Eteri Bakhsoliani

IL-33–Dependent Type 2 Inflammation during Rhinovirus-induced Asthma Exacerbations In Vivo

RATIONALE Rhinoviruses are the major cause of asthma exacerbations; however, its underlying mechanisms are poorly understood. We hypothesized that the epithelial cell-derived cytokine IL-33 plays a central role in exacerbation pathogenesis through augmentation of type 2 inflammation. OBJECTIVES To assess whether rhinovirus induces a type 2 inflammatory response in asthma in vivo and to define a role for IL-33 in this pathway. METHODS We used a human experimental model of rhinovirus infection and novel airway sampling techniques to measure IL-4, IL-5, IL-13, and IL-33 levels in the asthmatic and healthy airways during a rhinovirus infection. Additionally, we cultured human T cells and type 2 innate lymphoid cells (ILC2s) with the supernatants of rhinovirus-infected bronchial epithelial cells (BECs) to assess type 2 cytokine production in the presence or absence of IL-33 receptor blockade. MEASUREMENTS AND MAIN RESULTS IL-4, IL-5, IL-13, and IL-33 are all induced by rhinovirus in the asthmatic airway in vivo and relate to exacerbation severity. Further, induction of IL-33 correlates with viral load and IL-5 and IL-13 levels. Rhinovirus infection of human primary BECs induced IL-33, and culture of human T cells and ILC2s with supernatants of rhinovirus-infected BECs strongly induced type 2 cytokines. This induction was entirely dependent on IL-33. CONCLUSIONS IL-33 and type 2 cytokines are induced during a rhinovirus-induced asthma exacerbation in vivo. Virus-induced IL-33 and IL-33-responsive T cells and ILC2s are key mechanistic links between viral infection and exacerbation of asthma. IL-33 inhibition is a novel therapeutic approach for asthma exacerbations.

Assessing the association of early life antibiotic prescription with asthma exacerbations, impaired antiviral immunity, and genetic variants in 17q21: A population-based birth cohort study

BACKGROUND The relationship between early-life antibiotic use and the development of wheeze and asthma has been reported in several studies but might arise as a consequence of bias rather than causal relationship. We investigated the association between antibiotic prescription and subsequent development of atopy, wheeze, and asthma exacerbations, and the relation of early life antibiotic prescription with anti-infective immunity and genetic variants on asthma susceptibility locus 17q21. METHODS Children in a population-based birth cohort were followed from birth to age 11 years. Information on antibiotic prescription, wheeze, and asthma exacerbations was extracted from medical records, and the effect of antibiotic prescription assessed with longitudinal analyses. We assessed immune responses of peripheral blood mononuclear cells, taken at age 11 years, to viruses (rhinovirus and respiratory syncytial virus; RSV) and bacteria (Haemophilus influenzae and Streptococcus pneumoniae) in children who either received at least one or no antibiotic prescriptions in infancy. Finally, we assessed the association of 17q21 polymorphisms with antibiotic prescription. FINDINGS Of 984 families who gave consent, we extracted data for 916 children. We noted significantly higher risk of physician-confirmed wheezing after antibiotic prescription (hazard ratio [HR] 1·71, 95% CI 1·32-2·23; p<0·0001) and severe wheeze or asthma exacerbation after antibiotic prescription (HR 2·26, 95% CI 1·03-4·94; p=0·041). In children who wheezed, the hazards of exacerbations (2·09, 1·51-2·90; p<0·0001) and admissions to hospital (2·64, 1·49-4·70; p=0·0009) were significantly increased in the 2 years after the first antibiotic prescription. Children who received antibiotics in infancy had significantly lower induction of cytokines, which are important in host defence against virus infections to both RSV and rhinovirus; there were no differences in antibacterial responses. Variants in 17q21 were associated with an increased risk of early life antibiotic prescription. INTERPRETATION The association between antibiotics and asthma might arise through a complex confounding by indication. Hidden factors that may increase the likelihood of both early life antibiotic prescription and later asthma are an increased susceptibility to viral infections consequent upon impaired antiviral immunity and genetic variants on 17q21. FUNDING Moulton Charitable Foundation and Medical Research Council.

Mucosal type 2 innate lymphoid cells are a key component of the allergic response to aeroallergen

Rationale: Newly characterized type 2 innate lymphoid cells (ILC2s) display potent type 2 effector functionality; however, their contribution to allergic airways inflammation and asthma is poorly understood. Mucosal biopsy used to characterize the airway mucosa is invasive, poorly tolerated, and does not allow for sequential sampling. Objectives: To assess the role of ILC2s during nasal allergen challenge in subjects with allergic rhinitis using novel noninvasive methodology. Methods: We used a human experimental allergen challenge model, with flow cytometric analysis of nasal curettage samples, to assess the recruitment of ILC2s and granulocytes to the upper airways of subjects with atopy and healthy subjects after allergen provocation. Soluble mediators in the nasal lining fluid were measured using nasosorption. Measurements and Main Results: After an allergen challenge, subjects with atopy displayed rapid induction of upper airway symptoms, an enrichment of ILC2s, eosinophils, and neutrophils, along with increased production of IL‐5, prostaglandin D2, and eosinophil and T‐helper type 2 cell chemokines compared with healthy subjects. The most pronounced ILC2 recruitment was observed in subjects with elevated serum IgE and airway eosinophilia. Conclusions: The rapid recruitment of ILC2s to the upper airways of allergic patients with rhinitis, and their association with key type 2 mediators, highlights their likely important role in the early allergic response to aeroallergens in the airways. The novel methodology described herein enables the analysis of rare cell populations from noninvasive serial tissue sampling.

A Comprehensive Evaluation of Nasal and Bronchial Cytokines and Chemokines Following Experimental Rhinovirus Infection in Allergic Asthma: Increased Interferons (IFN-γ and IFN-λ) and Type 2 Inflammation (IL-5 and IL-13)

Background Rhinovirus infection is a major cause of asthma exacerbations. Objectives We studied nasal and bronchial mucosal inflammatory responses during experimental rhinovirus-induced asthma exacerbations. Methods We used nasosorption on days 0, 2–5 and 7 and bronchosorption at baseline and day 4 to sample mucosal lining fluid to investigate airway mucosal responses to rhinovirus infection in patients with allergic asthma (n = 28) and healthy non-atopic controls (n = 11), by using a synthetic absorptive matrix and measuring levels of 34 cytokines and chemokines using a sensitive multiplex assay. Results Following rhinovirus infection asthmatics developed more upper and lower respiratory symptoms and lower peak expiratory flows compared to controls (all P < 0.05). Asthmatics also developed higher nasal lining fluid levels of an anti-viral pathway (including IFN-γ, IFN-λ/IL-29, CXCL11/ITAC, CXCL10/IP10 and IL-15) and a type 2 inflammatory pathway (IL-4, IL-5, IL-13, CCL17/TARC, CCL11/eotaxin, CCL26/eotaxin-3) (area under curve day 0–7, all P < 0.05). Nasal IL-5 and IL-13 were higher in asthmatics at day 0 (P < 0.01) and levels increased by days 3 and 4 (P < 0.01). A hierarchical correlation matrix of 24 nasal lining fluid cytokine and chemokine levels over 7 days demonstrated expression of distinct interferon-related and type 2 pathways in asthmatics. In asthmatics IFN-γ, CXCL10/IP10, CXCL11/ITAC, IL-15 and IL-5 increased in bronchial lining fluid following viral infection (all P < 0.05). Conclusions Precision sampling of mucosal lining fluid identifies robust interferon and type 2 responses in the upper and lower airways of asthmatics during an asthma exacerbation. Nasosorption and bronchosorption have potential to define asthma endotypes in stable disease and at exacerbation.

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 IFNmodInflamhighestTh2‐chemhighestReghighest rhinovirus‐16‐induced pattern had a PHA‐Th2low 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 IFNlowestInflamhighTh2‐chemlowRegmod cluster exhibited a PHA‐Th2lowest 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 IFNhighestInflammodTh2‐chemmodReghigh cluster with a rhinovirus‐16‐cytokine pattern was characterized by a PHA‐Th2highest 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.

Efficacy of novel antibody-based drugs against rhinovirus infection: In vitro and in vivo results

Abstract Rhinoviruses (RVs) cause the common cold and are associated with exacerbations of chronic inflammatory respiratory diseases, especially asthma and chronic obstructive pulmonary disease (COPD). We have assessed the antiviral drugs Anaferon for Children (AC) and Ergoferon (containing AC as one of the active pharmaceutical ingredients) in in vitro and in vivo experimental models, in order to evaluate their anti‐rhinoviral and immunomodulatory potential. HeLa cells were pretreated with AC, and levels of the interferon‐stimulated gene (ISG), 2′‐5′‐oligoadenylate synthetase 1 (OAS1‐A) and viral replication were analyzed. In a mouse model of RV‐induced exacerbation of allergic airway inflammation we administered Ergoferon and analyzed its effect on type I (IFN‐&bgr;), type II (IFN‐&ggr;) and type III (IFN‐&lgr;) IFNs induction, cell counts in bronchoalveolar lavage (BAL), cytokine (interleukin (IL)‐4; IL‐6) and chemokine (CXCL10/IP‐10; CXCL1/KC) levels. It was shown that AC increased OAS1‐A production and significantly decreased viral replication in vitro. Increased IFNs expression together with reduced neutrophils/lymphocytes recruitment and correlated IL‐4/IL‐6 declination was demonstrated for Ergoferon in vivo. However, there was no effect on examined chemokines. We conclude that AC and Ergoferon possess effects against RV infection and may have potential as novel therapies against RV‐induced exacerbations of asthma. HighlightsAnaferon for Children and Ergoferon demonstrated an anti‐rhinoviral effect in vitro and in vivo.Anaferon for Children treatment demonstrated an evident induction in OAS1A expression.Anaferon for Children inhibited virus replication in vitro.Ergoferon showed an increase in IFN production and reduction in cells and cytokines in vivo.

Role of airway glucose in bacterial infections in patients with chronic obstructive pulmonary disease

Background Patients with chronic obstructive pulmonary disease (COPD) have increased susceptibility to respiratory tract infection, which contributes to disease progression and mortality, but mechanisms of increased susceptibility to infection remain unclear. Objectives The aim of this study was to determine whether glucose concentrations were increased in airway samples (nasal lavage fluid, sputum, and bronchoalveolar lavage fluid) from patients with stable COPD and to determine the effects of viral infection on sputum glucose concentrations and how airway glucose concentrations relate to bacterial infection. Methods We measured glucose concentrations in airway samples collected from patients with stable COPD and smokers and nonsmokers with normal lung function. Glucose concentrations were measured in patients with experimentally induced COPD exacerbations, and these results were validated in patients with naturally acquired COPD exacerbations. Relationships between sputum glucose concentrations, inflammatory markers, and bacterial load were examined. Results Sputum glucose concentrations were significantly higher in patients with stable COPD compared with those in control subjects without COPD. In both experimental virus‐induced and naturally acquired COPD exacerbations, sputum and nasal lavage fluid glucose concentrations were increased over baseline values. There were significant correlations between sputum glucose concentrations and sputum inflammatory markers, viral load, and bacterial load. Airway samples with higher glucose concentrations supported more Pseudomonas aeruginosa growth in vitro. Conclusions Airway glucose concentrations are increased in patients with stable COPD and further increased during COPD exacerbations. Increased airway glucose concentrations might contribute to bacterial infections in both patients with stable and those with exacerbated COPD. This has important implications for the development of nonantibiotic therapeutic strategies for the prevention or treatment of bacterial infection in patients with COPD.