Rhinovirus-induced CCL17 and CCL22 in Asthma Exacerbations and Differential Regulation by STAT6

The interplay of type-2 inflammation and antiviral immunity underpins asthma exacerbation pathogenesis. Virus infection induces type-2 inflammation-promoting chemokines CCL17 and CCL22 in asthma; however, mechanisms regulating induction are poorly understood. By using a human rhinovirus (RV) challenge model in human airway epithelial cells in vitro and mice in vivo, we assessed mechanisms regulating CCL17 and CCL22 expression. Subjects with mild to moderate asthma and healthy volunteers were experimentally infected with RV and airway CCL17 and CCL22 protein quantified. In vitro airway epithelial cell- and mouse-RV infection models were then used to define STAT6- and NF-κB-mediated regulation of CCL17 and CCL22 expression. Following RV infection, CCL17 and CCL22 expression was higher in asthma, which differentially correlated with clinical and immunological parameters. Air-liquid interface-differentiated primary epithelial cells from donors with asthma also expressed higher levels of RV-induced CCL22. RV infection boosted type-2 cytokine-induced STAT6 activation. In epithelial cells, type-2 cytokines and STAT6 activation had differential effects on chemokine expression, increasing CCL17 and suppressing CCL22, whereas NF-κB promoted expression of both chemokines. In mice, RV infection activated pulmonary STAT6, which was required for CCL17 but not CCL22 expression. STAT6-knockout mice infected with RV expressed increased levels of NF-κB-regulated chemokines, which was associated with rapid viral clearance. Therefore, RV-induced upregulation of CCL17 and CCL22 was mediated by NF-κB activation, whereas expression was differentially regulated by STAT6. Together, these findings suggest that therapeutic targeting of type-2 STAT6 activation alone will not block all inflammatory pathways during RV infection in asthma.

Development and evaluation of a novel pre-operative surgery school and behavioural change intervention for patients undergoing elective major surgery: Fit-4-Surgery School

Group pre-operative education has usually been limited to conditioning expectations and providing education. Prehabilitation has highlighted modifiable lifestyle factors that are amenable to change and may improve clinical outcomes. We instituted a pre-operative 'Fit-4-Surgery School' for patients scheduled for major surgery, to educate and promote healthy behaviour. We evaluated patients' views having attended the school, and after surgery we asked how it had changed their behaviour with a lifestyle questionnaire. The school was launched in May 2016 and was attended by 586/1017 (58%) of invited patients. Patients who did not attend: lived further away, median (IQR [range]) 8 (4-19 [0-123]) miles vs. 5 (3-14 [0-172]) miles, p < 0.001; and were more deprived, Index of Multiple Deprivation Rank decile median (IQR [range]), 6 (4-8 [1-10]) vs. 7 (4-9 [1-10]), p = 0.04. Of the 492/586 (84%) participants who completed an evaluation questionnaire, 462 (94%) would recommend the school to a friend having surgery and 296 (60%) planned lifestyle changes. After surgery, 232/586 (40%) completed a behavioural change questionnaire, 106 (46%) of whom reported changing at least one lifestyle factor, most commonly by increasing exercise. The pre-operative school was acceptable to patients.

Profiling of H3K27Ac Reveals the Influence of Asthma on the Epigenome of the Airway Epithelium

Background

Asthma is a chronic airway disease driven by complex genetic–environmental interactions. The role of epigenetic modifications in bronchial epithelial cells (BECs) in asthma is poorly understood.

Methods

We piloted genome-wide profiling of the enhancer-associated histone modification H3K27ac in BECs from people with asthma (n = 4) and healthy controls (n = 3).

Results

We identified n = 4,321 (FDR < 0.05) regions exhibiting differential H3K27ac enrichment between asthma and health, clustering at genes associated predominately with epithelial processes (EMT). We identified initial evidence of asthma-associated Super-Enhancers encompassing genes encoding transcription factors (TP63) and enzymes regulating lipid metabolism (PTGS1). We integrated published datasets to identify epithelium-specific transcription factors associated with H3K27ac in asthma (TP73) and identify initial relationships between asthma-associated changes in H3K27ac and transcriptional profiles. Finally, we investigated the potential of CRISPR-based approaches to functionally evaluate H3K27ac-asthma landscape in vitro by identifying guide-RNAs capable of targeting acetylation to asthma DERs and inducing gene expression (TLR3).

Conclusion

Our small pilot study validates genome-wide approaches for deciphering epigenetic mechanisms underlying asthma pathogenesis in the airways.

A multi-terawatt two-color beam for high-power field-controlled nonlinear optics

Two-color laser beams are instrumental in light-field control and enhancement of high-order harmonic, spectral supercontinuum, and terahertz radiation generated in gases, plasmas, and solids. We demonstrate a multi-terawatt two-color beam produced using a relativistic plasma mirror, with 110 mJ at 800 nm and 30 mJ at 400 nm. Both color components have high spatial quality and can be simultaneously focused, provided that the plasma mirror lies within a Rayleigh range of the driving fundamental beam. Favorable scaling of second-harmonic generation by plasma mirrors at relativistic intensities suggests them as an excellent tool for multi-color waveform synthesis beyond the petawatt level.

Gut Microbiota and Bacterial DNA Suppress Autoimmunity by Stimulating Regulatory B Cells in a Murine Model of Lupus

Autoimmune diseases, such as systemic lupus erythematosus, are characterized by excessive inflammation in response to self-antigens. Loss of appropriate immunoregulatory mechanisms contribute to disease exacerbation. We previously showed the suppressive effect of vancomycin treatment during the "active-disease" stage of lupus. In this study, we sought to understand the effect of the same treatment given before disease onset. To develop a model in which to test the regulatory role of the gut microbiota in modifying autoimmunity, we treated lupus-prone mice with vancomycin in the period before disease development (3-8 weeks of age). We found that administration of vancomycin to female MRL/lpr mice early, only during the pre-disease period but not from 3 to 15 weeks of age, led to disease exacerbation. Early vancomycin administration also reduced splenic regulatory B (Breg) cell numbers, as well as reduced circulating IL-10 and IL-35 in 8-week old mice. Further, we found that during the pre-disease period, administration of activated IL-10 producing Breg cells to mice treated with vancomycin suppressed lupus initiation, and that bacterial DNA from the gut microbiota was an inducer of Breg function. Oral gavage of bacterial DNA to mice treated with vancomycin increased Breg cells in the spleen and mesenteric lymph node at 8 weeks of age and reduced autoimmune disease severity at 15 weeks. This work suggests that a form of oral tolerance induced by bacterial DNA-mediated expansion of Breg cells suppress disease onset in the autoimmune-prone MRL/lpr mouse model. Future studies are warranted to further define the mechanism behind bacterial DNA promoting Breg cells.

Inhaled corticosteroid suppression of cathelicidin drives dysbiosis and bacterial infection in chronic obstructive pulmonary disease

Bacterial infection commonly complicates inflammatory airway diseases such as chronic obstructive pulmonary disease (COPD). The mechanisms of increased infection susceptibility and how use of the commonly prescribed therapy inhaled corticosteroids (ICS) accentuates pneumonia risk in COPD are poorly understood. Here, using analysis of samples from patients with COPD, we show that ICS use is associated with lung microbiota disruption leading to proliferation of streptococcal genera, an effect that could be recapitulated in ICS-treated mice. To study mechanisms underlying this effect, we used cellular and mouse models of streptococcal expansion with Streptococcus pneumoniae, an important pathogen in COPD, to demonstrate that ICS impairs pulmonary clearance of bacteria through suppression of the antimicrobial peptide cathelicidin. ICS impairment of pulmonary immunity was dependent on suppression of cathelicidin because ICS had no effect on bacterial loads in mice lacking cathelicidin (Camp ^-/-) and exogenous cathelicidin prevented ICS-mediated expansion of streptococci within the microbiota and improved bacterial clearance. Suppression of pulmonary immunity by ICS was mediated by augmentation of the protease cathepsin D. Collectively, these data suggest a central role for cathepsin D/cathelicidin in the suppression of antibacterial host defense by ICS in COPD. Therapeutic restoration of cathelicidin to boost antibacterial immunity and beneficially modulate the lung microbiota might be an effective strategy in COPD.

Low-dose 17α-ethinyl estradiol (EE) exposure exacerbates lupus renal disease and modulates immune responses to TLR7/9 agonists in genetically autoimmune-prone mice

Estrogens have been shown to regulate the immune system and modulate multiple autoimmune diseases. 17α-ethinyl estradiol (EE), a synthetic analog of 17β-estradiol, is prescribed commonly and found in oral contraceptives and hormone replacement therapies. Surprisingly, few studies have investigated the immunoregulatory effects of exposure to EE, especially in autoimmunity. In this study, we exposed autoimmune-prone female MRL/lpr mice to a human-relevant dose of EE through the oral route of exposure. Since lupus patients are prone to infections, groups of mice were injected with viral (Imiquimod, a TLR7 agonist) or bacterial (ODN 2395, a TLR9 agonist) surrogates. We then evaluated autoimmune disease parameters, kidney disease, and response to in vivo TLR7/9 pathogenic signals. EE-exposed mice had increased proteinuria as early as 7 weeks of age. Proteinuria, blood urea nitrogen, and glomerular immune complex deposition were also exacerbated when compared to controls. Production of cytokines by splenic leukocytes were altered in EE-exposed mice. Our study shows that oral exposure to EE, even at a very low dose, can exacerbate azotemia, increase clinical markers of renal disease, enhance glomerular immune complex deposition, and modulate TLR7/9 cytokine production in female MRL/lpr mice. This study may have implications for EE-exposure risk for genetically lupus-prone individuals.

Human Rhinovirus Impairs the Innate Immune Response to Bacteria in Alveolar Macrophages in Chronic Obstructive Pulmonary Disease

Rationale: Human rhinovirus (HRV) is a common cause of chronic obstructive pulmonary disease (COPD) exacerbations. Secondary bacterial infection is associated with more severe symptoms and delayed recovery. Alveolar macrophages clear bacteria from the lung and maintain lung homeostasis through cytokine secretion. These processes are defective in COPD. The effect of HRV on macrophage function is unknown. Objectives: To investigate the effect of HRV on phagocytosis and cytokine response to bacteria by alveolar macrophages and monocyte-derived macrophages (MDM) in COPD and healthy control subjects. Methods: Alveolar macrophages were obtained by bronchoscopy and MDM by adherence. Macrophages were exposed to HRV16 (multiplicity of infection 5), polyinosinic:polycytidylic acid (poly I:C) 30 μg/ml, IFN-β 10 μg/ml, IFN-γ 10 μg/ml, or medium control for 24 hours. Phagocytosis of fluorescently labeled Haemophilus influenzae or Streptococcus pneumoniae was assessed by fluorimetry. CXCL8 (IL-8), IL-6, TNF-α (tumor necrosis factor-α), and IL-10 release was measured by ELISA. Measurements and Main Results: HRV significantly impaired phagocytosis of H. influenzae by 23% in MDM (n = 37; P = 0.004) and 18% in alveolar macrophages (n = 20; P < 0.0001) in COPD. HRV also significantly reduced phagocytosis of S. pneumoniae by 33% in COPD MDM (n = 20; P = 0.0192). There was no effect in healthy control subjects. Phagocytosis of H. influenzae was also impaired by poly I:C but not IFN-β or IFN-γ in COPD MDM. HRV significantly reduced cytokine responses to H. influenzae. The IL-10 response to H. influenzae was significantly impaired by poly I:C, IFN-β, and IFN-γ in COPD cells. Conclusions: HRV impairs phagocytosis of bacteria in COPD, which may lead to an outgrowth of bacteria. HRV also impairs cytokine responses to bacteria via the TLR3/IFN pathway, which may prevent resolution of inflammation leading to prolonged exacerbations in COPD.

Airway Epithelial Cells Generate Pro-inflammatory Tenascin-C and Small Extracellular Vesicles in Response to TLR3 Stimuli and Rhinovirus Infection

Viral infections are a common cause of asthma exacerbations, with human rhinoviruses (RV) the most common trigger. RV signals through a number of different receptors, including toll-like receptor (TLR)3. Tenascin-C (TN-C) is an immunomodulatory extracellular matrix protein present in high quantities in the airway of people with asthma, and expression is also upregulated in nasal lavage fluid in response to RV infection. Respiratory viral infection has been demonstrated to induce the release of small extracellular vesicles (sEV) such as exosomes, whilst exosomal cargo can also be modified in the bronchoalveolar lavage fluid of people with asthma. These sEVs may potentiate airway inflammation and regulate the immune response to infection. This study characterizes the relationship between RV infection of bronchial epithelial cells and the release of TN-C, and the release of sEVs following stimulation with the TLR3 agonist and synthetic viral mimic, poly(I:C), as well as the function of the released protein/vesicles. The BEAS-2B airway epithelial cell line and primary human bronchial epithelial cells (PBECs) from asthmatic and non-asthmatic donors were infected with RV or treated with poly(I:C). TN-C expression, release and localization to sEVs was quantified. TN-C expression was also assessed following intra-nasal challenge of C57BL/6 mice with poly(I:C). BEAS-2B cells and macrophages were subsequently challenged with TN-C, or with sEVs generated from BEAS-2B cells pre-treated with siRNA targeted to TN-C or control. The results revealed that poly(I:C) stimulation induced TN-C release in vivo, whilst both poly(I:C) stimulation and RV infection promoted release in vitro, with elevated TN-C release from PBECs obtained from people with asthma. Poly(I:C) also induced the release of TN-C-rich sEVs from BEAS-2B cells. TN-C, and sEVs from poly(I:C) challenged cells, induced cytokine synthesis in macrophages and BEAS-2B cells, whilst sEVs from control cells did not. Moreover, sEVs with ~75% reduced TN-C content did not alter the capacity of sEVs to induce inflammation. This study identifies two novel components of the inflammatory pathway that regulates the immune response following RV infection and TLR3 stimulation, highlighting TN-C release and pro-inflammatory sEVs in the airway as relevant to the biology of virally induced exacerbations of asthma.

Cytokine Responses to Rhinovirus and Development of Asthma, Allergic Sensitization, and Respiratory Infections during Childhood

RATIONALE

Immunophenotypes of antiviral responses, and their relationship with asthma, allergy, and lower respiratory tract infections, are poorly understood.

OBJECTIVES

We characterized multiple cytokine responses of peripheral blood mononuclear cells to rhinovirus stimulation, and their relationship with clinical outcomes.

METHODS

In a population-based birth cohort, we measured 28 cytokines after stimulation with rhinovirus-16 in 307 children aged 11 years. We used machine learning to identify patterns of cytokine responses, and related these patterns to clinical outcomes, using longitudinal models. We also ascertained phytohemagglutinin-induced T-helper cell type 2 (Th2)-cytokine responses (PHA-Th2).

MEASUREMENTS AND MAIN RESULTS

We identified six clusters of children based on their rhinovirus-16 responses, which were differentiated by the expression of four cytokine/chemokine groups: interferon-related (IFN), proinflammatory (Inflam), Th2-chemokine (Th2-chem), and regulatory (Reg). Clusters differed in their clinical characteristics. Children with an IFN^modInflam^highestTh2-chem^highestReg^highest rhinovirus-16-induced pattern had a PHA-Th2^low response, and a very low asthma risk (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.01-0.81; P = 0.03). Two clusters had a high risk of asthma and allergic sensitization, but with different trajectories from infancy to adolescence. The IFN^lowestInflam^highTh2-chem^lowReg^mod cluster exhibited a PHA-Th2^lowest response and was associated with early-onset asthma and sensitization, and the highest risk of asthma exacerbations (OR, 1.37; 95% CI, 1.07-1.76; P = 0.014) and lower respiratory tract infection hospitalizations (OR, 2.40; 95% CI, 1.26-4.58; P = 0.008) throughout childhood. In contrast, the IFN^highestInflam^modTh2-chem^modReg^high cluster with a rhinovirus-16-cytokine pattern was characterized by a PHA-Th2^highest response, and a low prevalence of asthma/sensitization in infancy that increased sharply to become the highest among all clusters by adolescence (but with a low risk of asthma exacerbations).

CONCLUSIONS

Early-onset troublesome asthma with early-life sensitization, later-onset milder allergic asthma, and disease protection are each associated with different patterns of rhinovirus-induced immune responses.

Bronchial mucosal IFN-α/β and pattern recognition receptor expression in patients with experimental rhinovirus-induced asthma exacerbations

BACKGROUND

The innate immune system senses viral infection through pattern recognition receptors (PRRs), leading to type I interferon production. The role of type I interferon and PPRs in rhinovirus-induced asthma exacerbations in vivo are uncertain.

OBJECTIVES

We sought to compare bronchial mucosal type I interferon and PRR expression at baseline and after rhinovirus infection in atopic asthmatic patients and control subjects.

METHODS

Immunohistochemistry was used to detect expression of IFN-α, IFN-β, and the PRRs: Toll-like receptor 3, melanoma differentiation-associated gene 5, and retinoic acid-inducible protein I in bronchial biopsy specimens from 10 atopic asthmatic patients and 15 nonasthmatic nonatopic control subjects at baseline and on day 4 and 6 weeks after rhinovirus infection.

RESULTS

We observed IFN-α/β deficiency in the bronchial epithelium at 3 time points in asthmatic patients in vivo. Lower epithelial IFN-α/β expression was related to greater viral load, worse airway symptoms, airway hyperresponsiveness, and reductions in lung function during rhinovirus infection. We found lower frequencies of bronchial subepithelial monocytes/macrophages expressing IFN-α/β in asthmatic patients during infection. Interferon deficiency at baseline was not accompanied by deficient PRR expression in asthmatic patients. Both epithelial and subepithelial PRR expression were induced during rhinovirus infection. Rhinovirus infection-increased numbers of subepithelial interferon/PRR-expressing inflammatory cells were related to greater viral load, airway hyperresponsiveness, and reductions in lung function.

CONCLUSIONS

Bronchial epithelial IFN-α/β expression and numbers of subepithelial IFN-α/β-expressing monocytes/macrophages during infection were both deficient in asthmatic patients. Lower epithelial IFN-α/β expression was associated with adverse clinical outcomes after rhinovirus infection in vivo. Increases in numbers of subepithelial cells expressing interferon/PRRs during infection were also related to greater viral load/illness severity.

17β-Estradiol and 17α-Ethinyl Estradiol Exhibit Immunologic and Epigenetic Regulatory Effects in NZB/WF1 Female Mice

17α-Ethinyl estradiol (EE), a synthetic analog of natural estrogen 17β-estradiol (E2), is extensively used in hormonal contraceptives and estrogen replacement therapy, and it has also been found in sewage effluents. Given that E2 is a well-known immunomodulator, surprisingly there has been only limited information on the cellular and molecular immunologic consequences of exposure to EE. To address this fundamental gap, we directly compared the effects of EE with E2 on splenic leukocytes of New Zealand Black × New Zealand White F1 progeny (NZB/WF1) mice during the preautoimmune period. We found that EE and E2 have common, as well as distinctive, immunologic effects, with EE exposure resulting in more profound effects. Both EE and E2 increased numbers of splenic neutrophils, enhanced neutrophil serine proteases and myeloperoxidase expression, promoted the production of nitric oxide and monocyte chemoattractant protein-1, and altered adaptive immune T cell subsets. However, activation of splenic leukocytes through the T cell receptor or Toll-like receptor (TLR)4 revealed not only common (IL-10), but also hormone-specific alterations of cytokines (IFNγ, IL-1β, ΤΝFα, IL-2). Furthermore, in EE-exposed mice, TLR9 stimulation suppressed IFNα, in contrast to increased IFNα from E2-exposed mice. EE and E2 regulated common and hormone-specific expression of immune-related genes. Furthermore, EE exposure resulted in more marked alterations in miRNA expression levels than for E2. Only EE was able to reduce global DNA methylation significantly in splenic leukocytes. Taken together, our novel data revealed that EE and E2 exposure confers more similar effects in innate immune system-related cell development and responses, but has more differential regulatory effects in adaptive immune-related cell development and responses.

Effect of Bismuth Subsalicylate on Gastrointestinal Tolerability in Healthy Volunteers Receiving Oral Delayed-release Dimethyl Fumarate: PREVENT, a Randomized, Multicenter, Double-blind, Placebo-controlled Study

PURPOSE

Flushing and gastrointestinal (GI) events are commonly associated with the use of delayed-release dimethyl fumarate (DMF) treatment for relapsing multiple sclerosis.

METHODS

PREVENT (A Multicenter, Double-Blind, Placebo-Controlled Study of Pepto-Bismol [Bismuth Subsalicylate] on Gastrointestinal Tolerability in Healthy Volunteers Receiving Oral TECFIDERA [Dimethyl Fumarate] Delayed-Release Capsules Twice Daily) is a double-blind, placebo-controlled, 8-week study that evaluated the effect of bismuth subsalicylate on DMF-related GI events. Bismuth subsalicylate 524 mg or placebo were administered 30 min before DMF (weeks 1-4). DMF was dosed twice-daily (BID) at 120 mg (week 1) and 240 mg (weeks 2-8). Using an e-diary device, participants recorded GI and flushing events on the Modified Overall Gastrointestinal Symptom Scale once daily for the preceding 24 h. The primary end point was time to first GI-related event. Secondary end points included frequency and severity of GI-related events.

FINDINGS

A total of 175 participants were enrolled (placebo, n = 87; bismuth subsalicylate, n = 88), and 17 discontinued treatment (placebo, n = 8; bismuth subsalicylate n = 9). A total of 146 participants reported ≥1 GI event: placebo, n = 72 (82.8%); and bismuth subsalicylate, n = 74 (84.1%). There was no statistical difference in risk of a GI event between the groups (P = 0.8292). Mean (SD) time from DMF initiation to first GI event was similar: placebo, 5.4 (8.73) days; and bismuth subsalicylate, 5.6 (10.87) days. Incidence of flatulence (38.6% vs 50.6%) and diarrhea (36.4% vs 48.2%) during weeks 1-4 was numerically lower in the bismuth subsalicylate group compared with the placebo group. Mean worst severity scores for flatulence (1.1 vs 1.8; P = 0.0219) and diarrhea (1.0 vs 1.6; P = 0.0500) were lower with bismuth subsalicylate than with placebo.

IMPLICATIONS

Although coadministration of bismuth subsalicylate did not affect the occurrence of DMF-related GI events overall, it reduced the severity and incidence of flatulence and diarrhea. ClinicalTrials.gov identifier: NCT01915901.

Development and characterization of DNAzyme candidates demonstrating significant efficiency against human rhinoviruses

BACKGROUND

Infections with human rhinoviruses (RVs) are responsible for millions of common cold episodes and the majority of asthma exacerbations, especially in childhood. No drugs specifically targeting RVs are available.

OBJECTIVE

We sought to identify specific anti-RV molecules based on DNAzyme technology as candidates to a clinical study.

METHODS

A total of 226 candidate DNAzymes were designed against 2 regions of RV RNA genome identified to be sufficiently highly conserved between virus strains (ie, the 5'-untranslated region and cis-acting replication element) by using 3 test strains: RVA1, RVA16, and RVA29. All DNAzymes were screened for their cleavage efficiency against in vitro-expressed viral RNA. Those showing any catalytic activity were subjected to bioinformatic analysis of their reverse complementarity to 322 published RV genomic sequences. Further molecular optimization was conducted for the most promising candidates. Cytotoxic and off-target effects were excluded in HEK293 cell-based systems. Antiviral efficiency was analyzed in infected human bronchial BEAS-2B cells and ex vivo-cultured human sinonasal tissue.

RESULTS

Screening phase-generated DNAzymes characterized by either good catalytic activity or by high RV strain coverage but no single molecule represented a satisfactory combination of those 2 features. Modifications in length of the binding domains of 2 lead candidates, Dua-01(-L12R9) and Dua-02(-L10R11), improved their cleavage efficiency to an excellent level, with no loss in eminent strain coverage (about 98%). Both DNAzymes showed highly favorable cytotoxic/off-target profiles. Subsequent testing of Dua-01-L12R9 in BEAS-2B cells and sinonasal tissue demonstrated its significant antiviral efficiency.

CONCLUSIONS

Effective and specific management of RV infections with Dua-01-L12R9 might be useful in preventing asthma exacerbations, which should be verified by clinical trials.

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

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

Gut Microbiota in Human Systemic Lupus Erythematosus and a Mouse Model of Lupus

Gut microbiota dysbiosis has been observed in a number of autoimmune diseases. However, the role of the gut microbiota in systemic lupus erythematosus (SLE), a prototypical autoimmune disease characterized by persistent inflammation in multiple organs of the body, remains elusive. Here we report the dynamics of the gut microbiota in a murine lupus model, NZB/W F1, as well as intestinal dysbiosis in a small group of SLE patients with active disease. The composition of the gut microbiota changed markedly before and after the onset of lupus disease in NZB/W F1 mice, with greater diversity and increased representation of several bacterial species as lupus progressed from the predisease stage to the diseased stage. However, we did not control for age and the cage effect. Using dexamethasone as an intervention to treat SLE-like signs, we also found that a greater abundance of a group of lactobacilli (for which a species assignment could not be made) in the gut microbiota might be correlated with more severe disease in NZB/W F1 mice. Results of the human study suggest that, compared to control subjects without immune-mediated diseases, SLE patients with active lupus disease possessed an altered gut microbiota that differed in several particular bacterial species (within the genera Odoribacter and Blautia and an unnamed genus in the family Rikenellaceae) and was less diverse, with increased representation of Gram-negative bacteria. The Firmicutes/Bacteroidetes ratios did not differ between the SLE microbiota and the non-SLE microbiota in our human cohort.IMPORTANCE SLE is a complex autoimmune disease with no known cure. Dysbiosis of the gut microbiota has been reported for both mice and humans with SLE. In this emerging field, however, more studies are required to delineate the roles of the gut microbiota in different lupus-prone mouse models and people with diverse manifestations of SLE. Here, we report changes in the gut microbiota in NZB/W F1 lupus-prone mice and a group of SLE patients with active disease.

Innate Immune Response to Viral Infections in Primary Bronchial Epithelial Cells is Modified by the Atopic Status of Asthmatic Patients

Purpose

In order to gain an insight into determinants of reported variability in immune responses to respiratory viruses in human bronchial epithelial cells (HBECs) from asthmatics, the responses of HBEC to viral infections were evaluated in HBECs from phenotypically heterogeneous groups of asthmatics and in healthy controls.

Methods

HBECs were obtained during bronchoscopy from 10 patients with asthma (6 atopic and 4 non-atopic) and from healthy controls (n=9) and grown as undifferentiated cultures. HBECs were infected with parainfluenza virus (PIV)-3 (MOI 0.1) and rhinovirus (RV)-1B (MOI 0.1), or treated with medium alone. The cell supernatants were harvested at 8, 24, and 48 hours. IFN-α, CXCL10 (IP-10), and RANTES (CCL5) were analyzed by using Cytometric Bead Array (CBA), and interferon (IFN)-β and IFN-λ1 by ELISA. Gene expression of IFNs, chemokines, and IFN-regulatory factors (IRF-3 and IRF-7) was determined by using quantitative PCR.

Results

PIV3 and RV1B infections increased IFN-λ1 mRNA expression in HBECs from asthmatics and healthy controls to a similar extent, and virus-induced IFN-λ1 expression correlated positively with IRF-7 expression. Following PIV3 infection, IP-10 protein release and mRNA expression were significantly higher in asthmatics compared to healthy controls (median 36.03-fold). No differences in the release or expression of RANTES, IFN-λ1 protein and mRNA, or IFN-α and IFN-β mRNA between asthmatics and healthy controls were observed. However, when asthmatics were divided according to their atopic status, HBECs from atopic asthmatics (n=6) generated significantly more IFN-λ1 protein and demonstrated higher IFN-α, IFN-β, and IRF-7 mRNA expressions in response to PIV3 compared to non-atopic asthmatics (n=4) and healthy controls (n=9). In response to RV1B infection, IFN-β mRNA expression was lower (12.39-fold at 24 hours and 19.37-fold at 48 hours) in non-atopic asthmatics compared to atopic asthmatics.

Conclusions

The immune response of HBECs to virus infections may not be deficient in asthmatics, but seems to be modified by atopic status.

Immune response to vaccines is maintained in patients treated with dimethyl fumarate

Objectives:

To investigate the immune response to vaccinations in patients with relapsing forms of MS treated with delayed-release dimethyl fumarate (DMF) vs nonpegylated interferon (IFN).

Methods:

In this open-label, multicenter study, patients received 3 vaccinations: (1) tetanus-diphtheria toxoid (Td) to test T-cell–dependent recall response, (2) pneumococcal vaccine polyvalent to test T-cell–independent humoral response, and (3) meningococcal (groups A, C, W-135, and Y) oligosaccharide CRM₁₉₇ conjugate to test T-cell–dependent neoantigen response. Eligible patients were aged 18–55 years, diagnosed with relapsing-remitting MS (RRMS), and either treated for ≥6 months with an approved dose of DMF or for ≥3 months with an approved dose of nonpegylated IFN. Primary end point was the proportion of patients with ≥2-fold rise in antitetanus serum IgG levels from prevaccination to 4 weeks after vaccination.

Results:

Seventy-one patients (DMF treated, 38; IFN treated, 33) were enrolled. The mean age was 45.3 years (range 27–55); 86% were women. Responder rates (≥2-fold rise) to Td vaccination were comparable between DMF- and IFN-treated groups (68% vs 73%). Responder rates (≥2-fold rise) were also similar between DMF- and IFN-treated groups for diphtheria antitoxoid (58% vs 61%), pneumococcal serotype 3 (66% vs 79%), pneumococcal serotype 8 (95% vs 88%), and meningococcal serogroup C (53% vs 53%), all p > 0.05. In a post hoc analysis, no meaningful differences were observed between groups in the proportion of responders when stratified by age category or lymphocyte count.

Conclusions:

DMF-treated patients mount an immune response to recall, neoantigens, and T-cell–independent antigens, which was comparable with that of IFN-treated patients and provided adequate seroprotection.

ClinicalTrials.gov identifier:

NCT02097849.

Classification of evidence:

This study provides Class II evidence that patients with RRMS treated with DMF respond to vaccinations comparably with IFN-treated patients.

Corrigendum: Host DNA released by NETosis promotes rhinovirus-induced type-2 allergic asthma exacerbation

This corrects the article DOI: 10.1038/nm.4332.

Viral infections in allergy and immunology: How allergic inflammation influences viral infections and illness

Viral respiratory tract infections are associated with asthma inception in early life and asthma exacerbations in older children and adults. Although how viruses influence asthma inception is poorly understood, much research has focused on the host response to respiratory viruses and how viruses can promote; or how the host response is affected by subsequent allergen sensitization and exposure. This review focuses on the innate interferon-mediated host response to respiratory viruses and discusses and summarizes the available evidence that this response is impaired or suboptimal. In addition, the ability of respiratory viruses to act in a synergistic or additive manner with TH2 pathways will be discussed. In this review we argue that these 2 outcomes are likely linked and discuss the available evidence that shows reciprocal negative regulation between innate interferons and TH2 mediators. With the renewed interest in anti-TH2 biologics, we propose a rationale for why they are particularly successful in controlling asthma exacerbations and suggest ways in which future clinical studies could be used to find direct evidence for this hypothesis.