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Di Pilato V, Willison E, Marchese A. The microbiology and pathogenesis of nonfermenting Gram-negative infections. Curr Opin Infect Dis 2023; 36:537-544. [PMID: 37732777 PMCID: PMC10624403 DOI: 10.1097/qco.0000000000000969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
PURPOSE OF REVIEW This review provides an overview of most recent evidence about pathogenesis traits and virulence factors contributing to successful colonization or infection by P. aeruginosa , A. baumannii , S. maltophilia and B. cepacia complex, among the most clinically relevant nonfermenting Gram-negative bacteria (NFGNB). RECENT FINDINGS The growing clinical importance of NFGNB as important opportunistic pathogens causing difficult-to-treat infections in a fragile patients' population in stressed by numerous studies. Identification of novel virulence factors and deciphering of their mechanisms of action have greatly furthered our understanding of NFGNB pathogenesis, revealing that each pathogen-specific armamentarium of virulence factors (adhesins, motility, capsule, biofilm, lipopolysaccharide, exotoxins, exoenzymes, secretion systems, siderophores) can be likely responsible for the difference in the pathophysiology even in the context of a similar infection site. Emerging evidence of the immunomodulatory effect of some virulence factors is also acknowledged. SUMMARY NFGNB continue to be a serious global problem as cause of life-threatening opportunistic infections, owing to a highly heterogeneous content of virulence factors and their extensive number of intrinsic resistance mechanisms. Further efforts in development of novel effective antimicrobials and of alternative strategies targeting key virulence factors are warranted.
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Affiliation(s)
- Vincenzo Di Pilato
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa
| | - Edward Willison
- Microbiology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Marchese
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa
- Microbiology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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2
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DHEA and Its Metabolites Reduce the Cytokines Involved in the Inflammatory Response and Fibrosis in Primary Biliary Cholangitis. Int J Mol Sci 2023; 24:ijms24065301. [PMID: 36982376 PMCID: PMC10049419 DOI: 10.3390/ijms24065301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/02/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
Dehydroepiandrosterone (DHEA) is an abundant steroid and precursor of sex hormones. During aging, the reduction in DHEA synthesis causes a significant depletion of estrogens and androgens in different organs, such as the ovaries, brain, and liver. Primary Biliary Cholangitis (PBC) is a cholestatic liver disease that begins with immune-mediated bile duct damage, and is followed by liver fibrosis, and finally, cirrhosis. PBC primarily affects postmenopausal women, with an average age of diagnosis of 65 years, but younger women are also affected. Here, we analyzed the levels of DHEA, estradiol (E2), and estriol (E3) in the PBC sera of females at an age of diagnosis under 40 (n = 37) and above 65 (n = 29). Our results indicate that in PBC patients at an age of diagnosis under 40, E2 was significantly lower compared to that in healthy women. In contrast, the levels of DHEA and E3 were in a normal range. Furthermore, ELISA assays revealed that in PBC patients at an age of diagnosis above 65, the levels of DHEA, E2, and E3 significantly declined in comparison to those in younger patients. In addition, flow cytometry analysis showed that the level of IL-8 significantly decreased while the level of TNF-α increased in older PBC patients compared to younger ones. Moreover, we showed for the first time that the sulfonated form of DHEA, DHEA-S, reduces the levels of both pro-inflammatory interleukins, IL-8 and TNF-α, in PBC-like cholangiocytes (H69-miR506), while it diminishes the level of the pro-fibrotic interleukin, IL-13, in hepatocytes (Hep-G2). Finally, we demonstrated that the expression of the pro-fibrotic agent TGF-β significantly increased in both the early (F0–F3) and cirrhotic (F4) stages of PBC, and this elevation was accompanied by higher α-SMA expression.
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Williamson M, Casey M, Gabillard-Lefort C, Alharbi A, Teo YQJ, McElvaney NG, Reeves EP. Current evidence on the effect of highly effective CFTR modulation on interleukin-8 in cystic fibrosis. Expert Rev Respir Med 2021; 16:43-56. [PMID: 34726115 DOI: 10.1080/17476348.2021.2001333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Cystic fibrosis (CF) is a genetically inherited disease, with mortality and morbidity associated with respiratory disease. The inflammatory response in CF is characterized by excessive neutrophil influx to the airways, mainly due to the increased local production and retention of interleukin-8 (IL-8), a potent neutrophil chemoattractant. AREAS COVERED We discuss how the chemokine IL-8 dominates the inflammatory profile of the airways in CF lung disease. Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies are designed to correct the malfunctioning protein resulting from specific CFTR mutations. This review covers current evidence on the impact of CFTR impairment on levels of IL-8 and outlines the influence of effective CFTR modulation on inflammation in CF with a focus on cytokine production. Review of the literature was carried out using the PUBMED database, Google Scholar, and The Cochrane Library databases, using several appropriate generic terms. EXPERT OPINION Therapeutic interventions specifically targeting the defective CFTR protein have improved the outlook for CF. Accumulating studies on the effect of highly effective CFTR modulation on inflammation indicate an impact on IL-8 levels. Further studies are required to increase our knowledge of early onset innate inflammatory dysregulation and on anti-inflammatory mechanisms of CFTR modulators.
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Affiliation(s)
- Michael Williamson
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Michelle Casey
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Claudie Gabillard-Lefort
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Aram Alharbi
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Yu Qing Jolene Teo
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Noel G McElvaney
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Emer P Reeves
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
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Immune Recognition of the Epidemic Cystic Fibrosis Pathogen Burkholderia dolosa. Infect Immun 2017; 85:IAI.00765-16. [PMID: 28348057 DOI: 10.1128/iai.00765-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/20/2017] [Indexed: 12/31/2022] Open
Abstract
Burkholderia dolosa caused an outbreak in the cystic fibrosis (CF) clinic at Boston Children's Hospital from 1998 to 2005 and led to the infection of over 40 patients, many of whom died due to complications from infection by this organism. To assess whether B. dolosa significantly contributes to disease or is recognized by the host immune response, mice were infected with a sequenced outbreak B. dolosa strain, AU0158, and responses were compared to those to the well-studied CF pathogen Pseudomonas aeruginosa In parallel, mice were also infected with a polar flagellin mutant of B. dolosa to examine the role of flagella in B. dolosa lung colonization. The results showed a higher persistence in the host by B. dolosa strains, and yet, neutrophil recruitment and cytokine production were lower than those with P. aeruginosa The ability of host immune cells to recognize B. dolosa was then assessed, B. dolosa induced a robust cytokine response in cultured cells, and this effect was dependent on the flagella only when bacteria were dead. Together, these results suggest that B. dolosa can be recognized by host cells in vitro but may avoid or suppress the host immune response in vivo through unknown mechanisms. B. dolosa was then compared to other Burkholderia species and found to induce similar levels of cytokine production despite being internalized by macrophages more than Burkholderia cenocepacia strains. These data suggest that B. dolosa AU0158 may act differently with host cells and is recognized differently by immune systems than are other Burkholderia strains or species.
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5
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Using dendritic cells to evaluate how Burkholderia cenocepacia clonal isolates from a chronically infected cystic fibrosis patient subvert immune functions. Med Microbiol Immunol 2016; 206:111-123. [DOI: 10.1007/s00430-016-0488-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 11/29/2016] [Indexed: 12/24/2022]
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Mil‐Homens D, Pinto SN, Matos RG, Arraiano C, Fialho AM. Burkholderia cenocepacia
K56‐2 trimeric autotransporter adhesin BcaA binds TNFR1 and contributes to induce airway inflammation. Cell Microbiol 2016; 19. [DOI: 10.1111/cmi.12677] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 09/22/2016] [Accepted: 09/24/2016] [Indexed: 01/10/2023]
Affiliation(s)
- Dalila Mil‐Homens
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico University of Lisbon Lisbon Portugal
| | - Sandra N. Pinto
- Centro de Química Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico University of Lisbon Lisbon Portugal
| | - Rute G. Matos
- Instituto de Tecnologia Química e Biológica – ITQB Universidade Nova de Lisboa Oeiras Portugal
| | - Cecília Arraiano
- Instituto de Tecnologia Química e Biológica – ITQB Universidade Nova de Lisboa Oeiras Portugal
| | - Arsenio M. Fialho
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico University of Lisbon Lisbon Portugal
- Department of Bioengineering, Instituto Superior Técnico University of Lisbon Lisbon Portugal
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Wijers CDM, Vagedes R, Weingart C. A novel method for investigating Burkholderia cenocepacia infections in patients with cystic fibrosis and other chronic diseases of the airways. BMC Microbiol 2016; 16:200. [PMID: 27586172 PMCID: PMC5009706 DOI: 10.1186/s12866-016-0811-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/18/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Burkholderia cenocepacia is a Gram-negative, opportunistic pathogen that is a cause of morbidity and mortality in patients with cystic fibrosis (CF). Research efforts over the past few decades contributed to our understanding of these infections by identifying virulence factors. However, little is known about how this pathogen adapts to the harsh environment found inside the CF airways, which is characterized by a unique mucus containing high concentrations of inflammatory markers. The current study developed a novel model to further investigate this phenomenon. RESULTS Monolayers of human A549 lung carcinoma cells (HLCCs) were exposed to a mixture of artificial CF sputum medium (ASMDM) in tissue culture growth medium, and subsequently infected with B. cenocepacia K56-2 for 24 h. The data showed that this model supported B. cenocepacia growth. In addition, consistent with similar studies using current models such as CF airway tissue samples, HLCC viability was reduced by more than 70 % when grown in 60 % ASMDM and infected with B. cenocepacia compared to mock-infected controls and medium alone. Furthermore, the amount of B. cenocepacia cells associated with the HLCC monolayer was more than 10 times greater in 60 % ASMDM when compared to medium controls. CONCLUSIONS These findings suggest that HLCC monolayers in 60 % ASMDM serve as a valid alternative to study B. cenocepacia infections in patients with CF, and possibly other chronic diseases of the airways. Furthermore, the results obtained in this study suggest an important role for CF sputum in B. cenocepacia pathogenesis.
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Affiliation(s)
- Christiaan D M Wijers
- Department of Biological Sciences, Denison University, 100 West College Street, Granville, OH, 43023, USA
| | - Ryan Vagedes
- Department of Biological Sciences, Denison University, 100 West College Street, Granville, OH, 43023, USA
| | - Christine Weingart
- Department of Biological Sciences, Denison University, 100 West College Street, Granville, OH, 43023, USA.
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8
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Bhagwat SS, Larsen AK, Seternes OM, Bang BE. Mixed exposure to bacterial lipopolysaccharide and seafood proteases augments inflammatory signalling in an airway epithelial cell model (A549). Toxicol Ind Health 2016; 32:1866-1874. [PMID: 26149191 DOI: 10.1177/0748233715590914] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Seafood industry workers exhibit increased prevalence of respiratory symptoms due to exposure to bioaerosols containing a mixture of bioactive agents. In this study, a human pulmonary epithelial cell model (A549) was exposed to mixtures of bacterial lipopolysaccharide (LPS) and protease-activated receptor-2 (PAR-2) agonists H-Ser-Leu-Ile-Gly-Lys-Val-NH2 (SLIGKV-NH2), purified salmon ( Salmo salar) trypsin or purified king crab ( Paralithodes camtschaticus) trypsin. The inflammatory response was measured based on nuclear factor-kappa B (NF-κB) activation of transcription in a luciferase reporter gene assay and interleukin 8 (IL-8) secretion in an enzyme-linked immunosorbent assay. We observed that mixtures of SLIGKV-NH2 or trypsins with LPS augmented the activation of NF-κB and secretion of IL-8. The effect on IL-8 secretion was synergistic when both trypsins and LPS were used in the lower concentration range. The results demonstrate that exposure to mixtures of agents that are relevant to seafood industry workplaces may lead to increased inflammatory signalling compared with exposure to the individual agents alone. Furthermore, the results indicate that synergism may occur with the combined exposure to seafood trypsins and LPS and is most likely to occur when exposure to either agent is low.
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Affiliation(s)
- Sampada S Bhagwat
- 1 Department of Occupational and Environmental Medicine, University Hospital of North Norway, Tromsø, Norway.,2 Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Anett K Larsen
- 3 Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ole-Morten Seternes
- 4 Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Berit E Bang
- 1 Department of Occupational and Environmental Medicine, University Hospital of North Norway, Tromsø, Norway.,2 Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
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9
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David J, Bell RE, Clark GC. Mechanisms of Disease: Host-Pathogen Interactions between Burkholderia Species and Lung Epithelial Cells. Front Cell Infect Microbiol 2015; 5:80. [PMID: 26636042 PMCID: PMC4649042 DOI: 10.3389/fcimb.2015.00080] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/30/2015] [Indexed: 11/17/2022] Open
Abstract
Members of the Burkholderia species can cause a range of severe, often fatal, respiratory diseases. A variety of in vitro models of infection have been developed in an attempt to elucidate the mechanism by which Burkholderia spp. gain entry to and interact with the body. The majority of studies have tended to focus on the interaction of bacteria with phagocytic cells with a paucity of information available with regard to the lung epithelium. However, the lung epithelium is becoming more widely recognized as an important player in innate immunity and the early response to infections. Here we review the complex relationship between Burkholderia species and epithelial cells with an emphasis on the most pathogenic species, Burkholderia pseudomallei and Burkholderia mallei. The current gaps in knowledge in our understanding are highlighted along with the epithelial host-pathogen interactions that offer potential opportunities for therapeutic intervention.
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Affiliation(s)
- Jonathan David
- Microbiology, Biomedical Sciences, Defence Science and Technology Laboratory Salisbury, UK
| | - Rachel E Bell
- Microbiology, Biomedical Sciences, Defence Science and Technology Laboratory Salisbury, UK ; Division of Immunology, Infection and Inflammatory Disease, Centre for Molecular and Cellular Biology of Inflammation, King's College London London, UK
| | - Graeme C Clark
- Microbiology, Biomedical Sciences, Defence Science and Technology Laboratory Salisbury, UK
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10
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Gillette DD, Shah PA, Cremer T, Gavrilin MA, Besecker BY, Sarkar A, Knoell DL, Cormet-Boyaka E, Wewers MD, Butchar JP, Tridandapani S. Analysis of human bronchial epithelial cell proinflammatory response to Burkholderia cenocepacia infection: inability to secrete il-1β. J Biol Chem 2012; 288:3691-5. [PMID: 23269671 DOI: 10.1074/jbc.c112.430298] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Burkholderia cenocepacia, the causative agent of cepacia syndrome, primarily affects cystic fibrosis patients, often leading to death. In the lung, epithelial cells serve as the initial barrier to airway infections, yet their responses to B. cenocepacia have not been fully investigated. Here, we examined the molecular responses of human airway epithelial cells to B. cenocepacia infection. Infection led to early signaling events such as activation of Erk, Akt, and NF-κB. Further, TNFα, IL-6, IL-8, and IL-1β were all significantly induced upon infection, but no IL-1β was detected in the supernatants. Because caspase-1 is required for IL-1β processing and release, we examined its expression in airway epithelial cells. Interestingly, little to no caspase-1 was detectable in airway epithelial cells. Transfection of caspase-1 into airway epithelial cells restored their ability to secrete IL-1β following B. cenocepacia infection, suggesting that a deficiency in caspase-1 is responsible, at least in part, for the attenuated IL-1β secretion.
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Affiliation(s)
- Devyn D Gillette
- Integrated Biomedical Graduate Program, The Ohio State University, Columbus, Ohio 43210, USA
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Kotrange S, Kopp B, Akhter A, Abdelaziz D, Abu Khweek A, Caution K, Abdulrahman B, Wewers MD, McCoy K, Marsh C, Loutet SA, Ortega X, Valvano MA, Amer AO. Burkholderia cenocepacia O polysaccharide chain contributes to caspase-1-dependent IL-1beta production in macrophages. J Leukoc Biol 2010; 89:481-8. [PMID: 21178113 DOI: 10.1189/jlb.0910513] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Burkholderia cenocepacia infections in CF patients involve heightened inflammation, fatal sepsis, and high antibiotic resistance. Proinflammatory IL-1β secretion is important in airway inflammation and tissue damage. However, little is known about this pathway in macrophages upon B. cenocepacia infection. We report here that murine macrophages infected with B. cenocepacia K56-2 produce proinflammatory cytokine IL-1β in a TLR4 and caspase-1-mediated manner. We also determined that the OPS (O antigen) of B. cenocepacia LPS contributes to IL-1β production and pyroptotic cell death. Furthermore, we showed that the malfunction of the CFTR channel augmented IL-1β production upon B. cenocepacia infection of murine macrophages. Taken together, we identified eukaryotic and bacterial factors that contribute to inflammation during B. cenocepacia infection, which may aid in the design of novel approaches to control pulmonary inflammation.
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Affiliation(s)
- Sheetal Kotrange
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Center for Microbial Interface Biology and the Department of Internal Medicine, Ohio State University, Columbus, Ohio 43210, USA
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Anas A, van der Poll T, de Vos AF. Role of CD14 in lung inflammation and infection. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:209. [PMID: 20236452 PMCID: PMC2887102 DOI: 10.1186/cc8850] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855.
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Affiliation(s)
- Adam Anas
- Center for Experimental and Molecular Medicine, Center of Infection and Immunity, Academic Medical Center, Meibergdreef 9, Amsterdam, Netherlands
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Abate W, Alghaithy AA, Parton J, Jones KP, Jackson SK. Surfactant lipids regulate LPS-induced interleukin-8 production in A549 lung epithelial cells by inhibiting translocation of TLR4 into lipid raft domains. J Lipid Res 2010; 51:334-44. [PMID: 19648651 PMCID: PMC2803235 DOI: 10.1194/jlr.m000513] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 08/01/2009] [Indexed: 01/24/2023] Open
Abstract
In addition to providing mechanical stability, growing evidence suggests that surfactant lipid components can modulate inflammatory responses in the lung. However, little is known of the molecular mechanisms involved in the immunomodulatory action of surfactant lipids. This study investigates the effect of the lipid-rich surfactant preparations Survanta, Curosurf, and the major surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) on interleukin-8 (IL-8) gene and protein expression in human A549 lung epithelial cells using immunoassay and PCR techniques. To examine potential mechanisms of the surfactant lipid effects, Toll-like receptor 4 (TLR4) expression was analyzed by flow cytometry, and membrane lipid raft domains were separated by density gradient ultracentrifugation and analyzed by immunoblotting with anti-TLR4 antibody. The lipid-rich surfactant preparations Survanta, Curosurf, and DPPC, at physiological concentrations, significantly downregulated lipopolysaccharide (LPS)-induced IL-8 expression in A549 cells both at the mRNA and protein levels. The surfactant preparations did not affect the cell surface expression of TLR4 or the binding of LPS to the cells. However, LPS treatment induced translocation of TLR4 into membrane lipid raft microdomains, and this translocation was inhibited by incubation of the cells with the surfactant lipid. This study provides important mechanistic details of the immune-modulating action of pulmonary surfactant lipids.
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Affiliation(s)
- Wondwossen Abate
- Centre for Research in Biomedicine, Faculty of Health and Life Science, University of the West of England, Bristol, UK
| | | | - Joan Parton
- Department of Medical Microbiology, School of Medicine, Cardiff University, Cardiff, UK
| | - Kenneth P. Jones
- School of Applied Sciences, University of Wales Institute Cardiff, Cardiff, UK
| | - Simon K. Jackson
- Centre for Research in Biomedicine, Faculty of Health and Life Science, University of the West of England, Bristol, UK
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14
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Anas A, Van Der Poll T, De Vas AF. Role of CD14 in Lung Inflammation and Infection. Intensive Care Med 2010. [PMCID: PMC7120299 DOI: 10.1007/978-1-4419-5562-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Toll-like receptors (TLR) on the surface of cells of the respiratory tract play an essential role in sensing the presence of microorganisms in the airways and lungs. These receptors trigger inflammatory responses, activate innate immune responses, and prime adaptive immune responses to eradicate invading microbes [1]. TLR are members of a family of pattern-recognition receptors, which recognize molecular structures of bacteria, viruses, fungi and protozoa (pathogen-associated molecular patterns or PAMPs), as well as endogenous structures and proteins released during inflammation (damage/danger-associated molecular patterns or DAMPs). To date, ten different TLR have been identified in humans and twelve in mice. TLR are expressed on all cells of the immune system, but also on parenchymal cells of many organs and tissues. The binding of a PAMP to a TLR results in cellular activation and initiates a variety of effector functions, including cytokine secretion, proliferation’ co-stimulation or phagocyte maturation. To facilitate microbial recognition and to amplify cellular responses, certain TLR require additional proteins, such as lipopolysaccharide (LPS) binding protein (LBP), CD14, CD36 and high mobility group box-l protein (HMGB-l). In this chapter, the role of CD14 as an accessory receptor for TLR in lung inflammation and infection is discussed. The central role of CD14 in the recognition of various PAMPs and amplification of immune and inflammatory responses in the lung is depicted in Fig. 1. Central role of CD14 in pathogen- and pathogen-associated molecular pattern (PAMP)-induced responses in the lung. CD14, which lacks an intracellular domain for signal transduction, is expressed on the surface of alveolar macrophages, infiltrating monocytes and neutrophils, and at lower levels also on epithelial and endothelial cells in the lung. CD14 recognizes and binds various structures from invading microbes, such as lipopolysaccharide (LPS) from Gram-negative bacteria, lipoteichoic acid (LTA) from Gram-positive bacteria, lipoarabinomannan (LAM) from mycobacteria, viral double stranded (ds) RNA and F glycoprotein (F-gp) from respiratory syncytial virus (RSV). CD14 subsequently transfers these bound components to Toll-like receptors (TLR) which than trigger cell activation. Binding of LPS to CD14 is regulated by additional accessory receptors in the lung, including LPS-binding protein (LBP) and a number of surfactant proteins (SP). Furthermore, soluble CD14 (sCD14) enhances LPS-induced activation of cells with low CD14 expression. Depending on the microbe and the PAMPs it expresses, CD14-amplified responses can either be beneficial to the host by induction of an adequate inflammatory and immune response to eradicate the invading microbe, or detrimental to the host by excessive inflammation and/or dissemination of the pathogen. ![]()
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15
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Role of CD14 in Lung Inflammation and Infection. YEARBOOK OF INTENSIVE CARE AND EMERGENCY MEDICINE 2010. [PMCID: PMC7124092 DOI: 10.1007/978-3-642-10286-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Toll-like receptors (TLR) on the surface of cells of the respiratory tract play an essential role in sensing the presence of microorganisms in the airways and lungs. These receptors trigger inflammatory responses, activate innate immune responses, and prime adaptive immune responses to eradicate invading microbes [1]. TLR are members of a family of pattern-recognition receptors, which recognize molecular structures of bacteria, viruses, fungi and protozoa (pathogen-associated molecular patterns or PAMPs), as well as endogenous structures and proteins released during inflammation (damage/danger-associated molecular patterns or DAMPs). To date, ten different TLR have been identified in humans and twelve in mice. TLR are expressed on all cells of the immune system, but also on parenchymal cells of many organs and tissues. The binding of a PAMP to a TLR results in cellular activation and initiates a variety of effector functions, including cytokine secretion, proliferation, co-stimulation or phagocyte maturation. To facilitate microbial recognition and to amplify cellular responses, certain TLR require additional proteins, such as lipopolysaccharide (LPS) binding protein (LBP), CD14, CD36 and high mobility group box-1 protein (HMGB-1). In this chapter, the role of CD14 as an accessory receptor for TLR in lung inflammation and infection is discussed. The central role of CD14 in the recognition of various PAMPs and amplification of immune and inflammatory responses in the lung is depicted in Figure 1.
Central role of CD14 in pathogen- and pathogen-associated molecular pattern (PAMP)-induced responses in the lung. CD14, which lacks an intracellular domain for signal transduction, is expressed on the surface of alveolar macrophages, infiltrating monocytes and neutrophils, and at lower levels also on epithelial and endothelial cells in the lung. CD14 recognizes and binds various structures from invading microbes, such as lipopolysaccharide (LPS) from Gram-negative bacteria, lipoteichoic acid (LTA) from Grampositive bacteria, lipoarabinomannan (LAM) from mycobacteria, viral double stranded (ds) RNA and F glycoprotein (F-gp) from respiratory syncytial virus (RSV). CD14 subsequently transfers these bound components to Toll-like receptors (TLR) which than trigger cell activation. Binding of LPS to CD14 is regulated by additional accessory receptors in the lung, including LPS-binding protein (LBP) and a number of surfactant proteins (SP). Furthermore, soluble CD14 (sCD14) enhances LPS-induced activation of cells with low CD14 expression. Depending on the microbe and the PAMPs it expresses, CD14-amplified responses can either be beneficial to the host by induction of an adequate inflammatory and immune response to eradicate the invading microbe, or detrimental to the host by excessive inflammation and/or dissemination of the pathogen. ![]()
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Saldías MS, Valvano MA. Interactions of Burkholderia cenocepacia and other Burkholderia cepacia complex bacteria with epithelial and phagocytic cells. Microbiology (Reading) 2009; 155:2809-2817. [DOI: 10.1099/mic.0.031344-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Burkholderia cenocepacia is a member of the B. cepacia complex (Bcc), a group of opportunistic bacteria that infect the airways of patients with cystic fibrosis (CF) and are extraordinarily resistant to almost all clinically useful antibiotics. Infections in CF patients with Bcc bacteria generally lead to a more rapid decline in lung function, and in some cases to the ‘cepacia syndrome’, a virtually deadly exacerbation of the lung infection with systemic manifestations. These characteristics of Bcc bacteria contribute to higher morbidity and mortality in infected CF patients. In the last 10 years considerable progress has been made in understanding the interactions between Bcc bacteria and mammalian host cells. Bcc isolates can survive either intracellularly within eukaryotic cells or extracellularly in host tissues. They survive within phagocytes and respiratory epithelial cells, and they have the ability to breach the respiratory epithelium layer. Survival and persistence of Bcc bacteria within host cells and tissues are believed to play a key role in pulmonary infection and to contribute to the persistent inflammation observed in patients with CF. This review summarizes recent findings concerning the interaction between Bcc bacteria and epithelial and phagocytic cells.
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Affiliation(s)
- M. Soledad Saldías
- Infectious Diseases Research Group, Siebens-Drake Research Institute, Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Miguel A. Valvano
- Department of Medicine, University of Western Ontario, London, ON N6A 5C1, Canada
- Infectious Diseases Research Group, Siebens-Drake Research Institute, Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
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Abstract
Bacteria infect the respiratory tract early in the course of cystic fibrosis disease, often fail to be eradicated, and together with an aggressive host inflammatory response, are thought to be key players in the irreversible airway damage from which most patients ultimately die. Although incompletely understood, certain aspects of the cystic fibrosis airway itself appear to favor the development of chronic modes of survival, in particular biofilm formation; this and the development of antibiotic resistance following exposure to multiple antibiotic courses lead to chronic, persistent infection. In addition to the common cystic fibrosis pathogens, such as Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa, several newer species are becoming more common. Furthermore, new molecular techniques have led to the identification of multiple different organisms within respiratory secretions, many of which are not cultured with conventional tools. Future work should aim to develop clinically applicable methods to identify these and to determine which have the potential to impact pulmonary health. We outline the basic tenets of infection control and treatment.
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Affiliation(s)
- Jane C Davies
- Department of Gene Therapy, Imperial College, Emmanuel Kaye Building, Manresa Road, London SW3 6NP, United Kingdom.
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McClean S, Callaghan M. Burkholderia cepacia complex: epithelial cell–pathogen confrontations and potential for therapeutic intervention. J Med Microbiol 2009; 58:1-12. [DOI: 10.1099/jmm.0.47788-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Burkholderia cepaciacomplex (Bcc) is an important and virulent pathogen in cystic fibrosis patients. The interactions between this pathogen and the host lung epithelium are being widely investigated but remain to be elucidated. The complex is very versatile and its interactions with the lung epithelial cells are many and varied. The first steps in the interaction are penetration of the mucosal blanket and subsequent adherence to the epithelial cell surface. A range of epithelial receptors have been reported to bind to Bcc. The next step in pathogenesis is the invasion of the lung epithelial cell and also translocation across the epithelium to the serosal side. Furthermore, pathogenesis is mediated by a range of virulence factors that elicit their effects on the epithelial cells. This review outlines these interactions and examines the therapeutic implications of understanding the mechanisms of pathogenesis of this difficult, antibiotic-resistant, opportunistic pathogen.
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Affiliation(s)
- Siobhán McClean
- Centre of Microbial Host Interactions, Institute of Technology Tallaght Dublin, Dublin 24, Ireland
| | - Máire Callaghan
- Centre of Microbial Host Interactions, Institute of Technology Tallaght Dublin, Dublin 24, Ireland
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Rodriguez S, Kunde YA, McCleskey TM, Hong-Geller E. Upregulation of I-CAM1 in response to beryllium exposure in small airway epithelial cells. Toxicol Lett 2008; 179:140-7. [DOI: 10.1016/j.toxlet.2008.04.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 04/28/2008] [Accepted: 04/28/2008] [Indexed: 01/10/2023]
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Pace E, Ferraro M, Siena L, Melis M, Montalbano AM, Johnson M, Bonsignore MR, Bonsignore G, Gjomarkaj M. Cigarette smoke increases Toll-like receptor 4 and modifies lipopolysaccharide-mediated responses in airway epithelial cells. Immunology 2008; 124:401-11. [PMID: 18217953 PMCID: PMC2440834 DOI: 10.1111/j.1365-2567.2007.02788.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 11/19/2007] [Accepted: 11/19/2007] [Indexed: 12/21/2022] Open
Abstract
Airway epithelium is emerging as a regulator of innate immune responses to a variety of insults including cigarette smoke. The main goal of this study was to explore the effects of cigarette smoke extracts (CSE) on Toll-like receptor (TLR) expression and activation in a human bronchial epithelial cell line (16-HBE). The CSE increased the expression of TLR4 and the lipopolysaccharide (LPS) binding, the nuclear factor-kappaB (NF-kappaB) activation, the release of interleukin-8 (IL-8) and the chemotactic activity toward neutrophils. It did not induce TLR2 expression or extracellular signal-regulated signal kinase 1/2 (ERK1/2) activation. The LPS increased the expression of TLR4 and induced both NF-kappaB and ERK1/2 activation. The combined exposure of 16-HBE to CSE and LPS was associated with ERK activation rather than NF-kappaB activation and with a further increase of IL-8 release and of chemotactic activity toward neutrophils. Furthermore, CSE decreased the constitutive interferon-inducible protein-10 (IP-10) release and counteracted the effect of LPS in inducing both the IP-10 release and the chemotactic activity toward lymphocytes. In conclusion, cigarette smoke, by altering the expression and the activation of TLR4 via the preferential release of IL-8, may contribute to the accumulation of neutrophils within the airways of smokers.
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Affiliation(s)
- Elisabetta Pace
- Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
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Sajjan US, Hershenson MB, Forstner JF, LiPuma JJ. Burkholderia cenocepacia ET12 strain activates TNFR1 signalling in cystic fibrosis airway epithelial cells. Cell Microbiol 2007; 10:188-201. [PMID: 17697131 PMCID: PMC3226749 DOI: 10.1111/j.1462-5822.2007.01029.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Burkholderia cenocepacia is an important pulmonary pathogen in individuals with cystic fibrosis (CF). Infection is often associated with severe pulmonary inflammation, and some patients develop a fatal necrotizing pneumonia and sepsis ('cepacia syndrome'). The mechanisms by which this species causes severe pulmonary inflammation are poorly understood. Here, we demonstrate that B. cenocepacia BC7, a potentially virulent representative of the epidemic ET12 lineage, binds to tumour necrosis factor receptor 1 (TNFR1) and activates TNFR1-related signalling pathway similar to TNF-alpha, a natural ligand for TNFR1. This interaction participates in stimulating a robust IL-8 production from CF airway epithelial cells. In contrast, BC45, a less virulent ET12 representative, and ATCC 25416, an environmental B. cepacia strain, do not bind to TNFR1 and stimulate only minimal IL-8 production from CF cells. Further, TNFR1 expression is increased in CF airway epithelial cells compared with non-CF cells. We also show that B. cenocepacia ET12 strain colocaizes with TNFR1 in vitro and in the lungs of CF patients who died due to infection with B. cenocepacia, ET12 strain. Together, these results suggest that interaction of B. cenocepacia, ET12 strain with TNFR1 may contribute to robust inflammatory responses elicited by this organism.
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Affiliation(s)
- Umadevi S Sajjan
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA.
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Fan H, Luttrell LM, Tempel GE, Senn JJ, Halushka PV, Cook JA. Beta-arrestins 1 and 2 differentially regulate LPS-induced signaling and pro-inflammatory gene expression. Mol Immunol 2007; 44:3092-9. [PMID: 17418896 PMCID: PMC1945129 DOI: 10.1016/j.molimm.2007.02.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 02/05/2007] [Indexed: 01/01/2023]
Abstract
Toll like receptors, the critical receptor family in innate immunity, have been shown to signal via both ERK 1/2 and transcription factor NFkappaB. beta-Arrestins 1 and 2 have recently been implicated in modulation of NFkappaB signaling and ERK 1/2 activation. Using a number of approaches: mouse embryonic fibroblasts (MEF) from wild-type (WT), beta-arrestins knockouts (KO), beta-arrestins 1 and 2 double KO, and MEFs with reconstituted WT beta-arrestins in the double KO cells, RNA interference (siRNA) specific knockdown of beta-arrestins, and overexpression of WT beta-arrestins, it was demonstrated that beta-arrestin 2 positively regulates LPS-induced ERK 1/2 activation and both beta-arrestins 1 and 2 negatively regulate LPS-induced NFkappaB activation. Also beta-arrestin 2 positively regulate LPS-induced IL-6 production and both beta-arrestins 1 and 2 positively regulate LPS-induced IL-8 production. The specific ERK1/2 inhibitor PD98059 significantly decreased LPS-induced IL-6 and IL-8 production suggesting that IL-6 and IL-8 production is, in part, mediated by ERK 1/2 activation. Over expression of wild type beta-arrestins 1 and 2 had no effect on LPS-induced ERK1/2 activation and LPS-induced IL-8 production suggesting that endogenous beta-arrestins 1 and 2 are sufficient to mediate maximum ERK 1/2 activity and IL-8 production. beta-Arrestins thus not only negatively regulate LPS-induced NFkappaB activation but also positively regulate ERK 1/2 activation and specific pro-inflammatory gene expression. Understanding the role of beta-arrestins in regulation of TLR signaling pathways may provide novel insights into control mechanisms for inflammatory gene expression.
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Affiliation(s)
- Hongkuan Fan
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, United States
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Thorley AJ, Ford PA, Giembycz MA, Goldstraw P, Young A, Tetley TD. Differential regulation of cytokine release and leukocyte migration by lipopolysaccharide-stimulated primary human lung alveolar type II epithelial cells and macrophages. THE JOURNAL OF IMMUNOLOGY 2007; 178:463-73. [PMID: 17182585 DOI: 10.4049/jimmunol.178.1.463] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bacterial colonization is a secondary feature of many lung disorders associated with elevated cytokine levels and increased leukocyte recruitment. We hypothesized that, alongside macrophages, the epithelium would be an important source of these mediators. We investigated the effect of LPS (0, 10, 100, and 1000 ng/ml LPS, up to 24 h) on primary human lung macrophages and alveolar type II epithelial cells (ATII; isolated from resected lung tissue). Although macrophages produced higher levels of the cytokines TNF-alpha and IL-1beta (p < 0.0001), ATII cells produced higher levels of chemokines MCP-1, IL-8, and growth-related oncogene alpha (p < 0.001), in a time- and concentration-dependent manner. Macrophage (but not ATII cell) responses to LPS required activation of ERK1/2 and p38 MAPK signaling cascades; phosphorylated ERK1/2 was constitutively up-regulated in ATII cells. Blocking Abs to TNF-alpha and IL-1beta during LPS exposure showed that ATII cell (not macrophage) MCP-1 release depended on the autocrine effects of IL-1beta and TNF-alpha (p < 0.003, 24 h). ATII cell release of IL-6 depended on autocrine effects of TNF-alpha (p < 0.006, 24 h). Macrophage IL-6 release was most effectively inhibited when both TNF-alpha and IL-1beta were blocked (p < 0.03, 24 h). Conditioned media from ATII cells stimulated more leukocyte migration in vitro than conditioned media from macrophages (p < 0.0002). These results show differential activation of cytokine and chemokine release by ATII cells and macrophages following LPS exposure. Activated alveolar epithelium is an important source of chemokines that orchestrate leukocyte migration to the peripheral lung; early release of TNF-alpha and IL-1beta by stimulated macrophages may contribute to alveolar epithelial cell activation and chemokine production.
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Affiliation(s)
- Andrew J Thorley
- Lung Cell Biology, Section of Airways Disease, National Heart and Lung Institute, Imperial College, London, United Kingdom
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24
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Blau H, Klein K, Shalit I, Halperin D, Fabian I. Moxifloxacin but not ciprofloxacin or azithromycin selectively inhibits IL-8, IL-6, ERK1/2, JNK, and NF-κB activation in a cystic fibrosis epithelial cell line. Am J Physiol Lung Cell Mol Physiol 2007; 292:L343-52. [PMID: 17012372 DOI: 10.1152/ajplung.00030.2006] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cystic fibrosis (CF) is associated with severe neutrophilic airway inflammation. We showed that moxifloxacin (MXF) inhibits IL-8 and MAPK activation in monocytic and respiratory epithelial cells. Azithromycin (AZM) and ciprofloxacin (CIP) are used clinically in CF. Thus we now examined effects of MXF, CIP, and AZM directly on CF cells. IB3, a CF bronchial cell line, and corrected C38 cells were treated with TNF-α, IL-1β, or LPS with or without 5–50 μg/ml MXF, CIP, or AZM. IL-6 and IL-8 secretion (ELISA), MAPKs ERK1/2, JNK, p38, and p65 NF-κB (Western blot) activation were measured. Baseline IL-6 was sixfold higher in IB3 than C38 cells but IL-8 was similar. TNF-α and IL-1β increased IL-6 and IL-8 12- to 67-fold with higher levels in IB3 than C38 cells post-TNF-α ( P < 0.05). Levels were unchanged following LPS. Baseline phosphorylated form of ERK1/2 (p-ERK1/2), JNK, and NF-κB p65 were higher in IB3 than C38 cells (5-, 1.4-, and 1.4-fold), and following TNF-α increased, as did the p-p38, by 1.6- to 2-fold. MXF (5–50 μg/ml) and CIP (50 μg/ml), but not AZM, suppressed IL-6 and IL-8 secretion by up to 69%. MXF inhibited TNF-α-stimulated MAPKs ERK1/2, 46-kDa JNK, and NF-κB up to 60%, 40%, and 40%, respectively. In contrast, MXF did not inhibit p38 activation, implying a highly selective pretranslational effect. In conclusion, TNF-α and IL-1β induce an exaggerated inflammatory response in CF airway cells, inhibited by MXF more than by CIP or AZM. Clinical trials are recommended to assess efficacy in CF and other chronic lung diseases.
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Affiliation(s)
- Hannah Blau
- Schneider Children's Medical Center of Israel, 14 Kaplan Street, Petah Tikva, Israel 49202.
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Sohn EJ, Paape MJ, Bannerman DD, Connor EE, Fetterer RH, Peters RR. Shedding of sCD14 by bovine neutrophils following activation with bacterial lipopolysaccharide results in down-regulation of IL-8. Vet Res 2006; 38:95-108. [PMID: 17156740 DOI: 10.1051/vetres:2006052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 10/03/2006] [Indexed: 12/29/2022] Open
Abstract
CD14, the leukocyte co-receptor for lipopolysaccharide (LPS), is important in the response of bovine polymorphonuclear neutrophil leukocytes (PMN) to Gram-negative bacteria. In other species, the expression of CD14 on the surface of PMN was shown to increase after exposure to inflammatory stimuli. These newly expressed molecules may originate from either an intracellular pool or through new gene expression. We sought to characterize bovine PMN cell surface expression and shedding of CD14 molecules, and CD14's effect on secretion of the chemoattractants IL-8 and IL-1beta by PMN. Bovine PMN were incubated in RPMI for 20 h at 37 degrees C with LPS (1, 10, 100 microg/mL). IL-8 release increased with treatment of 1 microg/mL LPS, but decreased 41.5 and 95% at the 10 and 100 microg/mL concentrations of LPS, respectively. In contrast, shedding of CD14 from the surface of PMN only increased at the highest concentration of LPS (100 microg/mL). Secretion of IL-1beta was similar regardless of the LPS concentration used to stimulate PMN. The effect of PMN concentration (1 x 10(7), 2.5 x 10(7), 5 x 10(7), and 10 x 10(7)/mL) on CD14 cell surface expression and shedding of IL-8 and IL-1beta were also determined. Shedding of CD14 by PMN increased with increasing concentration of PMN after exposure to 0.1 and 10 microg/mL of LPS, while secretion of IL-8 decreased. IL-1beta increased at the highest concentration of PMN. The use of real time polymerase chain reaction showed that CD14 mRNA expression was not different between control and LPS-stimulated cells, indicating that the sCD14 came from either membrane bound CD14 or a preformed pool. Our results demonstrate that release of CD14 from PMN suppresses secretion of IL-8, and may be an important regulatory mechanism for controlling excessive migration of PMN into the bovine mammary gland.
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Affiliation(s)
- Eun J Sohn
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA
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Barbosa FM, Fonseca FL, Figueiredo RT, Bozza MT, Casadevall A, Nimrichter L, Rodrigues ML. Binding of glucuronoxylomannan to the CD14 receptor in human A549 alveolar cells induces interleukin-8 production. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 14:94-8. [PMID: 17093102 PMCID: PMC1797707 DOI: 10.1128/cvi.00296-06] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glucuronoxylomannan (GXM) is the major capsular polysaccharide of Cryptococcus neoformans. GXM receptors have been characterized in phagocytes and endothelial cells, but epithelial molecules recognizing the polysaccharide remain unknown. In the current study, we demonstrate that GXM binds to the CD14 receptor in human type II alveolar epithelial cells, resulting in the production of the proinflammatory chemokine interleukin-8.
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Affiliation(s)
- Fabiane M Barbosa
- Laboratório de Estudos Integrados em Bioquímica Microbiana, Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude (CCS), Rio de Janeiro, Brazil
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Bamford S, Ryley H, Jackson SK. Highly purified lipopolysaccharides from Burkholderia cepacia complex clinical isolates induce inflammatory cytokine responses via TLR4-mediated MAPK signalling pathways and activation of NFkappaB. Cell Microbiol 2006; 9:532-43. [PMID: 17002785 DOI: 10.1111/j.1462-5822.2006.00808.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In cystic fibrosis (CF), bacteria of the Burkholderia cepacia complex (Bcc) can induce a fulminant inflammation with pneumonitis and sepsis. Lipopolysaccharide (LPS) may be an important virulence factor associated with this decline but little is known about the molecular pathogenesis of Bcc LPS. In this study we have investigated the inflammatory response to highly purified LPS from different Bcc clinical isolates and the cellular signalling pathways employed. The inflammatory response (TNFalpha, IL-6) was measured in human MonoMac 6 monocytes and inhibition experiments were used to investigate the Toll-like receptors and associated adaptor molecules and pathways utilized. LPS from all clinical Bcc isolates induced significant pro-inflammatory cytokines and utilized TLR4 and CD14 to mediate activation of mitogen-activated protein kinase pathways, IkappaB-alpha degradation and NFkappaB activation. However, LPS from different clinical isolates of the same clonal strain of Burkholderia cenocepacia were found to induce a varied inflammatory response. LPS from clinical isolates of Burkholderia multivorans was found to activate the inflammatory response via MyD88-independent pathways. This study suggests that LPS alone from clinical isolates of Bcc is an important virulence factor in CF and utilizes TLR4-mediated signalling pathways to induce a significant inflammatory response.
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Affiliation(s)
- Sarah Bamford
- Department of Medical Microbiology, School of Medicine, Cardiff University, Cardiff, UK
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28
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Raia V, Maiuri L, Ciacci C, Ricciardelli I, Vacca L, Auricchio S, Cimmino M, Cavaliere M, Nardone M, Cesaro A, Malcolm J, Quaratino S, Londei M. Inhibition of p38 mitogen activated protein kinase controls airway inflammation in cystic fibrosis. Thorax 2005; 60:773-80. [PMID: 15994249 PMCID: PMC1747526 DOI: 10.1136/thx.2005.042564] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Cystic fibrosis (CF) airways are characterised by chronic inflammation, increased interleukin (IL)-8 secretion, and neutrophil activation which are considered the principal factors of morbidity and mortality in CF patients. Optimising management of this chronic inflammatory response is therefore a key issue of basic and clinical CF research. Several reports have addressed ways to manage CF airways inflammation, and an attractive therapeutic strategy may be the inhibition of the p38-mitogen activated protein kinase (p38-MAP-k) pathway. METHODS A new ex vivo model was used to study the mucosal inflammatory response to environmental airways stimuli. Nasal biopsy tissues from CF patients and controls were cultured ex vivo for 20 minutes, 4 hours, and 24 hours in the presence of lipopolysaccharide (LPS) from Pseudomonas aeruginosa (PA) with and without the p38-MAP-k inhibitor SB203580. Quantitative mRNA assessment, immunohistochemistry, and Western blots were used to detect the expression and modulation of inflammatory markers. RESULTS PA-LPS challenge induced a time dependent mucosal inflammation indicated by rapid epithelial activation, IL-8 release, COX-2 upregulation, and neutrophil migration to the upper mucosal layers. Some of these LPS induced changes (IL-8 release and neutrophil migration) were specific to CF tissues. SB203580 significantly controlled all LPS induced mucosal changes in CF tissues. CONCLUSION These findings provide a rationale and proof of principle for the potential use of p38-MAP-k inhibitors to control inflammation in patients with CF.
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Affiliation(s)
- V Raia
- Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
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CAO H, WANG A, MARTIN B, KOEHLER DR, ZEITLIN PL, TANAWELL AK, HU J. Down-regulation of IL-8 expression in human airway epithelial cells through helper-dependent adenoviral-mediated RNA interference. Cell Res 2005; 15:111-9. [PMID: 15740640 PMCID: PMC4497818 DOI: 10.1038/sj.cr.7290275] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Interleukin (IL)-8 is a potent neutrophil chemotactic factor and a crucial mediator in neutrophil-dependent inflammation. Various cell types produce IL-8, either in response to external stimuli such as cytokines or bacterial infection, or after malignant transformation. Anti-IL-8 strategies have been considered for anti-inflammatory therapy. In this paper we demonstrate that the RNA interference technique can be used to efficiently down-regulate IL-8 protein expression in airway epithelial cells. We used a helper-dependent adenoviral vector to express a small hairpin (sh)RNA targeting human IL-8 in cultured airway epithelial cells (IB3-1, Cftr-/-; C38, Cftr-corrected) stimulated with TNF-alpha, IL-1beta or heat-inactivated Burkholderia cenocepacia. Stimulated IL-8 expression in IB3-1 and C38 cells was significantly reduced by shRNA expression. The shRNA targeting IL-8 had no effect on the activation of NF-kappaB, or on the protein levels of IkappaB or IL-6, suggesting that this anti-IL-8 strategy was highly specific, and therefore may offer potential for the treatment of inflammatory diseases.
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Affiliation(s)
- Huibi CAO
- Programme in Lung Biology Research and the Canadian Institutes of Health Research Group in Lung Development, Hospital for Sick Children, Toronto, M5G 1X8 Canada
- Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A1 Canada
| | - Anan WANG
- Programme in Lung Biology Research and the Canadian Institutes of Health Research Group in Lung Development, Hospital for Sick Children, Toronto, M5G 1X8 Canada
| | - Bernard MARTIN
- Programme in Lung Biology Research and the Canadian Institutes of Health Research Group in Lung Development, Hospital for Sick Children, Toronto, M5G 1X8 Canada
| | - David R KOEHLER
- Programme in Lung Biology Research and the Canadian Institutes of Health Research Group in Lung Development, Hospital for Sick Children, Toronto, M5G 1X8 Canada
- Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A1 Canada
| | - Pamela L ZEITLIN
- Departments of Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287 USA
| | - A Keith TANAWELL
- Programme in Lung Biology Research and the Canadian Institutes of Health Research Group in Lung Development, Hospital for Sick Children, Toronto, M5G 1X8 Canada
- Department of Paediatrics, University of Toronto, Toronto, M5S 1A1 Canada
- Department of Physiology, University of Toronto, Toronto, M5S 1A1 Canada
| | - Jim HU
- Programme in Lung Biology Research and the Canadian Institutes of Health Research Group in Lung Development, Hospital for Sick Children, Toronto, M5G 1X8 Canada
- Department of Paediatrics, University of Toronto, Toronto, M5S 1A1 Canada
- Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A1 Canada
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Phagoo SB, Reddi K, Silvallana BJ, Leeb-Lundberg LMF, Warburton D. Infection-Induced Kinin B1Receptors in Human Pulmonary Fibroblasts: Role of Intact Pathogens and p38 Mitogen-Activated Protein Kinase-Dependent Signaling. J Pharmacol Exp Ther 2005; 313:1231-8. [PMID: 15743925 DOI: 10.1124/jpet.104.083030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kinin B(1) receptors (B(1)R) are involved in many pathophysiological processes, and its expression is up-regulated in inflammatory pulmonary disease. Although bacteria can generate kinin peptides, the molecular signaling mechanisms regulating B(1)R during infection by intact pathogens is unknown. The serious opportunistic clinical isolate Burkholderia cenocepacia (B. cen.) belongs to the important B. cepacia complex (Bcc) of gram-negative pathogens that rapidly causes fatal pulmonary disease in hospitalized and immunocompromised patients and those with cystic fibrosis. We demonstrate here that B. cen. infection induced a rapid increase in B(1)R mRNA (1 h) proceeded by an increase in B(1)R protein expression (2 h), without affecting B(2) receptor expression in human pulmonary fibroblasts. The B(1)R response was dose-dependent and maximal by 6 to 8 h (3- to 4-fold increase), however, brief B. cen. infection could sustain B(1)R up-regulation. In contrast, nonclinical Bcc phytopathogens were much less B(1)R inducive. The protein synthesis inhibitor cycloheximide and transcriptional inhibitor actinomycin D abrogated the B(1) response to B. cen. indicating de novo B(1)R synthesis. B. cen. activated p38 mitogen-activated protein kinase (MAPK), and blocking p38 MAPK with the specific inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB 203580) dramatically reduced B. cen.-induced B(1)R. Furthermore, B. cen. regulation of B(1)R was diminished by the anti-inflammatory glucocorticoid dexamethasone. In conclusion, this study is the first demonstration that infection with intact pulmonary pathogens like B. cen. positively modulates the selective expression of B(1)R. Thus, providing evidence that B(1)R regulation may be an important and novel mechanism in the inflammatory cascade in response to chronic pulmonary infection and disease.
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Affiliation(s)
- Stephen B Phagoo
- Developmental Biology Program, Saban Research Institute, Childrens Hospital Los Angeles, Department of Surgery, Keck School of Medicine, University of Southern California, 90027, USA.
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Mahenthiralingam E, Urban TA, Goldberg JB. The multifarious, multireplicon Burkholderia cepacia complex. Nat Rev Microbiol 2005; 3:144-56. [PMID: 15643431 DOI: 10.1038/nrmicro1085] [Citation(s) in RCA: 622] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Burkholderia cepacia complex (Bcc) is a collection of genetically distinct but phenotypically similar bacteria that are divided into at least nine species. Bcc bacteria are found throughout the environment, where they can have both beneficial and detrimental effects on plants and some members can also degrade natural and man-made pollutants. Bcc bacteria are now recognized as important opportunistic pathogens that can cause variable lung infections in cystic fibrosis patients, which result in asymptomatic carriage, chronic infection or 'cepacia syndrome', which is characterized by a rapid decline in lung function that can include invasive disease. Here we highlight the unique characteristics of the Bcc, focusing on the factors that determine virulence.
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Urban TA, Griffith A, Torok AM, Smolkin ME, Burns JL, Goldberg JB. Contribution of Burkholderia cenocepacia flagella to infectivity and inflammation. Infect Immun 2004; 72:5126-34. [PMID: 15322006 PMCID: PMC517433 DOI: 10.1128/iai.72.9.5126-5134.2004] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen that can cause severe lung infections in cystic fibrosis patients. To understand the contribution of B. cenocepacia flagella to infection, a strain mutated in the major flagellin subunit, fliCII, was constructed in B. cenocepacia K56-2 and tested in a murine agar bead model of lung infection. C57/BL6 mice infected with approximately 10(8) wild-type K56-2 bacteria exhibited 40% mortality after 3 days, whereas no mortality was noted in mice infected with the fliCII mutant. Among the mice surviving the infection with either strain, there was no significant difference in the bacterial loads in the lungs and spleen, bacteremia, weight loss, or infiltration of immune effector cells at 3 days postinfection. Similar results were observed at 24 h, prior to expression of the lethality phenotype. KC, a murine interleukin-8 (IL-8) homolog, was elevated in both the bronchoalveolar lavage fluid and serum of mice infected with the wild type compared to the fliCII mutant at 24 h, suggesting that flagella stimulated host cells. To demonstrate that flagella contributed to these responses, the interaction between B. cenocepacia and Toll-like receptor 5 (TLR5) was investigated. Infection of HEK293 cells with heat-killed wild-type K56-2, but not infection with the fliCII mutant, resulted in both NF-kappaB activation and IL-8 secretion that was dependent upon expression of TLR5. Together, these results demonstrate that B. cenocepacia flagella contribute to virulence in an in vivo infection model, and that induction of host immune responses through interaction with TLR5 may contribute to its overall pathogenic potential.
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Affiliation(s)
- Teresa A Urban
- Department of Microbiology, University of Virginia Health System, Box 800734, Charlottesville, VA 22908, USA
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Groneberg DA, Witt H, Adcock IM, Hansen G, Springer J. Smads as intracellular mediators of airway inflammation. Exp Lung Res 2004; 30:223-50. [PMID: 15195555 DOI: 10.1080/01902140490276320] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Transforming growth factor-beta (TGF-beta) plays an important role in the pathogenesis of allergic asthma and other airway diseases. Signals from the activated TGF-beta receptor complex are transduced to the nucleus of airway cells by Smad proteins, which represent a family of transcription factors that have recently been implicated to play a major role as intracellular mediators of inflammation. The Smad family consists of the receptor-regulated Smads, a common pathway Smad, and inhibitory Smads. Receptor-regulated Smads (R-Smads) are phosphorylated by the TGF-beta type Ireceptor. They include Smad2 and Smad3, which are recognized by TGF-beta and activin receptors, and Smads 1, 5, 8, and 9, which are recognized by bone morphogenetic protein (BMP) receptors. Smad4 is a common pathway Smad, which is also defined as cooperating Smad (co-Smad) and is not phosphorylated by the TGF-beta type I receptor. Inhibitory Smads(anti-Smads) include Smad6 and Smad7, which down-regulate TGF-beta signaling. To date, the Smads are the only TGF-beta receptor substrates with a demonstrated ability to propagate signals and with regard to the growing number of investigations of Smad-mediated effects in the airways, Smads may prove to be an important target for future development of new therapeutic strategies for asthma and chronic obstructive pulmonary disease.
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Affiliation(s)
- David A Groneberg
- Division of Allergy Research, Department of Pediatric Pneumology and Immunology, Charité Campus-Virchow, Humboldt-University, Berlin, Germany.
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Affiliation(s)
- John R W Govan
- Cystic Fibrosis Microbiology Laboratory and Strain Repository, Medical Microbiology Division, University of Edinburgh Medical School, Teviot Place, Edinburgh, EH8 9AG, UK.
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