ORCID Profile
0000-0003-1288-3026
Current Organisation
University of Manchester
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Publisher: IOP Publishing
Date: 07-09-2023
Abstract: Introduction& #xD Volatile organic compounds (VOCs) have shown promise as potential biomarkers in idiopathic pulmonary fibrosis (IPF). Measuring VOCs in the headspace of in vitro models of lung fibrosis may offer a method of determining the origin of those detected in exhaled breath. The aim of this study was to determine the VOCs associated with two lung cell lines (A549 and MRC-5 cells) and changes associated with stimulation of cells with the pro-fibrotic cytokine, transforming growth factor (TGF)-β1.& #xD Methods& #xD A dynamic headspace s ling method was used to s le the headspace of A549 cells and MRC-5 cells. These were compared to media control s les and to each other to identify VOCs which discriminated between cell lines. Cells were then stimulated with the TGF-β1 and s les were compared between stimulated and unstimulated cells. S les were analysed using thermal desorption-gas chromatography-mass spectrometry and supervised analysis was performed using sparse partial least squares-discriminant analysis (sPLS-DA).& #xD Results& #xD Supervised analysis revealed differential VOC profiles unique to each of the cell lines and from the media control s les. Significant changes in VOC profiles were induced by stimulation of cell lines with TGF-β1. In particular, several terpenoids (isopinocarveol, sativene and 3-carene) were increased in stimulated cells compared to unstimulated cells.& #xD Conclusions& #xD VOC profiles differ between lung cell lines and alter in response to pro-fibrotic stimulation. Increased abundance of terpenoids in the headspace of stimulated cells may reflect TGF-β1 cell signalling activity and metabolic reprogramming. This may offer a potential biomarker target in exhaled breath in IPF. & #xD
Publisher: Cold Spring Harbor Laboratory
Date: 16-10-2020
DOI: 10.1101/2020.10.10.20207449
Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection resulting in the clinical syndrome COVID-19 is associated with an exaggerated immune response and monocyte infiltrates in the lungs and other peripheral tissues. It is now increasingly recognised that chronic morbidity persists in some patients. We recently demonstrated profound alterations of monocytes in hospitalised COVID-19 patients. It is currently unclear whether these abnormalities resolve or progress following patient discharge. We show here that blood monocytes in convalescent patients at their 12 week follow up, have a greater propensity to produce pro-inflammatory cytokines TNFα and IL-6, which was consistently higher in patients with resolution of lung injury as indicated by a normal chest X-ray and no shortness of breath (a key symptom of lung injury). Furthermore, monocytes from convalescent patients also displayed enhanced levels of molecules involved in leucocyte migration, including chemokine receptor CXCR6, adhesion molecule CD31/PECAM and integrins VLA-4 and LFA-1. Expression of migration molecules on monocytes was also consistently higher in convalescent patients with a normal chest X-ray. These data suggest persistent changes in innate immune function following recovery from COVID-19 and indicate that immune modulating therapies targeting monocytes and leucocyte migration may be useful in recovering COVID-19 patients with persistent symptoms.
Publisher: Cold Spring Harbor Laboratory
Date: 16-06-2020
DOI: 10.1101/2020.06.13.20127605
Abstract: The pathogenesis of COVID-19, caused by a novel strain of coronavirus (SARS-CoV-2), involves a complex host-virus interaction and is characterised by an exaggerated immune response, the specific components of which are poorly understood. Here we report the outcome of a longitudinal immune profiling study in hospitalised patients during the peak of the COVID-19 pandemic in the UK and show the relationship between immune responses and severity of the clinical presentation. The Coronavirus Immune Response and Clinical Outcomes (CIRCO) study was conducted at four hospitals in Greater Manchester. Patients with SARS-CoV-2 infection, recruited as close to admission as possible, provided peripheral blood s les at enrolment and sequentially thereafter. Fresh s les were assessed for immune cells and proteins in whole blood and serum. Some s les were also stimulated for 3 hours with LPS and analysed for intracellular proteins. Results were stratified based on patient-level data including severity of symptoms and date of reported symptom onset. Longitudinal analysis showed a very high neutrophil to T cell ratio and abnormal activation of monocytes in the blood, which displayed high levels of the cell cycle marker, Ki67 and low COX-2. These properties all reverted in patient with good outcome. Unexpectedly, multiple aspects of inflammation were diminished as patients progressed in severity and time, even in ITU patients not recovering. This is the first detailed longitudinal analysis of COVID-19 patients of varying severity and outcome, revealing common features and aspects that track with severity. Patients destined for a severe outcome can be identified at admission when still displaying mild-moderate symptoms. We provide clues concerning pathogenesis that should influence clinical trials and therapeutics. Targeting pathways involved in neutrophil and monocyte release from the bone marrow should be tested in patients with COVID-19. The Kennedy Trust for Rheumatology Research, The Wellcome Trust, The Royal Society, The BBSRC, National Institute for Health Research (NIHR) Biomedical Research Centres (BRC). Analysis of the literature before the study via pubmed and bioRxiv searches using the terms COVID-19, SARS-CoV2, immune and inflammation (with the last search performed on 27th April 2020) showed evidence of an overactive immune response in a handful of studies in cross-sectional analyses all done at a single time point. To determine the role of the immune response in a disease process, it is necessary to correlate immune activity with clinical parameters dynamically. In this study patients presented to hospital at different stages of disease so we took s les at different time-points to provide an accurate picture of the relevant pathobiology. In order to avoid loss of large components of the immune system due to the processes of storage, longitudinal s les were interrogated in real time to reveal the full immune alterations in COVID-19. Respiratory viruses continue to cause devastating global disease. The finding of altered myelopoiesis, with excess neutrophils and altered monocyte function, as dominant features in our study provides an incentive for clinical testing of therapeutics that specifically target this pathobiology. Given that inflammation is greatest prior to admission to intensive care, trials of specific immune-modulating therapies should be considered earlier in admission. Future studies of COVID-19 mechanisms should place more emphasis on longitudinal analyses since disease changes dramatically over time.
Publisher: Cold Spring Harbor Laboratory
Date: 21-08-2020
DOI: 10.1101/2020.08.18.20159608
Abstract: Early clinical reports have suggested that the prevalence of thrombotic complications in the pathogenesis of COVID-19 may be as high as 30% in intensive care unit (ICU)-admitted patients and could be a major factor contributing to mortality. However, mechanisms underlying COVID-19-associated thrombo-coagulopathy, and its impact on patient morbidity and mortality, are still poorly understood. We performed a comprehensive analysis of coagulation and thromboinflammatory factors in plasma from COVID-19 patients with varying degrees of disease severity. Furthermore, we assessed the functional impact of these factors on clot formation and clot lysis. Across all COVID-19 disease severities (mild, moderate and severe) we observed a significant increase (6-fold) in the concentration of ultra-large von Willebrand factor (UL-VWF) multimers compared to healthy controls. This is likely the result of an interleukin (IL)-6 driven imbalance of VWF and the regulatory protease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13). Upregulation of this key pro-coagulant pathway may also be influenced by the observed increase (~6-fold) in plasma α-defensins, a consequence of increased numbers of neutrophils and neutrophil activation. Markers of endothelial, platelet and leukocyte activation were accompanied by increased plasma concentrations of Factor XIII (FXIII) and plasminogen activator inhibitor (PAI)-1. In patients with high FXIII we observed alteration of the fibrin network structure in in vitro assays of clot formation, which coupled with increased PAI-1, prolonged the time to clot lysis by the t-PA lasmin fibrinolytic pathway by 52% across all COVID-19 patients (n=23). We show that an imbalance in the VWF/ADAMTS13 axis causing increased VWF reactivity may contribute to the formation of platelet-rich thrombi in the pulmonary vasculature of COVID-19 patients. Through immune and inflammatory responses, COVID-19 also alters the balance of factors involved in fibrin generation and fibrinolysis which accounts for the persistent fibrin deposition previously observed in post-mortem lung tissue. In all COVID-19 patients, even mild cases, UL-VWF is present in plasma due to the alteration of VWF and ADAMTS13 concentrations, likely driven by increased IL-6 and α-defensins. Increased plasma FXIII alters fibrin structure and enhances incorporation of VWF into fibrin clusters. Defective fibrin structure, coupled with increased plasma PAI-1 and α2-antiplasmin, inhibits fibrinolysis by t-PA lasmin. Prophylactic anticoagulation and management of thrombotic complications in COVID-19 patients are ongoing challenges requiring a better understanding of the coagulopathic mechanisms involved. We have identified FXIII and VWF as potential therapeutic targets for treating fibrin formation defects in COVID-19 patients. We have identified a multifaceted fibrinolytic resistance in COVID-19 patient plasma with potential implications in the treatment of secondary thrombotic events such as acute ischaemic stroke or massive pulmonary embolism.
Publisher: European Respiratory Society (ERS)
Date: 15-03-2023
DOI: 10.1183/13993003.02226-2022
Abstract: COVID-19 is associated with a dysregulated immune response but it is unclear how immune dysfunction contributes to the chronic morbidity persisting in many COVID-19 patients during convalescence (long COVID). We assessed phenotypical and functional changes of monocytes in COVID-19 patients during hospitalisation and up to 9 months of convalescence following COVID-19, respiratory syncytial virus or influenza A. Patients with progressive fibrosing interstitial lung disease were included as a positive control for severe, ongoing lung injury. Monocyte alterations in acute COVID-19 patients included aberrant expression of leukocyte migration molecules, continuing into convalescence (n=142) and corresponding with specific symptoms of long COVID. Long COVID patients with unresolved lung injury, indicated by sustained shortness of breath and abnormal chest radiology, were defined by high monocyte expression of C-X-C motif chemokine receptor 6 (CXCR6) (p .0001) and adhesion molecule P-selectin glycoprotein ligand 1 (p .01), alongside preferential migration of monocytes towards the CXCR6 ligand C-X-C motif chemokine ligand 16 (CXCL16) (p .05), which is abundantly expressed in the lung. Monocyte CXCR6 and lung CXCL16 were heightened in patients with progressive fibrosing interstitial lung disease (p .001), confirming a role for the CXCR6–CXCL16 axis in ongoing lung injury. Conversely, monocytes from long COVID patients with ongoing fatigue exhibited a sustained reduction of the prostaglandin-generating enzyme cyclooxygenase 2 (p .01) and CXCR2 expression (p .05). These monocyte changes were not present in respiratory syncytial virus or influenza A convalescence. Our data define unique monocyte signatures that define subgroups of long COVID patients, indicating a key role for monocyte migration in COVID-19 pathophysiology. Targeting these pathways may provide novel therapeutic opportunities in COVID-19 patients with persistent morbidity.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Laurence Pearmain.