24 results found
Dhariwal J, Cameron A, Wong E, et al., 2021, Pulmonary innate lymphoid cell responses during rhinovirus-induced asthma exacerbations, Journal of Allergy and Clinical Immunology, Vol: 204, Pages: 1259-1273, ISSN: 0091-6749
Rationale Type 2 innate lymphoid cells (ILC2s) are significant sources of type 2 cytokines, which are implicated in the pathogenesis of asthma and asthma exacerbations. The role of ILC2s in virus-induced asthma exacerbations is not well-characterized. Objectives To characterize pulmonary ILC responses following experimental rhinovirus challenge in patients with moderate asthma and healthy subjects. Methods Patients with moderate asthma and healthy subjects were inoculated with rhinovirus-16, and underwent bronchoscopy at baseline, day 3 and day 8 post-inoculation. Pulmonary ILC1s and ILC2s were quantified in bronchoalveolar lavage (BAL) using flow cytometry. The ratio of BAL ILC2:ILC1 was assessed to determine their relative contributions to the clinical and immune response to rhinovirus challenge. Measurements and Main Results At baseline, ILC2s were significantly higher in patients with asthma than healthy subjects. At day 8, ILC2s significantly increased from baseline in both groups, which was significantly higher in asthma than in healthy subjects (all comparisons P<0.05). In healthy subjects, ILC1s increased from baseline at day 3 (P=0.001), while in patients with asthma, ILC1s increased from baseline at day 8 (P=0.042). Patients with asthma had significantly higher ILC2:ILC1 ratios at baseline (P=0.024) and day 8 (P=0.005). Increased ILC2:ILC1 ratio in asthma correlated with clinical exacerbation severity and type 2 cytokines in nasal mucosal lining fluid. Conclusions An ILC2-predominant inflammatory profile in asthma was associated with increased severity and duration of rhinovirus infection compared with healthy subjects, supporting the potential role of ILC2s in the pathogenesis of virus-induced asthma exacerbations. Clinical trial registration available at www.clinicaltrials.gov, ID: NCT01773590
Hearn AP, Hug OD, Somani ZA, et al., 2021, Real world effectiveness of anti-IL-5/5R therapies is independent of co-eligibility for anti-IgE therapy., Eur Respir J, Vol: 57
Kavanagh JE, Hearn AP, Dhariwal J, et al., 2021, Real-World Effectiveness of Benralizumab in Severe Eosinophilic Asthma, CHEST, Vol: 159, Pages: 496-506, ISSN: 0012-3692
Nanzer AM, Dhariwal J, Kavanagh J, et al., 2020, Steroid-sparing effects of benralizumab in patients with eosinophilic granulomatosis with polyangiitis, ERJ OPEN RESEARCH, Vol: 6
Kavanagh JE, d'Ancona G, Elstad M, et al., 2020, Real-World Effectiveness and the Characteristics of a "Super-Responder" to Mepolizumab in Severe Eosinophilic Asthma, CHEST, Vol: 158, Pages: 491-500, ISSN: 0012-3692
Nanzer AM, Chowdhury A, Raheem A, et al., 2020, Prevalence and recovery of adrenal insufficiency in steroid-dependent asthma patients receiving biologic therapy., Eur Respir J, Vol: 56
d'Ancona G, Kavanagh J, Roxas C, et al., 2020, Adherence to corticosteroids and clinical outcomes in mepolizumab therapy for severe asthma, EUROPEAN RESPIRATORY JOURNAL, Vol: 55, ISSN: 0903-1936
Guvenel A, Jozwik A, Ascough S, et al., 2020, Epitope-specific airway-resident CD4+ T-cell dynamics during experimental human RSV infection, Journal of Clinical Investigation, Vol: 130, Pages: 523-538, ISSN: 0021-9738
Background: Respiratory syncytial virus (RSV) is an important cause of acute pulmonary disease and one of the last remaining major infections of childhood for which there is no vaccine. CD4+ T-cells play a key role in antiviral immunity, but they have been little studied in the human lung. Methods: Healthy adult volunteers were inoculated intranasally with RSV A Memphis 37. CD4+ T-cells in blood and lower airway were analysed by flow cytometry and immunohistochemistry. Bronchial soluble mediators were measured using quantitative PCR and MesoScale Discovery. Epitope mapping was performed by IFN-γ ELISpot screening, confirmed by in vitro MHC binding. Results: Activated CD4+ T-cell frequencies in bronchoalveolar lavage correlated strongly with local CXCL10 levels. Thirty-nine epitopes were identified, predominantly towards the 3’ end of the viral genome. Five novel MHC-II tetramers were made using an immunodominant F-EFY epitope restricted to HLA-DR4, -DR9 and -DR11 (combined allelic frequency: 15% in Europeans) and G- DDF restricted to HLA-DPA1*01:03/DPB1*02:01 and -DPA1*01:03/DPB1*04:01 (allelic frequency: 55%). Tetramer labelling revealed enrichment of resident memory CD4+ T-cells (TRM) cells in the lower airway; these TRM displayed progressive differentiation, down-regulation of co- stimulatory molecules and elevated CXCR3 expression as infection evolved. Conclusion: Human infection challenge provides a unique opportunity to study the breadth of specificity and dynamics of RSV-specific T-cell responses in the target organ, allowing the precise investigation of TRM recognising novel viral antigens over time. The new tools that we describe enable precise tracking of RSV-specific CD4+ cells, potentially accelerating the development of effective vaccines.
McErlean P, Kelly A, Dhariwal J, et al., 2018, Genome-wide profiling of an enhancer-associated histone modification reveals the influence of asthma on the epigenome of the airway epithelium., Biorxiv
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. We undertook genome-wide profiling of the enhancer-associated histone modification H3K27ac in BECs from people with asthma and healthy controls. We identified 49,903 regions exhibiting differential H3K27ac enrichment in asthma, clustered at genes associated with type-2-high asthma (CLCA1) and epithelial processes (EMT). Asthma dramatically influenced the BEC enhancer landscape and we identified asthma-associated Super-Enhancers encompassing genes encoding transcription factors (TP63) and enzymes regulating lipid metabolism (NOX4). We integrated published protein, epigenomic and transcriptomic datasets and identified epithelium-specific transcription factors associated with H3K27ac in asthma (TP73) and dynamic relationships between asthma-associated changes in H3K27ac, DNA methylation, genetic susceptibility and transcriptional profiles. Finally, we used a CRISPR-based approach to recapitulate the H3K27ac-asthma landscape in vitro and provide proof of principal that asthma-associated gene expression (SERPINB2) is driven in part by aberrant histone acetylation, validating the combination of genome-wide and epigenome-editing approaches in deciphering the molecular mechanisms underlying asthma pathogenesis.
Dhariwal J, Cameron A, Wong E, et al., 2018, Pulmonary Innate Lymphoid Cell Responses During Rhinovirus-Induced Asthma Exacerbations, JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY, Vol: 141, Pages: AB195-AB195, ISSN: 0091-6749
Wong E, Dhariwal J, Cuthbertson L, et al., 2017, An imbalanced airway microbiota correlates with greater peak flow decline in virus-induced asthma exacerbations, European-Respiratory-Society (ERS) International Congress, Publisher: EUROPEAN RESPIRATORY SOC JOURNALS LTD, ISSN: 0903-1936
Tunstall T, Kon OM, Bartlett N, et al., 2017, 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), EBioMedicine, Vol: 19, Pages: 128-138, ISSN: 2352-3964
BackgroundRhinovirus infection is a major cause of asthma exacerbations.ObjectivesWe studied nasal and bronchial mucosal inflammatory responses during experimental rhinovirus-induced asthma exacerbations.MethodsWe 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.ResultsFollowing 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).ConclusionsPrecision 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.
Dhariwal J, Cameron A, Trujillo-Torralbo MB, et al., 2017, Mucosal type 2 innate lymphoid cells are a key component of the allergic response to aeroallergen, American Journal of Respiratory and Critical Care Medicine, Vol: 195, Pages: 1586-1596, ISSN: 1535-4970
RATIONALE: Newly characterised type 2 innate lymphoid cells display potent type 2 effector functionality, however their contribution to allergic airways inflammation and asthma is poorly understood. Mucosal biopsy used to characterise the airway mucosa is invasive, poorly tolerated and does not allow sequential sampling. OBJECTIVES: To assess the role of type 2 innate lymphoid cells during nasal allergen challenge in subjects with allergic rhinitis, using novel non-invasive methodology. METHODS: We used a human experimental allergen challenge model, with flow cytometric analysis of nasal curettage samples, to assess the recruitment of type 2 innate lymphoid cells and granulocytes to the upper airways of atopic and healthy subjects following allergen provocation. Soluble mediators in the nasal lining fluid were measured using nasosorption. MEASUREMENTS AND MAIN RESULTS: Following allergen challenge, atopic subjects displayed rapid induction of upper airway symptoms, an enrichment of type 2 innate lymphoid cells, eosinophils and neutrophils, along with increased production of interleukin-5, prostaglandin D2, and eosinophil and T-helper type 2 cell chemokines compared to healthy subjects. The most pronounced type 2 innate lymphoid cell recruitment was observed in patients with elevated serum IgE and airway eosinophilia. CONCLUSIONS: The rapid recruitment of type 2 innate lymphoid cells to the upper airways of allergic rhinitis patients, and their association with key type 2 mediators, highlights their likely important role in the early allergic response to aeroallergen in the airways. The novel methodology described herein enables the analysis of rare cell populations from non-invasive, serial tissue sampling.
Porter JD, Watson J, Groves H, et al., 2016, Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III IFN-augmenting activity in airway epithelium, Journal of Antimicrobial Chemotherapy, Vol: 71, Pages: 2767-2781, ISSN: 1460-2091
Background Exacerbations of asthma and COPD are triggered by rhinoviruses. Uncontrolled inflammatory pathways, pathogenic bacterial burden and impaired antiviral immunity are thought to be important factors in disease severity and duration. Macrolides including azithromycin are often used to treat the above diseases, but exhibit variable levels of efficacy. Inhaled corticosteroids are also readily used in treatment, but may lack specificity. Ideally, new treatment alternatives should suppress unwanted inflammation, but spare beneficial antiviral immunity.Methods In the present study, we screened 225 novel macrolides and tested them for enhanced antiviral activity against rhinovirus, as well as anti-inflammatory activity and activity against Gram-positive and Gram-negative bacteria. Primary bronchial epithelial cells were grown from 10 asthmatic individuals and the effects of macrolides on rhinovirus replication were also examined. Another 30 structurally similar macrolides were also examined.Results The oleandomycin derivative Mac5, compared with azithromycin, showed superior induction (up to 5-fold, EC50 = 5–11 μM) of rhinovirus-induced type I IFNβ, type III IFNλ1 and type III IFNλ2/3 mRNA and the IFN-stimulated genes viperin and MxA, yet had no effect on IL-6 and IL-8 mRNA. Mac5 also suppressed rhinovirus replication at 48 h, proving antiviral activity. Mac5 showed antibacterial activity against Gram-positive Streptococcus pneumoniae; however, it did not have any antibacterial properties compared with azithromycin when used against Gram-negative Escherichia coli (as a model organism) and also the respiratory pathogens Pseudomonas aeruginosa and non-typeable Haemophilus influenzae. Further non-toxic Mac5 derivatives were identified with various anti-inflammatory, antiviral and antibacterial activities.Conclusions The data support the idea that macrolides have antiviral properties through a mechanism that is yet to be ascertained. We also
Jozwik A, Habibi MS, Paras A, et al., 2016, Erratum: RSV-specific airway resident memory CD8+ T cells and differential disease severity after experimental human infection, Nature Communications, Vol: 7, ISSN: 2041-1723
Jozwik A, Habibi MS, Paras A, et al., 2015, RSV-specific airway resident memory CD8+ T cells and differential disease severity after experimental human infection, Nature Communications, Vol: 6, Pages: 1-17, ISSN: 2041-1723
In animal models, resident memory CD8+ T (Trm) cells assist in respiratory virus elimination but their importance in man has not been determined. Here, using experimental human respiratory syncytial virus (RSV) infection, we investigate systemic and local virus-specific CD8+ T cell responses in adult volunteers. Having defined the immunodominance hierarchy, we analyze phenotype and function longitudinally in blood and by serial bronchoscopy. Despite rapid clinical recovery, we note surprisingly extensive lower airway inflammation with persistent viral antigen and cellular infiltrates. Pulmonary virus-specific CD8+ T cells display a CD69+CD103+ Trm phenotype and accumulate to strikingly high frequencies into convalescence without continued proliferation. These are more highly differentiated but express fewer cytotoxicity markers than in blood, but their abundance prior to infection correlates with protection from more severe disease.
Dhariwal J, Kitson J, Jones RE, et al., 2015, Nasal Lipopolysaccharide Challenge and Cytokine Measurement Reflects Innate Mucosal Immune Responsiveness, PLOS One, Vol: 10, ISSN: 1932-6203
BackgroundPractical methods of monitoring innate immune mucosal responsiveness are lacking. Lipopolysaccharide(LPS) is a component of the cell wall of Gram negative bacteria and a potentactivator of Toll-like receptor (TLR)-4. To measure LPS responsiveness of the nasalmucosa, we administered LPS as a nasal spray and quantified chemokine and cytokine levelsin mucosal lining fluid (MLF).MethodsWe performed a 5-way cross-over, single blind, placebo-controlled study in 15 healthy nonatopicsubjects (n = 14 per protocol). Doses of ultrapure LPS (1, 10, 30 or 100μg/100μl) orplacebo were administered by a single nasal spray to each nostril. Using the recently developedmethod of nasosorption with synthetic adsorptive matrices (SAM), a series of sampleswere taken. A panel of seven cytokines/chemokines were measured by multiplex immunoassayin MLF. mRNA for intercellular cell adhesion molecule-1 (ICAM-1) was quantifiedfrom nasal epithelial curettage samples taken before and after challenge.ResultsTopical nasal LPS was well tolerated, causing no symptoms and no visible changes to thenasal mucosa. LPS induced dose-related increases in MLF levels of IL-1β, IL-6, CXCL8 (IL-8) and CCL3 (MIP-1α) (AUC at 0.5 to 10h, compared to placebo, p<0.05 at 30 and 100μgLPS). At 100μg LPS, IL-10, IFN-α and TNF-α were also increased (p<0.05). Dose-relatedchanges in mucosal ICAM-1 mRNA were also seen after challenge, and neutrophilsappeared to peak in MLF at 8h. However, 2 subjects with high baseline cytokine levelsshowed prominent cytokine and chemokine responses to relatively low LPS doses (10μgand 30μg LPS).
Jackson DJ, Makrinioti H, Rana BMJ, et al., 2014, IL-33-dependent Type 2 inflammation during rhinovirus-induced asthma exacerbations in vivo, American Journal of Respiratory and Critical Care Medicine, Vol: 190, Pages: 1373-1382, ISSN: 1535-4970
Rationale: Rhinoviruses are the major cause of asthmaexacerbations; however, its underlying mechanisms are poorlyunderstood. We hypothesized that the epithelial cell–derivedcytokine IL-33 plays a central role in exacerbation pathogenesisthrough augmentation of type 2 inflammation.Objectives: To assess whether rhinovirus induces a type 2inflammatory response in asthma in vivo and to define a role for IL-33in this pathway.Methods: We used a human experimental model of rhinovirusinfection and novel airway sampling techniques to measure IL-4, IL-5,IL-13, and IL-33 levels in the asthmatic and healthy airways duringa rhinovirus infection. Additionally, we cultured human T cells and type2 innate lymphoid cells (ILC2s) with the supernatants of rhinovirusinfectedbronchial epithelial cells (BECs) to assess type 2 cytokineproduction in the presence or absence of IL-33 receptor blockade.Measurements and Main Results: IL-4, IL-5, IL-13, and IL-33 areall induced by rhinovirus in the asthmatic airway in vivo and relate toexacerbation severity. Further, induction of IL-33 correlates withviral load and IL-5 and IL-13 levels. Rhinovirus infection of humanprimary BECs induced IL-33, and culture of human T cells and ILC2swith supernatants of rhinovirus-infected BECs strongly inducedtype 2 cytokines. This induction was entirely dependent on IL-33.Conclusions: IL-33 and type 2 cytokines are induced duringa rhinovirus-induced asthma exacerbation in vivo. Virus-inducedIL-33 and IL-33–responsive T cells and ILC2s are key mechanisticlinks between viral infection and exacerbation of asthma. IL-33inhibition is a novel therapeutic approach for asthma exacerbations
Dhariwal J, Tennant RC, Hansell DM, et al., 2014, Smoking cessation in COPD causes a transient improvement in spirometry and decreases micronodules on high-resolution CT imaging., Chest, Vol: 145, Pages: 1006-1015
BACKGROUND: Smoking cessation is of major importance for all smokers; however, in patients with COPD, little information exists on how smoking cessation influences lung function and high-resolution CT (HRCT) scan appearances. METHODS: In this single-center study, we performed screening spirometry in a group of heavy smokers aged 40 to 80 years (N = 358). We then studied the effects of smoking cessation in two groups of selected subjects: smokers with COPD (n = 38) and smokers with normal spirometry (n = 55). In parallel to subjects undergoing smoking cessation, we studied a control group of nonsmokers (n = 19). RESULTS: Subjects with COPD who quit smoking had a marked, but transient improvement in FEV1 at 6 weeks (184 mL, n = 17, P < .01) that was still present at 12 weeks (81 mL, n = 17, P < .05) and only partially maintained at 1 year. In contrast, we saw improvement in the transfer factor of lung for carbon monoxide at 6 weeks in both subjects with COPD who quit smoking (0.47 mmol/min/kPa, n = 17, P < .01) and subjects who quit smoking with normal spirometry (0.40 mmol/min/kPa, n = 35, P < .01). An upper-zone single HRCT image slice reliably identified emphysema at baseline in 74% of smokers with COPD (28 of 38) and 29% of healthy smokers (16 of 55). Smoking cessation had no significant effect on the appearances of emphysema but decreased the presence of micronodules on HRCT imaging. CONCLUSIONS: Cigarette smoking causes extensive lung function and HRCT image abnormalities, even in patients with normal spirometry. Smoking cessation has differential effects on lung function (FEV1 and gas transfer) and features on HRCT images (emphysema and micronodules). Cessation of smoking in patients with COPD causes a transient improvement in FEV1 and decreases the presence of micronodules, offering an opportunity for concomitant therapy during smoking cessation to augment these effects. Smoking cessation at the earliest possible opportunity is vita
Dhariwal J, Edwards MR, Johnston SL, 2013, Anti-viral agents: potential utility in exacerbations of asthma, CURRENT OPINION IN PHARMACOLOGY, Vol: 13, Pages: 331-336, ISSN: 1471-4892
Singanayagam A, Sridhar S, Dhariwal J, et al., 2012, A comparison between two strategies for monitoring hepatic function during antituberculous therapy, Am J Respir Crit Care Med, Vol: 185, Pages: 653-659, ISSN: 1535-4970
RATIONALE: The optimum strategy for monitoring liver function during antituberculous therapy is unclear. OBJECTIVES: To assess the value of the American Thoracic Society risk-factor approach for predicting drug-induced liver injury and to compare with a uniform policy of liver function testing in all patients at 2 weeks. METHODS: We conducted an observational study of adult patients undergoing therapy for active tuberculosis at a tertiary center. All patients had alanine transferase measurement at baseline and 2 weeks following commencement of therapy. Sensitivity, specificity, and positive and negative predictive values were used to assess strategies. MEASUREMENTS AND MAIN RESULTS: There were 288 patients included, and 21 (7.3%) developed drug-induced liver injury (57.1% "early" at 2 wk and 42.9% "late," after 2 wk). There were increased rates of individuals with HIV infection in the early drug-induced liver injury group compared with no drug-induced liver injury and late drug-induced liver injury groups (33% vs. 7.1% vs. 0%; P = 0.004). The American Thoracic Society algorithm had a sensitivity and specificity of 66.7 and 65.6%, respectively, for prediction of early and 22.2% and 63.7% for late drug-induced liver injury. The uniform monitoring policy had poor sensitivity but better specificity (22.2 and 82.1%) for prediction of late drug-induced liver injury. CONCLUSIONS: In our urban, ethnically diverse population, a risk-factor approach is neither sensitive nor specific for prediction of drug-induced liver injury. A uniform policy of liver function testing at 2 weeks is useful for prompt identification of a subgroup who develop early drug-induced liver injury and may offer better specificity in ruling out late drug-induced liver injury.
George PM, Mehta M, Dhariwal J, et al., 2011, Post-bronchoscopy sputum: Improving the diagnostic yield in smear negative pulmonary TB., Respir Med. 2011 Nov;105(11):1726-31
George PM, Mehta M, Dhariwal J, et al., 2010, Post bronchoscopy sputum: Increasing the diagnostic yield in smear negative pulmonary tuberculosis., Winter meeting of the British Thoracic Society
Singanayagam A, George PM, Connell DW, et al., 2010, Characterisation of tuberculous mediastinal lymphadenopathy on CT and correlation with biomarkers and chest radiograph findings., British Thoracic Society
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.