the actions of a number of classes of inhaled medications is discussed, as are the potential mechanisms by which selected drugs may alter epithelial function.