Publications by authors named "Jeremy S Brown"

93 Publications

Post-COVID-19 assessment in a specialist clinical service: a 12-month, single-centre, prospective study in 1325 individuals.

BMJ Open Respir Res 2021 11;8(1)

University College London Hospitals NHS Foundation Trust, London, UK

Introduction: Post-COVID-19 complications require simultaneous characterisation and management to plan policy and health system responses. We describe the 12-month experience of the first UK dedicated post-COVID-19 clinical service to include hospitalised and non-hospitalised patients.

Methods: In a single-centre, observational analysis, we report the demographics, symptoms, comorbidities, investigations, treatments, functional recovery, specialist referral and rehabilitation of 1325 individuals assessed at the University College London Hospitals post-COVID-19 service between April 2020 and April 2021, comparing by referral route: posthospitalised (PH), non-hospitalised (NH) and post emergency department (PED). Symptoms associated with poor recovery or inability to return to work full time were assessed using multivariable logistic regression.

Results: 1325 individuals were assessed (PH: 547, 41.3%; PED: 212, 16%; NH: 566, 42.7%). Compared with the PH and PED groups, the NH group were younger (median 44.6 (35.6-52.8) years vs 58.3 (47.0-67.7) years and 48.5 (39.4-55.7) years), more likely to be female (68.2%, 43.0% and 59.9%), less likely to be of ethnic minority (30.9%, 52.7% and 41.0%) or seen later after symptom onset (median (IQR): 194 (118-298) days, 69 (51-111) days and 76 (55-128) days; all p<0.0001). All groups had similar rates of onward specialist referral (NH 18.7%, PH 16.1% and PED 18.9%, p=0.452) and were more likely to require support for breathlessness (23.7%, 5.5% and 15.1%, p<0.001) and fatigue (17.8%, 4.8% and 8.0%, p<0.001). Hospitalised patients had higher rates of pulmonary emboli, persistent lung interstitial abnormalities and other organ impairment. 716 (54.0%) individuals reported <75% optimal health (median 70%, IQR 55%-85%). Less than half of employed individuals could return to work full time at first assessment.

Conclusion: Post-COVID-19 symptoms were significant in PH and NH patients, with significant ongoing healthcare needs and utilisation. Trials of interventions and patient-centred pathways for diagnostic and treatment approaches are urgently required.
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http://dx.doi.org/10.1136/bmjresp-2021-001041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8587466PMC
November 2021

Erratum for Betts et al., "Complete Genome Sequence of Streptococcus pneumoniae Strain BVJ1JL, a Serotype 1 Carriage Isolate from Malawi".

Microbiol Resour Announc 2021 Oct 21;10(42):e0098521. Epub 2021 Oct 21.

NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, United Kingdom.

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http://dx.doi.org/10.1128/MRA.00985-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8530034PMC
October 2021

Physical, cognitive, and mental health impacts of COVID-19 after hospitalisation (PHOSP-COVID): a UK multicentre, prospective cohort study.

Lancet Respir Med 2021 11 7;9(11):1275-1287. Epub 2021 Oct 7.

Hywel Dda University Health Board, Wales, UK; University of Swansea, Swansea, UK; Respiratory Innovation Wales, Llanelli, UK.

Background: The impact of COVID-19 on physical and mental health and employment after hospitalisation with acute disease is not well understood. The aim of this study was to determine the effects of COVID-19-related hospitalisation on health and employment, to identify factors associated with recovery, and to describe recovery phenotypes.

Methods: The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a multicentre, long-term follow-up study of adults (aged ≥18 years) discharged from hospital in the UK with a clinical diagnosis of COVID-19, involving an assessment between 2 and 7 months after discharge, including detailed recording of symptoms, and physiological and biochemical testing. Multivariable logistic regression was done for the primary outcome of patient-perceived recovery, with age, sex, ethnicity, body-mass index, comorbidities, and severity of acute illness as covariates. A post-hoc cluster analysis of outcomes for breathlessness, fatigue, mental health, cognitive impairment, and physical performance was done using the clustering large applications k-medoids approach. The study is registered on the ISRCTN Registry (ISRCTN10980107).

Findings: We report findings for 1077 patients discharged from hospital between March 5 and Nov 30, 2020, who underwent assessment at a median of 5·9 months (IQR 4·9-6·5) after discharge. Participants had a mean age of 58 years (SD 13); 384 (36%) were female, 710 (69%) were of white ethnicity, 288 (27%) had received mechanical ventilation, and 540 (50%) had at least two comorbidities. At follow-up, only 239 (29%) of 830 participants felt fully recovered, 158 (20%) of 806 had a new disability (assessed by the Washington Group Short Set on Functioning), and 124 (19%) of 641 experienced a health-related change in occupation. Factors associated with not recovering were female sex, middle age (40-59 years), two or more comorbidities, and more severe acute illness. The magnitude of the persistent health burden was substantial but only weakly associated with the severity of acute illness. Four clusters were identified with different severities of mental and physical health impairment (n=767): very severe (131 patients, 17%), severe (159, 21%), moderate along with cognitive impairment (127, 17%), and mild (350, 46%). Of the outcomes used in the cluster analysis, all were closely related except for cognitive impairment. Three (3%) of 113 patients in the very severe cluster, nine (7%) of 129 in the severe cluster, 36 (36%) of 99 in the moderate cluster, and 114 (43%) of 267 in the mild cluster reported feeling fully recovered. Persistently elevated serum C-reactive protein was positively associated with cluster severity.

Interpretation: We identified factors related to not recovering after hospital admission with COVID-19 at 6 months after discharge (eg, female sex, middle age, two or more comorbidities, and more acute severe illness), and four different recovery phenotypes. The severity of physical and mental health impairments were closely related, whereas cognitive health impairments were independent. In clinical care, a proactive approach is needed across the acute severity spectrum, with interdisciplinary working, wide access to COVID-19 holistic clinical services, and the potential to stratify care.

Funding: UK Research and Innovation and National Institute for Health Research.
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http://dx.doi.org/10.1016/S2213-2600(21)00383-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8497028PMC
November 2021

Complete Genome Sequence of Streptococcus pneumoniae Strain BVJ1JL, a Serotype 1 Carriage Isolate from Malawi.

Microbiol Resour Announc 2021 Sep 30;10(39):e0071521. Epub 2021 Sep 30.

NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, United Kingdom.

Streptococcus pneumoniae is a leading cause of pneumonia, meningitis, and bacteremia. Serotype 1 is rarely carried but is commonly associated with invasive pneumococcal disease, and in the African "meningitis belt," it is prone to cause cyclical epidemics. We report the complete genome sequence of S. pneumoniae serotype 1 strain BVJ1JL, isolated in Malawi.
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http://dx.doi.org/10.1128/MRA.00715-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8483660PMC
September 2021

ICAM-1 and ICAM-2 Are Differentially Expressed and Up-Regulated on Inflamed Pulmonary Epithelium, but Neither ICAM-2 nor LFA-1: ICAM-1 Are Required for Neutrophil Migration Into the Airways .

Front Immunol 2021 16;12:691957. Epub 2021 Aug 16.

Centre for Inflammation and Tissue Repair, Division of Medicine, University College London, London, United Kingdom.

Neutrophil migration into the airways is an important process to fight infection and is mediated by cell adhesion molecules. The intercellular adhesion molecules, ICAM-1 (CD54) and ICAM-2 (CD102) are known ligands for the neutrophil integrins, lymphocyte function associated antigen (LFA)-1 (αβ; CD11a/CD18), and macrophage-1 antigen (Mac-1;αβ;CD11b/CD18) and are implicated in leukocyte migration into the lung. However, it is ill-defined how neutrophils exit the lung and the role for ICAMs in trans-epithelial migration (TEpM) across the bronchial or alveolar epithelium. We found that human and murine alveolar epithelium expressed ICAM-1, whilst the bronchial epithelium expressed ICAM-2, and both were up-regulated during inflammatory stimulation  and in inflammatory lung diseases such as cystic fibrosis. Although β integrins interacting with ICAM-1 and -2 mediated neutrophil migration across human bronchial epithelium , neither ICAM-2 nor LFA-1 binding of ICAM-1 mediated murine neutrophil migration into the lung or broncho-alveolar space during LPS-induced inflammation Furthermore, TEpM of neutrophils themselves resulted in increased epithelial junctional permeability and reduced barrier function . This suggests that although β integrins interacting with ICAMs may regulate low levels of neutrophil traffic in healthy lung or early in inflammation when the epithelial barrier is intact; these interactions may be redundant later in inflammation when epithelial junctions are disrupted and no longer limit TEpM.
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http://dx.doi.org/10.3389/fimmu.2021.691957DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8415445PMC
October 2021

Single-Nucleotide Polymorphisms within the Loci: Another Potential Source of Clinically Important Genetic Variation for Streptococcus pneumoniae?

Authors:
Jeremy S Brown

Infect Immun 2021 10 2;89(11):e0037421. Epub 2021 Aug 2.

Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom.

The Streptococcus pneumoniae capsule is essential for disease pathogenesis, suggesting that even minor genetic changes within the locus could potentially have important consequences. Arends et al. (D. W. Arends, W. R. Miellet, J. D. Langereis, T. H. A. Ederveen, et al., Infect Immun 89:e00246-21, 2021, https://doi.org/10.1128/IAI.00246-21) have identified 79 different nonsynonymous single-nucleotide polymorphisms (SNPs) in the locus of 338 19A serotype strains and shown significant variations between strains in nucleotide sugar content and capsule shedding. Further work is required to characterize whether any of these changes have important functional consequences on capsule-host interactions.
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http://dx.doi.org/10.1128/IAI.00374-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8519266PMC
October 2021

Insights Into the Effects of Mucosal Epithelial and Innate Immune Dysfunction in Older People on Host Interactions With .

Front Cell Infect Microbiol 2021 25;11:651474. Epub 2021 May 25.

Research Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom.

In humans, nasopharyngeal carriage of is common and although primarily asymptomatic, is a pre-requisite for pneumonia and invasive pneumococcal disease (IPD). Together, these kill over 500,000 people over the age of 70 years worldwide every year. Pneumococcal conjugate vaccines have been largely successful in reducing IPD in young children and have had considerable indirect impact in protection of older people in industrialized country settings (herd immunity). However, serotype replacement continues to threaten vulnerable populations, particularly older people in whom direct vaccine efficacy is reduced. The early control of pneumococcal colonization at the mucosal surface is mediated through a complex array of epithelial and innate immune cell interactions. Older people often display a state of chronic inflammation, which is associated with an increased mortality risk and has been termed 'Inflammageing'. In this review, we discuss the contribution of an altered microbiome, the impact of inflammageing on human epithelial and innate immunity to , and how the resulting dysregulation may affect the outcome of pneumococcal infection in older individuals. We describe the impact of the pneumococcal vaccine and highlight potential research approaches which may improve our understanding of respiratory mucosal immunity during pneumococcal colonization in older individuals.
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http://dx.doi.org/10.3389/fcimb.2021.651474DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8185287PMC
July 2021

CSF Levels of Elongation Factor Tu Is Associated With Increased Mortality in Malawian Adults With Meningitis.

Front Cell Infect Microbiol 2020 11;10:603623. Epub 2020 Dec 11.

UCL Respiratory, Division of Medicine, University College London, London, United Kingdom.

Background: Mortality from bacterial meningitis, predominately caused by , exceeds 50% in sub-Saharan African countries with high HIV prevalence. Underlying causes of high mortality are poorly understood. We examined the host and pathogen proteome in the CSF of adults with proven pneumococcal meningitis (PM), testing if there was an association between differentially expressed proteins and outcome.

Materials/methods: CSF proteomes were analyzed by quantitative Mass-Spectrometry. Spectra were identified using the Swissprot human and TIGR4 pneumococcal protein libraries. Proteins were quantitated and analyzed against mortality. Unique proteins in PM were identified against published normal CSF proteome. Random-Forest models were used to test for protein signatures discriminating outcome. Proteins of interest were tested for their effects on growth and neutrophil opsonophagocytic killing of .

Results: CSF proteomes were available for 57 Adults with PM (median age 32 years, 60% male, 70% HIV-1 co-infected, mortality 63%). Three hundred sixty individual human and 23 pneumococcal proteins were identified. Of the human protein hits, 30% were not expressed in normal CSF, and these were strongly associated with inflammation and primarily related to neutrophil activity. No human protein signature predicted outcome. However, expression of the essential protein Elongation Factor Tu (EF-Tu) was significantly increased in CSF of non-survivors [False Discovery Rate (q) <0.001]. Expression of EF-Tu was negatively cocorrelated against expression of Neutrophil defensin (r 0.4 p p < 0.002), but not against complement proteins C3 or Factor H. , addition of EF-Tu protein impaired neutrophil killing in CSF.

Conclusions: Excessive EF-Tu protein in CSF was associated with reduced survival in meningitis in a high HIV prevalence population. We show EF-Tu may inhibit neutrophil mediated killing of in CSF. Further mechanistic work is required to better understand how avoids essential innate immune responses during PM through production of excess EF-Tu.
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http://dx.doi.org/10.3389/fcimb.2020.603623DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7759504PMC
June 2021

'Long-COVID': a cross-sectional study of persisting symptoms, biomarker and imaging abnormalities following hospitalisation for COVID-19.

Thorax 2021 04 10;76(4):396-398. Epub 2020 Nov 10.

Respiratory Medicine, Royal Free London NHS Foundation Trust, London, UK

Large numbers of people are being discharged from hospital following COVID-19 without assessment of recovery. In 384 patients (mean age 59.9 years; 62% male) followed a median 54 days post discharge, 53% reported persistent breathlessness, 34% cough and 69% fatigue. 14.6% had depression. In those discharged with elevated biomarkers, 30.1% and 9.5% had persistently elevated d-dimer and C reactive protein, respectively. 38% of chest radiographs remained abnormal with 9% deteriorating. Systematic follow-up after hospitalisation with COVID-19 identifies the trajectory of physical and psychological symptom burden, recovery of blood biomarkers and imaging which could be used to inform the need for rehabilitation and/or further investigation.
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http://dx.doi.org/10.1136/thoraxjnl-2020-215818DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7661378PMC
April 2021

Targeting coagulation activation in severe COVID-19 pneumonia: lessons from bacterial pneumonia and sepsis.

Eur Respir Rev 2020 Sep 1;29(157). Epub 2020 Oct 1.

Centre for Inflammation and Tissue Repair, University College London, London, UK.

Novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has rapidly spread throughout the world, resulting in a pandemic with high mortality. There are no effective treatments for the management of severe COVID-19 and current therapeutic trials are focused on antiviral therapy and attenuation of hyper-inflammation with anti-cytokine therapy. Severe COVID-19 pneumonia shares some pathological similarities with severe bacterial pneumonia and sepsis. In particular, it disrupts the haemostatic balance, which results in a procoagulant state locally in the lungs and systemically. This culminates in the formation of microthrombi, disseminated intravascular coagulation and multi-organ failure. The deleterious effects of exaggerated inflammatory responses and activation of coagulation have been investigated in bacterial pneumonia and sepsis and there is recognition that although these pathways are important for the host immune response to pathogens, they can lead to bystander tissue injury and are negatively associated with survival. In the past two decades, evidence from preclinical studies has led to the emergence of potential anticoagulant therapeutic strategies for the treatment of patients with pneumonia, sepsis and acute respiratory distress syndrome, and some of these anticoagulant approaches have been trialled in humans. Here, we review the evidence from preclinical studies and clinical trials of anticoagulant treatment strategies in bacterial pneumonia and sepsis, and discuss the importance of these findings in the context of COVID-19.
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http://dx.doi.org/10.1183/16000617.0240-2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7537941PMC
September 2020

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43.

J Vis Exp 2020 09 11(163). Epub 2020 Sep 11.

Faculty of Infections and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine.

Streptococcus pneumoniae serotype 1 remains a huge problem in low-and-middle income countries, particularly in sub-Saharan Africa. Despite its importance, studies in this serotype have been hindered by the lack of genetic tools to modify it. In this study, we describe a method to genetically modify a serotype 1 clinical isolate (strain 519/43). Interestingly, this was achieved by exploiting the Pneumococcus' ability to naturally acquire DNA. However, unlike most pneumococci, the use of linear DNA was not successful; to mutate this important strain, a suicide plasmid had to be used. This methodology has provided the means for a deeper understanding of this elusive serotype, both in terms of its biology and pathogenicity. To validate the method, the major known pneumococcal toxin, pneumolysin, was mutated because it has a well-known and easy to follow phenotype. We showed that the mutant, as expected, lost its ability to lyse red blood cells. By being able to mutate an important gene in the serotype of interest, we were able to observe different phenotypes for loss of function mutants upon intraperitoneal and intranasal infections from the ones observed for other serotypes. In summary, this study proves that strain 519/43 (serotype 1) can be genetically modified.
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http://dx.doi.org/10.3791/61594DOI Listing
September 2020

Management of community-acquired pneumonia: essential tips for the physician on call.

Br J Hosp Med (Lond) 2020 May 23;81(5):1-9. Epub 2020 May 23.

UCL Respiratory, Department of Medicine, University College London, Rayne Institute, London, UK.

Community-acquired pneumonia is a common clinical problem requiring admission to hospital, with a particularly high incidence in the elderly population and those with significant comorbidities. Diagnosis is made on the combination of a short history of respiratory symptoms and systemic ill-health with new examination and/or radiological features of consolidation. Multiple other infective and non-infective conditions can mimic community-acquired pneumonia, leading to misdiagnosis in 5-17% of cases. The CURB-65 score can identify patients with community-acquired pneumonia with a higher risk of mortality, but is insensitive at identifying patients requiring intensive care support and needs to be combined with clinical markers of potential severity. Both high admission levels of C-reactive protein and the failure of levels of C-reactive protein to decline by >50% by day 4 after admission are associated with higher risk of complications, need for ventilation or inotropic support, and mortality. Empirical antibiotic therapy for most patients admitted to hospital is combination of a ß-lactam and a macrolide. Short courses of antibiotics do not result in significantly different outcomes to longer courses unless the patient has developed complications such as a complex parapneumonic effusion. Implementation of a community-acquired pneumonia care bundle into clinical practice reduces mortality, and should be a high priority for all acute hospitals.
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http://dx.doi.org/10.12968/hmed.2020.0124DOI Listing
May 2020

Opportunistic bacterial, viral and fungal infections of the lung.

Medicine (Abingdon) 2020 Jun 8;48(6):366-372. Epub 2020 May 8.

is a Consultant in respiratory medicine at the Royal Brompton & Harefield NHS Foundation Trust, London, UK. His specialist interest is in respiratory infections and bronchiectasis in immunocompromised hosts, particularly immunodeficiency secondary to cancer and biological therapy. Competing interests: none declared.

Opportunistic infections are a major cause of morbidity and mortality in severely immunocompromised patients, such as those given chemotherapy or biological therapies, and those with haematological malignancy, aplastic anaemia or HIV infection, or recipients of solid organ or stem cell transplants. The type and degree of immune defect dictates the profile of potential opportunistic pathogens; T-cell-mediated defects increase the risk of viral (cytomegalovirus, respiratory viruses) and infections, whereas neutrophil defects are associated with bacterial pneumonia and invasive aspergillosis. However, patients often have combinations of immune defects, and a wide range of other opportunistic infections can cause pneumonia. Importantly, conventional non-opportunistic pathogens are frequently encountered in immunocompromised hosts and should not be overlooked The radiological pattern of disease (best assessed by computed tomography) and speed of onset help identify the likely pathogen(s); this can then be supported by targeted investigation including early use of bronchoscopy in selected patients. Rapid and expert clinical assessment can identify the most likely pathogens, allowing timely appropriate therapy.
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http://dx.doi.org/10.1016/j.mpmed.2020.03.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7206443PMC
June 2020

Deletion of the Zinc Transporter Lipoprotein AdcAII Causes Hyperencapsulation of Streptococcus pneumoniae Associated with Distinct Alleles of the Type I Restriction-Modification System.

mBio 2020 03 31;11(2). Epub 2020 Mar 31.

Centre for Inflammation and Tissue Repair, Department of Medicine, Royal Free and University College Medical School, Rayne Institute, London, United Kingdom.

The capsule is the dominant virulence factor, yet how variation in capsule thickness is regulated is poorly understood. Here, we describe an unexpected relationship between mutation of , which encodes a zinc uptake lipoprotein, and capsule thickness. Partial deletion of in three of five capsular serotypes frequently resulted in a mucoid phenotype that biochemical analysis and electron microscopy of the D39 mutants confirmed was caused by markedly increased capsule thickness. Compared to D39, the hyperencapsulated mutant strain was more resistant to complement-mediated neutrophil killing and was hypervirulent in mouse models of invasive infection. Transcriptome analysis of D39 and the mutant identified major differences in transcription of the Sp_0505-0508 locus, which encodes an SpnD39III (ST5556II) type I restriction-modification system and allelic variation of which correlates with capsule thickness. A PCR assay demonstrated close linkage of the SpnD39IIIC and F alleles with the hyperencapsulated strains. However, transformation of with fixed SpnD39III alleles associated with normal capsule thickness did not revert the hyperencapsulated phenotype. Half of hyperencapsulated strains contained the same single nucleotide polymorphism in the capsule locus gene , which is required for the initiation of capsule synthesis. These results provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identified an unexpected linkage between capsule thickness and mutation of Further investigation will be needed to characterize how mutation of affects SpnD39III (ST5556II) allele dominance and results in the hyperencapsulated phenotype. The capsule affects multiple interactions with the host including contributing to colonization and immune evasion. During infection, the capsule thickness varies, but the mechanisms regulating this are poorly understood. We have identified an unsuspected relationship between mutation of , a gene that encodes a zinc uptake lipoprotein, and capsule thickness. Mutation of resulted in a striking hyperencapsulated phenotype, increased resistance to complement-mediated neutrophil killing, and increased virulence in mouse models of infection. Transcriptome and PCR analysis linked the hyperencapsulated phenotype of the strain to specific alleles of the SpnD39III (ST5556II) type I restriction-modification system, a system which has previously been shown to affect capsule thickness. Our data provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identify an unexpected link between capsule thickness and , further investigation of which could further characterize mechanisms of capsule regulation.
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http://dx.doi.org/10.1128/mBio.00445-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7157770PMC
March 2020

Construction of a pneumolysin deficient mutant in streptococcus pneumoniae serotype 1 strain 519/43 and phenotypic characterisation.

Microb Pathog 2020 Apr 26;141:103999. Epub 2020 Jan 26.

Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom. Electronic address:

Streptococcus pneumoniae capsular serotype 1 continues to pose a huge infectious disease burden in low- and middle-income countries, particularly in West Africa. However, studies on this important serotype have been hampered by the inability to genetically modify these strains. In this study we have genetically modified a serotype 1 strain (519/43), the first time that this has been achieved for this serotype, providing the methodology for a deeper understanding of its biology and pathogenicity. As proof of principle we constructed a defined pneumolysin mutant and showed that it lost its ability to lyse red blood cells. We also showed that when mice were infected intranasally with the mutant 519/43Δply there was no significant difference between the load of bacteria in lungs and blood when compared to the wild type 519/43. When mice were infected intraperitoneally there were significantly fewer bacteria recovered from blood for the mutant 519/43Δply strain, although all mice still displayed signs of disease. Our study demonstrates S. pneumoniae serotype 1 strains can be genetically manipulated using our methodology and demonstrate that the ability to cause pneumonia in mice is independent of active pneumolysin for the 519/43 serotype 1 strain.
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http://dx.doi.org/10.1016/j.micpath.2020.103999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7212698PMC
April 2020

Can animal models really teach us anything about pneumonia? Pro.

Eur Respir J 2020 01 2;55(1). Epub 2020 Jan 2.

UCL Respiratory, University College London, London, UK

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http://dx.doi.org/10.1183/13993003.01539-2019DOI Listing
January 2020

bronchiectasis in haematological malignancies: patient characteristics, risk factors and survival.

ERJ Open Res 2019 Oct 4;5(4). Epub 2019 Nov 4.

Centre for Inflammation and Tissue Repair, UCL Respiratory, London, UK.

http://bit.ly/2KZwCZt.
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http://dx.doi.org/10.1183/23120541.00166-2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826250PMC
October 2019

Improving Pulmonary Immunity to Bacterial Pathogens through Colonization of the Nasopharynx.

Authors:
Jeremy S Brown

Am J Respir Crit Care Med 2020 02;201(3):268-270

UCL RespiratoryUniversity College LondonLondon, United Kingdom.

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http://dx.doi.org/10.1164/rccm.201910-2047EDDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6999096PMC
February 2020

Relative Contributions of Extracellular and Internalized Bacteria to Early Macrophage Proinflammatory Responses to Streptococcus pneumoniae.

mBio 2019 09 24;10(5). Epub 2019 Sep 24.

Centre for Inflammation and Tissue Repair, UCL Respiratory, Division of Medicine, University College Medical School, Rayne Institute, London, United Kingdom

Both intracellular immune sensing and extracellular innate immune sensing have been implicated in initiating macrophage proinflammatory cytokine responses to The capsule, a major virulence determinant, prevents phagocytosis, and we hypothesized that this would reduce activation of host innate inflammatory responses by preventing activation of intracellular proinflammatory signaling pathways. We investigated this hypothesis in human monocyte-derived macrophages stimulated with encapsulated or isogenic unencapsulated mutant Unexpectedly, despite strongly inhibiting bacterial internalization, the capsule resulted in enhanced inflammatory cytokine production by macrophages infected with Experiments using purified capsule material and a mutant expressing an serotype 4 capsule indicated these differences required whole bacteria and were not due to proinflammatory effects of the capsule itself. Transcriptional profiling demonstrated relatively few differences in macrophage gene expression profiles between infections with encapsulated and those with unencapsulated , largely limited to reduced expression of proinflammatory genes in response to unencapsulated bacteria, predicted to be due to reduced activation of the NF-κB family of transcription factors. Blocking internalization using cytochalasin D had minimal effects on the inflammatory response to Experiments using murine macrophages indicated that the affected genes were dependent on Toll-like receptor 2 (TLR2) activation, although not through direct stimulation of TLR2 by capsule polysaccharide. Our data demonstrate that the early macrophage proinflammatory response to is mainly dependent on extracellular bacteria and reveal an unexpected proinflammatory effect of encapsulated that could contribute to disease pathogenesis. Multiple extra- and intracellular innate immune receptors have been identified that recognize , but the relative contributions of intra- versus extracellular bacteria to the inflammatory response were unknown. We have shown that intracellular contributes surprisingly little to the inflammatory responses, with production of important proinflammatory cytokines largely dependent on extracellular bacteria. Furthermore, although we expected the polysaccharide capsule to block activation of the host immune system by reducing bacterial internalization and therefore activation of intracellular innate immune receptors, there was an increased inflammatory response to encapsulated compared to unencapsulated bacteria, which is likely to contribute to disease pathogenesis.
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http://dx.doi.org/10.1128/mBio.02144-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6759765PMC
September 2019

Reproducibility of an airway tapering measurement in computed tomography with application to bronchiectasis.

J Med Imaging (Bellingham) 2019 Jul 16;6(3):034003. Epub 2019 Sep 16.

University College London, Center for Medical Image Computing, London, United Kingdom.

We propose a pipeline to acquire a scalar tapering measurement from the carina to the most distal point of an individual airway visible on computed tomography (CT). We show the applicability of using tapering measurements on clinically acquired data by quantifying the reproducibility of the tapering measure. We generate a spline from the centerline of an airway to measure the area and arclength at contiguous intervals. The tapering measurement is the gradient of the linear regression between area in log space and arclength. The reproducibility of the measure was assessed by analyzing different radiation doses, voxel sizes, and reconstruction kernel on single timepoint and longitudinal CT scans and by evaluating the effect of airway bifurcations. Using 74 airways from 10 CT scans, we show a statistical difference, , in tapering between healthy airways ( ) and those affected by bronchiectasis ( ). The difference between the mean of the two populations is , and the difference between the medians of the two populations was . The tapering measurement retained a 95% confidence interval of in a simulated 25 mAs scan and retained a 95% confidence of on simulated CTs up to 1.5 times the original voxel size. We have established an estimate of the precision of the tapering measurement and estimated the effect on precision of the simulated voxel size and CT scan dose. We recommend that the scanner calibration be undertaken with the phantoms as described, on the specific CT scanner, radiation dose, and reconstruction algorithm that are to be used in any quantitative studies.
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http://dx.doi.org/10.1117/1.JMI.6.3.034003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6745534PMC
July 2019

Pulmonary rehabilitation, physical activity and aortic stiffness in COPD.

Respir Res 2019 Jul 24;20(1):166. Epub 2019 Jul 24.

UCL Respiratory, University College London, London, UK.

Background: Patients with chronic obstructive pulmonary disease (COPD) have elevated cardiovascular risk, and cardiovascular disease is a major cause of death in COPD. The current literature indicates that changes in cardiovascular risk during pulmonary rehabilitation (assessed using aortic stiffness) are heterogeneous suggesting that there may be sub-groups of patients who do and do not benefit.

Objectives: To investigate the characteristics of COPD patients who do and do not experience aortic stiffness reduction during pulmonary rehabilitation, examine how changes relate to physical activity and exercise capacity, and assess whether changes in aortic stiffness are maintained at 6 weeks following rehabilitation.

Methods: We prospectively measured arterial stiffness (aortic pulse-wave velocity), exercise capacity (Incremental Shuttle Walk Test) and physical activity (daily step count) in 92 COPD patients who started a six week pulmonary rehabilitation programme, 54 of whom completed rehabilitation, and 29 of whom were re-assessed six weeks later.

Results: Whilst on average there was no influence of pulmonary rehabilitation on aortic stiffness (pre- vs. post pulse-wave velocity 11.3 vs. 11.1 m/s p = 0.34), 56% patients responded with a significant reduction in aortic stiffness. Change in aortic stiffness (absolute and/or percentage) during rehabilitation was associated with both increased physical activity (rho = - 0.30, p = 0.042) and change in exercise capacity (rho = - 0.32, p = 0.02), but in multivariable analysis most closely with physical activity. 92% of the responders who attended maintained this response six weeks later.

Conclusion: Elevated aortic stiffness in COPD is potentially modifiable in a subgroup of patients during pulmonary rehabilitation and is associated with increased physical activity.

Trial Registration: ClinicalTrials.gov Identifier: NCT03003208. Registered 26/12/ 2016.
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http://dx.doi.org/10.1186/s12931-019-1135-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6657099PMC
July 2019

Microinvasion by Streptococcus pneumoniae induces epithelial innate immunity during colonisation at the human mucosal surface.

Nat Commun 2019 07 16;10(1):3060. Epub 2019 Jul 16.

Division of Infection and Immunity, University College London, London, UK.

Control of Streptococcus pneumoniae colonisation at human mucosal surfaces is critical to reducing the burden of pneumonia and invasive pneumococcal disease, interrupting transmission, and achieving herd protection. Here, we use an experimental human pneumococcal carriage model (EHPC) to show that S. pneumoniae colonisation is associated with epithelial surface adherence, micro-colony formation and invasion, without overt disease. Interactions between different strains and the epithelium shaped the host transcriptomic response in vitro. Using epithelial modules from a human epithelial cell model that recapitulates our in vivo findings, comprising of innate signalling and regulatory pathways, inflammatory mediators, cellular metabolism and stress response genes, we find that inflammation in the EHPC model is most prominent around the time of bacterial clearance. Our results indicate that, rather than being confined to the epithelial surface and the overlying mucus layer, the pneumococcus undergoes micro-invasion of the epithelium that enhances inflammatory and innate immune responses associated with clearance.
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http://dx.doi.org/10.1038/s41467-019-11005-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6635362PMC
July 2019

Mechanisms of Naturally Acquired Immunity to .

Front Immunol 2019 1;10:358. Epub 2019 Mar 1.

Centre for Inflammation and Tissue Repair, UCL Respiratory, London, United Kingdom.

In this review we give an update on the mechanisms of naturally acquired immunity against , one of the major human bacterial pathogens that is a common cause of pneumonia, septicaemia, and meningitis. A clear understanding of the natural mechanisms of immunity to is necessary to help define why the very young and elderly are at high risk of disease, and for devising new prevention strategies. Recent data has shown that nasopharynx colonization by induces antibody responses to protein and capsular antigens in both mice and humans, and also induces Th17 CD4+ cellular immune responses in mice and increases pre-existing responses in humans. These responses are protective, demonstrating that colonization is an immunizing event. We discuss the data from animal models and humans on the relative importance of naturally acquired antibody and Th17 cells on immunity to at three different anatomical sites of infection, the nasopharynx (the site of natural asymptomatic carriage), the lung (site of pneumonia), and the blood (site of sepsis). Mouse data suggest that CD4+ Th17 cells prevent both primary and secondary nasopharyngeal carriage with no role for antibody induced by previous colonization. In contrast, antibody is necessary for prevention of sepsis but CD4+ cellular responses are not. Protection against pneumonia requires a combination of both antibody and Th17 cells, in both cases targeting protein rather than capsular antigen. Proof of which immune component prevents human infection is less easily available, but two recent papers demonstrate that human IgG targeting protein antigens is highly protective against septicaemia. The role of CD4+ responses to prior nasopharyngeal colonization for protective immunity in humans is unclear. The evidence that there is significant naturally-acquired immunity to independent of anti-capsular polysaccharide has clinical implications for the detection of subjects at risk of infections, and the data showing the importance of protein antigens as targets for antibody and Th17 mediated immunity should aid the development of new vaccine strategies.
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http://dx.doi.org/10.3389/fimmu.2019.00358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6405633PMC
September 2020

Invasive aspergillosis complicating treatment with tyrosine kinase inhibitors.

BMJ Case Rep 2019 Jan 29;12(1). Epub 2019 Jan 29.

Respiratory Division of Medicine, University College London, London, UK.

We describe three cases of pulmonary aspergillosis (PA) in three patients without traditional risk factors for invasive aspergillosis infection, such as prolonged neutropenia or high dose systemic corticosteroid therapy. All three patients developed PA while taking tyrosine kinase inhibitors (TKI) and sustained greater clinical improvement once TKI were withdrawn. Our case series supports the theory TKI treatment can increase susceptibility to PA without causing neutropenia. Recognition that TKI treatment may predispose to invasive aspergillosis will allow for rapid recognition of affected patients and more effective management of future cases.
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http://dx.doi.org/10.1136/bcr-2018-226121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6352846PMC
January 2019

A Novel, Multiple-Antigen Pneumococcal Vaccine Protects against Lethal Challenge.

Infect Immun 2019 03 21;87(3). Epub 2019 Feb 21.

Centre for Inflammation and Tissue Repair, UCL Respiratory, Division of Medicine, University College Medical School Rayne Institute, London, United Kingdom

Current vaccination against uses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared from TIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains of were opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologous strains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection against .
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http://dx.doi.org/10.1128/IAI.00846-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6386546PMC
March 2019

A recombinant conjugated pneumococcal vaccine that protects against murine infections with a similar efficacy to Prevnar-13.

NPJ Vaccines 2018 31;3:53. Epub 2018 Oct 31.

1Department of Respiratory Medicine, Centre for Inflammation and Tissue Repair, University College London, London, UK.

The pneumococcal conjugate vaccine (PCV) strongly protects against vaccine serotypes, but the rapid expansion of non-vaccine serotype disease and the vaccine's high expense has reduced its overall impact. We have developed Protein Glycan Coupling Technology (PGCT) as a flexible methodology for making low-cost polysaccharide/protein glycoconjugates recombinantly in . We have used PGCT to make a recombinant PCV containing serotype 4 capsular polysaccharide linked to the proteins NanA, PiuA, and Sp0148. The introduction of the UDP-glucose 4-epimerase gene GalE () into improved the yield of the resulting glycoprotein. PGCT glycoconjugate vaccination generated strong antibody responses in mice to both the capsule and the carrier protein antigens, with the PiuA/capsule glycoconjugate inducing similar anti-capsular antibody responses as the commercial PCV Prevnar-13. Antibody responses to PGCT glycoconjugates opsonised and expressing the serotype 4 capsule and promoted neutrophil phagocytosis of to a similar level as antisera generated by vaccination with Prevnar-13. Vaccination with the PGCT glycoconjugates protected mice against meningitis and septicaemia with the same efficacy as vaccination with Prevnar-13. In addition, vaccination with the protein antigen components from PGCT glycoconjugates alone provided partial protection against septicaemia and colonisation. These data demonstrate that a vaccine made by PGCT is as effective as Prevnar-13, identifies PiuA as a carrier protein for glycoconjugate vaccines, and demonstrates that linking capsular antigen to protein antigens has additional protective benefits that could provide a degree of serotype-independent immunity.
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http://dx.doi.org/10.1038/s41541-018-0090-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6208403PMC
October 2018

Streptococcus pneumoniae potently induces cell death in mesothelial cells.

PLoS One 2018 30;13(7):e0201530. Epub 2018 Jul 30.

Centre for Respiratory Health, University of Western Australia, Perth, Western Australia, Australia.

Pleural infection/empyema is common and its incidence continues to rise. Streptococcus pneumoniae is the commonest bacterial cause of empyema in children and among the commonest in adults. The mesothelium represents the first line of defense against invading microorganisms, but mesothelial cell responses to common empyema pathogens, including S. pneumoniae, have seldom been studied. We assessed mesothelial cell viability in vitro following exposure to common empyema pathogens. Clinical isolates of S. pneumoniae from 25 patients with invasive pneumococcal disease and three reference strains were tested. All potently induced death of cultured mesothelial cells (MeT-5A) in a dose- and time-dependent manner (>90% at 107 CFU/mL after 24 hours). No significant mesothelial cell killing was observed when cells were co-cultured with Staphylococcus aureus, Streptococcus sanguinis and Streptococcus milleri group bacteria. S. pneumoniae induced mesothelial cell death via secretory product(s) as cytotoxicity could be: i) reproduced using conditioned media derived from S. pneumoniae and ii) in transwell studies when the bacteria and mesothelial cells were separated. No excess cell death was seen when heat-killed S. pneumoniae were used. Pneumolysin, a cytolytic S. pneumoniae toxin, induced cell death in a time- and dose-dependent manner. S. pneumoniae lacking the pneumolysin gene (D39 ΔPLY strain) failed to kill mesothelial cells compared to wild type (D39) controls, confirming the necessity of pneumolysin in D39-induced mesothelial cell death. However, pneumolysin gene mutation in other S. pneumoniae strains (TIGR4, ST3 and ST23F) only partly abolished their cytotoxic effects, suggesting different strains may induce cell death via different mechanisms.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201530PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066251PMC
January 2019

Human pleural fluid is a potent growth medium for Streptococcus pneumoniae.

PLoS One 2017 30;12(11):e0188833. Epub 2017 Nov 30.

Division of Medicine, University of Western Australia, Perth, Western Australia, Australia.

Empyema is defined by the presence of bacteria and/or pus in pleural effusions. However, the biology of bacteria within human pleural fluid has not been studied. Streptococcus pneumoniae is the most common cause of pediatric and frequent cause of adult empyema. We investigated whether S. pneumoniae can proliferate within human pleural fluid and if growth is affected by the cellular content of the fluid and/or characteristics of pneumococcal surface proteins. Invasive S. pneumoniae isolates (n = 24) and reference strain recovered from human blood or empyema were inoculated (1.5×106CFU/mL) into sterile human malignant pleural fluid samples (n = 11). All S. pneumoniae (n = 25) strains proliferated rapidly, increasing by a median of 3009 (IQR 1063-9846) from baseline at 24hrs in all pleural effusions tested. Proliferation was greater than in commercial pneumococcal culture media and concentrations were maintained for 48hrs without autolysis. A similar magnitude of proliferation was observed in pleural fluid before and after removal of its cellular content, p = 0.728. S. pneumoniae (D39 strain) wild-type, and derivatives (n = 12), each with mutation(s) in a different gene required for full virulence were inoculated into human pleural fluid (n = 8). S. pneumoniae with pneumococcal surface antigen A (ΔpsaA) mutation failed to grow (2207-fold lower than wild-type), p<0.001, however growth was restored with manganese supplementation. Growth of other common respiratory pathogens (n = 14) across pleural fluid samples (n = 7) was variable and inconsistent, with some strains failing to grow. We establish for the first time that pleural fluid is a potent growth medium for S. pneumoniae and proliferation is dependent on the PsaA surface protein and manganese.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188833PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5708656PMC
December 2017

Correlates and assessment of excess cardiovascular risk in bronchiectasis.

Eur Respir J 2017 11 22;50(5). Epub 2017 Nov 22.

Centre for Inflammation and Tissue Repair, UCL Respiratory Medicine, Royal Free Campus, University College London, London, UK.

Patients with bronchiectasis are at increased risk of cardiovascular disease. We aimed to identify factors associated with elevated cardiovascular risk in bronchiectasis, measured using aortic stiffness and cardiac biomarkers. In addition, we sought to compare these direct measures against calculated QRISK2 scores.Aortic stiffness, cardiac biomarkers and systemic inflammation were measured in 101 adults with stable bronchiectasis. In addition, clinical and demographic data were collected to allow calculation of QRISK2 score and the bronchiectasis severity index (BSI) for each patient.The BSI score correlated with measured cardiovascular risk assessments, partly due to greater exacerbation frequency and lower forced expiratory volume in 1 s. Pulse-wave velocity was significantly higher in frequent exacerbators (≥3 events·year) than infrequent exacerbators (<3 events·year; 10.5 9.2 m·s, p=0.01). In addition, frequent exacerbators had elevated serum C-reactive protein concentration, suggesting increased systemic inflammation (4.8 2.2 mg·L, p=0.005). QRISK2 systematically underestimated cardiovascular risk in this population (median change in relative risk 1.29). Underestimation was associated with frequent exacerbations and male sex.Patients with bronchiectasis have greater cardiovascular risk than published reference populations. Excess cardiovascular risk is associated with exacerbation frequency and impaired lung function. Cardiovascular risk assessment in bronchiectasis should be individualised, as calculation tools are likely to underestimate the risk in this population.
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http://dx.doi.org/10.1183/13993003.01127-2017DOI Listing
November 2017
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