Osteoblasts Are Rapidly Ablated by Virus-Induced Systemic Inflammation following Lymphocytic Choriomeningitis Virus or Pneumonia Virus of Mice Infection in Mice.

A link between inflammatory disease and bone loss is now recognized. However, limited data exist on the impact of virus infection on bone loss and regeneration. Bone loss results from an imbalance in remodeling, the physiological process whereby the skeleton undergoes continual cycles of formation and resorption. The specific molecular and cellular mechanisms linking virus-induced inflammation to bone loss remain unclear. In the current study, we provide evidence that infection of mice with either lymphocytic choriomeningitis virus (LCMV) or pneumonia virus of mice (PVM) resulted in rapid and substantial loss of osteoblasts from the bone surface. Osteoblast ablation was associated with elevated levels of circulating inflammatory cytokines, including TNF-α, IFN-γ, IL-6, and CCL2. Both LCMV and PVM infections resulted in reduced osteoblast-specific gene expression in bone, loss of osteoblasts, and reduced serum markers of bone formation, including osteocalcin and procollagen type 1 N propeptide. Infection of Rag-1-deficient mice (which lack adaptive immune cells) or specific depletion of CD8+ T lymphocytes limited osteoblast loss associated with LCMV infection. By contrast, CD8+ T cell depletion had no apparent impact on osteoblast ablation in association with PVM infection. In summary, our data demonstrate dramatic loss of osteoblasts in response to virus infection and associated systemic inflammation. Further, the inflammatory mechanisms mediating viral infection-induced bone loss depend on the specific inflammatory condition.

IL-22 and its receptors are increased in human and experimental COPD and contribute to pathogenesis.

Chronic obstructive pulmonary disease (COPD) is the third leading cause of morbidity and death globally. The lack of effective treatments results from an incomplete understanding of the underlying mechanisms driving COPD pathogenesis.Interleukin (IL)-22 has been implicated in airway inflammation and is increased in COPD patients. However, its roles in the pathogenesis of COPD is poorly understood. Here, we investigated the role of IL-22 in human COPD and in cigarette smoke (CS)-induced experimental COPD.IL-22 and IL-22 receptor mRNA expression and protein levels were increased in COPD patients compared to healthy smoking or non-smoking controls. IL-22 and IL-22 receptor levels were increased in the lungs of mice with experimental COPD compared to controls and the cellular source of IL-22 included CD4+ T-helper cells, γδ T-cells, natural killer T-cells and group 3 innate lymphoid cells. CS-induced pulmonary neutrophils were reduced in IL-22-deficient (Il22 -/-) mice. CS-induced airway remodelling and emphysema-like alveolar enlargement did not occur in Il22 -/- mice. Il22 -/- mice had improved lung function in terms of airway resistance, total lung capacity, inspiratory capacity, forced vital capacity and compliance.These data highlight important roles for IL-22 and its receptors in human COPD and CS-induced experimental COPD.

Th22 Cells Form a Distinct Th Lineage from Th17 Cells In Vitro with Unique Transcriptional Properties and Tbet-Dependent Th1 Plasticity.

Th22 cells are a major source of IL-22 and have been found at sites of infection and in a range of inflammatory diseases. However, their molecular characteristics and functional roles remain largely unknown because of our inability to generate and isolate pure populations. We developed a novel Th22 differentiation assay and generated dual IL-22/IL-17A reporter mice to isolate and compare pure populations of cultured Th22 and Th17 cells. Il17a fate-mapping and transcriptional profiling provide evidence that these Th22 cells have never expressed IL-17A, suggesting that they are potentially a distinct cell lineage from Th17 cells under in vitro culture conditions. Interestingly, Th22 cells also expressed granzymes, IL-13, and increased levels of Tbet. Using transcription factor-deficient cells, we demonstrate that RORγt and Tbet act as positive and negative regulators of Th22 differentiation, respectively. Furthermore, under Th1 culture conditions in vitro, as well as in an IFN-γ-rich inflammatory environment in vivo, Th22 cells displayed marked plasticity toward IFN-γ production. Th22 cells also displayed plasticity under Th2 conditions in vitro by upregulating IL-13 expression. Our work has identified conditions to generate and characterize Th22 cells in vitro. Further, it provides evidence that Th22 cells develop independently of the Th17 lineage, while demonstrating plasticity toward both Th1- and Th2-type cells.

A critical role for donor-derived IL-22 in cutaneous chronic GVHD.

Graft-versus-host disease (GVHD) is the major cause of nonrelapse morbidity and mortality after allogeneic stem cell transplantation (allo-SCT). Prevention and treatment of GVHD remain inadequate and commonly lead to end-organ dysfunction and opportunistic infection. The role of interleukin (IL)-17 and IL-22 in GVHD remains uncertain, due to an apparent lack of lineage fidelity and variable and contextually determined protective and pathogenic effects. We demonstrate that donor T cell-derived IL-22 significantly exacerbates cutaneous chronic GVHD and that IL-22 is produced by highly inflammatory donor CD4+ T cells posttransplantation. IL-22 and IL-17A derive from both independent and overlapping lineages, defined as T helper (Th)22 and IL-22+ Th17 cells. Donor Th22 and IL-22+ Th17 cells share a similar IL-6-dependent developmental pathway, and while Th22 cells arise independently of the IL-22+ Th17 lineage, IL-17 signaling to donor Th22 directly promotes their development in allo-SCT. Importantly, while both IL-22 and IL-17 mediate skin GVHD, Th17-induced chronic GVHD can be attenuated by IL-22 inhibition in preclinical systems. In the clinic, high levels of both IL-17A and IL-22 expression are present in the skin of patients with GVHD after allo-SCT. Together, these data demonstrate a key role for donor-derived IL-22 in patients with chronic skin GVHD and confirm parallel but symbiotic developmental pathways of Th22 and Th17 differentiation.

Correction: Antagonism of miR-328 Increases the Antimicrobial Function of Macrophages and Neutrophils and Rapid Clearance of Non-typeable Haemophilus Influenzae (NTHi) from Infected Lung.

[This corrects the article DOI: 10.1371/journal.ppat.1004549.].

Antagonism of miR-328 increases the antimicrobial function of macrophages and neutrophils and rapid clearance of non-typeable Haemophilus influenzae (NTHi) from infected lung.

Pathogenic bacterial infections of the lung are life threatening and underpin chronic lung diseases. Current treatments are often ineffective potentially due to increasing antibiotic resistance and impairment of innate immunity by disease processes and steroid therapy. Manipulation miRNA directly regulating anti-microbial machinery of the innate immune system may boost host defence responses. Here we demonstrate that miR-328 is a key element of the host response to pulmonary infection with non-typeable haemophilus influenzae and pharmacological inhibition in mouse and human macrophages augments phagocytosis, the production of reactive oxygen species, and microbicidal activity. Moreover, inhibition of miR-328 in respiratory models of infection, steroid-induced immunosuppression, and smoke-induced emphysema enhances bacterial clearance. Thus, miRNA pathways can be targeted in the lung to enhance host defence against a clinically relevant microbial infection and offer a potential new anti-microbial approach for the treatment of respiratory diseases.

The emerging role of microRNAs in regulating immune and inflammatory responses in the lung.

Chronic inflammatory diseases of the lung are leading causes of morbidity and mortality worldwide. Many of these disorders can be attributed to abnormal immune responses to environmental stimuli and infections. As such, understanding the innate host defense pathways and their regulatory systems will be critical to developing new approaches to treatment. In this regard, there is increasing interest in the role of microRNAs (miRNAs) in the regulation of pulmonary innate host defense responses and the inflammatory sequelae in respiratory disease. In this review, we discuss recent findings that indicate an important role for miRNAs in the regulation in mouse models of various respiratory diseases and in host defense against bacterial and viral infection. We also discuss the potential utility and limitations of targeting these molecules as anti-inflammatory strategies and also as a means to improve pathogen clearance from the lung.

Production and differentiation of myeloid cells driven by proinflammatory cytokines in response to acute pneumovirus infection in mice.

Respiratory virus infections are often pathogenic, driving severe inflammatory responses. Most research has focused on localized effects of virus infection and inflammation. However, infection can induce broad-reaching, systemic changes that are only beginning to be characterized. In this study, we assessed the impact of acute pneumovirus infection in C57BL/6 mice on bone marrow hematopoiesis. We hypothesized that inflammatory cytokine production in the lung upregulates myeloid cell production in response to infection. We demonstrate a dramatic increase in the percentages of circulating myeloid cells, which is associated with pronounced elevations in inflammatory cytokines in serum (IFN-γ, IL-6, CCL2), bone (TNF-α), and lung tissue (TNF-α, IFN-γ, IL-6, CCL2, CCL3, G-CSF, osteopontin). Increased hematopoietic stem/progenitor cell percentages (Lineage(-)Sca-I(+)c-kit(+)) were also detected in the bone marrow. This increase was accompanied by an increase in the proportions of committed myeloid progenitors, as determined by colony-forming unit assays. However, no functional changes in hematopoietic stem cells occurred, as assessed by competitive bone marrow reconstitution. Systemic administration of neutralizing Abs to either TNF-α or IFN-γ blocked expansion of myeloid progenitors in the bone marrow and also limited virus clearance from the lung. These findings suggest that acute inflammatory cytokines drive production and differentiation of myeloid cells in the bone marrow by inducing differentiation of committed myeloid progenitors. Our findings provide insight into the mechanisms via which innate immune responses regulate myeloid cell progenitor numbers in response to acute respiratory virus infection.

Pharmacological Basis of Differences in Dose Response, Dose Equivalence, and Duration of Action of Inhaled Corticosteroids.

INTRODUCTION: Asthma treatment guidelines classify inhaled corticosteroid (ICS) regimens as low, medium, or high dose. However, efficacy and safety are not independently assessed accordingly. Moreover, differences in ICS duration of action are not considered when a dose regimen is selected. We investigated the efficacy and safety implications of these limitations for available ICS molecules. METHODS: Published pharmacodynamic and pharmacokinetic parameters were used, alongside physiological and pharmacological principles, to estimate the efficacy and safety of available ICS molecules. Extent and duration of glucocorticoid receptor (GR) occupancy in the lung (efficacy) and cortisol suppression (systemic exposure and safety) were estimated. RESULTS: Some ICS regimens (e.g., fluticasone furoate, fluticasone propionate, and ciclesonide) rank high for efficacy but low for systemic exposure, contrary to how ICS dose equivalence is currently viewed. Differences in dose-response relationships for efficacy and systemic exposure were unique for each ICS regimen and reflected in their therapeutic indices. Notably, even low doses of most ICSs can generate high GR occupancy (≥ 90%) across the entire dose interval at steady state, which may explain previously reported difficulties in obtaining dose responses within the clinical dose range and observations that most clinical benefit typically occurs at low doses. The estimated post dose duration of lung GR occupancy for ICS molecules was categorized as 4-6 h (short), 14-16 h (medium), 25-40 h (long), or > 80 h (ultra-long), suggesting potentially large differences in anti-inflammatory duration of action. CONCLUSION: In a real-world clinical setting where there may be poor adherence to prescribed therapy, our findings suggest a significant therapeutic advantage for longer-acting ICS molecules in patients with asthma.

Patients with asthma often rely on inhaled corticosteroids to manage their symptoms by controlling lung inflammation. Inhaled corticosteroids can be used at low, medium, or high doses; however, the effectiveness, safety, and how long the effects last for a particular inhaled corticosteroid molecule are not considered when choosing them. This study investigated the safety and efficacy of different inhaled corticosteroid molecules. Leveraging published data on the mode of anti-inflammatory action and the rates these molecules are absorbed and eliminated from the body, we estimated their effectiveness and safety profiles, including duration of action in the lungs and systemic exposure levels. Some inhaled corticosteroid molecules such as fluticasone furoate, fluticasone propionate, and ciclesonide were found to exhibit high anti-inflammatory effectiveness in the lungs with minimal systemic exposure, contrasting the perceived similarities among currently used drug molecules. Anti-inflammatory duration of the unwanted systemic effect in the rest of the body was unique for each inhaled corticosteroid molecule. Notably, even the lowest doses of most inhaled corticosteroids were found to be effective in the lungs when taken as prescribed, supporting previous observations that clinical benefits are mostly realized at lower doses. Furthermore, estimated post dose durations of effectiveness for different inhaled corticosteroid molecules varied widely among different molecules, with some lasting a few hours and others lasting more than 80 h, suggesting significant differences in their duration of action. Overall, these findings demonstrate the potential advantage of using longer-acting inhaled corticosteroids, particularly for patients with asthma who may face challenges in adhering to prescribed regimens.

Baseline Characteristics and Maintenance Therapy Choice on Symptom Control, Reliever Use, Exacerbation Risk in Moderate-Severe Asthma: A Clinical Modelling and Simulation Study.

INTRODUCTION: Although some factors associated with asthma symptom deterioration and risk of exacerbation have been identified, these are not yet fully characterised. We conducted a clinical modelling and simulation study to understand baseline factors affecting symptom control, reliever use and exacerbation risk in patients with moderate-severe asthma during follow-up on regularly dosed inhaled corticosteroid (ICS) monotherapy, or ICS/long-acting beta2-agonist (LABA) combination therapy. METHODS: Individual patient data from randomised clinical trials (undertaken between 2001 and 2019) were used to model the time course of symptoms (n = 7593), patterns of reliever medication use (n = 3768) and time-to-first exacerbation (n = 6763), considering patient-specific and extrinsic factors, including treatment. Model validation used standard graphical and statistical criteria. Change in symptom control scores (Asthma Control Questionnaire 5 [ACQ-5]), reduction in reliever use and annualised exacerbation rate were then simulated in patient cohorts with different baseline characteristics and treatment settings. RESULTS: Being a smoker, having higher baseline ACQ-5 and body mass index affected symptom control scores, reliever use and exacerbation risk (p < 0.01). In addition, low forced expiratory volume in 1 s percent predicted, female sex, season and previous exacerbations were found to contribute to a further increase in exacerbation risk (p < 0.01), whereas long asthma history was associated with more frequent reliever use (p < 0.01). These effects were independent from the underlying maintenance therapy. In different scenarios, fluticasone furoate (FF)/vilanterol was associated with greater reductions in reliever use and exacerbation rates compared with FF or fluticasone propionate (FP) alone or budesonide/formoterol, independently from other factors (p < 0.01). CONCLUSIONS: This study provided further insight into the effects of individual baseline characteristics on treatment response and highlighted significant differences in the performance of ICS/LABA combination therapy on symptom control, reliever use and exacerbation risk. These factors should be incorporated into clinical practice as the basis for tailored management of patients with moderate-severe asthma.

In this study we quantified how individual baseline patient characteristics at the start of treatment influence the response to regular maintenance medication. Specifically, using computer modelling and simulations based on data from individual patients enrolled into clinical trials in moderate­severe asthma, we predicted how much reliever inhaler they need, how well they rate their asthma control, and how likely an asthma attack (exacerbation) is to occur within the next 12 months. Simulation scenarios were then implemented to evaluate opportunities to improve and personalise real-life management of patients in clinical practice. Considering symptom control level, reliever use and other patient-specific factors at the start of treatment, we assessed how well maintenance therapy with inhaled corticosteroids/bronchodilators contributes to symptom improvement and/or reduction in the risk of asthma attacks. These scenarios show that current smokers, people with higher asthma symptom scores, who are obese, and have a longer history of asthma tend to use their reliever inhalers more often. Moreover, this was linked to a higher risk of having an asthma attack and worse symptom control. This pattern appears to compensate in most cases for the effect of the same baseline factors on symptom control. Switching patients who are not responding well to initial treatment with the inhaled corticosteroid, fluticasone propionate, to fluticasone furoate/vilanterol resulted in a significantly greater reduction in reliever inhaler use and risk of asthma attack, compared with those switched to budesonide/formoterol. These findings highlight the importance of tailored choices for optimal management of patients with moderate­severe asthma.

Exploring Clinical Remission in Moderate Asthma - Perspectives from Asia, the Middle East, and South America.

INTRODUCTION: Clinical remission is a relatively new concept in asthma but recent research initiatives suggest it could be an ambitious and achievable therapeutic target for patients with asthma. METHODS: In this modified Delphi study (comprising two online surveys, completed either side of a virtual scientific workshop), the opinions of a panel of respiratory physicians were evaluated to summarize perspective statements on key therapeutic outcomes and criteria for on-treatment clinical remission in patients with moderate asthma. An agreement threshold was pre-defined as agreement by ≥ 75% of participants. RESULTS: Surveys 1 and 2 were completed by 20 and 18 participants, respectively. Most participants (95%) agreed with the concept of clinical remission in moderate asthma and that this should be a desirable treatment goal (90%). Based on a composite measure of 4-6 desirable therapeutic outcomes, current understanding of clinical remission was considered as 12 months with no exacerbations, no oral corticosteroids, no daytime or night-time asthma symptoms (Asthma Control Test score ≥ 20 or Asthma Control Questionnaire score ≤ 0.75), stable lung function, and no treatment-related adverse events. No agreement was reached on the role of relievers in defining therapeutic outcomes or on the wider use of biomarkers and airway hyperresponsiveness for defining asthma remission in clinical practice. CONCLUSIONS: In line with recent consensus statements from the United States and Europe, there was a high level of agreement on the elements of clinical remission among a panel of respiratory physicians from Asia, the Middle East, and South America. Extension of the concept of clinical remission to patients with moderate asthma was considered aligned with the potential of clinical remission as a goal of therapy.

Assessing the Effects of Changing Patterns of Inhaled Corticosteroid Dosing and Adherence with Fluticasone Furoate and Budesonide on Asthma Management.

INTRODUCTION: Pharmacological asthma management focuses on the use of inhaled corticosteroid (ICS)-containing therapies, which reduce airway inflammation and provide bronchoprotection, improving symptom control and reducing exacerbation risk. ICS underuse due to poor adherence is common, leading to poor clinical outcomes including increased risk of mortality. This article reviews efficacy versus systemic activity profiles for various adherence patterns and dosing regimens of fluticasone furoate (FF)-containing and budesonide (BUD)-containing asthma therapies in clinical trials and real-world studies. METHODS: We performed a structured literature review (1 January 2000-3 March 2022) and mathematical modelling analysis of FF-containing and BUD-containing regular daily dosing in patients with mild-to-severe asthma, as-needed BUD/formoterol (FOR) in mild asthma, and BUD/FOR maintenance and reliever therapy (MART) dosing in moderate-to-severe asthma, to assess efficacy (bronchoprotection) and systemic activity (cortisol suppression) profiles of dosing patterns of ICS use in multiple adherence scenarios. RESULTS: A total of 22 manuscripts were included in full-text review and 18 in the model simulations. Focusing on FF-containing or BUD-containing treatments at comparable adherence rates, regular daily FF or FF/vilanterol (VI) dosing provided more prolonged bronchoprotection and fewer systemic effects than daily BUD, daily BUD/FOR, or BUD/FOR MART dosing, especially in low adherence scenarios. In model simulations and the real-world setting, FF/VI generally provided longer bronchoprotection, lower systemic activity, and greater clinical benefits over BUD/FOR as well as consistently higher adherence. CONCLUSION: In this literature review and modelling analysis, FF/VI was found to show clinical advantages on asthma control over BUD/FOR. These findings have implications for helping clinicians select the most suitable inhaled therapy for their patients with asthma.

Blockade of ROS production inhibits oncogenic signaling in acute myeloid leukemia and amplifies response to precision therapies.

Mutations in the type III receptor tyrosine kinase FLT3 are frequent in patients with acute myeloid leukemia (AML) and are associated with a poor prognosis. AML is characterized by the overproduction of reactive oxygen species (ROS), which can induce cysteine oxidation in redox-sensitive signaling proteins. Here, we sought to characterize the specific pathways affected by ROS in AML by assessing oncogenic signaling in primary AML samples. The oxidation or phosphorylation of signaling proteins that mediate growth and proliferation was increased in samples from patient subtypes with FLT3 mutations. These samples also showed increases in the oxidation of proteins in the ROS-producing Rac/NADPH oxidase-2 (NOX2) complex. Inhibition of NOX2 increased the apoptosis of FLT3-mutant AML cells in response to FLT3 inhibitors. NOX2 inhibition also reduced the phosphorylation and cysteine oxidation of FLT3 in patient-derived xenograft mouse models, suggesting that decreased oxidative stress reduces the oncogenic signaling of FLT3. In mice grafted with FLT3 mutant AML cells, treatment with a NOX2 inhibitor reduced the number of circulating cancer cells, and combining FLT3 and NOX2 inhibitors increased survival to a greater extent than either treatment alone. Together, these data raise the possibility that combining NOX2 and FLT3 inhibitors could improve the treatment of FLT3 mutant AML.

Antagonism of microRNA-126 suppresses the effector function of TH2 cells and the development of allergic airways disease.

Allergic asthma is an inflammatory disease of the lung characterized by abnormal T helper-2 (T(H)2) lymphocyte responses to inhaled antigens. The molecular mechanisms leading to the generation of T(H)2 responses remain unclear, although toll-like receptors (TLRs) present on innate immune cells play a pivotal role in sensing molecular patterns and in programming adaptive T cell responses. Here we show that in vivo activation of TLR4 by house dust mite antigens leads to the induction of allergic disease, a process that is associated with expression of a unique subset of small, noncoding microRNAs. Selective blockade of microRNA (miR)-126 suppressed the asthmatic phenotype, resulting in diminished T(H)2 responses, inflammation, airways hyperresponsiveness, eosinophil recruitment, and mucus hypersecretion. miR-126 blockade resulted in augmented expression of POU domain class 2 associating factor 1, which activates the transcription factor PU.1 that alters T(H)2 cell function via negative regulation of GATA3 expression. In summary, this study presents a functional connection between miRNA expression and asthma pathogenesis, and our data suggest that targeting miRNA in the airways may lead to anti-inflammatory treatments for allergic asthma.

Inhibition of house dust mite-induced allergic airways disease by antagonism of microRNA-145 is comparable to glucocorticoid treatment.

BACKGROUND: Glucocorticoids are used as mainstay therapy for asthma, but some patients remain resistant to therapy. MicroRNAs (miRNAs) are important regulators of the immune system by promoting the catabolism of their target transcripts as well as attenuating their translation. The role of miRNA in regulating allergic inflammation remains largely unknown. Blocking miRNA function may provide a new nonsteroidal anti-inflammatory approach to treatment. OBJECTIVES: To (1) determine the role of specific miRNAs in the regulation of hallmark features of allergic airways inflammation and (2) compare the efficacy of antagonizing miRNA function with that of steroid treatment. METHODS: Mice were sensitized and then aeroallergen-challenged with house dust mite to induce allergic airways disease, and alterations in the expression of miRNAs were characterized. Next mice were treated with antagomirs that inhibited the function of specific miRNAs in the lung or treated with dexamethasone and inflammatory lesions, and airway hyperresponsiveness was measured. RESULTS: miR-145, miR-21, and let-7b have been implicated in airway smooth muscle function, inflammation, and airways epithelial cell function, respectively. Inhibition of miR-145, but not miR-21 or lethal-7b, inhibited eosinophilic inflammation, mucus hypersecretion, T(H)2 cytokine production, and airway hyperresponsiveness. The anti-inflammatory effects of miR-145 antagonism were comparable to steroid treatment. CONCLUSION: Our study highlights the importance of understanding the contribution of miRNAs to pathogenesis of human allergic disease and their potential as novel anti-inflammatory targets.

A randomized, cross-over study comparing critical and overall errors, learning time, and preference of the ELLIPTA versus BREEZHALER dry powder inhalers in patients with asthma.

BACKGROUND: Many patients with asthma make errors using inhalers, affecting the amount of medication received. Previous evidence demonstrated that patients with asthma or chronic obstructive pulmonary disease make fewer critical errors with the ELLIPTA inhaler after reading the patient information leaflet (PIL) versus other dry powder inhalers. We assessed errors made by patients with asthma using placebo ELLIPTA or BREEZHALER inhalers. METHODS: This randomized, multicenter, open-label placebo inhaler-handling study (ClinicalTrials.gov: NCT04813354) with 2x2 complete block crossover design was conducted at three centers in the Netherlands and enrolled patients aged ≥18 years with mild-to-moderate asthma. Inclusion criteria were inhaler use for ≥12 weeks prior to enrollment and naivety to ELLIPTA and BREEZHALER inhalers. Patients were randomized to ELLIPTA or BREEZHALER inhaler first and were assessed for errors in use of both inhalers after 1) reading PIL instructions, 2) receiving further instruction from a healthcare professional (HCP) if they made an error. RESULTS: 114 patients with asthma (57% female; mean age of 55.3 years) were assessed. After reading the PIL, 6% of patients made ≥1 critical error with ELLIPTA versus 26% with BREEZHALER (odds ratio [OR]: 0.11 [95% confidence interval (CI): 0.01-0.40]; p < 0.001). With ELLIPTA, 27% of patients made ≥1 overall error after reading the PIL versus 41% with BREEZHALER (OR: 0.25 [95% CI: 0.03-0.74]; p = 0.005). Fewer patients required HCP instruction with ELLIPTA than BREEZHALER (25% versus 32%). CONCLUSIONS: Fewer patients made critical and overall errors using the ELLIPTA inhaler versus BREEZHALER after reading the PIL.

T-helper 22 cells develop as a distinct lineage from Th17 cells during bacterial infection and phenotypic stability is regulated by T-bet.

CD4+ T-helper 22 (Th22) cells are a phenotypically distinct lymphocyte subset that produces high levels of interleukin (IL)-22 without co-production of IL-17A. However, the developmental origin and lineage classification of Th22 cells, their interrelationship to Th17 cells, and potential for plasticity at sites of infection and inflammation remain largely undefined. An improved understanding of the mechanisms underpinning the outgrowth of Th22 cells will provide insights into their regulation during homeostasis, infection, and disease. To address this knowledge gap we generated 'IL-17A-fate-mapping IL-17A/IL-22 reporter transgenic mice' and show that Th22 cells develop in the gastrointestinal tract and lung during bacterial infection without transitioning via an Il17a-expressing intermediate, although in some compartments alternative transition pathways exist. Th22-cell development was not dependent on T-bet; however, this transcription factor functioned as a promiscuous T-cell-intrinsic regulator of IL-17A and IL-22 production, in addition to regulating the outgrowth, phenotypic stability, and plasticity of Th22 cells. Thus, we demonstrate that at sites of mucosal bacterial infection Th22 cells develop as a distinct lineage independently of Th17 cells; though both lineages exhibit bidirectional phenotypic flexibility within infected tissues and their draining lymph nodes, and that T-bet plays a critical regulatory role in Th22-cell function and identity.

Targeting MicroRNA Function in Respiratory Diseases: Mini-Review.

MicroRNAs (miRNAs) are small non-coding RNA molecules that modulate expression of the majority of genes by inhibiting protein translation. Growing literature has identified functional roles for miRNAs across a broad range of biological processes. As such, miRNAs are recognized as potential disease biomarkers and novel targets for therapies. While several miRNA-targeted therapies are currently in clinical trials (e.g., for the treatment of hepatitis C virus infection and cancer), no therapies have targeted miRNAs in respiratory diseases in the clinic. In this mini-review, we review the current knowledge on miRNA expression and function in respiratory diseases, intervention strategies to target miRNA function, and considerations specific to respiratory diseases. Altered miRNA expression profiles have been reported in a number of respiratory diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and idiopathic pulmonary fibrosis. These include alterations in isolated lung tissue, as well as sputum, bronchoalveolar lavage fluids and peripheral blood or serum. The observed alterations in easily accessible body fluids (e.g., serum) have been proposed as new biomarkers that may inform disease diagnosis and patient management. In a subset of studies, miRNA-targeted interventions also improved disease outcomes, indicating functional roles for altered miRNA expression in disease pathogenesis. In fact, direct administration of miRNA-targeting molecules to the lung has yielded promising results in a number of animal models. The ability to directly administer compounds to the lung holds considerable promise and may limit potential off-target effects and side effects caused by the systemic administration required to treat other diseases.

MicroRNA function in mast cell biology: protocols to characterize and modulate microRNA expression.

MicroRNAs (miRNAs) are small noncoding RNA molecules that can modulate mRNA levels through RNA-induced silencing complex (RISC)-mediated degradation. Recognition of target mRNAs occurs through imperfect base pairing between an miRNA and its target, meaning that each miRNA can target a number of different mRNAs to modulate gene expression. miRNAs have been proposed as novel therapeutic targets and many studies are aimed at characterizing miRNA expression patterns and functions within a range of cell types. To date, limited research has focused on the function of miRNAs specifically in mast cells; however, this is an emerging field. In this chapter, we will briefly overview miRNA synthesis and function and the current understanding of miRNAs in hematopoietic development and immune function, emphasizing studies related to mast cell biology. The chapter will conclude with fundamental techniques used in miRNA studies, including RNA isolation, real-time PCR and microarray approaches for quantification of miRNA expression levels, and antagomir design to interfere with miRNA function.