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Cogdale J, Kele B, Myers R, Harvey R, Lofts A, Mikaiel T, Hoschler K, Banyard AC, James J, Mollett BC, Byrne AM, Lopez-Bernal J, Watson CH, Chand M, Welfare W, Williamson DA, Oliver I, Padfield S, Lee A, Calvert S, Bewley MA, Wallace L, deLusignan S, Lewis NS, Brown IH, Zambon M. A case of swine influenza A(H1N2)v in England, November 2023. Euro Surveill 2024; 29:2400002. [PMID: 38240057 PMCID: PMC10797662 DOI: 10.2807/1560-7917.es.2024.29.3.2400002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 01/18/2024] [Indexed: 01/22/2024] Open
Abstract
Under International Health Regulations from 2005, a human infection caused by a novel influenza A virus variant is considered an event that has potential for high public health impact and is immediately notifiable to the World Health Organisation. We here describe the clinical, epidemiological and virological features of a confirmed human case of swine influenza A(H1N2)v in England detected through community respiratory virus surveillance. Swabbing and contact tracing helped refine public health risk assessment, following this unusual and unexpected finding.
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Affiliation(s)
- Jade Cogdale
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - Beatrix Kele
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - Richard Myers
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - Ruth Harvey
- The Francis Crick Institute, London, United Kingdom
| | - Abi Lofts
- The Francis Crick Institute, London, United Kingdom
| | | | - Katja Hoschler
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - Ashley C Banyard
- Animal and Plant Health Agency (APHA), Weybridge, United Kingdom
| | - Joe James
- Animal and Plant Health Agency (APHA), Weybridge, United Kingdom
| | - Benjamin C Mollett
- Animal and Plant Health Agency (APHA), Weybridge, United Kingdom
- Royal Veterinary College, London, United Kingdom
| | | | | | - Conall H Watson
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - Meera Chand
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - William Welfare
- United Kingdom Health Security Agency (UKHSA), Manchester, United Kingdom
| | | | - Isabel Oliver
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
| | - Simon Padfield
- United Kingdom Health Security Agency (UKHSA), Leeds, United Kingdom
| | - Andrew Lee
- United Kingdom Health Security Agency (UKHSA), Leeds, United Kingdom
| | - Suzanne Calvert
- United Kingdom Health Security Agency (UKHSA), Leeds, United Kingdom
| | - Martin A Bewley
- United Kingdom Health Security Agency (UKHSA), Leeds, United Kingdom
| | - Louise Wallace
- Yorkshire and Humber Public Health Network (YHPHN), Yorkshire, United Kingdom
| | - Simon deLusignan
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford United Kingdom
- Royal College of General Practice (RCGP) Research and Surveillance Centre (RSC), Oxford, United Kingdom
| | - Nicola S Lewis
- The Francis Crick Institute, London, United Kingdom
- Royal Veterinary College, London, United Kingdom
| | - Ian H Brown
- Animal and Plant Health Agency (APHA), Weybridge, United Kingdom
| | - Maria Zambon
- United Kingdom Health Security Agency (UKHSA), London, United Kingdom
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2
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Preston JA, Bewley MA, Marriott HM, McGarry Houghton A, Mohasin M, Jubrail J, Morris L, Stephenson YL, Cross S, Greaves DR, Craig RW, van Rooijen N, Bingle CD, Read RC, Mitchell TJ, Whyte MKB, Shapiro SD, Dockrell DH. Alveolar Macrophage Apoptosis-associated Bacterial Killing Helps Prevent Murine Pneumonia. Am J Respir Crit Care Med 2020; 200:84-97. [PMID: 30649895 DOI: 10.1164/rccm.201804-0646oc] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Rationale: Antimicrobial resistance challenges therapy of pneumonia. Enhancing macrophage microbicidal responses would combat this problem but is limited by our understanding of how alveolar macrophages (AMs) kill bacteria. Objectives: To define the role and mechanism of AM apoptosis-associated bacterial killing in the lung. Methods: We generated a unique CD68.hMcl-1 transgenic mouse with macrophage-specific overexpression of the human antiapoptotic Mcl-1 protein, a factor upregulated in AMs from patients at increased risk of community-acquired pneumonia, to address the requirement for apoptosis-associated killing. Measurements and Main Results: Wild-type and transgenic macrophages demonstrated comparable ingestion and initial phagolysosomal killing of bacteria. Continued ingestion (for ≥12 h) overwhelmed initial killing, and a second, late-phase microbicidal response killed viable bacteria in wild-type macrophages, but this response was blunted in CD68.hMcl-1 transgenic macrophages. The late phase of bacterial killing required both caspase-induced generation of mitochondrial reactive oxygen species and nitric oxide, the peak generation of which coincided with the late phase of killing. The CD68.hMcl-1 transgene prevented mitochondrial reactive oxygen species but not nitric oxide generation. Apoptosis-associated killing enhanced pulmonary clearance of Streptococcus pneumoniae and Haemophilus influenzae in wild-type mice but not CD68.hMcl-1 transgenic mice. Bacterial clearance was enhanced in vivo in CD68.hMcl-1 transgenic mice by reconstitution of apoptosis with BH3 mimetics or clodronate-encapsulated liposomes. Apoptosis-associated killing was not activated during Staphylococcus aureus lung infection. Conclusions: Mcl-1 upregulation prevents macrophage apoptosis-associated killing and establishes that apoptosis-associated killing is required to allow AMs to clear ingested bacteria. Engagement of macrophage apoptosis should be investigated as a novel, host-based antimicrobial strategy.
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Affiliation(s)
- Julie A Preston
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Martin A Bewley
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Helen M Marriott
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - A McGarry Houghton
- 3 Clinical Research Division, Fred Hutchinson Cancer Research Center, and.,4 Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, Washington
| | - Mohammed Mohasin
- 5 Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
| | | | - Lucy Morris
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Yvonne L Stephenson
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Simon Cross
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom.,7 Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - David R Greaves
- 8 Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Ruth W Craig
- 9 Department of Pharmacology and Toxicology, Geissel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Nico van Rooijen
- 10 Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, the Netherlands
| | - Colin D Bingle
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Robert C Read
- 11 University of Southampton Medical School, Southampton, United Kingdom.,12 National Institute for Health Research Southampton Biomedical Research Centre, Southampton, United Kingdom
| | - Timothy J Mitchell
- 13 Institute of Microbiology and Infection, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom; and
| | - Moira K B Whyte
- 6 MRC Centre for Inflammation Research.,14 Department of Respiratory Medicine, and
| | - Steven D Shapiro
- 15 Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - David H Dockrell
- 6 MRC Centre for Inflammation Research.,16 Infection Medicine, University of Edinburgh, Edinburgh, United Kingdom
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3
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Bewley MA, Budd RC, Ryan E, Cole J, Collini P, Marshall J, Kolsum U, Beech G, Emes RD, Tcherniaeva I, Berbers GAM, Walmsley SR, Donaldson G, Wedzicha JA, Kilty I, Rumsey W, Sanchez Y, Brightling CE, Donnelly LE, Barnes PJ, Singh D, Whyte MKB, Dockrell DH. Opsonic Phagocytosis in Chronic Obstructive Pulmonary Disease Is Enhanced by Nrf2 Agonists. Am J Respir Crit Care Med 2019; 198:739-750. [PMID: 29547002 DOI: 10.1164/rccm.201705-0903oc] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
RATIONALE Previous studies have identified defects in bacterial phagocytosis by alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD), but the mechanisms and clinical consequences remain incompletely defined. OBJECTIVES To examine the effect of COPD on AM phagocytic responses and identify the mechanisms, clinical consequences, and potential for therapeutic manipulation of these defects. METHODS We isolated AMs and monocyte-derived macrophages (MDMs) from a cohort of patients with COPD and control subjects within the Medical Research Council COPDMAP consortium and measured phagocytosis of bacteria in relation to opsonic conditions and clinical features. MEASUREMENTS AND MAIN RESULTS COPD AMs and MDMs have impaired phagocytosis of Streptococcus pneumoniae. COPD AMs have a selective defect in uptake of opsonized bacteria, despite the presence of antipneumococcal antibodies in BAL, not observed in MDMs or healthy donor AMs. AM defects in phagocytosis in COPD are significantly associated with exacerbation frequency, isolation of pathogenic bacteria, and health-related quality-of-life scores. Bacterial binding and initial intracellular killing of opsonized bacteria in COPD AMs was not reduced. COPD AMs have reduced transcriptional responses to opsonized bacteria, such as cellular stress responses that include transcriptional modules involving antioxidant defenses and Nrf2 (nuclear factor erythroid 2-related factor 2)-regulated genes. Agonists of the cytoprotective transcription factor Nrf2 (sulforaphane and compound 7) reverse defects in phagocytosis of S. pneumoniae and nontypeable Haemophilus influenzae by COPD AMs. CONCLUSIONS Patients with COPD have clinically relevant defects in opsonic phagocytosis by AMs, associated with impaired transcriptional responses to cellular stress, which are reversed by therapeutic targeting with Nrf2 agonists.
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Affiliation(s)
- Martin A Bewley
- 1 Department of Infection, Immunity and Cardiovascular Disease and.,2 The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Richard C Budd
- 1 Department of Infection, Immunity and Cardiovascular Disease and.,2 The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom.,3 Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Eilise Ryan
- 4 Department of Respiratory Medicine.,5 MRC Centre for Inflammation Research, and
| | - Joby Cole
- 1 Department of Infection, Immunity and Cardiovascular Disease and.,2 The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom.,3 Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Paul Collini
- 1 Department of Infection, Immunity and Cardiovascular Disease and.,2 The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom.,3 Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Jennifer Marshall
- 5 MRC Centre for Inflammation Research, and.,6 Department of Infection Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Umme Kolsum
- 7 Medicines Evaluation Unit, University of Manchester, Manchester, United Kingdom.,8 University Hospital of South Manchester NHS Foundation Trust, Manchester, United Kingdom
| | - Gussie Beech
- 7 Medicines Evaluation Unit, University of Manchester, Manchester, United Kingdom.,8 University Hospital of South Manchester NHS Foundation Trust, Manchester, United Kingdom
| | - Richard D Emes
- 9 School of Veterinary Medicine and Science and.,10 Advanced Data Analysis Centre, University of Nottingham, United Kingdom
| | - Irina Tcherniaeva
- 11 Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Utrecht, the Netherlands
| | - Guy A M Berbers
- 11 Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Utrecht, the Netherlands
| | - Sarah R Walmsley
- 4 Department of Respiratory Medicine.,5 MRC Centre for Inflammation Research, and
| | - Gavin Donaldson
- 12 National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Jadwiga A Wedzicha
- 12 National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Iain Kilty
- 13 Pfizer Inc., Cambridge, Massachusetts
| | - William Rumsey
- 14 Stress and Repair Discovery Performance Unit, Respiratory Therapy Area, GSK, King of Prussia, Pennsylvania; and
| | - Yolanda Sanchez
- 14 Stress and Repair Discovery Performance Unit, Respiratory Therapy Area, GSK, King of Prussia, Pennsylvania; and
| | | | - Louise E Donnelly
- 12 National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter J Barnes
- 12 National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Dave Singh
- 7 Medicines Evaluation Unit, University of Manchester, Manchester, United Kingdom.,8 University Hospital of South Manchester NHS Foundation Trust, Manchester, United Kingdom
| | - Moira K B Whyte
- 4 Department of Respiratory Medicine.,5 MRC Centre for Inflammation Research, and
| | - David H Dockrell
- 5 MRC Centre for Inflammation Research, and.,6 Department of Infection Medicine, University of Edinburgh, Edinburgh, United Kingdom
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4
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Collini PJ, Bewley MA, Mohasin M, Marriott HM, Miller RF, Geretti AM, Beloukas A, Papadimitropoulos A, Read RC, Noursadeghi M, Dockrell DH. HIV gp120 in the Lungs of Antiretroviral Therapy-treated Individuals Impairs Alveolar Macrophage Responses to Pneumococci. Am J Respir Crit Care Med 2019; 197:1604-1615. [PMID: 29365279 DOI: 10.1164/rccm.201708-1755oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
RATIONALE People living with HIV are at significantly increased risk of invasive pneumococcal disease, despite long-term antiretroviral therapy (ART). The mechanism explaining this observation remains undefined. OBJECTIVES To determine if apoptosis-associated microbicidal mechanisms, required to clear intracellular pneumococci that survive initial phagolysosomal killing, are perturbed. METHODS Alveolar macrophages (AM) were obtained by BAL from healthy donors or HIV-1-seropositive donors on long-term ART with undetectable plasma viral load. Monocyte-derived macrophages (MDM) were obtained from healthy donors and infected with HIV-1BaL or treated with gp120. Macrophages were challenged with opsonized serotype 2 Streptococcus pneumoniae and assessed for apoptosis, bactericidal activity, protein expression, and mitochondrial reactive oxygen species (mROS). AM phenotyping, ultrasensitive HIV-1 RNA quantification, and gp120 measurement were also performed in BAL. MEASUREMENTS AND MAIN RESULTS HIV-1BaL infection impaired apoptosis, induction of mROS, and pneumococcal killing by MDM. Apoptosis-associated pneumococcal killing was also reduced in AM from ART-treated HIV-1-seropositive donors. BAL fluid from these individuals demonstrated persistent lung CD8+ T lymphocytosis, and gp120 or HIV-1 RNA was also detected. Despite this, transcriptional activity in AM freshly isolated from people living with HIV was broadly similar to healthy volunteers. Instead, gp120 phenocopied the defect in pneumococcal killing in healthy MDM through post-translational modification of Mcl-1, preventing apoptosis induction, caspase activation, and increased mROS generation. Moreover, gp120 also inhibited mROS-dependent pneumococcal killing in MDM. CONCLUSIONS Despite ART, HIV-1, via gp120, drives persisting innate immune defects in AM microbicidal mechanisms, enhancing susceptibility to pneumococcal disease.
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Affiliation(s)
- Paul J Collini
- 1 The Florey Institute for Host-Pathogen Interactions and Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom.,2 Academic Directorate of Communicable Diseases and Specialised Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Martin A Bewley
- 1 The Florey Institute for Host-Pathogen Interactions and Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Mohamed Mohasin
- 1 The Florey Institute for Host-Pathogen Interactions and Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Helen M Marriott
- 1 The Florey Institute for Host-Pathogen Interactions and Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Robert F Miller
- 3 Research Department of Infection and Population Health, Institute of Epidemiology & Health Care, Faculty of Population Health Sciences, and
| | - Anna-Maria Geretti
- 4 Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Apostolos Beloukas
- 4 Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Athanasios Papadimitropoulos
- 4 Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Robert C Read
- 5 Academic Unit of Clinical and Experimental Sciences, University of Southampton and National Institute for Health Research Southampton Biomedical Research Centre, Southampton, United Kingdom; and
| | - Mahdad Noursadeghi
- 6 Division of Infection & Immunity, Faculty of Medical Sciences, University College London, London, United Kingdom
| | - David H Dockrell
- 1 The Florey Institute for Host-Pathogen Interactions and Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom.,2 Academic Directorate of Communicable Diseases and Specialised Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom.,7 MRC/UoE Centre for Inflammation Research, The University of Edinburgh, Edinburgh, United Kingdom
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5
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Bewley MA, Preston JA, Mohasin M, Marriott HM, Budd RC, Swales J, Collini P, Greaves DR, Craig RW, Brightling CE, Donnelly LE, Barnes PJ, Singh D, Shapiro SD, Whyte MKB, Dockrell DH. Impaired Mitochondrial Microbicidal Responses in Chronic Obstructive Pulmonary Disease Macrophages. Am J Respir Crit Care Med 2017; 196:845-855. [PMID: 28557543 DOI: 10.1164/rccm.201608-1714oc] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
RATIONALE Chronic obstructive pulmonary disease (COPD) is characterized by impaired clearance of pulmonary bacteria. OBJECTIVES The effect of COPD on alveolar macrophage (AM) microbicidal responses was investigated. METHODS AMs were obtained from bronchoalveolar lavage from healthy donors or patients with COPD and challenged with opsonized serotype 14 Streptococcus pneumoniae. Cells were assessed for apoptosis, bactericidal activity, and mitochondrial reactive oxygen species (mROS) production. A transgenic mouse line in which the CD68 promoter ensures macrophage-specific expression of human induced myeloid leukemia cell differentiation protein Mcl-1 (CD68.hMcl-1) was used to model the molecular aspects of COPD. MEASUREMENTS AND MAIN RESULTS COPD AMs had elevated levels of Mcl-1, an antiapoptotic B-cell lymphoma 2 family member, with selective reduction of delayed intracellular bacterial killing. CD68.hMcl-1 AMs phenocopied the microbicidal defect because transgenic mice demonstrated impaired clearance of pulmonary bacteria and increased neutrophilic inflammation. Murine bone marrow-derived macrophages and human monocyte-derived macrophages generated mROS in response to pneumococci, which colocalized with bacteria and phagolysosomes to enhance bacterial killing. The Mcl-1 transgene increased oxygen consumption rates and mROS expression in mock-infected bone marrow-derived macrophages but reduced caspase-dependent mROS production after pneumococcal challenge. COPD AMs also increased basal mROS expression, but they failed to increase production after pneumococcal challenge, in keeping with reduced intracellular bacterial killing. The defect in COPD AM intracellular killing was associated with a reduced ratio of mROS/superoxide dismutase 2. CONCLUSIONS Up-regulation of Mcl-1 and chronic adaption to oxidative stress alter mitochondrial metabolism and microbicidal function, reducing the delayed phase of intracellular bacterial clearance in COPD.
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Affiliation(s)
- Martin A Bewley
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Julie A Preston
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Mohammed Mohasin
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Helen M Marriott
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Richard C Budd
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom.,3 Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Julie Swales
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Paul Collini
- 1 The Florey Institute for Host-Pathogen Interactions and.,2 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom.,3 Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - David R Greaves
- 4 Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Ruth W Craig
- 5 Department of Pharmacology and Toxicology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | | | - Louise E Donnelly
- 7 Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter J Barnes
- 7 Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Dave Singh
- 8 Centre for Respiratory and Allergy, University of Manchester, Manchester, United Kingdom.,9 Medicines Evaluation Unit, Manchester, United Kingdom.,10 University Hospital of South Manchester NHS Foundation Trust, Manchester, United Kingdom
| | - Steven D Shapiro
- 11 Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; and
| | - Moira K B Whyte
- 12 Department of Respiratory Medicine.,13 MRC Centre for Inflammation Research, and
| | - David H Dockrell
- 13 MRC Centre for Inflammation Research, and.,14 Department of Infection Medicine, University of Edinburgh, Edinburgh, United Kingdom
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6
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Bewley MA, Belchamber KBR, Chana KK, Budd RC, Donaldson G, Wedzicha JA, Brightling CE, Kilty I, Donnelly LE, Barnes PJ, Singh D, Whyte MKB, Dockrell DH. Differential Effects of p38, MAPK, PI3K or Rho Kinase Inhibitors on Bacterial Phagocytosis and Efferocytosis by Macrophages in COPD. PLoS One 2016; 11:e0163139. [PMID: 27680884 PMCID: PMC5040258 DOI: 10.1371/journal.pone.0163139] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 09/02/2016] [Indexed: 12/22/2022] Open
Abstract
Pulmonary inflammation and bacterial colonization are central to the pathogenesis of chronic obstructive pulmonary disease (COPD). Defects in macrophage phagocytosis of both bacteria and apoptotic cells contribute to the COPD phenotype. Small molecule inhibitors with anti-inflammatory activity against p38 mitogen activated protein kinases (MAPKs), phosphatidyl-inositol-3 kinase (PI3K) and Rho kinase (ROCK) are being investigated as novel therapeutics in COPD. Concerns exist, however, about off-target effects. We investigated the effect of p38 MAPK inhibitors (VX745 and SCIO469), specific inhibitors of PI3K α (NVS-P13K-2), δ (NVS-P13K-3) or γ (NVS-P13K-5) and a ROCK inhibitor PF4950834 on macrophage phagocytosis, early intracellular killing of bacteria and efferocytosis of apoptotic neutrophils. Alveolar macrophages (AM) obtained from broncho-alveolar lavage (BAL) or monocyte-derived macrophages (MDM) from COPD patients (GOLD stage II/III) enrolled from a well characterized clinical cohort (MRC COPD-MAP consortium) or from healthy ex-smoker controls were studied. Both COPD AM and MDM exhibited lower levels of bacterial phagocytosis (using Streptococcus pneumoniae and non-typeable Haemophilus influenzae) and efferocytosis than healthy controls. None of the inhibitors altered bacterial internalization or early intracellular bacterial killing in AM or MDM. Conversely PF4950834, but not other inhibitors, enhanced efferocytosis in COPD AM and MDM. These results suggest none of these inhibitors are likely to exacerbate phagocytosis-related defects in COPD, while confirming ROCK inhibitors can enhance efferocytosis in COPD.
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Affiliation(s)
- Martin A. Bewley
- Department of Infection, Immunity and Cardiovascular Disease and The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom
- * E-mail:
| | - Kylie B. R. Belchamber
- Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Kirandeep K. Chana
- Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Richard C. Budd
- Department of Infection, Immunity and Cardiovascular Disease and The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom
- Sheffield Teaching Hospitals Foundation Trust, Sheffield, United Kingdom
- Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester and University Hospital of South Manchester NHS Foundation Trust, Manchester, United Kingdom
| | - Gavin Donaldson
- Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Jadwiga A. Wedzicha
- Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | | | - Iain Kilty
- Pfizer Inc, Cambridge, Massachusetts, United States of America
| | - Louise E. Donnelly
- Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter J. Barnes
- Airway Disease National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Dave Singh
- Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester and University Hospital of South Manchester NHS Foundation Trust, Manchester, United Kingdom
| | - Moira K. B. Whyte
- Department of Respiratory Medicine and MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - David H. Dockrell
- Department of Infection, Immunity and Cardiovascular Disease and The Florey Institute for Host-Pathogen Interactions, University of Sheffield Medical School, Sheffield, United Kingdom
- Sheffield Teaching Hospitals Foundation Trust, Sheffield, United Kingdom
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7
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Gill SK, Yao Y, Kay LJ, Bewley MA, Marriott HM, Peachell PT. The anti-inflammatory effects of PGE 2 on human lung macrophages are mediated by the EP 4 receptor. Br J Pharmacol 2016; 173:3099-3109. [PMID: 27460634 DOI: 10.1111/bph.13565] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/19/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE PGE2 inhibits cytokine generation from human lung macrophages. However, the EP receptor that mediates this beneficial anti-inflammatory effect of PGE2 has not been defined. The aim of this study was to identify the EP receptor by which PGE2 inhibits cytokine generation from human lung macrophages. This was determined by using recently developed EP receptor ligands. EXPERIMENTAL APPROACH The effects of PGE2 and EP-selective agonists on LPS-induced generation of TNF-α and IL-6 from macrophages were evaluated. The effects of EP2 -selective (PF-04852946, PF-04418948) and EP4 -selective (L-161,982, CJ-042794) receptor antagonists on PGE2 responses were studied. The expression of EP receptor subtypes by human lung macrophages was determined by RT-PCR. KEY RESULTS PGE2 inhibited LPS-induced and Streptococcus pneumoniae-induced cytokine generation from human lung macrophages. Analysis of mRNA levels indicated that macrophages expressed EP2 and EP4 receptors. L-902,688 (EP4 receptor-selective agonist) was considerably more potent than butaprost (EP2 receptor-selective agonist) as an inhibitor of TNF-α generation from macrophages. EP2 receptor-selective antagonists had marginal effects on the PGE2 inhibition of TNF-α generation, whereas EP4 receptor-selective antagonists caused rightward shifts in the PGE2 concentration-response curves. CONCLUSIONS AND IMPLICATIONS These studies demonstrate that the EP4 receptor is the principal receptor that mediates the anti-inflammatory effects of PGE2 on human lung macrophages. This suggests that EP4 receptor agonists could be effective anti-inflammatory agents in human lung disease.
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Affiliation(s)
- Sharonjit K Gill
- Academic Unit of Respiratory Medicine, Department of Infection, Immunity and Cardiovascular Disease, The Medical School (Floor L), University of Sheffield, Sheffield, UK
| | - Yiwen Yao
- Academic Unit of Respiratory Medicine, Department of Infection, Immunity and Cardiovascular Disease, The Medical School (Floor L), University of Sheffield, Sheffield, UK
| | - Linda J Kay
- Academic Unit of Respiratory Medicine, Department of Infection, Immunity and Cardiovascular Disease, The Medical School (Floor L), University of Sheffield, Sheffield, UK
| | - Martin A Bewley
- Academic Unit of Respiratory Medicine, Department of Infection, Immunity and Cardiovascular Disease, The Medical School (Floor L), University of Sheffield, Sheffield, UK
| | - Helen M Marriott
- Academic Unit of Respiratory Medicine, Department of Infection, Immunity and Cardiovascular Disease, The Medical School (Floor L), University of Sheffield, Sheffield, UK
| | - Peter T Peachell
- Academic Unit of Respiratory Medicine, Department of Infection, Immunity and Cardiovascular Disease, The Medical School (Floor L), University of Sheffield, Sheffield, UK.
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8
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Jubrail J, Morris P, Bewley MA, Stoneham S, Johnston SA, Foster SJ, Peden AA, Read RC, Marriott HM, Dockrell DH. Inability to sustain intraphagolysosomal killing of Staphylococcus aureus predisposes to bacterial persistence in macrophages. Cell Microbiol 2015; 18:80-96. [PMID: 26248337 PMCID: PMC4778410 DOI: 10.1111/cmi.12485] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 07/07/2015] [Indexed: 12/25/2022]
Abstract
Macrophages are critical effectors of the early innate response to bacteria in tissues. Phagocytosis and killing of bacteria are interrelated functions essential for bacterial clearance but the rate-limiting step when macrophages are challenged with large numbers of the major medical pathogen Staphylococcus aureus is unknown. We show that macrophages have a finite capacity for intracellular killing and fail to match sustained phagocytosis with sustained microbial killing when exposed to large inocula of S. aureus (Newman, SH1000 and USA300 strains). S. aureus ingestion by macrophages is associated with a rapid decline in bacterial viability immediately after phagocytosis. However, not all bacteria are killed in the phagolysosome, and we demonstrate reduced acidification of the phagolysosome, associated with failure of phagolysosomal maturation and reduced activation of cathepsin D. This results in accumulation of viable intracellular bacteria in macrophages. We show macrophages fail to engage apoptosis-associated bacterial killing. Ultittop mately macrophages with viable bacteria undergo cell lysis, and viable bacteria are released and can be internalized by other macrophages. We show that cycles of lysis and reuptake maintain a pool of viable intracellular bacteria over time when killing is overwhelmed and demonstrate intracellular persistence in alveolar macrophages in the lungs in a murine model.
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Affiliation(s)
- Jamil Jubrail
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK
| | - Paul Morris
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK
| | - Martin A Bewley
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK
| | - Simon Stoneham
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK
| | - Simon A Johnston
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK.,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Simon J Foster
- The Florey Institute, University of Sheffield, Sheffield, UK.,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Andrew A Peden
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - Robert C Read
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Medical School, Southampton, UK
| | - Helen M Marriott
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK
| | - David H Dockrell
- Department of Infection and Immunity, University of Sheffield, Sheffield, UK.,The Florey Institute, University of Sheffield, Sheffield, UK.,Academic Directorate of Communicable Diseases, Sheffield Teaching Hospitals, Sheffield, UK
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9
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Aberdein JD, Cole J, Bewley MA, Marriott HM, Dockrell DH. Alveolar macrophages in pulmonary host defence the unrecognized role of apoptosis as a mechanism of intracellular bacterial killing. Clin Exp Immunol 2013; 174:193-202. [PMID: 23841514 DOI: 10.1111/cei.12170] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2013] [Indexed: 01/12/2023] Open
Abstract
Alveolar macrophages play an essential role in clearing bacteria from the lower airway, as the resident phagocyte alveolar macrophages must both phagocytose and kill bacteria, and if unable to do this completely must co-ordinate an inflammatory response. The decision to escalate the inflammatory response represents the transition between subclinical infection and the development of pneumonia. Alveolar macrophages are well equipped to phagocytose bacteria and have a large phagolysosomal capacity in which ingested bacteria are killed. The rate-limiting step in control of extracellular bacteria, such as Streptococcus pneumoniae, is the capacity of alveolar macrophages to kill ingested bacteria. Therefore, alveolar macrophages complement canonical microbicidal strategies with an additional level of apoptosis-associated killing to help kill ingested bacteria.
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Affiliation(s)
- J D Aberdein
- Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield, UK
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10
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Daigneault M, De Silva TI, Bewley MA, Preston JA, Marriott HM, Mitchell AM, Mitchell TJ, Read RC, Whyte MKB, Dockrell DH. Monocytes regulate the mechanism of T-cell death by inducing Fas-mediated apoptosis during bacterial infection. PLoS Pathog 2012; 8:e1002814. [PMID: 22829769 PMCID: PMC3400568 DOI: 10.1371/journal.ppat.1002814] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 06/04/2012] [Indexed: 12/24/2022] Open
Abstract
Monocytes and T-cells are critical to the host response to acute bacterial infection but monocytes are primarily viewed as amplifying the inflammatory signal. The mechanisms of cell death regulating T-cell numbers at sites of infection are incompletely characterized. T-cell death in cultures of peripheral blood mononuclear cells (PBMC) showed 'classic' features of apoptosis following exposure to pneumococci. Conversely, purified CD3(+) T-cells cultured with pneumococci demonstrated necrosis with membrane permeabilization. The death of purified CD3(+) T-cells was not inhibited by necrostatin, but required the bacterial toxin pneumolysin. Apoptosis of CD3(+) T-cells in PBMC cultures required 'classical' CD14(+) monocytes, which enhanced T-cell activation. CD3(+) T-cell death was enhanced in HIV-seropositive individuals. Monocyte-mediated CD3(+) T-cell apoptotic death was Fas-dependent both in vitro and in vivo. In the early stages of the T-cell dependent host response to pneumococci reduced Fas ligand mediated T-cell apoptosis was associated with decreased bacterial clearance in the lung and increased bacteremia. In summary monocytes converted pathogen-associated necrosis into Fas-dependent apoptosis and regulated levels of activated T-cells at sites of acute bacterial infection. These changes were associated with enhanced bacterial clearance in the lung and reduced levels of invasive pneumococcal disease.
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Affiliation(s)
- Marc Daigneault
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Thushan I. De Silva
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
- Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - Martin A. Bewley
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Julie A. Preston
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Helen M. Marriott
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Andrea M. Mitchell
- Institute of Microbiology and Infection, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Timothy J. Mitchell
- Institute of Microbiology and Infection, School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Robert C. Read
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
- Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - Moira K. B. Whyte
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
- Sheffield Teaching Hospitals, Sheffield, United Kingdom
| | - David H. Dockrell
- Department of Infection and Immunity, University of Sheffield Medical School, Sheffield, United Kingdom
- Sheffield Teaching Hospitals, Sheffield, United Kingdom
- * E-mail:
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11
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Bewley MA, Pham TK, Marriott HM, Noirel J, Chu HP, Ow SY, Ryazanov AG, Read RC, Whyte MKB, Chain B, Wright PC, Dockrell DH. Proteomic evaluation and validation of cathepsin D regulated proteins in macrophages exposed to Streptococcus pneumoniae. Mol Cell Proteomics 2011; 10:M111.008193. [PMID: 21474794 PMCID: PMC3108842 DOI: 10.1074/mcp.m111.008193] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/01/2011] [Indexed: 11/23/2022] Open
Abstract
Macrophages are central effectors of innate immune responses to bacteria. We have investigated how activation of the abundant macrophage lysosomal protease, cathepsin D, regulates the macrophage proteome during killing of Streptococcus pneumoniae. Using the cathepsin D inhibitor pepstatin A, we demonstrate that cathepsin D differentially regulates multiple targets out of 679 proteins identified and quantified by eight-plex isobaric tag for relative and absolute quantitation. Our statistical analysis identified 18 differentially expressed proteins that passed all paired t-tests (α = 0.05). This dataset was enriched for proteins regulating the mitochondrial pathway of apoptosis or inhibiting competing death programs. Five proteins were selected for further analysis. Western blotting, followed by pharmacological inhibition or genetic manipulation of cathepsin D, verified cathepsin D-dependent regulation of these proteins, after exposure to S. pneumoniae. Superoxide dismutase-2 up-regulation was temporally related to increased reactive oxygen species generation. Gelsolin, a known regulator of mitochondrial outer membrane permeabilization, was down-regulated in association with cytochrome c release from mitochondria. Eukaryotic elongation factor (eEF2), a regulator of protein translation, was also down-regulated by cathepsin D. Using absence of the negative regulator of eEF2, eEF2 kinase, we confirm that eEF2 function is required to maintain expression of the anti-apoptotic protein Mcl-1, delaying macrophage apoptosis and confirm using a murine model that maintaining eEF2 function is associated with impaired macrophage apoptosis-associated killing of Streptococcus pneumoniae. These findings demonstrate that cathepsin D regulates multiple proteins controlling the mitochondrial pathway of macrophage apoptosis or competing death processes, facilitating intracellular bacterial killing.
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Affiliation(s)
| | - Trong K. Pham
- §ChELSI Institute, Department of Chemical and Processing Engineering, University of Sheffield, Sheffield, UK
| | | | - Josselin Noirel
- §ChELSI Institute, Department of Chemical and Processing Engineering, University of Sheffield, Sheffield, UK
| | - Hseuh-Ping Chu
- ‖Department of Pharmacology University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Jersey, USA
| | - Saw Y. Ow
- §ChELSI Institute, Department of Chemical and Processing Engineering, University of Sheffield, Sheffield, UK
| | - Alexey G. Ryazanov
- ‖Department of Pharmacology University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Jersey, USA
| | - Robert C. Read
- From the ‡Medical School
- ‡‡Sheffield Teaching Hospitals and
| | | | - Benny Chain
- ¶Division of Infection and Immunity, University College London, London, UK
| | - Phillip C. Wright
- §ChELSI Institute, Department of Chemical and Processing Engineering, University of Sheffield, Sheffield, UK
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12
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Bewley MA, Marriott HM, Tulone C, Francis SE, Mitchell TJ, Read RC, Chain B, Kroemer G, Whyte MKB, Dockrell DH. A cardinal role for cathepsin d in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci. PLoS Pathog 2011; 7:e1001262. [PMID: 21298030 PMCID: PMC3029254 DOI: 10.1371/journal.ppat.1001262] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 12/21/2010] [Indexed: 11/23/2022] Open
Abstract
The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D−/− hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function. Tissue macrophages frequently undergo a program of cell death, termed apoptosis, following sustained ingestion and killing of bacteria. In macrophages, induction of apoptosis enhances bacterial killing when macrophages' initial killing capacity is exhausted. We have investigated the mechanism of apoptosis in macrophages exposed to pneumococci, the commonest cause of bacterial pneumonia. We show that the cell structure containing ingested bacteria, the phagolysosome, becomes permeabilized early in the death process. Pneumococcal exposure activates a phagolysosomal enzyme, cathepsin D, which induces apoptosis. Cathepsin D activation is required for permeabilization of mitochondria, an organelle implicated in apoptosis induction. Cathepsin D reduces levels of a negative regulator of apoptosis in macrophages, Mcl-1, by enhancing its association with an enzyme, which mediates its degradation. The importance of these findings was confirmed in a bone marrow transplant model in which mice either received bone marrow from mice containing or lacking the cathepsin D gene. This model showed that reduced apoptosis of alveolar macrophages occurred when cathepsin D was lacking, and that this impaired clearance of pneumococci in the mouse lung. We conclude that during bacterial challenge, lysosomal permeabilization and cathepsin D activation triggers a novel death pathway, in a timely fashion, linking bacterial killing to apoptosis induction.
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Affiliation(s)
- Martin A Bewley
- Medical School, University of Sheffield, Sheffield, United Kingdom
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13
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Webster SJ, Daigneault M, Bewley MA, Preston JA, Marriott HM, Walmsley SR, Read RC, Whyte MKB, Dockrell DH. Distinct cell death programs in monocytes regulate innate responses following challenge with common causes of invasive bacterial disease. J Immunol 2010; 185:2968-79. [PMID: 20656927 DOI: 10.4049/jimmunol.1000805] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Peripheral blood monocytes represent the rapid response component of mononuclear phagocyte host defense, generating vigorous but finite antibacterial responses. We investigated the fate of highly purified primary human monocytes following phagocytosis of different bacteria. Exposure to high bacterial loads resulted in rapid loss of cell viability and decreased functional competence. Cell death typically involved classical apoptosis. Exposure to high numbers of Escherichia coli and Klebsiella pneumoniae induced nonapoptotic death with loss of cell membrane integrity, marked disruption of phagolysosomes, and caspase-1 activation, while a subset of cells also released caspase-1-regulated extracellular traps. Classical apoptosis increased if extracellular bacterial replication was reduced and decreased if intracellular ATP levels were reduced during these infections. Both classical apoptosis and the alternative forms of cell death allowed monocytes, whose functional competence was exhausted, to downregulate reactive oxygen species and proinflammatory cytokine responses. In contrast, sustained stimulation of glycolytic metabolism and mitochondrial oxidative phosphorylation, with associated hypoxia inducible factor-1alpha upregulation, maintained intracellular ATP levels and prolonged monocyte functional longevity, as assessed by maintenance of phagocytosis, reactive oxygen species production, and proinflammatory cytokine generation. Monocyte innate responses to bacteria are short-lived and are limited by an intrinsic program of apoptosis, a response that is subverted by overwhelming infection with E. coli and K. pneumoniae or bacterial stimulation of cell metabolism. In this regard, the fate of monocytes following bacterial challenge more closely resembles neutrophils than macrophages.
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Affiliation(s)
- Steve J Webster
- Department of Infection and Immunity, Medical School, University of Sheffield, Sheffield, United Kingdom
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14
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Prince LR, Bianchi SM, Vaughan KM, Bewley MA, Marriott HM, Walmsley SR, Taylor GW, Buttle DJ, Sabroe I, Dockrell DH, Whyte MKB. Subversion of a lysosomal pathway regulating neutrophil apoptosis by a major bacterial toxin, pyocyanin. J Immunol 2008; 180:3502-11. [PMID: 18292577 DOI: 10.4049/jimmunol.180.5.3502] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Neutrophils undergo rapid constitutive apoptosis that is accelerated following bacterial ingestion as part of effective immunity, but is also accelerated by bacterial exotoxins as a mechanism of immune evasion. The paradigm of pathogen-driven neutrophil apoptosis is exemplified by the Pseudomonas aeruginosa toxic metabolite, pyocyanin. We previously showed pyocyanin dramatically accelerates neutrophil apoptosis both in vitro and in vivo, impairs host defenses, and favors bacterial persistence. In this study, we investigated the mechanisms of pyocyanin-induced neutrophil apoptosis. Pyocyanin induced early lysosomal dysfunction, shown by altered lysosomal pH, within 15 min of exposure. Lysosomal disruption was followed by mitochondrial membrane permeabilization, caspase activation, and destabilization of Mcl-1. Pharmacological inhibitors of a lysosomal protease, cathepsin D (CTSD), abrogated pyocyanin-induced apoptosis, and translocation of CTSD to the cytosol followed pyocyanin treatment and lysosomal disruption. A stable analog of cAMP (dibutyryl cAMP) impeded the translocation of CTSD and prevented the destabilization of Mcl-1 by pyocyanin. Thus, pyocyanin activated a coordinated series of events dependent upon lysosomal dysfunction and protease release, the first description of a bacterial toxin using a lysosomal cell death pathway. This may be a pathological pathway of cell death to which neutrophils are particularly susceptible, and could be therapeutically targeted to limit neutrophil death and preserve host responses.
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Affiliation(s)
- Lynne R Prince
- Academic Unit of Respiratory Medicine, University of Sheffield, Sheffield, UK
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15
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Berry RJ, Bewley MA. Change in oxygen enhancement ratio with depth in tissue-equivalent material for a collimated beam of fast neutrons. Br J Radiol 1976; 49:458-62. [PMID: 949580 DOI: 10.1259/0007-1285-49-581-458] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Survival of reproductive capacity of murine leukaemia P-388 cells was assayed in vivo after the cells had been irradiated in vitro under aerobic or hypoxic conditions with collimated beams of X rays or 16 MeV D-Be fast neutrons at various depths in tissue-equivalent phantom material. The response to X-irradiation was the same in the absence of the phantom and at 8-7 cm depth. The response to fast neutrons under aerobic conditions was unchanged from 0 to 23 cm depth within the phantom. However, under hypoxic conditions, the dose-response curve for fast neutrons became significantly steeper with increasing depth in the phantom. The OER decreased from 2-0 in the absence of the phantom to 1-5 at 15 cm deep.
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