Professor Phil Hansbro

© 2017 Asian Pacific Society of RespirologyThere is currently enormous interest in studying the role of the microbiome in health and disease. Microbiome's role is increasingly being applied to respiratory diseases, in particular COPD, asthma, cystic fibrosis and bronchiectasis. The changes in respiratory microbiomes that occur in these diseases and how they are modified by environmental challenges such as cigarette smoke, air pollution and infection are being elucidated. There is also emerging evidence that gut microbiomes play a role in lung diseases through the modulation of systemic immune responses and can be modified by diet and antibiotic treatment. There are issues that are particular to the Asia-Pacific region involving diet and prevalence of specific respiratory diseases. Each of these issues is further complicated by the effects of ageing. The challenges now are to elucidate the cause and effect relationships between changes in microbiomes and respiratory diseases and how to translate these into new treatments and clinical care. Here we review the current understanding and progression in these areas.

© 2016 American Academy of Allergy, Asthma & ImmunologyBackground Severe steroid-insensitive asthma is a substantial clinical problem. Effective treatments are urgently required, however, their development is hampered by a lack of understanding of the mechanisms of disease pathogenesis. Steroid-insensitive asthma is associated with respiratory tract infections and noneosinophilic endotypes, including neutrophilic forms of disease. However, steroid-insensitive patients with eosinophil-enriched inflammation have also been described. The¿mechanisms that underpin infection-induced, severe steroid-insensitive asthma can be elucidated by using mouse models of disease. Objective We sought to develop representative mouse models of severe, steroid-insensitive asthma and to use them to identify pathogenic mechanisms and investigate new treatment approaches. Methods Novel mouse models of Chlamydia, Haemophilus influenzae, influenza, and respiratory syncytial virus respiratory¿tract infections and ovalbumin-induced, severe, steroid-insensitive allergic airway disease (SSIAAD) in BALB/c mice were developed and interrogated. Results Infection induced increases in the levels of microRNA (miRNA)-21 (miR-21) expression in the lung during SSIAAD, whereas expression of the miR-21 target phosphatase and tensin homolog was reduced. This was associated with an increase in levels of phosphorylated Akt, an indicator of phosphoinositide 3-kinase (PI3K) activity, and decreased nuclear histone deacetylase (HDAC)2 levels. Treatment with an miR-21¿specific antagomir (Ant-21) increased phosphatase and tensin homolog levels. Treatment with Ant-21, or the pan-PI3K inhibitor LY294002, reduced PI3K activity and restored HDAC2 levels. This led to suppression of airway hyperresponsiveness and restored steroid sensitivity to allergic airway disease. These observations were replicated with SSIAAD associated with 4 different pathogens. Conclusion We identify a previously unrecognized role for an¿miR-21/PI3K/HDAC2 axis in SSIAAD. Our data highlight miR-21 as a novel therapeutic target for the treatment of this form of asthma.

© 2017 the American Physiological Society.The aim of this study is to elucidate the role of TRAIL during rhinovirus (RV) infection in vivo. Naïve wild-type and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-deficient (Tnfsf10-/-) BALB/c mice were infected intranasally with RV1B. In separate experiments, Tnfsf10-/-mice were sensitized and challenged via the airway route with house dust mite (HDM) to induce allergic airways disease and then challenged with RVIB or UV-RVIB. Airway hyperreactivity (AHR) was invasively assessed as total airways resistance in response to increasing methacholine challenge and inflammation was assessed in bronchoalveolar lavage fluid at multiple time points postinfection. Chemokines were quantified by ELISA of whole lung lysates and viral load was determined by quantitative RT-PCR and tissue culture infective dose (TCID50). Human airway epithelial cells (BEAS2B) were infected with RV1B and stimulated with recombinant TRAIL or neutralizing anti-TRAIL antibodies and viral titer assessed by TCID50. HDM-challenged Tnfsf10-/-mice were protected against RV-induced AHR and had suppressed cellular infiltration in the airways upon RV infection. Chemokine C-X-C-motif ligand 2 (CXCL2) production was suppressed in naïve Tnfsf10-/-mice infected with RV1B, with less RV1B detected 24 h postinfection. This was associated with reduced apoptotic cell death and a reduction of interferon (IFN)-¿2/3 but not IFN-a or IFN-ß. TRAIL stimulation increased, whereas anti-TRAIL antibodies reduced viral replication in RV1B-infected BEAS2B cells in vitro. In conclusion, TRAIL promotes RV-induced AHR, inflammation and RV1B replication, implicating this molecule and its downstream signaling pathways as a possible target for the amelioration of RV1B-induced allergic and nonallergic lung inflammation and AHR.

© 2016, Controlled Release Society.The rapid advancement in the area of microRNAs (miRNAs) from discovery to their translation into therapeutic moieties reflects their significance as important regulators in the management of disease pathology. The miRNAs can potentially be a new class of drugs in the near future for the treatment of various lung diseases, but it lacks the current knowledge how these identified therapeutic moieties can be designed into an effective, patient complaint and targeted drug delivery system. miRNAs have characteristic features like small size and low molecular weight which makes them easily translated into an effective drug delivery system. In this review, we have summarised the concept of miRNAs and different approaches which can be employed to deliver miRNAs effectively and safely to the target cells including the challenges associated with their development in particular emphasis on pulmonary diseases. Such approaches will be of interest for both the biological and formulation scientists to understand and explore the new vistas in the area of miRNA delivery for pulmonary inflammatory diseases.

© 2016, Controlled Release Society.Biofilm comprises a community of microorganisms which form on medical devices and can lead to various threatening infections. It is a major concern in various respiratory diseases like cystic fibrosis, chronic obstructive pulmonary disease, etc. The treatment strategies for such infections are difficult due to the resistance of the microflora existing in the biofilms against various antimicrobial agents, thus posing threats to the patient population. The present era witnesses the beginning of research to understand the biofilm physiology and the associated microfloral diversity by applying -omics approaches. There is very limited information about how the deposition of biofilm on the respiratory devices and lung itself affects the drug delivered, the delivery system, and other implications. The present mini review summarizes the basic introduction to the biofilms and its avoidance using various drug delivery systems with special emphasis on the respiratory diseases. Understanding the approaches, principles, and modes of drug delivery involved in preventing biofilm deposition will be of interest to both biological and formulation scientists, thereby opening avenues to explore the new vistas in biofilm research for identifying better treatments for pulmonary infectious diseases.

© 2016 the American Physiological Society.Food antigens are common inflammatory triggers in pediatric eosinophilic esophagitis (EoE). TNFrelated apoptosis-inducing ligand (TRAIL) promotes eosinophilic inflammation through the upregulation of the E3 ubiquitin ligase Midline (MID)-1 and subsequent downregulation of protein phosphatase 2A (PP2A), but the role of this pathway in EoE that is experimentally induced by repeated food antigen challenges has not been investigated. Esophageal mucosal biopsies were collected from children with EoE and controls and assessed for TRAIL and MID-1 protein and mRNA transcript levels. Wild-type and TRAIL-deficient (Tnfsf10-/-) mice were administered subcutaneous ovalbumin (OVA) followed by oral OVA challenges. In separate experiments, OVA-challenged mice were intraperitoneally administered salmeterol or dexamethasone. Esophageal biopsies from children with EoE revealed increased levels of TRAIL and MID-1 and reduced PP2A activation compared with controls. Tnfsf10-/- mice were largely protected from esophageal fibrosis, eosinophilic inflammation, and the upregulation of TSLP, IL-5, IL-13, and CCL11 when compared with wild-type mice. Salmeterol administration to wild-type mice with experimental EoE restored PP2A activity and also prevented esophageal eosinophilia, inflammatory cytokine expression, and remodeling, which was comparable to the treatment effect of dexamethasone. TRAIL and PP2A regulate inflammation and fibrosis in experimental EoE, which can be therapeutically modulated by salmeterol.

Copyright © 2016 Russell et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction. Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine associated with acute and chronic inflammatory disorders and corticosteroid insensitivity. Its expression in the airways of patients with chronic obstructive pulmonary disease (COPD), a relatively steroid insensitive inflammatory disease is unclear, however. Methods. Sputum, bronchoalveolar lavage (BAL) macrophages and serum were obtained from nonsmokers, smokers and COPD patients. To mimic oxidative stress-induced COPD, mice were exposed to ozone for six-weeks and treated with ISO-1, a MIF inhibitor, and/or dexamethasone before each exposure. BAL fluid and lung tissue were collected after the final exposure. Airway hyperresponsiveness (AHR) and lung function were measured using whole body plethysmography. HIF-1a binding to the Mif promoter was determined by Chromatin Immunoprecipitation assays. Results. MIF levels in sputum and BAL macrophages from COPD patients were higher than those from non-smokers, with healthy smokers having intermediate levels. MIF expression correlated with that of HIF-1a in all patients groups and in ozone-exposed mice. BAL cell counts, cytokine mRNA and protein expression in lungs and BAL, including MIF, were elevated in ozone-exposed mice and had increased AHR. Dexamethasone had no effect on these parameters in the mouse but ISO-1 attenuated cell recruitment, cytokine release and AHR. Conclusion MIF and HIF-1a levels are elevated in COPD BAL macrophages and inhibition of MIF function blocks corticosteroid-insensitive lung inflammation and AHR. Inhibition of MIF may provide a novel anti-inflammatory approach in COPD.

© 2016 Asian Pacific Society of Respirology.Background and objective Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and inflammation. Airway bacterial colonization is increased in COPD; however, the role of potentially pathogenic and non-pathogenic bacteria in the pathogenesis of disease is unclear. This study characterized the presence of bacteria in a well-characterized cohort of adults with COPD and healthy controls. Methods Adults with COPD (n = 70) and healthy controls (n = 51) underwent clinical assessment and sputum induction. Sputum was dispersed, and total and differential cell counts were performed. Bacteria were cultured, identified and enumerated. Supernatants were assessed for neutrophil elastase (NE) and IL-1ß. Common respiratory pathogens were also determined using real-time PCR. Results Participants with COPD had a typical neutrophilic inflammatory profile. The total load of bacteria was increased in COPD and was associated with poorer respiratory health status, as measured by the St George's Respiratory Questionnaire (Spearman's r = 0.336, P = 0.013). Significantly lower levels of culturable Bacillus species were identified compared with healthy controls. PCR analyses revealed increased rates of detection of potentially pathogenic bacteria with Haemophilus influenzae detection associated with higher sputum levels of NE and IL-1ß, while Streptococcus pneumoniae was more common in male ex-smokers with emphysema and a deficit in diffusion capacity. Conclusion Non-pathogenic and pathogenic bacteria were altered in the sputum of patients with COPD. These observations highlight the potential to identify treatment and management strategies that both target specific bacterial pathogens and restore the microbial balance, which may lead to reductions in inflammation and subsequent improvements in lung health.

Chronic obstructive pulmonary disease (COPD) is a life-Threatening inflammatory respiratory disorder, often induced by cigarette smoke (CS) exposure. The development of effective therapies is impaired by a lack of understanding of the underlining mechanisms. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine with inflammatory and apoptotic properties. We interrogated a mouse model of CS-induced experimental COPD and human tissues to identify a novel role for TRAIL in COPD pathogenesis. CS exposure of wild-Type mice increased TRAIL and its receptor messenger RNA (mRNA) expression and protein levels, as well as the number of TRAIL + CD11b + monocytes in the lung. TRAIL and its receptor mRNA were also increased in human COPD. CS-exposed TRAIL-deficient mice had decreased pulmonary inflammation, pro-inflammatory mediators, emphysema-like alveolar enlargement, and improved lung function. TRAIL-deficient mice also developed spontaneous small airway changes with increased epithelial cell thickness and collagen deposition, independent of CS exposure. Importantly, therapeutic neutralization of TRAIL, after the establishment of early-stage experimental COPD, reduced pulmonary inflammation, emphysema-like alveolar enlargement, and small airway changes. These data provide further evidence for TRAIL being a pivotal inflammatory factor in respiratory diseases, and the first preclinical evidence to suggest that therapeutic agents that target TRAIL may be effective in COPD therapy.

© 2017 Elsevier Ltd.Innate immune responses act as first line defences upon exposure to potentially noxious stimuli. The innate immune system has evolved numerous intracellular and extracellular receptors that undertake surveillance for potentially damaging particulates. Inflammasomes are intracellular innate immune multiprotein complexes that form and are activated following interaction with these stimuli. Inflammasome activation leads to the cleavage of pro-IL-1ß and release of the pro-inflammatory cytokine, IL-1ß, which initiates acute phase pro-inflammatory responses, and other responses are also involved (IL-18, pyroptosis). However, excessive activation of inflammasomes can result in chronic inflammation, which has been implicated in a range of chronic inflammatory diseases. The airways are constantly exposed to a wide variety of stimuli. Inflammasome activation and downstream responses clears these stimuli. However, excessive activation may drive the pathogenesis of chronic respiratory diseases such as severe asthma and chronic obstructive pulmonary disease. Thus, there is currently intense interest in the role of inflammasomes in chronic inflammatory lung diseases and in their potential for therapeutic targeting. Here we review the known associations between inflammasome-mediated responses and the development and exacerbation of chronic lung diseases.

© 2016 Published by the BMJ Publishing Group Limited.Background Rhinovirus (RV) infections are the major precipitant of asthma exacerbations. While neutrophilic lung inflammation occurs during such infections, its role remains unclear. Neutrophilic inflammation is associated with increased asthma severity and steroid refractory disease. Neutrophils are vital for controlling infections but also have immunomodulatory functions. Previously, we found that neutrophils respond to viral mimetics but not replication competent RV. We aimed to investigate if neutrophils are activated and/or modulate immune responses of monocytes during RV16 infection. Methods Primary human monocytes and autologous neutrophils were cocultured with or without RV16, in direct contact or separated by transwells. RV16-stimulated monocytes were also exposed to lysed neutrophils, neutrophil membrane components or soluble neutrophil intracellular components. Interleukin 6 (IL-6) and C-X-C motif (CXC)L8 mRNA and proteins were measured by quantitative PCR and ELISA at 24â ¿..hours. Results RV16 induced IL-6 and CXCL8 in monocytes, but not neutrophils. RV16-induced IL-6 and CXCL8 from monocytes was reduced in the presence of live neutrophils. Transwell separation abolished the inhibitory effects. Lysed neutrophils inhibited RV16-induced IL-6 and CXCL8 from monocytes. Neutrophil intracellular components alone effectively inhibited RV16-induced monocyte-derived IL-6 and CXCL8. Neutrophil intracellular components reduced RV16-induced IL-6 and CXCL8 mRNA in monocytes. Conclusions Cell contact between monocytes and neutrophils is required, and preformed neutrophil mediator(s) are likely to be involved in the suppression of cytokine mRNA and protein production. This study demonstrates a novel regulatory function of neutrophils on RV-Activated monocytes in vitro, challenging the paradigm that neutrophils are predominantly proinflammatory.

© 2016.Chronic respiratory diseases are driven by inflammation, but some clinical conditions (severe asthma, COPD) are refractory to conventional anti-inflammatory therapies. Thus, novel anti-inflammatory strategies are necessary. The mRNA destabilizing protein, tristetraprolin (TTP), is an anti-inflammatory molecule that functions to induce mRNA decay of cytokines that drive pathogenesis of respiratory disorders. TTP is regulated by phosphorylation and protein phosphatase 2A (PP2A) is responsible for dephosphorylating (and hence activating) TTP, amongst other targets. PP2A is activated by small molecules, FTY720 and AAL(S), and in this study we examine whether these compounds repress cytokine production in a cellular model of airway inflammation using A549 lung epithelial cells stimulated with tumor necrosis factor a (TNFa) in vitro. PP2A activators significantly increase TNFa-induced PP2A activity and inhibit mRNA expression and protein secretion of interleukin 8 (IL-8) and IL-6; two key pro-inflammatory cytokines implicated in respiratory disease and TTP targets. The effect of PP2A activators is not via an increase in TNFa-induced TTP mRNA expression; instead we demonstrate a link between PP2A activation and TTP anti-inflammatory function by showing that specific knockdown of TTP with siRNA reversed the repression of TNFa-induced IL-8 and IL-6 mRNA expression and protein secretion by FTY720. Therefore we propose that PP2A activators affect the dynamic equilibrium regulating TTP; shifting the equilibrium from phosphorylated (inactive) towards unphosphorylated (active) but unstable TTP. PP2A activators boost the anti-inflammatory function of TTP and have implications for future pharmacotherapeutic strategies to combat inflammation in respiratory disease.

Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM 10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM 10 -induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma.

© 2016 The British Pharmacological SocietyBackground and Purpose: Chronic obstructive pulmonary disease (COPD) is a major cause of illness and death, often induced by cigarette smoking (CS). It is characterized by pulmonary inflammation and fibrosis that impairs lung function. Existing treatments aim to control symptoms but have low efficacy, and there are no broadly effective treatments. A new potential target is the ectoenzyme, semicarbazide-sensitive mono-amine oxidase (SSAO; also known as vascular adhesion protein-1). SSAO is elevated in smokers¿ serum and is a pro-inflammatory enzyme facilitating adhesion and transmigration of leukocytes from the vasculature to sites of inflammation. Experimental Approach: PXS-4728A was developed as a low MW inhibitor of SSAO. A model of COPD induced by CS in mice reproduces key aspects of human COPD, including chronic airway inflammation, fibrosis and impaired lung function. This model was used to assess suppression of SSAO activity and amelioration of inflammation and other characteristic features of COPD. Key Results: Treatment with PXS-4728A completely inhibited lung and systemic SSAO activity induced by acute and chronic CS-exposure. Daily oral treatment inhibited airway inflammation (immune cell influx and inflammatory factors) induced by acute CS-exposure. Therapeutic treatment during chronic CS-exposure, when the key features of experimental COPD develop and progress, substantially suppressed inflammatory cell influx and fibrosis in the airways and improved lung function. Conclusions and Implications: Treatment with a low MW inhibitor of SSAO, PXS-4728A, suppressed airway inflammation and fibrosis and improved lung function in experimental COPD, demonstrating the therapeutic potential of PXS-4728A for this debilitating disease.

Chronic obstructive pulmonary disease (COPD) is a serious lung disease that progressively worsens lung function. Those affected are highly susceptible to influenza virus infections that result in exacerbations with exaggerated symptoms with increased mortality. The mechanisms underpinning this increased susceptibility to infection in COPD are unclear. In this study, we show that primary bronchial epithelial cells (pBECs) from subjects with COPD have impaired induction of type I IFN (IFN-ß) and lead to heightened viral replication after influenza viral infection. COPD pBECs have reduced protein levels of protein kinase (PK) R and decreased formation of PKR-mediated antiviral stress granules, which are critical in initiating type I IFNinductions. In addition, reduced protein expression of p300 resulted in decreased activation of IFN regulatory factor 3 and subsequent formation of IFN-ß enhanceosome in COPD pBECs. The decreased p300 induction was the result of enhanced levels of microRNA (miR)-132. Ectopic expression of PKR or miR-132 antagomiR alone failed to restore IFN-ß induction, whereas cotreatment increased antiviral stress granule formation, induction of p300, and IFN-ß in COPD pBECs. This study reveals that decreased induction of both PKR and p300 proteins contribute to impaired induction of IFN-ß in COPD pBECs upon influenza infection.

© 2016 Elsevier LtdCorticosteroids are effective anti-inflammatory therapies widely utilized in chronic respiratory diseases. But these medicines can lose their efficacy during respiratory infection resulting in disease exacerbation. Further in vitro research is required to understand how infection worsens lung function control in order to advance therapeutic options to treat infectious exacerbation in the future. In this study, we utilize a cellular model of bacterial exacerbation where we pretreat A549 lung epithelial cells with the synthetic bacterial lipoprotein Pam3CSK4 (a TLR2 ligand) to mimic bacterial infection and tumor necrosis factor a (TNFa) to simulate inflammation. Under these conditions, Pam3CSK4 induces corticosteroid insensitivity; demonstrated by substantially reduced ability of the corticosteroid dexamethasone to repress TNFa-induced interleukin 6 secretion. We then explored the molecular mechanism responsible and found that corticosteroid insensitivity induced by bacterial mimics was not due to altered translocation of the glucocorticoid receptor into the nucleus, nor an impact on the NF-¿B pathway. Moreover, Pam3CSK4 did not affect corticosteroid-induced upregulation of anti-inflammatory MAPK deactivating phosphatase¿MKP-1. However, Pam3CSK4 can induce oxidative stress and we show that a proportion of the MKP-1 produced in response to corticosteroid in the context of TLR2 ligation was rendered inactive by oxidation. Thus to combat inflammation in the context of bacterial exacerbation we sought to discover effective strategies that bypassed this road-block. We show for the first time that known (FTY720) and novel (theophylline) activators of the phosphatase PP2A can serve as non-steroidal anti-inflammatory alternatives and/or corticosteroid-sparing approaches in respiratory inflammation where corticosteroid insensitivity exists.

© BirdLife Australia 2016.Saemangeum, in the Republic of Korea (ROK, commonly called South Korea) was one of the most important shorebird staging sites in the Yellow Sea. It supported at least 330000 shorebirds annually between 1997 and 2001, including ~30% of the world population of Great Knots (Calidris tenuirostris) during both northward and southward migration. Construction of a 33-km long sea-wall was completed in April 2006. We show that shorebird numbers at Saemangeum and two adjacent wetlands decreased by 130000 during northward migration in the next two years and that all species have declined at Saemangeum since completion of the sea-wall. Great Knots were among the most rapidly affected species. Fewer than 5000 shorebirds were recorded at Saemangeum during northward migration in 2014. We found no evidence to suggest that most shorebirds of any species displaced from Saemangeum successfully relocated to other sites in the ROK. Instead, by 2011-13 nearly all species had declined substantially in the ROK since previous national surveys in 1998 and 2008, especially at more heavily reclaimed sites. It is likely that these declines were driven by increased mortality rather than movement to alternate staging sites given that other studies have shown concurrent declines in numbers and survival on the non-breeding grounds. This is the first study in the East Asian-Australasian Flyway to confirm declines of shorebirds at a range of geographical scales following a single reclamation project. The results indicate that if migratory shorebirds are displaced from major staging sites by reclamation they are probably unable to relocate successfully to alternate sites.

© 2014 Elsevier Ireland Ltd.Pregnancy provides a unique challenge for maternal immunity, requiring the ability to tolerate the presence of a semi-allogeneic foetus, and yet still being capable of inducing an immune response against invading pathogens. To achieve this, numerous changes must occur in the activity and function of maternal immune cells throughout the course of pregnancy. Respiratory viruses take advantage of these changes, altering the sensitive balance of maternal immunity, leaving the mother with increased susceptibility to viral infections and increased disease severity. Influenza virus is one of the most common respiratory virus infections during pregnancy, leading to an increased risk of ICU hospitalisations, pneumonia, acute respiratory distress syndrome and even death. Whilst much research has been performed to understand the changes that must take place in maternal immunity during pregnancy, considerable work is still needed to fully comprehend this tremendous feat. To date, few studies have focused on the alterations that occur in maternal immunity during respiratory virus infections. This review highlights the role of dendritic cells (DCs) and CD8 T cells during pregnancy, and the changes that occur in these antiviral cells following influenza virus infections.

© 2014.The immune and nociceptive systems are shaped during the neonatal period where they undergo fine-tuning and maturation. Painful experiences during this sensitive period of development are known to produce long-lasting effects on the immune and nociceptive responses. It is less clear, however, whether inflammatory pain responses are primed by neonatal exposure to mild immunological stimuli, such as with lipopolysaccharide (LPS). Here, we examine the impact of neonatal LPS exposure on inflammatory pain responses, peripheral and hippocampal interleukin-1ß (IL-1ß), as well as mast cell number and degranulation in preadolescent and adult rats. Wistar rats were injected with LPS (0.05 mg/kg IP, Salmonella enteritidis) or saline on postnatal days (PNDs) 3 and 5 and later subjected to the formalin test at PNDs 22 and 80-97. At both time-points, and one-hour after formalin injection, blood and hippocampus were collected for measuring circulating and central IL-1ß levels using ELISA and Western blot, respectively. Paw tissue was also isolated to assess mast cell number and degree of degranulation using Toluidine Blue staining. Behavioural analyses indicate that at PND 22, LPS-challenged rats displayed enhanced flinching (p<.01) and licking (p<.01) in response to formalin injection. At PNDs 80-97, LPS-challenged rats exhibited increased flinching (p<.05), an effect observed in males only. Furthermore, neonatal LPS exposure enhanced circulating IL-1ß and mast cell degranulation in preadolescent but not adult rats following formalin injection. Hippocampal IL-1ß levels were increased in LPS-treated adult but not preadolescent rats in response to formalin injection. These data suggest neonatal LPS exposure produces developmentally regulated changes in formalin-induced behavioural responses, peripheral and central IL-1ß levels, as well as mast cell degranulation following noxious stimulation later in life. These findings highlight the importance of immune activation during the neonatal period in shaping immune response and pain sensitivity later in life. This is of clinical relevance given the high prevalence of bacterial infection during the neonatal period, particularly in the vulnerable population of preterm infants admitted to neonatal intensive care units.

© 2015 Elsevier Ltd.The epithelium of asthmatics is characterized by reduced expression of E-cadherin and increased expression of the basal cell markers ck-5 and p63 that is indicative of a relatively undifferentiated repairing epithelium. This phenotype correlates with increased proliferation, compromised wound healing and an enhanced capacity to undergo epithelial-mesenchymal transition (EMT). The transcription factor ß-catenin plays a vital role in epithelial cell differentiation and regeneration, depending on the co-factor recruited. Transcriptional programs driven by the ß-catenin/CBP axis are critical for maintaining an undifferentiated and proliferative state, whereas the ß-catenin/p300 axis is associated with cell differentiation. We hypothesized that disrupting the ß-catenin/CBP signaling axis would promote epithelial differentiation and inhibit EMT. We treated monolayer cultures of human airway epithelial cells with TGFß1 in the presence or absence of the selective small molecule ICG-001 to inhibit ß-catenin/CBP signaling. We used western blots to assess expression of an EMT signature, CBP, p300, ß-catenin, fibronectin and ITGß1 and scratch wound assays to assess epithelial cell migration. Snai-1 and -2 expressions were determined using q-PCR. Exposure to TGFß1 induced EMT, characterized by reduced E-cadherin expression with increased expression of a-smooth muscle actin and EDA-fibronectin. Either co-treatment or therapeutic administration of ICG-001 completely inhibited TGFß1-induced EMT. ICG-001 also reduced the expression of ck-5 and -19 independent of TGFß1. Exposure to ICG-001 significantly inhibited epithelial cell proliferation and migration, coincident with a down regulation of ITGß1 and fibronectin expression. These data support our hypothesis that modulating the ß-catenin/CBP signaling axis plays a key role in epithelial plasticity and function.

Copyright © 2015 by the American Thoracic Society.Rationale: Chronic obstructive pulmonary disease (COPD) and influenza virus infections are major global health issues. Patients with COPD are more susceptible to infection, which exacerbates their condition and increases morbidity and mortality. The mechanisms of increased susceptibility remain poorly understood, and current preventions and treatments have substantial limitations. Objectives: To characterize the mechanisms of increased susceptibility to influenza virus infection in COPD and the potential for therapeutic targeting. Methods: We used a combination of primary bronchial epithelial cells (pBECs) from COPD and healthy control subjects, a mouse model of cigarette smoke-induced experimental COPD, and influenza infection. The role of the phosphoinositide-3-kinase (PI3K) pathway was characterized using molecular methods, and its potential for targeting assessed using inhibitors. Measurements and Main Results: COPDpBECs were susceptible to increased viral entry and replication. Infected mice with experimental COPD also had more severe infection (increased viral titer and pulmonary inflammation, and compromised lung function). These processes were associated with impaired antiviral immunity, reduced retinoic acid-inducible gene-I, and IFN/cytokine and chemokine responses. Increased PI3K-p110a levels and activity inCOPDpBECs and/or mice were responsible for increased infection and reduced antiviral responses. Global PI3K, specific therapeutic p110a inhibitors, or exogenous IFN-b restored protective antiviral responses, suppressed infection, and improved lung function. Conclusions: The increased susceptibility of individuals with COPD to influenza likely results from impaired antiviral responses, which are mediated by increased PI3K-p110a activity. This pathway may be targeted therapeutically in COPD, or in healthy individuals, during seasonal or pandemic outbreaks to prevent and/or treat influenza.

© 2015 Australian Veterinary Association.Background: Avian influenza viruses (AIVs) are found worldwide in numerous bird species, causing significant disease in gallinaceous poultry and occasionally other species. Surveillance of wild bird reservoirs provides an opportunity to add to the understanding of the epidemiology of AIVs. Methods: This study examined key findings from the National Avian Influenza Wild Bird Surveillance Program over a 5-year period (July 2007-June 2012), the main source of information on AIVs circulating in Australia. Results: The overall proportion of birds that tested positive for influenza A via PCR was 1.9±0.1%, with evidence of widespread exposure of Australian wild birds to most low pathogenic avian influenza (LPAI) subtypes (H1-13, H16). LPAI H5 subtypes were found to be dominant and widespread during this 5-year period. Conclusion: Given Australia's isolation, both geographically and ecologically, it is important for Australia not to assume that the epidemiology of AIV from other geographic regions applies here. Despite all previous highly pathogenic avian influenza outbreaks in Australian poultry being attributed to H7 subtypes, widespread detection of H5 subtypes in wild birds may represent an ongoing risk to the Australian poultry industry.

© 2015 Tolosa et al.Background Pregnancy increases susceptibility to influenza. The placenta releases an immunosuppressive endogenous retroviral protein syncytin-1.We hypothesised that exposure of peripheral monocytes (PBMCs) to syncytin-1 would impair responses to H1N1pdm09 influenza. Methods and Findings Recombinant syncytin-1 was produced. PBMCs from non-pregnant women (n=10) were exposed to H1N1pdm09 in the presence and absence of syncytin-1 and compared to responses of PBMCs from pregnant women (n=12). PBMCs were characterised using flow cytometry, release of interferon (IFN)-a, IFN-¿, IFN-¿, IL-10, IL-2, IL-6 and IL-1ß were measured by cytometric bead array or ELISA. Exposure of PBMCs to H1N1pdm09 resulted in the release of IFN-a, (14,787 pg/mL, 95% CI 7311-22,264 pg/mL) IFN-¿ (1486 pg/mL, 95% CI 756-2216 pg/mL) and IFN-¿ (852 pg/mL, 95% CI 193-1511 pg/mL) after 48 hours. This was significantly impaired in pregnant women (IFN-a; p<0.0001 and IFN-¿; p<0.001). Furthermore, in the presence of syncytin-1, PBMCs demonstrated marked reductions in IFN-a and IFN-¿, while enhanced release of IL-10 as well as IL-6 and IL-1ß. Conclusions Our data indicates that a placental derived protein, syncytin-1 may be responsible for the heightened vulnerability of pregnant women to influenza.

© 2015 Tay et al.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.

© 2015 Dhouib, Pg Othman, Essilfie, Hansbro, Hanson, McEwan and Kappler.Mononuclear molybdenum enzymes of the dimethylsulfoxide (DMSO) reductase family occur exclusively in prokaryotes, and a loss of some these enzymes has been linked to a loss of bacterial virulence in several cases. The MobA protein catalyzes the final step in the synthesis of the molybdenum guanine dinucleotide (MGD) cofactor that is exclusive to enzymes of the DMSO reductase family. MobA has been proposed as a potential target for control of virulence since its inhibition would affect the activities of all molybdoenzymes dependent upon MGD. Here, we have studied the phenotype of a mobA mutant of the host-adapted human pathogen Haemophilus influenzae. H. influenzae causes and contributes to a variety of acute and chronic diseases of the respiratory tract, and several enzymes of the DMSO reductase family are conserved and highly expressed in this bacterium. The mobA mutation caused a significant decrease in the activities of all Mo-enzymes present, and also resulted in a small defect in anaerobic growth. However, we did not detect a defect in in vitro biofilm formation nor in invasion and adherence to human epithelial cells in tissue culture compared to the wild-type. In a murine in vivo model, the mobA mutant showed only a mild attenuation compared to the wild-type. In summary, our data show that MobA is essential for the activities of molybdenum enzymes, but does not appear to affect the fitness of H. influenzae. These results suggest that MobA is unlikely to be a useful target for antimicrobials, at least for the purpose of treating H. influenzae infections.

Wild aquatic birds are recognized as the natural reservoir of avian influenza A viruses (AIV), but across high and low pathogenic AIV strains, scientists have yet to rigorously identify most competent hosts for the various subtypes. We examined 11,870 GenBank records to provide a baseline inventory and insight into patterns of global AIV subtype diversity and richness. Further, we conducted an extensive literature review and communicated directly with scientists to accumulate data from 50 non-overlapping studies and over 250,000 birds to assess the status of historic sampling effort. We then built virus subtype sample-based accumulation curves to better estimate sample size targets that capture a specific percentage of virus subtype richness at seven sampling locations. Our study identifies a sampling methodology that will detect an estimated 75% of circulating virus subtypes from a targeted bird population and outlines future surveillance and research priorities that are needed to explore the influence of host and virus biodiversity on emergence and transmission.

Background: Tumstatin is a segment of the collagen-IV protein that is markedly reduced in the airways of asthmatics. Tumstatin can play an important role in the development of airway remodelling associated with asthma due to its antiangiogenic properties. This study assessed the anti-angiogenic properties of smaller peptides derived from tumstatin, which contain the interface tumstatin uses to interact with the aVb3 integrin. Methods: Primary human lung endothelial cells were exposed to the LF-15, T3 and T7 tumstatin-derived peptides and assessed for cell viability and tube formation in vitro. The impact of the anti-angiogenic properties on airways hyperresponsiveness (AHR) was then examined using a murine model of chronic OVA-induced allergic airways disease. Results: The LF-15 and T7 peptides significantly reduced endothelial cell viability and attenuated tube formation in vitro. Mice exposed to OVA+ LF-15 or OVA+T7 also had reduced total lung vascularity and AHR was attenuated compared to mice exposed to OVA alone. T3 peptides reduced cell viability but had no effect on any other parameters. Conclusion: The LF-15 and T7 peptides may be appropriate candidates for use as novel pharmacotherapies due to their small size and anti-angiogenic properties observed in vitro and in vivo. © 2014 Grafton et al.

Copyright © 2014 by the American College of Rheumatology.Objective The spondyloarthritides share genetic susceptibility, interleukin-23 (IL-23) dependence, and the involvement of microbiota. The aim of the current study was to elucidate how host genetics influence gut microbiota and the relationship between microbiota and organ inflammation in spondyloarthritides.Methods BALB/c ZAP-70W163C-mutant (SKG) mice, Toll-like receptor 4 (TLR-4)-deficient SKG mice, and wild-type BALB/c mice were housed under specific pathogen-free conditions. SKG and wild-type BALB/c mice were maintained under germ-free conditions, and some of these mice were recolonized with altered Schaedler flora. All of the mice were injected intraperitoneally with microbial ß-1,3-glucan (curdlan). Arthritis, spondylitis, and ileitis were assessed histologically. Microbiome composition was analyzed in serial fecal samples obtained from mice that were co-housed beginning at the time of weaning, using 454 pyrosequencing. Infiltrating cells and cytokines in the peritoneal cavity were measured by flow cytometry and enzyme-linked immunosorbent assay. Cytokine, endoplasmic reticulum (ER) stress marker, and tight junction protein transcription was measured by quantitative real-time polymerase chain reaction.Results Microbiota content and response to curdlan varied according to whether T cell receptor signal strength was normal or was impaired due to the ZAP-70W163C mutation. Curdlan triggered acute inflammation regardless of the presence of the SKG allele or microbiota. However, no or limited microbiota content attenuated the severity of arthritis. In contrast, ileal IL-23 expression, ER stress, lymph node IL-17A production, goblet cell loss, and ileitis development were microbiota-dependent. Ileitis but not arthritis was suppressed by microbiota transfer upon co-housing SKG mice with wild-type BALB/c mice, as well as by TLR-4 deficiency.Conclusion The interaction between immunogenetic background and host microbiota leads to an IL-23-dependent loss of mucosal function, triggering ileitis in response to curdlan.

Protease serine member S31 (Prss31)/transmembrane tryptase/tryptase-¿ is a mast cell (MC)-restricted protease of unknown function that is retained on the outer leaflet of the plasma membrane when MCs are activated. We determined the nucleotide sequences of the Prss31 gene in different mouse strains and then used a Cre/loxP homologous recombination approach to create a novel Prss31 -/- C57BL/6 mouse line. The resulting animals exhibited no obvious developmental abnormality, contained normal numbers of granulated MCs in their tissues, and did not compensate for their loss of the membrane tryptase by increasing their expression of other granule proteases. When Prss31-null MCs were activated with a calcium ionophore or by their high affinity IgE receptors, they degranulated in a pattern similar to that of WT MCs. Prss31-null mice had increased baseline airway reactivity to methacholine but markedly reduced experimental chronic obstructive pulmonary disease and colitis, thereby indicating both beneficial and adverse functional roles for the tryptase. In a cigarette smokeinduced model of chronic obstructive pulmonary disease, WT mice had more pulmonary macrophages, higher histopathology scores, and more fibrosis in their small airways than similarly treated Prss31-null mice. In a dextran sodium sulfate-induced acute colitis model, WT mice lost more weight, had higher histopathology scores, and contained more Cxcl-2 and IL-6 mRNA in their colons than similarly treated Prss31-null mice. The accumulated data raise the possibility that inhibitors of this membrane tryptase may provide additional therapeutic benefit in the treatment of humans with these MC-dependent inflammatory diseases. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

© 2014 by The American Association of Immunologists, Inc.The dynamic interplay between regulatory T cells (Tregs) and effector T cells (Teffs) governs the balance between tolerance and effector immune responses. Perturbations of Treg frequency and function or imbalances in Treg/Teff levels are associated with the development of autoimmunity. The factors that mediate these changes remain poorly understood and were investigated in this study in murine autoimmune arthritis. Tregs displayed a stable phenotype in arthritic mice and were fully functional in in vitro suppression assays. However, their expansion was delayed relative to Teffs (T follicular helper cells and Th17 cells) during the early stages of autoimmune reactivity. This imbalance is likely to have led to insufficient Treg control of Teffs and induced autoimmunity. Moreover, a counterregulatory and probably IL-7-driven increase in thymic Treg production and recruitment to inflamed tissues was too slow for disease prevention. Increased Teff over Treg expansion was further aggravated by inflammation and lymphopenia. Both these conditions contribute to autoimmune pathogenesis and were accompanied by decreases in the availability of IL-2 and increases in levels of IL-21. IL-2 neutralization or supplementation was used to show that Treg expansion mainly depended on this cytokine. IL-21R2/2 cells were used to demonstrate that IL-21 promoted the maintenance of Teffs. Thus, at inflammatory sites in experimental arthritis, a deficit in IL-2 hampers Treg proliferation, whereas exaggerated IL-21 levels overwhelm Treg control by supporting Teff expansion. This identifies IL-2 and IL-21 as targets for manipulation in therapies for autoimmunity.

© 2014 The Authors.Introduction: Neutrophil extracellular traps (NETs) have not been demonstrated after trauma and subsequent surgery. Neutrophil extracellular traps are formed from pure mitochondrial DNA (mtDNA) under certain conditions, which is potently proinflammatory. We hypothesized that injury and orthopedic trauma surgery would induce NET production with mtDNA as a structural component. Methods: Neutrophils were isolated 8 trauma patients requiring orthopedic surgery postinjury and up to 5 days postoperatively. Four healthy volunteers provided positive and negative controls. Total hip replacement patients acted as an uninjured surgical control group. Neutrophil extracellular traps were visualized with DNA (Hoechst 33342TM/Sytox Green/MitoSox/MitoTracker) stains using live cell fluorescence microscopy with downstream quantitative polymerase chain reaction analysis of DNA composition. Results: Neutrophil extracellular traps were present after injury in all 8 trauma patients. They persisted for 5 days postoperatively. Delayed surgery resulted in NET resolution, but they reformed postoperatively. Total hip replacement patients developed NETs postoperatively, which resolved by day 5. Quantitative polymerase chain reaction analysis of NET-DNA composition revealed that NETs formed after injury and surgery were made of mtDNA with no detectable nuclear DNA component. Conclusions: Neutrophil extracellular traps formed after major trauma and subsequent surgery contain mtDNA and represent a novel marker of heightened innate immune activation. They could be considered when timing surgery after trauma to prevent systemic NET-induced inflammatory complications.

Tetramer-forming tryptase (hTryptase-ß) was recently discovered to have a prominent role in preventing the internal accumulation of life-threatening fibrin deposits and fibrin-platelet clots. The anticoagulant activity of hTryptase-ß is an explanation for the presence of hemorrhagic disorders in some patients with anaphylaxis or mastocytosis. The fragments of hFibrinogen formed by the proteolysis of this prominent protein by hTryptase-ß could be used as biomarkers in the blood and/or urine for the identification and monitoring of patients with mast cell-dependent disorders. Recombinant hTryptase-ß has potential to be used in clinical settings where it is desirable to inhibit blood coagulation. © 2014 Elsevier Inc.

Recent genetic, structural and functional studies have identified the airway and lung epithelium as a key orchestrator of the immune response. Further, there is now strong evidence that epithelium dysfunction is involved in the development of inflammatory disorders of the lung. Here we review the characteristic immune responses that are orchestrated by the epithelium in response to diverse triggers such as pollutants, cigarette smoke, bacterial peptides, and viruses. We focus in part on the role of epithelium-derived interleukin (IL)-25, IL-33 and thymic stromal lymphopoietin (TSLP), as well as CC family chemokines as critical regulators of the immune response. We cite examples of the function of the epithelium in host defense and the role of epithelium dysfunction in the development of inflammatory diseases. © 2013 Elsevier Inc.

Background and objective Airway epithelial cells represent the first line of defence against inhaled insults, including air pollution. Air pollution can activate innate immune signalling in airway epithelial cells leading to the production of soluble mediators that can influence downstream inflammatory cells. Our objective was to develop and validate a model of dendritic cell exposure to airway epithelial cell-conditioned media. After establishing the model, we explored how soluble mediators released from airway epithelial cells in response to air pollution influenced the phenotype of dendritic cells. Methods Human airway epithelial cells were cultured under control and urban particulate matter (PM10) exposure conditions with or without pharmacological inhibitors of the uric acid pathway. Culture supernatants were collected for conditioned media experiments with peripheral blood mononuclear cell-derived dendritic cells analysed by flow cytometry. Results Monocytes derived from peripheral blood mononuclear cells cultured in interleukin-4 and granulocyte macrophage colony stimulating factor differentiated into immature dendritic cells that phenotypically differentiated into mature dendritic cells in response to conditioned media from phorbol myristate acetate-activated THP-1 monocytes. Exposure of immature dendritic cells to conditioned media from airway epithelial cells exposed to PM10 resulted in dendritic cell maturation that was independent of uric acid. Conclusions We present a conditioned media model useful for interrogating the contribution of soluble mediators produced by airway epithelial cells to dendritic cell phenotype and function. Furthermore, we demonstrate that PM10 exposure induces airway epithelial cell production of soluble mediators that induce maturation of dendritic cells independent of uric acid. We developed and validated a model of airway epithelial cell conditioned media exposure to primary human dendritic cells. Using this model, we then tested the hypothesis that urban particulate matter exposure to airway epithelial cells resulted in production of soluble mediators capable of inducing dendritic cell maturation. © 2014 Asian Pacific Society of Respirology.

Introduction: Chronic obstructive pulmonary disease (COPD) is a leading global cause of mortality and chronic morbidity. Inhalation of cigarette smoke is the principal risk factor for development of this disease. COPD is a progressive disease that is typically characterised by chronic pulmonary inflammation, mucus hypersecretion, airway remodelling and emphysema that collectively reduce lung function. There are currently no therapies that effectively halt or reverse disease progression. It is hoped that the development of animal models that develop the hallmark features of COPD, in a short time frame, will aid in the identifying and testing of new therapeutic approaches. Areas covered: The authors review the recent developments in mouse models of chronic cigarette smoke-induced COPD as well as the principal findings. Furthermore, the authors discuss the use of mouse models to understand the pathogenesis and the contribution of infectious exacerbations. They also discuss the investigations of the systemic co-morbidities of COPD (pulmonary hypertension, cachexia and osteoporosis). Expert opinion: Recent advances in the field mark a point where animal models recapitulate the pathologies of COPD patients in a short time frame. They also reveal novel insights into the pathogenesis and potential treatment of this debilitating disease. © 2014 Informa UK, Ltd.

Preterm infants who receive supplemental oxygen for prolonged periods are at increased risk of impaired lung function later in life. This suggests that neonatal hyperoxia induces persistent changes in small conducting airways (bronchioles). Although the effects of neonatal hyperoxia on alveolarization are well documented, little is known about its effects on developing bronchioles. We hypothesized that neonatal hyperoxia would remodel the bronchiolar walls, contributing to altered lung function in adulthood. We studied three groups of mice (C57BL/6J) to postnatal day 56 (P56; adulthood) when they either underwent lung function testing or necropsy for histological analysis of the bronchiolar wall. One group inhaled 65% O2 from birth until P7, after which they breathed room air; this group experienced growth restriction (HE+GR group). We also used a group in which hyperoxia-induced GR was prevented by dam rotation (HE group). A control group inhaled room air from birth. At P56, the bronchiolar epithelium of HE mice contained fewer Clara cells and more ciliated cells, and the bronchiolar wall contained ~25% less collagen than controls; in HE+GR mice the bronchiolar walls had ~13% more collagen than controls. Male HE and HE+GR mice had significantly thicker bronchiolar epithelium than control males and altered lung function (HE males: greater dynamic compliance; HE+GR males: lower dynamic compliance). We conclude that neonatal hyperoxia remodels the bronchiolar wall and, in adult males, affects lung function, but effects are altered by concomitant growth restriction. Our findings may partly explain the reports of poor lung function in ex-preterm children and adults. Anat Rec, 297:758-769, 2014. © 2014 Wiley Periodicals, Inc.

Pharmacological stabilization of hypoxia-inducible factor (HIF) through prolyl hydroxylase (PHD) inhibition limits mucosal damage associated with models of murine colitis. However, little is known about how PHD inhibitors (PHDi) influence systemic immune function during mucosal inflammation or the relative importance of immunological changes to mucosal protection. We hypothesized that PHDi enhances systemic innate immune responses to colitis-associated bacteremia. Mice with colitis induced by trinitrobenzene sulfonic acid were treated with AKB-4924, a new HIF-1 isoform-predominant PHDi, and clinical, immunological, and biochemical endpoints were assessed. Administration of AKB-4924 led to significantly reduced weight loss and disease activity compared with vehicle controls. Treated groups were pyrexic but did not become subsequently hypothermic. PHDi treatment augmented epithelial barrier function and led to an approximately 50-fold reduction in serum endotoxin during colitis. AKB-4924 also decreased cytokines involved in pyrogenesis and hypothermia, significantly reducing serum levels of interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-a while increasing IL-10. Treatment offered no protection against colitis in epithelial-specific HIF-1a-deficient mice, strongly implicating epithelial HIF-1a as the tissue target for AKB-4924-mediated protection. Taken together, these results indicate that inhibition of prolyl hydroxylase with AKB-4924 enhances innate immunity and identifies that the epithelium is a central site of inflammatory protection afforded by PHDi in murine colitis. © 2014 Society for Mucosal Immunology.

© 2014 American Thoracic Society.The pathogenesis of chronic obstructive pulmonary disease (COPD) and its exacerbations, are intricately linked to colonisation and infection with bacteria and other microbes. Despite their undeniable importance, we have a poor understanding of the complex relationships between COPD phenotypes, physiology, cellular and molecular biology and the roles of colonising microbe or infecting pathogens. The management algorithms for the care of patients with COPD that include microbial influences, have almost exclusively been developed using microbial methods that were entirely dependent on the ability to grow bacteria on suitable media. The shortcomings of this approach are becoming clear now that it is possible to completely and accurately define the microbial ecology of ecosystems using genomic methods, which do not rely on the ability to cultivate the organisms present. Whilst our appreciation of the relationships between some bacterial ecosystems and the organ in which they reside in humans is now relatively advanced, this is not true for lung. This perspective serves to highlight the growing importance of including an accurate description of bacterial ecology in any attempt to decipher the pathobiology of COPD. While this field is in its infancy, there is significant potential to gain new insights which will translate into more rational and effective treatment algorithms for patients with COPD.

Copyright © 2014 by the American Thoracic SocietyAsthma affects 10% of the population in Westernized countries, being most common in children. It is a heterogeneous condition characterized by chronic allergic airway inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR) to normally innocuous antigens. Combination therapies with inhaled corticosteroids and bronchodilators effectively manage mild to moderate asthma, but there are no cures, and patients with severe asthma do not respond to these treatments. The inception of asthma is linked to respiratory viral (respiratory syncytial virus, rhinovirus) and bacterial (Chlamydia, Mycoplasma) infections. The examination of mouse models of early-life infections and allergic airway disease (AAD) provides valuable insights into the mechanisms of disease inception that may lead to the development of more effective therapeutics. For example, early-life, but not adult, Chlamydia respiratory infections in mice permanently modify immunity and lung physiology. This increases the severity of AAD by promoting IL-13 expression, mucus hypersecretion, and AHR. We have identified novel roles for tumor necrosis factor-related apoptosisinducing ligand (TRAIL) and IL-13 in promoting infection-induced pathology in early life and subsequent chronic lung disease. Genetic deletion of TRAIL or IL-13 variously protected against neonatal infection-induced inflammation, mucus hypersecretion, altered lung structure, AHR, and impaired lung function. Therapeutic neutralization of these factors prevented infection-induced severe AAD. Other novel mechanisms and avenues for intervention are also being explored. Such studies indicate the immunological mechanisms that may underpin the association between early-life respiratory infections and the development of more severe asthma and may facilitate the development of tailored preventions and treatments.