1
|
You J, Zhou L, San X, Li H, Li M, Wang B. NEDD4 Regulated Pyroptosis Occurred from Co-infection between Influenza A Virus and Streptococcus pneumoniae. J Microbiol 2023; 61:777-789. [PMID: 37792248 DOI: 10.1007/s12275-023-00076-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/15/2023] [Accepted: 08/22/2023] [Indexed: 10/05/2023]
Abstract
Co-infection of respiratory tract viruses and bacteria often result in excess mortality, especially pneumonia caused by influenza viruses and Streptococcus pneumoniae. However, the synergistic mechanisms remain poorly understood. Therefore, it is necessary to develop a clearer understanding of the molecular basis of the interaction between influenza virus and Streptococcus pneumonia. Here, we developed the BALB/c mouse model and the A549 cell model to investigate inflammation and pyroptotic cell death during co-infection. Co-infection significantly activated the NLRP3 inflammasome and induced pyroptotic cell death, correlated with excess mortality. The E3 ubiquitin ligase NEDD4 interacted with both NLRP3 and GSDMD, the executor of pyroptosis. NEDD4 negatively regulated NLRP3 while positively regulating GSDMD, thereby modulating inflammation and pyroptotic cell death. Our findings suggest that NEDD4 may play a crucial role in regulating the GSDMD-mediated pyroptosis signaling pathway. Targeting NEDD4 represents a promising approach to mitigate excess mortality during influenza pandemics by suppressing synergistic inflammation during co-infection of influenza A virus and Streptococcus pneumoniae.
Collapse
Affiliation(s)
- Jiangzhou You
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610000, People's Republic of China
| | - Linlin Zhou
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610000, People's Republic of China
| | - Xudong San
- Reproductive & Women-Children Hospital, Chengdu University of Traditional Chinese Medicine, Chengdu, 610000, People's Republic of China
| | - Hailing Li
- Department of Biochemistry, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610000, People's Republic of China
| | - Mingyuan Li
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610000, People's Republic of China.
| | - Baoning Wang
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610000, People's Republic of China.
| |
Collapse
|
2
|
Naturally-occurring serotype 3 Streptococcus pneumoniae strains that lack functional pneumolysin and autolysin have attenuated virulence but induce localized protective immune responses. PLoS One 2023; 18:e0282843. [PMID: 36897919 PMCID: PMC10004606 DOI: 10.1371/journal.pone.0282843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 02/23/2023] [Indexed: 03/11/2023] Open
Abstract
Streptococcus pneumoniae is an important cause of fatal pneumonia in humans. These bacteria express virulence factors, such as the toxins pneumolysin and autolysin, that drive host inflammatory responses. In this study we confirm loss of pneumolysin and autolysin function in a group of clonal pneumococci that have a chromosomal deletion resulting in a pneumolysin-autolysin fusion gene Δ(lytA'-ply')593. The Δ(lytA'-ply')593 pneumococci strains naturally occur in horses and infection is associated with mild clinical signs. Here we use immortalized and primary macrophage in vitro models, which include pattern recognition receptor knock-out cells, and a murine acute pneumonia model to show that a Δ(lytA'-ply')593 strain induces cytokine production by cultured macrophages, however, unlike the serotype-matched ply+lytA+ strain, it induces less tumour necrosis factor α (TNFα) and no interleukin-1β production. The TNFα induced by the Δ(lytA'-ply')593 strain requires MyD88 but, in contrast to the ply+lytA+ strain, is not reduced in cells lacking TLR2, 4 or 9. In comparison to the ply+lytA+ strain in a mouse model of acute pneumonia, infection with the Δ(lytA'-ply')593 strain resulted in less severe lung pathology, comparable levels of interleukin-1α, but minimal release of other pro-inflammatory cytokines, including interferon-γ, interleukin-6 and TNFα. These results suggest a mechanism by which a naturally occurring Δ(lytA'-ply')593 mutant strain of S. pneumoniae that resides in a non-human host has reduced inflammatory and invasive capacity compared to a human S. pneumoniae strain. These data probably explain the relatively mild clinical disease in response to S. pneumoniae infection seen in horses in comparison to humans.
Collapse
|
3
|
Kennedy II DE, Mody P, Gout JF, Tan W, Seo KS, Olivier AK, Rosch JW, Thornton JA. Contribution of Puma to Inflammatory Resolution During Early Pneumococcal Pneumonia. Front Cell Infect Microbiol 2022; 12:886901. [PMID: 35694536 PMCID: PMC9177954 DOI: 10.3389/fcimb.2022.886901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/25/2022] [Indexed: 11/17/2022] Open
Abstract
Apoptosis of cells at the site of infection is a requirement for shutdown of inflammatory signaling, avoiding tissue damage, and preventing progression of sepsis. Puma+/+ and Puma-/- mice were challenged with TIGR4 strain pneumococcus and cytokines were quantitated from lungs and blood using a magnetic bead panel analysis. Puma-/- mice exhibited higher lung and blood cytokine levels of several major inflammatory cytokines, including IL-6, G-CSF, RANTES, IL-12, IFN-ϒ, and IP-10. Puma-/- mice were more susceptible to bacterial dissemination and exhibited more weight loss than their wild-type counterparts. RNA sequencing analysis of whole pulmonary tissue revealed Puma-dependent regulation of Nrxn2, Adam19, and Eln. Enrichment of gene ontology groups differentially expressed in Puma-/- tissues were strongly correlated to IFN-β and -ϒ signaling. Here, we demonstrate for the first time the role of Puma in prohibition of the cytokine storm during bacterial pneumonia. These findings further suggest a role for targeting immunomodulation of IFN signaling during pulmonary inflammation. Additionally, our findings suggest previously undemonstrated roles for genes encoding regulatory and binding proteins during the early phase of the innate immune response of pneumococcal pneumonia.
Collapse
Affiliation(s)
- Daniel E. Kennedy II
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Perceus Mody
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Jean-Francois Gout
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Wei Tan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Keun Seok Seo
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Alicia K. Olivier
- Department of Population and Pathobiology, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Jason W. Rosch
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | - Justin A. Thornton
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
- *Correspondence: Justin A. Thornton,
| |
Collapse
|
4
|
Kopenhagen A, Ramming I, Camp B, Hammerschmidt S, Fulde M, Müsken M, Steinert M, Bergmann S. Streptococcus pneumoniae Affects Endothelial Cell Migration in Microfluidic Circulation. Front Microbiol 2022; 13:852036. [PMID: 35401456 PMCID: PMC8990767 DOI: 10.3389/fmicb.2022.852036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/04/2022] [Indexed: 01/12/2023] Open
Abstract
Bloodstream infections caused by Streptococcus pneumoniae induce strong inflammatory and procoagulant cellular responses and affect the endothelial barrier of the vascular system. Bacterial virulence determinants, such as the cytotoxic pore-forming pneumolysin, increase the endothelial barrier permeability by inducing cell apoptosis and cell damage. As life-threatening consequences, disseminated intravascular coagulation followed by consumption coagulopathy and low blood pressure is described. With the aim to decipher the role of pneumolysin in endothelial damage and leakage of the vascular barrier in more detail, we established a chamber-separation cell migration assay (CSMA) used to illustrate endothelial wound healing upon bacterial infections. We used chambered inlets for cell cultivation, which, after removal, provide a cell-free area of 500 μm in diameter as a defined gap in primary endothelial cell layers. During the process of wound healing, the size of the cell-free area is decreasing due to cell migration and proliferation, which we quantitatively determined by microscopic live cell monitoring. In addition, differential immunofluorescence staining combined with confocal microscopy was used to morphologically characterize the effect of bacterial attachment on cell migration and the velocity of gap closure. In all assays, the presence of wild-type pneumococci significantly inhibited endothelial gap closure. Remarkably, even in the presence of pneumolysin-deficient pneumococci, cell migration was significantly retarded. Moreover, the inhibitory effect of pneumococci on the proportion of cell proliferation versus cell migration within the process of endothelial gap closure was assessed by implementation of a fluorescence-conjugated nucleoside analogon. We further combined the endothelial CSMA with a microfluidic pump system, which for the first time enabled the microscopic visualization and monitoring of endothelial gap closure in the presence of circulating bacteria at defined vascular shear stress values for up to 48 h. In accordance with our CSMA results under static conditions, the gap remained cell free in the presence of circulating pneumococci in flow. Hence, our combined endothelial cultivation technique represents a complex in vitro system, which mimics the vascular physiology as close as possible by providing essential parameters of the blood flow to gain new insights into the effect of pneumococcal infection on endothelial barrier integrity in flow.
Collapse
Affiliation(s)
- Anna Kopenhagen
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Isabell Ramming
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
| | - Belinda Camp
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Pneumology, University Hospital Magdeburg, Magdeburg, Germany
| | - Sven Hammerschmidt
- Institute for Genetics and Functional Genomics, Department of Molecular Genetics and Infection Biology, Universität Greifswald, Greifswald, Germany
| | - Marcus Fulde
- Institute of Microbiology and Epizootics, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Mathias Müsken
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Simone Bergmann
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| |
Collapse
|
5
|
From pyroptosis, apoptosis and necroptosis to PANoptosis: A mechanistic compendium of programmed cell death pathways. Comput Struct Biotechnol J 2021; 19:4641-4657. [PMID: 34504660 PMCID: PMC8405902 DOI: 10.1016/j.csbj.2021.07.038] [Citation(s) in RCA: 193] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 02/07/2023] Open
Abstract
Pyroptosis, apoptosis and necroptosis are the most genetically well-defined programmed cell death (PCD) pathways, and they are intricately involved in both homeostasis and disease. Although the identification of key initiators, effectors and executioners in each of these three PCD pathways has historically delineated them as distinct, growing evidence has highlighted extensive crosstalk among them. These observations have led to the establishment of the concept of PANoptosis, defined as an inflammatory PCD pathway regulated by the PANoptosome complex with key features of pyroptosis, apoptosis and/or necroptosis that cannot be accounted for by any of these PCD pathways alone. In this review, we provide a brief overview of the research history of pyroptosis, apoptosis and necroptosis. We then examine the intricate crosstalk among these PCD pathways to discuss the current evidence for PANoptosis. We also detail the molecular evidence for the assembly of the PANoptosome complex, a molecular scaffold for contemporaneous engagement of key molecules from pyroptosis, apoptosis, and/or necroptosis. PANoptosis is now known to be critically involved in many diseases, including infection, sterile inflammation and cancer, and future discovery of novel PANoptotic components will continue to broaden our understanding of the fundamental processes of cell death and inform the development of new therapeutics.
Collapse
|
6
|
Van den Bossche S, Vandeplassche E, Ostyn L, Coenye T, Crabbé A. Bacterial Interference With Lactate Dehydrogenase Assay Leads to an Underestimation of Cytotoxicity. Front Cell Infect Microbiol 2020; 10:494. [PMID: 33042868 PMCID: PMC7523407 DOI: 10.3389/fcimb.2020.00494] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/10/2020] [Indexed: 12/21/2022] Open
Abstract
Models to study host-pathogen interactions in vitro are an important tool for investigating the infectious disease process and evaluating the efficacy of antimicrobial compounds. In these models, the viability of mammalian cells is often determined using the lactate dehydrogenase (LDH) cytotoxicity assay. In the present study we evaluated whether bacteria could interfere with the LDH assay. As a model for host-pathogen interactions, we co-cultured lung epithelial cells with eight bacteria encountered in the lower respiratory tract. We show that LDH activity is affected by Pseudomonas aeruginosa, Klebsiella pneumoniae, Stenotrophomonas maltophilia, and Streptococcus pneumoniae, and that this depends on the density of the start inoculum and the duration of infection. Two different mechanisms were discovered through which bacteria interfered with LDH activity, i.e., acidification of the cell culture medium (by K. pneumoniae and S. pneumoniae) and protease production (by P. aeruginosa and S. maltophilia). In addition, we developed and validated a modified protocol to evaluate cytotoxicity using the LDH assay, where bacterial interference with LDH quantification is avoided.
Collapse
Affiliation(s)
| | - Eva Vandeplassche
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Lisa Ostyn
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Aurélie Crabbé
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| |
Collapse
|
7
|
Nerlich A, von Wunsch Teruel I, Mieth M, Hönzke K, Rückert JC, Mitchell TJ, Suttorp N, Hippenstiel S, Hocke AC. Reversion of Pneumolysin-Induced Executioner Caspase Activation Redirects Cells to Survival. J Infect Dis 2020; 223:1973-1983. [PMID: 33045080 DOI: 10.1093/infdis/jiaa639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/06/2020] [Indexed: 01/23/2023] Open
Abstract
Apoptosis is an indispensable mechanism for eliminating infected cells and activation of executioner caspases is considered to be a point of no return. Streptococcus pneumoniae, the most common bacterial pathogen causing community-acquired pneumonia, induces apoptosis via its pore-forming toxin pneumolysin, leading to rapid influxes of mitochondrial calcium [Ca2+]m as well as fragmentation, and loss of motility and membrane potential, which is accompanied by caspase-3/7 activation. Using machine-learning and quantitative live-cell microscopy, we identified a significant number of alveolar epithelial cells surviving such executioner caspase activation after pneumolysin attack. Precise single-cell analysis revealed the [Ca2+]m amplitude and efflux rate as decisive parameters for survival and death, which was verified by pharmacological inhibition of [Ca2+]m efflux shifting the surviving cells towards the dying fraction. Taken together, we identified the regulation of [Ca2+]m as critical for controlling the cellular fate under pneumolysin attack, which might be useful for therapeutic intervention during pneumococcal infection.
Collapse
Affiliation(s)
- Andreas Nerlich
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany.,Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Iris von Wunsch Teruel
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Maren Mieth
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Katja Hönzke
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Jens C Rückert
- Department of General, Visceral, Vascular and Thoracic Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Timothy J Mitchell
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Norbert Suttorp
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Stefan Hippenstiel
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Andreas C Hocke
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
| |
Collapse
|
8
|
Zhang H, Zeng L, Xie M, Liu J, Zhou B, Wu R, Cao L, Kroemer G, Wang H, Billiar TR, Zeh HJ, Kang R, Jiang J, Yu Y, Tang D. TMEM173 Drives Lethal Coagulation in Sepsis. Cell Host Microbe 2020; 27:556-570.e6. [PMID: 32142632 DOI: 10.1016/j.chom.2020.02.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/14/2020] [Accepted: 02/10/2020] [Indexed: 12/14/2022]
Abstract
The discovery of TMEM173/STING-dependent innate immunity has recently provided guidance for the prevention and management of inflammatory disorders. Here, we show that myeloid TMEM173 occupies an essential role in regulating coagulation in bacterial infections through a mechanism independent of type I interferon response. Mechanistically, TMEM173 binding to ITPR1 controls calcium release from the endoplasmic reticulum in macrophages and monocytes. The TMEM173-dependent increase in cytosolic calcium drives Gasdermin D (GSDMD) cleavage and activation, which triggers the release of F3, the key initiator of blood coagulation. Genetic or pharmacological inhibition of the TMEM173-GSDMD-F3 pathway blocks systemic coagulation and improves animal survival in three models of sepsis (cecal ligation and puncture or bacteremia with Escherichia coli or Streptococcus pneumoniae infection). The upregulation of the TMEM173 pathway correlates with the severity of disseminated intravascular coagulation and mortality in patients with sepsis. Thus, TMEM173 is a key regulator of blood clotting during lethal bacterial infections.
Collapse
Affiliation(s)
- Hui Zhang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Ling Zeng
- Wound Trauma Medical Center, State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Min Xie
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jiao Liu
- The Third Affiliated Hospital, Protein Modification and Degradation Lab of Guangzhou and Guangdong, Guangzhou Medical University, Guang Zhou, Guangdong 510600, China
| | - Borong Zhou
- The Third Affiliated Hospital, Protein Modification and Degradation Lab of Guangzhou and Guangdong, Guangzhou Medical University, Guang Zhou, Guangdong 510600, China
| | - Runliu Wu
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lizhi Cao
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Guido Kroemer
- Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, INSERM U1138, Centre de Recherche des Cordeliers, Paris, France; Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94800 Villejuif, France; Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, 75015 Paris, France; Suzhou Institute for Systems Medicine, Chinese Academy of Sciences, Suzhou, Jiangsu 215163, China; Department of Women's and Children's Health, Karolinska University Hospital, 17176 Stockholm, Sweden
| | - Haichao Wang
- Laboratory of Emergency Medicine, North Shore University Hospital and the Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Herbert J Zeh
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jianxin Jiang
- Wound Trauma Medical Center, State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China.
| | - Yan Yu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China.
| | - Daolin Tang
- The Third Affiliated Hospital, Protein Modification and Degradation Lab of Guangzhou and Guangdong, Guangzhou Medical University, Guang Zhou, Guangdong 510600, China; Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
9
|
Mitochondrial DNA: A Key Regulator of Anti-Microbial Innate Immunity. Genes (Basel) 2020; 11:genes11010086. [PMID: 31940818 PMCID: PMC7017290 DOI: 10.3390/genes11010086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/25/2022] Open
Abstract
During the last few years, mitochondrial DNA has attained much attention as a modulator of immune responses. Due to common evolutionary origin, mitochondrial DNA shares various characteristic features with DNA of bacteria, as it consists of a remarkable number of unmethylated DNA as 2′-deoxyribose cytidine-phosphate-guanosine (CpG) islands. Due to this particular feature, mitochondrial DNA seems to be recognized as a pathogen-associated molecular pattern by the innate immune system. Under the normal physiological situation, mitochondrial DNA is enclosed in the double membrane structure of mitochondria. However, upon pathological conditions, it is usually released into the cytoplasm. Growing evidence suggests that this cytosolic mitochondrial DNA induces various innate immune signaling pathways involving NLRP3, toll-like receptor 9, and stimulator of interferon genes (STING) signaling, which participate in triggering downstream cascade and stimulating to produce effector molecules. Mitochondrial DNA is responsible for inflammatory diseases after stress and cellular damage. In addition, it is also involved in the anti-viral and anti-bacterial innate immunity. Thus, instead of entire mitochondrial importance in cellular metabolism and energy production, mitochondrial DNA seems to be essential in triggering innate anti-microbial immunity. Here, we describe existing knowledge on the involvement of mitochondrial DNA in the anti-microbial immunity by modulating the various immune signaling pathways.
Collapse
|
10
|
Gao Y, Xu W, Dou X, Wang H, Zhang X, Yang S, Liao H, Hu X, Wang H. Mitochondrial DNA Leakage Caused by Streptococcus pneumoniae Hydrogen Peroxide Promotes Type I IFN Expression in Lung Cells. Front Microbiol 2019; 10:630. [PMID: 30984149 PMCID: PMC6447684 DOI: 10.3389/fmicb.2019.00630] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 03/13/2019] [Indexed: 12/17/2022] Open
Abstract
Streptococcus pneumoniae (S. pn), the bacterial pathogen responsible for invasive pneumococcal diseases, is capable of producing substantial amounts of hydrogen peroxide. However, the impact of S. pn-secreted hydrogen peroxide (H2O2) on the host immune processes is not completely understood. Here, we demonstrated that S. pn-secreted H2O2 caused mitochondrial damage and severe histopathological damage in mouse lung tissue. Additionally, S. pn-secreted H2O2 caused not only oxidative damage to mitochondrial deoxyribonucleic acid (mtDNA), but also a reduction in the mtDNA content in alveolar epithelia cells. This resulted in the release of mtDNA into the cytoplasm, which subsequently induced type I interferons (IFN-I) expression. We also determined that stimulator of interferon genes (STING) signaling was probably involved in S. pn H2O2-inducing IFN-I expression in response to mtDNA damaged by S. pn-secreted H2O2. In conclusion, our study demonstrated that H2O2 produced by S. pn resulted in mtDNA leakage from damaged mitochondria and IFN-I production in alveolar epithelia cells, and STING may be required in this process, and this is a novel mitochondrial damage mechanism by which S. pn potentiates the IFN-I cascade in S. pn infection.
Collapse
Affiliation(s)
- Yue Gao
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Wenchun Xu
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xiaoyun Dou
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Hong Wang
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Shenghui Yang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Hongyi Liao
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xuexue Hu
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Hong Wang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| |
Collapse
|
11
|
Abstract
In the past decade, the field of the cellular microbiology of group A Streptococcus (S. pyogenes) infection has made tremendous advances and touched upon several important aspects of pathogenesis, including receptor biology, invasive and evasive phenomena, inflammasome activation, strain-specific autophagic bacterial killing, and virulence factor-mediated programmed cell death. The noteworthy aspect of S. pyogenes-mediated cell signaling is the recognition of the role of M protein in a variety of signaling events, starting with the targeting of specific receptors on the cell surface and on through the induction and evasion of NETosis, inflammasome, and autophagy/xenophagy to pyroptosis and apoptosis. Variations in reports on S. pyogenes-mediated signaling events highlight the complex mechanism of pathogenesis and underscore the importance of the host cell and S. pyogenes strain specificity, as well as in vitro/in vivo experimental parameters. The severity of S. pyogenes infection is, therefore, dependent on the virulence gene expression repertoire in the host environment and on host-specific dynamic signaling events in response to infection. Commonly known as an extracellular pathogen, S. pyogenes finds host macrophages as safe havens wherein it survives and even multiplies. The fact that endothelial cells are inherently deficient in autophagic machinery compared to epithelial cells and macrophages underscores the invasive nature of S. pyogenes and its ability to cause severe systemic diseases. S. pyogenes is still one of the top 10 causes of infectious mortality. Understanding the orchestration of dynamic host signaling networks will provide a better understanding of the increasingly complex mechanism of S. pyogenes diseases and novel ways of therapeutically intervening to thwart severe and often fatal infections.
Collapse
|
12
|
Transporters MRP1 and MRP2 Regulate Opposing Inflammatory Signals To Control Transepithelial Neutrophil Migration during Streptococcus pneumoniae Lung Infection. mSphere 2018; 3:3/4/e00303-18. [PMID: 29976647 PMCID: PMC6034076 DOI: 10.1128/msphere.00303-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Streptococcus pneumoniae is a Gram-positive bacterium that normally inhabits the human nasopharynx asymptomatically. However, it is also a major cause of pneumonia, bacteremia, and meningitis. The transition from pneumonia to bacteremia is critical, as patients that develop septicemia have ~20% mortality rates. Previous studies have shown that while neutrophils, a major bacterium-induced leukocyte, aid in S. pneumoniae elimination, they also contribute to pathology and may mediate the lung-to-blood passage of the bacteria. Herein, we show that epithelium-derived MRP1 and MRP2 efflux immunomodulatory agents that assist in controlling passage of neutrophils during infection and that limiting neutrophil infiltration produced less bacteremia and better survival during murine infection. The importance of our work is twofold: ours is the first to identify an MRP1/MRP2 axis of neutrophil control in the lung. The second is to provide possible therapeutic targets to reduce excess inflammation, thus reducing the chances of developing bacteremia during pneumococcal pneumonia. Streptococcus pneumoniae remains a source of morbidity and mortality in both developed and underdeveloped nations of the world. Disease can manifest as pneumonia, bacteremia, and meningitis, depending on the localization of infection. Interestingly, there is a correlation in experimental murine infections between the development of bacteremia and influx of neutrophils into the pulmonary lumen. Reduction of this neutrophil influx has been shown to improve survivability during infection. In this study, we use in vitro biotinylation and neutrophil transmigration and in vivo murine infection to identify a system in which two epithelium-localized ATP-binding cassette transporters, MRP1 and MRP2, have inverse activities dictating neutrophil transmigration into the lumen of infected mouse lungs. MRP1 effluxes an anti-inflammatory molecule that maintains homeostasis in uninfected contexts, thus reducing neutrophil infiltration. During inflammatory events, however, MRP1 decreases and MRP2 both increases and effluxes the proinflammatory eicosanoid hepoxilin A3. If we then decrease MRP2 activity during experimental murine infection with S. pneumoniae, we reduce both neutrophil infiltration and bacteremia, showing that MRP2 coordinates this activity in the lung. We conclude that MRP1 assists in depression of polymorphonuclear cell (PMN) migration by effluxing a molecule that inhibits the proinflammatory effects of MRP2 activity. IMPORTANCEStreptococcus pneumoniae is a Gram-positive bacterium that normally inhabits the human nasopharynx asymptomatically. However, it is also a major cause of pneumonia, bacteremia, and meningitis. The transition from pneumonia to bacteremia is critical, as patients that develop septicemia have ~20% mortality rates. Previous studies have shown that while neutrophils, a major bacterium-induced leukocyte, aid in S. pneumoniae elimination, they also contribute to pathology and may mediate the lung-to-blood passage of the bacteria. Herein, we show that epithelium-derived MRP1 and MRP2 efflux immunomodulatory agents that assist in controlling passage of neutrophils during infection and that limiting neutrophil infiltration produced less bacteremia and better survival during murine infection. The importance of our work is twofold: ours is the first to identify an MRP1/MRP2 axis of neutrophil control in the lung. The second is to provide possible therapeutic targets to reduce excess inflammation, thus reducing the chances of developing bacteremia during pneumococcal pneumonia.
Collapse
|
13
|
Fritscher J, Amberger D, Dyckhoff S, Bewersdorf JP, Masouris I, Voelk S, Hammerschmidt S, Schmetzer HM, Klein M, Pfister HW, Koedel U. Mast Cells Are Activated by Streptococcus pneumoniae In Vitro but Dispensable for the Host Defense Against Pneumococcal Central Nervous System Infection In Vivo. Front Immunol 2018; 9:550. [PMID: 29616039 PMCID: PMC5867309 DOI: 10.3389/fimmu.2018.00550] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/05/2018] [Indexed: 01/01/2023] Open
Abstract
Mast cells reside on and near the cerebral vasculature, the predominant site of pneumococcal entry into the central nervous system (CNS). Although mast cells have been reported to be crucial in protecting from systemic bacterial infections, their role in bacterial infections of the CNS remained elusive. Here, we assessed the role of mast cells in pneumococcal infection in vitro and in vivo. In introductory experiments using mouse bone marrow-derived mast cells (BMMC), we found that (i) BMMC degranulate and release selected cytokines upon exposure to Streptococcus pneumoniae, (ii) the response of BMMC varies between different pneumococcal serotypes and (iii) is dependent on pneumolysin. Intriguingly though, apart from a slight enhancement of cerebrospinal fluid (CSF) pleocytosis, neither two different mast cell-deficient Kit mutant mouse strains (WBB6F1-KitW/Wv and C57BL/6 KitW-sh/W-sh mice) nor pharmacologic mast cell stabilization with cromoglycate had any significant impact on the disease phenotype of experimental pneumococcal meningitis. The incomplete reversal of the enhanced CSF pleocytosis by local mast cell engraftment suggests that this phenomenon is caused by other c-Kit mutation-related mechanisms than mast cell deficiency. In conclusion, our study suggests that mast cells can be activated by S. pneumoniae in vitro. However, mast cells do not play a significant role as sentinels of pneumococcal CSF invasion and initiators of innate immunity in vivo.
Collapse
Affiliation(s)
- Johanna Fritscher
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Daniel Amberger
- Department of Internal Medicine III (Oncology), University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Susanne Dyckhoff
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Jan Philipp Bewersdorf
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Ilias Masouris
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Stefanie Voelk
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, Ernst Moritz Arndt University Greifswald, Greifswald, Germany
| | - Helga Maria Schmetzer
- Department of Internal Medicine III (Oncology), University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Matthias Klein
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Hans-Walter Pfister
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Uwe Koedel
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| |
Collapse
|
14
|
Nerlich A, Mieth M, Letsiou E, Fatykhova D, Zscheppang K, Imai-Matsushima A, Meyer TF, Paasch L, Mitchell TJ, Tönnies M, Bauer TT, Schneider P, Neudecker J, Rückert JC, Eggeling S, Schimek M, Witzenrath M, Suttorp N, Hippenstiel S, Hocke AC. Pneumolysin induced mitochondrial dysfunction leads to release of mitochondrial DNA. Sci Rep 2018; 8:182. [PMID: 29317705 PMCID: PMC5760655 DOI: 10.1038/s41598-017-18468-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 12/12/2017] [Indexed: 01/01/2023] Open
Abstract
Streptococcus pneumoniae (S.pn.) is the most common bacterial pathogen causing community acquired pneumonia. The pore-forming toxin pneumolysin (PLY) is the major virulence factor of S.pn. and supposed to affect alveolar epithelial cells thereby activating the immune system by liberation of danger-associated molecular patterns (DAMP). To test this hypothesis, we established a novel live-cell imaging based assay to analyse mitochondrial function and associated release of mitochondrial DNA (mtDNA) as DAMP in real-time. We first revealed that bacterially released PLY caused significant changes of the cellular ATP homeostasis and led to morphologic alterations of mitochondria in human alveolar epithelial cells in vitro and, by use of spectral live-tissue imaging, in human alveoli. This was accompanied by strong mitochondrial calcium influx and loss of mitochondrial membrane potential resulting in opening of the mitochondrial permeability transition pore and mtDNA release without activation of intrinsic apoptosis. Moreover, our data indicate cellular mtDNA liberation via microvesicles, which may contribute to S.pn. related pro-inflammatory immune activation in the human alveolar compartment.
Collapse
Affiliation(s)
- Andreas Nerlich
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Maren Mieth
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Eleftheria Letsiou
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Diana Fatykhova
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Katja Zscheppang
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Aki Imai-Matsushima
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | - Thomas F Meyer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | - Lisa Paasch
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Timothy J Mitchell
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, B15-2TT, UK
| | - Mario Tönnies
- Department of Pneumology and Department of Thoracic Surgery, HELIOS Clinic Emil von Behring, Walterhöferstr 11, 14165, Berlin, Germany
| | - Torsten T Bauer
- Department of Pneumology and Department of Thoracic Surgery, HELIOS Clinic Emil von Behring, Walterhöferstr 11, 14165, Berlin, Germany
| | - Paul Schneider
- Department for General and Thoracic Surgery, DRK Clinics, Drontheimer Strasse 39-40, 13359, Berlin, Germany
| | - Jens Neudecker
- Department of General, Visceral, Vascular and Thoracic Surgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Jens C Rückert
- Department of General, Visceral, Vascular and Thoracic Surgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Stephan Eggeling
- Department of Thoracic Surgery, Vivantes Clinics Neukölln, Rudower Straße 48, 12351, Berlin, Germany
| | - Maria Schimek
- Department of Thoracic Surgery, Vivantes Clinics Neukölln, Rudower Straße 48, 12351, Berlin, Germany
| | - Martin Witzenrath
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Norbert Suttorp
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Stefan Hippenstiel
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Andreas C Hocke
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
| |
Collapse
|
15
|
Bartel A, Göhler A, Hopf V, Breitbach K. Caspase-6 mediates resistance against Burkholderia pseudomallei infection and influences the expression of detrimental cytokines. PLoS One 2017; 12:e0180203. [PMID: 28686630 PMCID: PMC5501493 DOI: 10.1371/journal.pone.0180203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/13/2017] [Indexed: 01/09/2023] Open
Abstract
Caspase-6 is a member of the executioner caspases and known to play a role in innate and adaptive immune processes. However, its role in infectious diseases has rarely been addressed yet. We here examined the impact of caspase-6 in an in vivo infection model using the Gram-negative rod Burkholderia pseudomallei, causing the infectious disease melioidosis that is endemic in tropical and subtropical areas around the world. Caspase-6-/- and C57BL/6 wild type mice were challenged with B. pseudomallei for comparing mortality, bacterial burden and inflammatory cytokine expression. Bone-marrow derived macrophages were used to analyse the bactericidal activity in absence of caspase-6. Caspase-6 deficiency was associated with higher mortality and bacterial burden in vivo after B. pseudomallei infection. The bactericidal activity of caspase-6-/- macrophages was impaired compared to wild type cells. Caspase-6-/- mice showed higher expression of the IL-1β gene, known to be detrimental in murine melioidosis. Expression of the IL-10 gene was also increased in caspase-6-/- mice as early as 6 hours after infection. Treatment with exogenous IL-10 rendered mice more susceptible against B. pseudomallei challenge. Thus, caspase-6 seems to play a crucial role for determining resistance against the causative agent of melioidosis. To our knowledge this is the first report showing that caspase-6 is crucial for mediating resistance in an in vivo infection model. Caspase-6 influences the expression of detrimental cytokines and therefore seems to be important for achieving a well-balanced immune response that contributes for an efficient elimination of the pathogen.
Collapse
Affiliation(s)
- Alexander Bartel
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - André Göhler
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Verena Hopf
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Katrin Breitbach
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
- * E-mail:
| |
Collapse
|
16
|
Shikonin alleviates the biotoxicity produced by pneumococcal pneumolysin. Life Sci 2017; 177:1-7. [DOI: 10.1016/j.lfs.2017.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/31/2017] [Accepted: 04/01/2017] [Indexed: 11/19/2022]
|
17
|
Domínguez-Hüttinger E, Boon NJ, Clarke TB, Tanaka RJ. Mathematical Modeling of Streptococcus pneumoniae Colonization, Invasive Infection and Treatment. Front Physiol 2017; 8:115. [PMID: 28303104 PMCID: PMC5332394 DOI: 10.3389/fphys.2017.00115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/13/2017] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pneumoniae (Sp) is a commensal bacterium that normally resides on the upper airway epithelium without causing infection. However, factors such as co-infection with influenza virus can impair the complex Sp-host interactions and the subsequent development of many life-threatening infectious and inflammatory diseases, including pneumonia, meningitis or even sepsis. With the increased threat of Sp infection due to the emergence of new antibiotic resistant Sp strains, there is an urgent need for better treatment strategies that effectively prevent progression of disease triggered by Sp infection, minimizing the use of antibiotics. The complexity of the host-pathogen interactions has left the full understanding of underlying mechanisms of Sp-triggered pathogenesis as a challenge, despite its critical importance in the identification of effective treatments. To achieve a systems-level and quantitative understanding of the complex and dynamically-changing host-Sp interactions, here we developed a mechanistic mathematical model describing dynamic interplays between Sp, immune cells, and epithelial tissues, where the host-pathogen interactions initiate. The model serves as a mathematical framework that coherently explains various in vitro and in vitro studies, to which the model parameters were fitted. Our model simulations reproduced the robust homeostatic Sp-host interaction, as well as three qualitatively different pathogenic behaviors: immunological scarring, invasive infection and their combination. Parameter sensitivity and bifurcation analyses of the model identified the processes that are responsible for qualitative transitions from healthy to such pathological behaviors. Our model also predicted that the onset of invasive infection occurs within less than 2 days from transient Sp challenges. This prediction provides arguments in favor of the use of vaccinations, since adaptive immune responses cannot be developed de novo in such a short time. We further designed optimal treatment strategies, with minimal strengths and minimal durations of antibiotics, for each of the three pathogenic behaviors distinguished by our model. The proposed mathematical framework will help to design better disease management strategies and new diagnostic markers that can be used to inform the most appropriate patient-specific treatment options.
Collapse
Affiliation(s)
- Elisa Domínguez-Hüttinger
- Department of Bioengineering, Imperial College LondonLondon, UK; Instituto de Ecología, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | - Neville J Boon
- Department of Bioengineering, Imperial College London London, UK
| | | | - Reiko J Tanaka
- Department of Bioengineering, Imperial College London London, UK
| |
Collapse
|
18
|
Zhao X, Liu B, Liu S, Wang L, Wang J. Anticytotoxin Effects of Amentoflavone to Pneumolysin. Biol Pharm Bull 2017; 40:61-67. [PMID: 28049950 DOI: 10.1248/bpb.b16-00598] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pneumolysin (PLY) is a devastating bacterial protein toxin of Streptococcus pneumoniae that punctures the cytomembrane, leading to pathological reactions, such as cell disruption and inflammation. Drugs capable of closely impacting the toxin are considered advantageous in the treatment of bacterial infections. Amentoflavone (AMF) is a chemical substance extracted from traditional Chinese herbs. Previous studies have demonstrated that AMF has multiple pharmacological effects and mentioned without attenuating pneumolysin-mediated cytotoxicity. This work focuses on the influence of AMF on inhibitory hemolytic mechanisms. AMF interacts with the toxin at Ser254, Glu277, Arg359, and effectively weakens the oligomerization of wild-type PLY and provides considerable protection against pneumolysin-mediated human alveolar epithelial (A549) cell damage. The results of our study demonstrate that AMF could be a candidate against pneumolysin-related injury.
Collapse
Affiliation(s)
- Xiaoran Zhao
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University
| | | | | | | | | |
Collapse
|
19
|
Hocke AC, Suttorp N, Hippenstiel S. Human lung ex vivo infection models. Cell Tissue Res 2016; 367:511-524. [PMID: 27999962 PMCID: PMC7087833 DOI: 10.1007/s00441-016-2546-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 11/24/2016] [Indexed: 12/21/2022]
Abstract
Pneumonia is counted among the leading causes of death worldwide. Viruses, bacteria and pathogen-related molecules interact with cells present in the human alveolus by numerous, yet poorly understood ways. Traditional cell culture models little reflect the cellular composition, matrix complexity and three-dimensional architecture of the human lung. Integrative animal models suffer from species differences, which are of particular importance for the investigation of zoonotic lung diseases. The use of cultured ex vivo infected human lung tissue may overcome some of these limitations and complement traditional models. The present review gives an overview of common bacterial lung infections, such as pneumococcal infection and of widely neglected pathogens modeled in ex vivo infected lung tissue. The role of ex vivo infected lung tissue for the investigation of emerging viral zoonosis including influenza A virus and Middle East respiratory syndrome coronavirus is discussed. Finally, further directions for the elaboration of such models are revealed. Overall, the introduced models represent meaningful and robust methods to investigate principles of pathogen-host interaction in original human lung tissue.
Collapse
Affiliation(s)
- Andreas C Hocke
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Norbert Suttorp
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Stefan Hippenstiel
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
| |
Collapse
|
20
|
Salina AC, Souza TP, Serezani CH, Medeiros AI. Efferocytosis-induced prostaglandin E2 production impairs alveolar macrophage effector functions during Streptococcus pneumoniae infection. Innate Immun 2016; 23:219-227. [PMID: 28359217 DOI: 10.1177/1753425916684934] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Alveolar macrophages (AMs) are multitasking cells that maintain lung homeostasis by clearing apoptotic cells (efferocytosis) and performing antimicrobial effector functions. Different PRRs have been described to be involved in the binding and capture of non-opsonized Streptococcus pneumoniae, such as TLR-2, mannose receptor (MR) and scavenger receptors (SRs). However, the mechanism by which the ingestion of apoptotic cells negatively influences the clearance of non-opsonized S. pneumoniae remains to be determined. In this study, we evaluated whether the prostaglandin E2 (PGE2) produced during efferocytosis by AMs inhibits the ingestion and killing of non-opsonized S. pneumoniae. Resident AMs were pre-treated with an E prostanoid (EP) receptor antagonist, inhibitors of cyclooxygenase and protein kinase A (PKA), incubated with apoptotic Jurkat T cells, and then challenged with S. pneumoniae. Efferocytosis slightly decreased the phagocytosis of S. pneumoniae but greatly inhibited bacterial killing by AMs in a manner dependent on PGE2 production, activation of the EP2-EP4/cAMP/PKA pathway and inhibition of H2O2 production. Our data suggest that the PGE2 produced by AMs during efferocytosis inhibits H2O2 production and impairs the efficient clearance non-opsonized S. pneumoniae by EP2-EP4/cAMP/PKA pathway.
Collapse
Affiliation(s)
- Ana Cg Salina
- 1 Department of Biological Science, School of Pharmaceutical Science, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Tais P Souza
- 1 Department of Biological Science, School of Pharmaceutical Science, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Carlos H Serezani
- 2 Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alexandra I Medeiros
- 1 Department of Biological Science, School of Pharmaceutical Science, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| |
Collapse
|
21
|
Yin G, Zeng Q, Zhao H, Wu P, Cai S, Deng L, Jiang W. Effect and mechanism of calpains on pediatric lobar pneumonia. Bioengineered 2016; 8:374-382. [PMID: 27786573 PMCID: PMC5553339 DOI: 10.1080/21655979.2016.1234544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Lobar pneumonia, one of the community-acquired pneumonia (CAP), is a common pediatric low respiratory tract infection. Calpains are Ca2+-activated cysteine proteases whose activation mechanism is elusive. The present study was undertaken to detect the role and mechanism of calpains in pediatric lobar pneumonia. The human acute lung infection model (ALIM) was constructed and infected by Streptococcus. Enzyme-linked immunosorbent assay (ELISA) was used to measure interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-α. We observed the lactate dehydrogenase (LDH) release, calpains activity and calpain inhibitor effects in ALIM. The expression of proliferating cell nuclear antigen (PCNA) protein was quantified by western blotting. Then the effects of calpain 1 and 2 knockdown on expressions of inflammation factors and PCNA protein, LDH release and apoptosis were evaluated in lung MRC-5 cells. In constructed ALIM, expressions of IL-6 (P < 0.01), IL-8 (P < 0.01), TNF-α (P < 0.05) and PCNA protein (P < 0.05) were significantly reduced by the calpain inhibitor. Expressions of IL-6, IL-8, TNF-α, PCNA protein and relative LDH release were statistically reduced by the small interfering (si) RNA-calpain 1 and 2 in MRC-5 cells (P < 0.05). Calpains silence increased apoptotic cells from 5% (negative control) to more than 20% in MRC-5 cells. The present study suggests that calpains possess a significant effect on inflammations, cell proliferation and apoptosis. Suppression of calpains may provide a potential therapeutic target of lobar pneumonia.
Collapse
Affiliation(s)
- Genquan Yin
- a Chronic Airways Disease Laboratory, Department of Respiratory and Critical Care Medicine , Nanfang Hospital, Southern Medical University , Guangzhou , Guangdong Province , China.,b Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , China
| | - Qiang Zeng
- b Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , China
| | - Haijin Zhao
- a Chronic Airways Disease Laboratory, Department of Respiratory and Critical Care Medicine , Nanfang Hospital, Southern Medical University , Guangzhou , Guangdong Province , China
| | - Peiqiong Wu
- b Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , China
| | - Shaoxi Cai
- a Chronic Airways Disease Laboratory, Department of Respiratory and Critical Care Medicine , Nanfang Hospital, Southern Medical University , Guangzhou , Guangdong Province , China
| | - Li Deng
- b Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , China
| | - Wenhui Jiang
- b Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , China
| |
Collapse
|
22
|
Li Y, Li J, Huang H, Yang M, Zhuang D, Cheng X, Zhang H, Fu X. Microcystin-LR induces mitochondria-mediated apoptosis in human bronchial epithelial cells. Exp Ther Med 2016; 12:633-640. [PMID: 27446254 PMCID: PMC4950845 DOI: 10.3892/etm.2016.3423] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 04/11/2016] [Indexed: 12/15/2022] Open
Abstract
The present study aimed to investigate the toxicity of microcystin-LR (MC-LR) and to explore the mechanism of MC-LR-induced apoptosis in human bronchial epithelial (HBE) cells. HBE cells were treated with MC-LR (1, 10, 20, 30 and 40 µg/ml) alone or with MC-LR (0, 2.5, 5 and 10 µg/ml) and Z-VAD-FMK (0, 10, 20, 40, 60, 80, 100, 120 and 140 µM), which is a caspase inhibitor, for 24 and 48 h. Cell viability was assessed via an MTT assay and the half maximal effective concentration of MC-LR was determined. The optimal concentration of Z-VAD-FMK was established as 50 µm, which was then used in the subsequent experiments. MC-LR significantly inhibited cell viability and induced apoptosis of HBE cells in a dose-dependent manner, as detected by an Annexin V/propidium iodide assay. MC-LR induced cell apoptosis, excess reactive oxygen species production and mitochondrial membrane potential collapse, upregulated Bax expression and downregulated B-cell lymphoma-2 expression in HBE cells. Moreover, western blot analysis demonstrated that MC-LR increased the activity levels of caspase-3 and caspase-9 and induced cytochrome c release into the cytoplasm, suggesting that MC-LR-induced apoptosis is associated with the mitochondrial pathway. Furthermore, pretreatment with Z-VAD-FMK reduced MC-LR-induced apoptosis by blocking caspase activation in HBE cells. Therefore, the results of the present study suggested that MC-LR is capable of significantly inhibiting the viability of HBE cells by inducing apoptosis in a mitochondria-dependent manner. The present study provides a foundation for further understanding the mechanism underlying the toxicity of MC-LR in the respiratory system.
Collapse
Affiliation(s)
- Yang Li
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Jinhui Li
- Henan Science and Technology Exchange Center with Foreign Countries, Zhengzhou University, Zhengzhou, Henan 450003, P.R. China
| | - Hui Huang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Mingfeng Yang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Donggang Zhuang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Xuemin Cheng
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Xiaoli Fu
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| |
Collapse
|
23
|
Gold MJ, Hiebert PR, Park HY, Stefanowicz D, Le A, Starkey MR, Deane A, Brown AC, Liu G, Horvat JC, Ibrahim ZA, Sukkar MB, Hansbro PM, Carlsten C, VanEeden S, Sin DD, McNagny KM, Knight DA, Hirota JA. Mucosal production of uric acid by airway epithelial cells contributes to particulate matter-induced allergic sensitization. Mucosal Immunol 2016; 9:809-20. [PMID: 26509876 DOI: 10.1038/mi.2015.104] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 09/03/2015] [Indexed: 02/07/2023]
Abstract
Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM10-induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma.
Collapse
Affiliation(s)
- M J Gold
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - P R Hiebert
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - H Y Park
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - D Stefanowicz
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Le
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - M R Starkey
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - A Deane
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - A C Brown
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - G Liu
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - J C Horvat
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - Z A Ibrahim
- Discipline of Pharmacy, Graduate School of Health, The University of Technology Sydney, Sydney, Australia.,Woolcock Institute of Medical Research, Sydney Medical School, The University of Sydney, Sydney, Australia
| | - M B Sukkar
- Discipline of Pharmacy, Graduate School of Health, The University of Technology Sydney, Sydney, Australia.,Woolcock Institute of Medical Research, Sydney Medical School, The University of Sydney, Sydney, Australia
| | - P M Hansbro
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - C Carlsten
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Coastal Health Research Institute, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - S VanEeden
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - D D Sin
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - K M McNagny
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - D A Knight
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, Australia.,Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - J A Hirota
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Coastal Health Research Institute, Vancouver General Hospital, Vancouver, British Columbia, Canada
| |
Collapse
|
24
|
Du Bois I, Marsico A, Bertrams W, Schweiger MR, Caffrey BE, Sittka-Stark A, Eberhardt M, Vera J, Vingron M, Schmeck BT. Genome-wide Chromatin Profiling of Legionella pneumophila-Infected Human Macrophages Reveals Activation of the Probacterial Host Factor TNFAIP2. J Infect Dis 2016; 214:454-63. [PMID: 27130431 DOI: 10.1093/infdis/jiw171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 04/21/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Legionella pneumophila is a causative agent of severe pneumonia. Infection leads to a broad host cell response, as evident, for example, on the transcriptional level. Chromatin modifications, which control gene expression, play a central role in the transcriptional response to L. pneumophila METHODS We infected human-blood-derived macrophages (BDMs) with L. pneumophila and used chromatin immunoprecipitation followed by sequencing to screen for gene promoters with the activating histone 4 acetylation mark. RESULTS We found the promoter of tumor necrosis factor α-induced protein 2 (TNFAIP2) to be acetylated at histone H4. This factor has not been characterized in the pathology of L. pneumophila TNFAIP2 messenger RNA and protein were upregulated in response to L. pneumophila infection of human-BDMs and human alveolar epithelial (A549) cells. We showed that L. pneumophila-induced TNFAIP2 expression is dependent on the NF-κB transcription factor. Importantly, knock down of TNFAIP2 led to reduced intracellular replication of L. pneumophila Corby in A549 cells. CONCLUSIONS Taken together, genome-wide chromatin analysis of L. pneumophila-infected macrophages demonstrated induction of TNFAIP2, a NF-κB-dependent factor relevant for bacterial replication.
Collapse
Affiliation(s)
- Ilona Du Bois
- Institute for Lung Research/iLung Universities of Giessen and arburg Lung Centre, German Center for Lung Research
| | - Annalisa Marsico
- Max Planck Institute for Molecular Genetics Free University, Berlin
| | - Wilhelm Bertrams
- Institute for Lung Research/iLung Universities of Giessen and arburg Lung Centre, German Center for Lung Research
| | | | | | - Alexandra Sittka-Stark
- Institute for Lung Research/iLung Universities of Giessen and arburg Lung Centre, German Center for Lung Research
| | - Martin Eberhardt
- Laboratory of Systems Tumor Immunology, Department of Dermatology, Friedrich-Alexander University Erlangen-Nürnberg, University Hospital Erlangen, Germany
| | - Julio Vera
- Laboratory of Systems Tumor Immunology, Department of Dermatology, Friedrich-Alexander University Erlangen-Nürnberg, University Hospital Erlangen, Germany
| | | | - Bernd T Schmeck
- Institute for Lung Research/iLung Department of Medicine, Pulmonary, and Critical Care Medicine, University Medical Center Marburg, Philipps-University Universities of Giessen and arburg Lung Centre, German Center for Lung Research
| |
Collapse
|
25
|
Rai P, He F, Kwang J, Engelward BP, Chow VTK. Pneumococcal Pneumolysin Induces DNA Damage and Cell Cycle Arrest. Sci Rep 2016; 6:22972. [PMID: 27026501 PMCID: PMC4812240 DOI: 10.1038/srep22972] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/22/2016] [Indexed: 01/24/2023] Open
Abstract
Streptococcus pneumoniae produces pneumolysin toxin as a key virulence factor against host cells. Pneumolysin is a cholesterol-dependent cytolysin (CDC) toxin that forms lytic pores in host membranes and mediates pneumococcal disease pathogenesis by modulating inflammatory responses. Here, we show that pneumolysin, which is released during bacterial lysis, induces DNA double strand breaks (DSBs), as indicated by ataxia telangiectasia mutated (ATM)-mediated H2AX phosphorylation (γH2AX). Pneumolysin-induced γH2AX foci recruit mediator of DNA damage checkpoint 1 (MDC1) and p53 binding protein 1 (53BP1), to sites of DSBs. Importantly, results show that toxin-induced DNA damage precedes cell cycle arrest and causes apoptosis when DNA-dependent protein kinase (DNA-PK)-mediated non-homologous end joining is inhibited. Further, we observe that cells that were undergoing DNA replication harbored DSBs in greater frequency during pneumolysin treatment. This observation raises the possibility that DSBs might be arising as a result of replication fork breakdown. Additionally, neutralizing the oligomerization domain of pneumolysin with monoclonal antibody suppresses DNA damage and also cell cycle arrest, indicating that pneumolysin oligomerization is important for causing DNA damage. Taken together, this study reveals a previously unidentified ability of pneumolysin to induce cytotoxicity via DNA damage, with implications in the pathophysiology of S. pneumoniae infection.
Collapse
Affiliation(s)
- Prashant Rai
- Infectious Diseases Group, Singapore-MIT Alliance for Research &Technology, Singapore 138602.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545
| | - Fang He
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604
| | - Jimmy Kwang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545.,Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604
| | - Bevin P Engelward
- Infectious Diseases Group, Singapore-MIT Alliance for Research &Technology, Singapore 138602.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Vincent T K Chow
- Infectious Diseases Group, Singapore-MIT Alliance for Research &Technology, Singapore 138602.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545
| |
Collapse
|
26
|
Zhao X, Li H, Wang J, Guo Y, Liu B, Deng X, Niu X. Verbascoside Alleviates Pneumococcal Pneumonia by Reducing Pneumolysin Oligomers. Mol Pharmacol 2015; 89:376-87. [DOI: 10.1124/mol.115.100610] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/18/2015] [Indexed: 02/02/2023] Open
|
27
|
Streptococcus pneumoniae secretes hydrogen peroxide leading to DNA damage and apoptosis in lung cells. Proc Natl Acad Sci U S A 2015; 112:E3421-30. [PMID: 26080406 DOI: 10.1073/pnas.1424144112] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Streptococcus pneumoniae is a leading cause of pneumonia and one of the most common causes of death globally. The impact of S. pneumoniae on host molecular processes that lead to detrimental pulmonary consequences is not fully understood. Here, we show that S. pneumoniae induces toxic DNA double-strand breaks (DSBs) in human alveolar epithelial cells, as indicated by ataxia telangiectasia mutated kinase (ATM)-dependent phosphorylation of histone H2AX and colocalization with p53-binding protein (53BP1). Furthermore, results show that DNA damage occurs in a bacterial contact-independent fashion and that Streptococcus pyruvate oxidase (SpxB), which enables synthesis of H2O2, plays a critical role in inducing DSBs. The extent of DNA damage correlates with the extent of apoptosis, and DNA damage precedes apoptosis, which is consistent with the time required for execution of apoptosis. Furthermore, addition of catalase, which neutralizes H2O2, greatly suppresses S. pneumoniae-induced DNA damage and apoptosis. Importantly, S. pneumoniae induces DSBs in the lungs of animals with acute pneumonia, and H2O2 production by S. pneumoniae in vivo contributes to its genotoxicity and virulence. One of the major DSBs repair pathways is nonhomologous end joining for which Ku70/80 is essential for repair. We find that deficiency of Ku80 causes an increase in the levels of DSBs and apoptosis, underscoring the importance of DNA repair in preventing S. pneumoniae-induced genotoxicity. Taken together, this study shows that S. pneumoniae-induced damage to the host cell genome exacerbates its toxicity and pathogenesis, making DNA repair a potentially important susceptibility factor in people who suffer from pneumonia.
Collapse
|
28
|
Nita-Lazar M, Banerjee A, Feng C, Amin MN, Frieman MB, Chen WH, Cross AS, Wang LX, Vasta GR. Desialylation of airway epithelial cells during influenza virus infection enhances pneumococcal adhesion via galectin binding. Mol Immunol 2015; 65:1-16. [PMID: 25597246 DOI: 10.1016/j.molimm.2014.12.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 02/07/2023]
Abstract
The continued threat of worldwide influenza pandemics, together with the yearly emergence of antigenically drifted influenza A virus (IAV) strains, underscore the urgent need to elucidate not only the mechanisms of influenza virulence, but also those mechanisms that predispose influenza patients to increased susceptibility to subsequent infection with Streptococcus pneumoniae. Glycans displayed on the surface of epithelia that are exposed to the external environment play important roles in microbial recognition, adhesion, and invasion. It is well established that the IAV hemagglutinin and pneumococcal adhesins enable their attachment to the host epithelia. Reciprocally, the recognition of microbial glycans by host carbohydrate-binding proteins (lectins) can initiate innate immune responses, but their relevance in influenza or pneumococcal infections is poorly understood. Galectins are evolutionarily conserved lectins characterized by affinity for β-galactosides and a unique sequence motif, with critical regulatory roles in development and immune homeostasis. In this study, we examined the possibility that galectins expressed in the airway epithelial cells might play a significant role in viral or pneumococcal adhesion to airway epithelial cells. Our results in a mouse model for influenza and pneumococcal infection revealed that the murine lung expresses a diverse galectin repertoire, from which selected galectins, including galectin 1 (Gal1) and galectin 3 (Gal3), are released to the bronchoalveolar space. Further, the results showed that influenza and subsequent S. pneumoniae infections significantly alter the glycosylation patterns of the airway epithelial surface and modulate galectin expression. In vitro studies on the human airway epithelial cell line A549 were consistent with the observations made in the mouse model, and further revealed that both Gal1 and Gal3 bind strongly to IAV and S. pneumoniae, and that exposure of the cells to viral neuraminidase or influenza infection increased galectin-mediated S. pneumoniae adhesion to the cell surface. Our results suggest that upon influenza infection, pneumococcal adhesion to the airway epithelial surface is enhanced by an interplay among the host galectins and viral and pneumococcal neuraminidases. The observed enhancement of pneumococcal adhesion may be a contributing factor to the observed hypersusceptibility to pneumonia of influenza patients.
Collapse
Affiliation(s)
- Mihai Nita-Lazar
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA; Institute of Marine and Environmental Technology, Columbus Center, 701 East Pratt Street, Baltimore, MD 21202, USA
| | - Aditi Banerjee
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA; Institute of Marine and Environmental Technology, Columbus Center, 701 East Pratt Street, Baltimore, MD 21202, USA
| | - Chiguang Feng
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA; Institute of Marine and Environmental Technology, Columbus Center, 701 East Pratt Street, Baltimore, MD 21202, USA
| | - Mohammed N Amin
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Matthew B Frieman
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Wilbur H Chen
- Center for Vaccine Development, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Alan S Cross
- Center for Vaccine Development, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA
| | - Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Gerardo R Vasta
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA; Institute of Marine and Environmental Technology, Columbus Center, 701 East Pratt Street, Baltimore, MD 21202, USA.
| |
Collapse
|
29
|
Pneumolysin activates macrophage lysosomal membrane permeabilization and executes apoptosis by distinct mechanisms without membrane pore formation. mBio 2014; 5:e01710-14. [PMID: 25293758 PMCID: PMC4196231 DOI: 10.1128/mbio.01710-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Intracellular killing of Streptococcus pneumoniae is complemented by induction of macrophage apoptosis. Here, we show that the toxin pneumolysin (PLY) contributes both to lysosomal/phagolysosomal membrane permeabilization (LMP), an upstream event programing susceptibility to apoptosis, and to apoptosis execution via a mitochondrial pathway, through distinct mechanisms. PLY is necessary but not sufficient for the maximal induction of LMP and apoptosis. PLY's ability to induce both LMP and apoptosis is independent of its ability to form cytolytic pores and requires only the first three domains of PLY. LMP involves TLR (Toll-like receptor) but not NLRP3/ASC (nucleotide-binding oligomerization domain [Nod]-like receptor family, pyrin domain-containing protein 3/apoptosis-associated speck-like protein containing a caspase recruitment domain) signaling and is part of a PLY-dependent but phagocytosis-independent host response that includes the production of cytokines, including interleukin-1 beta (IL-1β). LMP involves progressive and selective permeability to 40-kDa but not to 250-kDa fluorescein isothiocyanate (FITC)-labeled dextran, as PLY accumulates in the cytoplasm. In contrast, the PLY-dependent execution of apoptosis requires phagocytosis and is part of a host response to intracellular bacteria that also includes NO generation. In cells challenged with PLY-deficient bacteria, reconstitution of LMP using the lysomotrophic detergent LeuLeuOMe favored cell necrosis whereas PLY reconstituted apoptosis. The results suggest that PLY contributes to macrophage activation and cytokine production but also engages LMP. Following bacterial phagocytosis, PLY triggers apoptosis and prevents macrophage necrosis as a component of a broad-based antimicrobial strategy. This illustrates how a key virulence factor can become the focus of a multilayered and coordinated innate response by macrophages, optimizing pathogen clearance and limiting inflammation. Importance: Streptococcus pneumoniae, the commonest cause of bacterial pneumonia, expresses the toxin pneumolysin, which can make holes in cell surfaces, causing tissue damage. Macrophages, resident immune cells essential for responses to bacteria in tissues, activate a program of cell suicide called apoptosis, maximizing bacterial clearance and limiting harmful inflammation. We examined pneumolysin's role in activating this response. We demonstrate that pneumolysin did not directly form holes in cells to trigger apoptosis and show that pneumolysin has two distinct roles which require only part of the molecule. Pneumolysin and other bacterial factors released by bacteria that have not been eaten by macrophages activate macrophages to release inflammatory factors but also make the cell compartment containing ingested bacteria leaky. Once inside the cell, pneumolysin ensures that the bacteria activate macrophage apoptosis, rather than necrosis, enhancing bacterial killing and limiting inflammation. This dual response to pneumolysin is critical for an effective immune response to S. pneumoniae.
Collapse
|
30
|
Jeong SY, Martchenko M, Cohen SN. Calpain-dependent cytoskeletal rearrangement exploited for anthrax toxin endocytosis. Proc Natl Acad Sci U S A 2013; 110:E4007-15. [PMID: 24085852 PMCID: PMC3801034 DOI: 10.1073/pnas.1316852110] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The protective antigen component of Bacillus anthracis toxins can interact with at least three distinct proteins on the host cell surface, capillary morphogenesis gene 2 (CMG2), tumor endothelial marker 8, and β1-integrin, and, with the assistance of other host proteins, enters targeted cells by receptor-mediated endocytosis. Using an antisense-based phenotypic screen, we discovered the role of calpains in this process. We show that functions of a ubiquitous Ca(2+)-dependent cysteine protease, calpain-2, and of the calpain substrate talin-1 are exploited for association of anthrax toxin and its principal receptor, CMG2, with higher-order actin filaments and consequently for toxin entry into host cells. Down-regulated expression of calpain-2 or talin-1, or pharmacological interference with calpain action, did not affect toxin binding but reduced endocytosis and increased the survival of cells exposed to anthrax lethal toxin. Adventitious expression of wild-type talin-1 promoted toxin endocytosis and lethality, whereas expression of a talin-1 mutant (L432G) that is insensitive to calpain cleavage did not. Disruption of talin-1, which links integrin-containing focal adhesion complexes to the actin cytoskeleton, facilitated association of toxin bound to its principal cell-surface receptor, CMG2, with higher-order actin filaments undergoing dynamic disassembly and reassembly during endocytosis. Our results reveal a mechanism by which a bacterial toxin uses constitutively occurring calpain-mediated cytoskeletal rearrangement for internalization.
Collapse
Affiliation(s)
| | | | - Stanley N. Cohen
- Departments of Genetics and
- Medicine, Stanford University School of Medicine, Stanford, CA 94305
| |
Collapse
|
31
|
Lee JO, Kim JY, Rhee DK, Pyo S. Streptococcus pneumoniae ClpP protease induces apoptosis via caspase-independent pathway in human neuroblastoma cells: cytoplasmic relocalization of p53. Toxicon 2013; 70:142-52. [PMID: 23643883 DOI: 10.1016/j.toxicon.2013.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 02/11/2013] [Accepted: 04/23/2013] [Indexed: 11/28/2022]
Abstract
Streptococcus pneumoniae causes the most severe form of the bacterial meningitis which is the major cause of bacterial meningitis. Virulence factors produced by S. pneumoniae have been known to contribute significantly to the disease process. ClpP protease (ClpP) which is essential for virulence and survival under stress conditions in S. pneumoniae was examined for the ability to induce apoptosis and the mechanism of the induction of apoptosis in human neuron-like cells, SK-N-SH neuroblastoma cells. ClpP inhibited cell growth and induced apoptosis in SK-N-SH cells. Treatment with ClpP resulted in hypodiploid DNA contents, increased Bax/Bcl-2 ratio and induction of reactive oxygen species (ROS) production. The release of cytochrome c from mitochondria into the cytosol, which is an initiator of the activation of caspase cascades, was not observed in ClpP-treated cells. In addition, pretreatment with Z-Val-Ala-Asp-fluoromethylketone (Z-VAD-fmk), a broad spectrum caspase inhibitor, could not rescue apoptotic cells from ClpP toxicity. Coincidently, caspase-3 and -8 activation and cleavage of PARP were not detected. Moreover, caspase independent apoptosis-inducing factor (AIF) was released from mitochondria and translocated to the nucleus in response to ClpP. We also found that ClpP treatment resulted in the increase of p53 activity and cytoplasmic p53 levels were increased by ClpP, suggesting that functional activation of p53 is intact despite increased cytoplasmic accumulation. Taken together, these data suggest that ClpP contributes to neuronal damage in meningitis and provide further insight into the mechanisms underlying action of pneumococcal virulence factors during bacterial pathogenesis.
Collapse
Affiliation(s)
- Jun-Oh Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-do 440-746, Republic of Korea
| | | | | | | |
Collapse
|
32
|
Cao J, Gong Y, Dong S, Zhang L, Lai X, Zhang X, Yin Y. Pneumococcal ClpP modulates the maturation and activation of human dendritic cells: implications for pneumococcal infections. J Leukoc Biol 2013; 93:737-49. [PMID: 23381472 DOI: 10.1189/jlb.0812428] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
DCs are essential for host immune response to pathogens. Pneumococcal diseases still remain to be a major global-health issue, and HSP100/ClpP is a ubiquitously present virulence determinant for Streptococcus pneumoniae. Here, we show that ClpP expression facilitates the uptake and phagocytosis of pneumococci by human DCs, and it could increase apoptosis of DCs infected with pneumococci. Furthermore, pneumococcal ClpP is required for optimal production of inflammatory cytokines and chemokines and an efficient activation of adaptive immune response in DCs. Complementary, purified rClpP protein recognizes TLR4 and functionally activates human DCs by augmenting the expression of surface molecules and the production of inflammatory cytokines and chemokines dependent on MAPKs and NF-κB signaling pathways. Besides, ClpP-treated DCs induce T cell proliferation and contribute to Th1 immune response. This study describes a novel role of ClpP in the interaction of DCs with pneumococci that could provide new insight for the progression of pneumococcal diseases and has important implications for designing pneumococcal protein vaccines.
Collapse
Affiliation(s)
- Ju Cao
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| | | | | | | | | | | | | |
Collapse
|
33
|
Mata M, Pallardo F, Morcillo EJ, Cortijo J. Piclamilast inhibits the pro-apoptotic and anti-proliferative responses of A549 cells exposed to H(2)O(2) via mechanisms involving AP-1 activation. Free Radic Res 2012; 46:690-9. [PMID: 22360706 DOI: 10.3109/10715762.2012.669040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
AIMS Reactive oxygen species (ROS) are involved in the pathogenesis of many inflammatory diseases such as chronic obstructive pulmonary disease (COPD). They can alter the expression of genes involved in cellular damage by activating transcription factors, including the NF-κB and the activator protein 1 (AP-1). Phosphodiesterase type 4 (PDE4) inhibitors have anti-inflammatory and antioxidant effects, as described in in vivo and in vitro COPD models. This study analysed the effects of piclamilast, a selective PDE4 inhibitor, on modulating the global gene expression profile in A549 cells exposed to H(2)O(2). MAIN METHODS Changes in gene expression were analysed using high-density Affymetrix microarrays and validated by RT-PCR. Cell proliferation was studied using BrdU incorporation. Apoptosis was assessed by flow cytometry using annexin V-fluorescein isothiocyanate. C-Jun phosphorylation and AP-1 activation were determined by ELISA and luciferase assay, respectively. KEY FINDINGS Our results indicate that H(2)O(2) modified the expression of several genes related to apoptosis, cell cycle control and cell signalling, including IL8, FAS, HIG2, CXCL2, CDKN25 and JUNB. Piclamilast pre-treatment significantly inhibited the changes in 23 genes via mechanisms involving AP-1 activation and c-Jun phosphorylation at Ser63. Functional experiments confirmed our results, suggesting new targets related to the antioxidant properties of PDE4 inhibitors. SIGNIFICANCE This is the first study to demonstrate antioxidant effects of a selective PDE4 inhibitor at the global gene expression level, and the results support the importance of AP-1 as a key regulator of the expression of genes involved in the inflammatory response of epithelial cells to oxidative damage.
Collapse
Affiliation(s)
- Manuel Mata
- Research Foundation of the University General Hospital of Valencia, Spain.
| | | | | | | |
Collapse
|
34
|
Kim EH, Choi SY, Kwon MK, Tran TDH, Park SS, Lee KJ, Bae SM, Briles DE, Rhee DK. Streptococcus pneumoniae pep27 mutant as a live vaccine for serotype-independent protection in mice. Vaccine 2012; 30:2008-19. [DOI: 10.1016/j.vaccine.2011.11.073] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 11/19/2011] [Accepted: 11/19/2011] [Indexed: 10/14/2022]
|
35
|
Langford MP, McGee DJ, Ta KH, Redens TB, Texada DE. Multiple caspases mediate acute renal cell apoptosis induced by bacterial cell wall components. Ren Fail 2011; 33:192-206. [PMID: 21332342 DOI: 10.3109/0886022x.2011.553304] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The stimulus for caspase-mediated renal cell apoptosis in septic acute renal failure (ARF) is unclear. To demonstrate the nephrotoxic effects of bacterial cell wall components, the anti-cellular activity of bacterial muropeptides (muramyl dipeptides), peptidoglycans, and lipopolysaccharides was investigated in rabbit kidney cells. Changes in the cell membrane (APOPercentage™ dye uptake), caspase activities, and DNA degradation were quantified colorimetrically and using densitometric assays and their inhibition by caspase-specific and pan-caspase inhibitors was determined. The onset and levels of APOPercentage™ dye-positive rabbit kidney cells, caspase activities, and DNA degradation were closely associated. Specific caspase-1, -2, -3, -4, -8, -10, and -12 inhibitors reduced caspase-3 activity by ≥40%, but only caspase-3 and -8-specific inhibitors reduced apoptotic DNA levels. Pan-caspase inhibitor Q-VD-OPh was 10-fold more effective at inhibiting rabbit kidney cell death, caspase activation, and DNA degradation than caspase-family inhibitor Z-VAD-FMK. Apoptosis was inhibited effectively by both pan-caspase inhibitors when applied early during the stimulus-to-response period. Multiple initiator and effector caspases were activated suggesting extrinsic, intrinsic, and endoplasmic reticulum/stress apoptotic pathway stimulation in rabbit kidney cells treated with bacterial cell wall components. The results provide in vitro support for bacterial cell wall-induced apoptosis as a pathogenic mechanism of renal cell death in septic ARF and support the potential prophylactic use of pan-caspase inhibitors to suppress septic ARF.
Collapse
Affiliation(s)
- Marlyn P Langford
- Department of Ophthalmology, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA.
| | | | | | | | | |
Collapse
|
36
|
Smani Y, Docobo-Pérez F, McConnell MJ, Pachón J. Acinetobacter baumannii-induced lung cell death: role of inflammation, oxidative stress and cytosolic calcium. Microb Pathog 2011; 50:224-32. [PMID: 21288481 DOI: 10.1016/j.micpath.2011.01.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 01/21/2011] [Accepted: 01/24/2011] [Indexed: 12/25/2022]
Abstract
A growing body of evidence supports the notion that susceptible Acinetobacter baumannii strain ATCC 19606 induces human epithelial cells death. However, most of the cellular and molecular mechanisms associated with this cell death remain unknown, and also the degree of the cytotoxic effects of a clinical panresistant strain compared with a susceptible strain has never been studied. Due to the role of proinflammatory cytokine release, oxidative stress and cytosolic calcium increase in the cell death-induced by other Gram-negative bacteria, we investigated whether these intracellular targets were involved in the cell death induced by clinical panresistant 113-16 and susceptible ATCC 19606 strains. Data presented here show that 113-16 and ATCC 19606 induce time-dependent cell death of lung epithelial cells involving a perturbation of cytosolic calcium homeostasis with subsequent calpain and caspase-3 activation. Prevention of this cell death by TNF-α and interleukin-6 blockers and antioxidant highlights the involvement of proinflammatory cytokines and oxidative stress in this phenomenon. These results demonstrate the involvement of calpain calcium-dependent in cell death induced by A. baumannii and the impact of proinflammatory cytokines and oxidative stress in this cell death; it is noteworthy to stress that some mechanisms are less induced by the panresistant strain.
Collapse
Affiliation(s)
- Younes Smani
- Service of Infectious Diseases, Institute of Biomedicine of Sevilla, University Hospital Virgen del Rocío/CSIC/University of Sevilla, Av. Manuel Siurot s/n, 41013 Sevilla, Spain.
| | | | | | | |
Collapse
|
37
|
Littmann M, Albiger B, Frentzen A, Normark S, Henriques-Normark B, Plant L. Streptococcus pneumoniae evades human dendritic cell surveillance by pneumolysin expression. EMBO Mol Med 2010; 1:211-22. [PMID: 20049723 PMCID: PMC3378134 DOI: 10.1002/emmm.200900025] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Dendritic cells (DCs) protect the respiratory epithelium via induction of innate immune responses and priming of naïve T cells during the initiation of adaptive immunity. Streptococcus pneumoniae, a commonly carried asymptomatic member of the human nasopharyngeal microflora, can cause invasive and inflammatory diseases and the cholesterol-dependent cytotoxin pneumolysin is a major pneumococcal virulence factor implicated in compounding tissue damage and mediating inflammatory responses. While most studies examining the impact of pneumolysin have been based on murine models, we have focused this study on human DC responses. We show that expression of haemolytic pneumolysin inhibits human DC maturation, induction of proinflammatory cytokines and activation of the inflammasome. Furthermore, intracellular production of pneumolysin induces caspase-dependent apoptosis in infected DCs. Similarly, clinical isolates with non-haemolytic pneumolysin were more proinflammatory and caused less apoptosis compared to clonally related strains with active pneumolysin. This study describes a novel role of pneumolysin in the evasion of human DC surveillance that could have a profound clinical impact upon inflammatory disease progression and highlights the need to study human responses to human-specific pathogens.
Collapse
Affiliation(s)
- Marie Littmann
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobels väg 16, Stockholm SE-171 77, Sweden
| | | | | | | | | | | |
Collapse
|
38
|
Temmesfeld-Wollbrück B, Brell B, zu Dohna C, Dorenberg M, Hocke AC, Martens H, Klar J, Suttorp N, Hippenstiel S. Adrenomedullin reduces intestinal epithelial permeability in vivo and in vitro. Am J Physiol Gastrointest Liver Physiol 2009; 297:G43-51. [PMID: 19423749 DOI: 10.1152/ajpgi.90532.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Leakage of the gut mucosal barrier in the critically ill patient may allow translocation of bacteria and their virulence factors, thereby perpetuating sepsis and inflammation. Present evidence suggests that adrenomedullin (AM) improves endothelial barrier function and stabilizes circulatory function in systemic inflammation. We tested the hypothesis that exogenously applied AM stabilizes gut epithelial barrier function. Infusion of Staphylococcus aureus alpha-toxin induced septic shock in rats. AM infusion in a therapeutic setting reduced translocation of labeled dextran from the gut into the systemic circulation in this model. AM also reduced alpha-toxin and hydrogen peroxide (H2O2)-related barrier disruption in Caco-2 cells in vitro and reduced H2O2-related rat colon barrier malfunction in Ussing chamber experiments. AM was shown to protect endothelial barrier function via cAMP elevation, but AM failed to induce cAMP accumulation in Caco-2 cells. cAMP is degraded via phosphodiesterases (PDE), and Caco-2 cells showed high activity of cAMP-degrading PDE3 and 4. However, AM failed to induce cAMP accumulation in Caco-2 cells even in the presence of sufficient PDE3/4 inhibition, whereas adenylyl cyclase activator forskolin induced strong cAMP elevation. Furthermore, PDE3/4 inhibition neither amplified AM-induced epithelial barrier stabilization nor affected AM cAMP-related rat colon short-circuit current, furthermore indicating that AM may act independently of cAMP in Caco-2 cells. Finally, experiments using chemical inhibitors indicated that PKC, phosphatidylinositide 3-kinase, p38, and ERK did not contribute to AM-related stabilization of barrier function in Caco-2 cells. In summary, during severe inflammation, elevated AM levels may substantially contribute to the stabilization of gut barrier function.
Collapse
Affiliation(s)
- Bettina Temmesfeld-Wollbrück
- Departments of Internal Medicine and Infectious Diseases, Charité-Universitätsmedizin Berlin, Berlin 13353, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
OBJECTIVES Community-acquired pneumonia is a very common infectious disease associated with significant morbidity and mortality. Streptococcus pneumoniae is the predominant pathogen in this disease, and pneumococcal resistance to multiple antibiotics is increasing. The recently purified bacteriophage endolysin Cpl-1 rapidly and specifically kills pneumococci on contact. The aim of this study was to determine the therapeutic potential of Cpl-1 in a mouse model of severe pneumococcal pneumonia. DESIGN Controlled, in vivo laboratory study. SUBJECTS Female C57/Bl6 mice, 8-12 weeks old. INTERVENTIONS Mice were transnasally infected with pneumococci and therapeutically treated with Cpl-1 or amoxicillin by intraperitoneal injections starting 24 or 48 hours after infection. MEASUREMENTS AND MAIN RESULTS Judged from clinical appearance, decreased body weight, reduced dynamic lung compliance and Pao2/Fio2 ratio, and morphologic changes in the lungs, mice suffered from severe pneumonia at the onset of therapy. When treatment was commenced 24 hours after infection, 100% Cpl-1-treated and 86% amoxicillin-treated mice survived otherwise fatal pneumonia and showed rapid recovery. When treatment was started 48 hours after infection, mice had developed bacteremia, and three of seven (42%) Cpl-1-treated and five of seven (71%) amoxicillin-treated animals survived. Cpl-1 dramatically reduced pulmonary bacterial counts, and prevented bacteremia, systemic hypotension, and lactate increase when treatment commenced at 24 hours. In vivo, treatment with Cpl-1 or amoxicillin effectively reduced counts of penicillin-susceptible pneumococci. The inflammatory response in Cpl-1-and amoxicillin-treated mice was lower than in untreated mice, as determined by multiplex cytokine assay of lung and blood samples. In human epithelial cell cultures, lysed bacteria evoked less proinflammatory cytokine release and cell death, as compared with viable bacteria. CONCLUSIONS Cpl-1 may provide a new therapeutic option in the treatment of pneumococcal pneumonia.
Collapse
|
40
|
Chang A. Caspase-6. CLASS 3 HYDROLASES 2009. [PMCID: PMC7122851 DOI: 10.1007/978-3-540-85705-1_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Antje Chang
- Bioinformatics & Systems Biology, Technical University Braunschweig, Langer Kamp 19b, 38106 Braunschweig, Germany
| |
Collapse
|
41
|
Bem RA, van Woensel JBM, Bos AP, Koski A, Farnand AW, Domachowske JB, Rosenberg HF, Martin TR, Matute-Bello G. Mechanical ventilation enhances lung inflammation and caspase activity in a model of mouse pneumovirus infection. Am J Physiol Lung Cell Mol Physiol 2008; 296:L46-56. [PMID: 18996903 DOI: 10.1152/ajplung.00467.2007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Severe infection with respiratory syncytial virus (RSV) in children can progress to respiratory distress and acute lung injury (ALI). Accumulating evidence suggests that mechanical ventilation (MV) is an important cofactor in the development of ALI by modulating the host immune responses to bacteria. This study investigates whether MV enhances the host response to pneumonia virus of mice (PVM), a mouse pneumovirus that has been used as a model for RSV infection in humans. BALB/c mice were inoculated intranasally with diluted clarified lung homogenates from mice infected with PVM strain J3666 or uninfected controls. Four days after inoculation, the mice were subjected to 4 h of MV (tidal volume, 10 ml/kg) or allowed to breathe spontaneously. When compared with that of mice inoculated with PVM only, the administration of MV to PVM-infected mice resulted in increased bronchoalveolar lavage fluid concentrations of the cytokines macrophage inflammatory protein (MIP)-2, MIP-1alpha (CCL3), and IL-6; increased alveolar-capillary permeability to high molecular weight proteins; and increased caspase-3 activity in lung homogenates. We conclude that MV enhances the activation of inflammatory and caspase cell death pathways in response to pneumovirus infection. We speculate that MV potentially contributes to the development of lung injury in patients with RSV infection.
Collapse
Affiliation(s)
- Reinout A Bem
- Pediatric Intensive Care Unit, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Liu L, Cheng G, Wang C, Pan X, Cong Y, Pan Q, Wang J, Zheng F, Hu F, Tang J. Identification and Experimental Verification of Protective Antigens Against Streptococcus suis Serotype 2 Based on Genome Sequence Analysis. Curr Microbiol 2008; 58:11-7. [DOI: 10.1007/s00284-008-9258-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2008] [Revised: 08/21/2008] [Accepted: 08/21/2008] [Indexed: 11/29/2022]
|
43
|
Schmeck B, Lorenz J, N'guessan PD, Opitz B, van Laak V, Zahlten J, Slevogt H, Witzenrath M, Flieger A, Suttorp N, Hippenstiel S. Histone acetylation and flagellin are essential for Legionella pneumophila-induced cytokine expression. THE JOURNAL OF IMMUNOLOGY 2008; 181:940-7. [PMID: 18606645 DOI: 10.4049/jimmunol.181.2.940] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Legionella pneumophila causes severe pneumonia. Acetylation of histones is thought to be an important regulator of gene transcription, but its impact on L. pneumophila-induced expression of proinflammatory cytokines is unknown. L. pneumophila strain 130b induced the expression of the important chemoattractant IL-8 and genome-wide histone modifications in human lung epithelial A549 cells. We analyzed the IL-8-promoter and found that histone H4 was acetylated and H3 was phosphorylated at Ser(10) and acetylated at Lys(14), followed by transcription factor NF-kappaB. Recruitment of RNA polymerase II to the IL-8 promoter corresponded with increases in gene transcription. Histone modification and IL-8 release were dependent on p38 kinase and NF-kappaB pathways. Legionella-induced IL-8 expression was decreased by histone acetylase (HAT) inhibitor anacardic acid and enhanced by histone deacetylase (HDAC) inhibitor trichostatin A. After Legionella infection, HATs p300 and CREB-binding protein were time-dependently recruited to the IL-8 promoter, whereas HDAC1 and HDAC5 first decreased and later reappeared at the promoter. Legionella specifically induced expression of HDAC5 but not of other HDACs in lung epithelial cells, but knockdown of HDAC1 or 5 did not alter IL-8 release. Furthermore, Legionella-induced cytokine release, promoter-specific histone modifications, and RNA polymerase II recruitment were reduced in infection with flagellin-deletion mutants. Legionella-induced histone modification as well as HAT-/HDAC-dependent IL-8 release could also be shown in primary lung epithelial cells. In summary, histone acetylation seems to be important for the regulation of proinflammatory gene expression in L. pneumophila infected lung epithelial cells. These pathways may contribute to the host response in Legionnaires' disease.
Collapse
Affiliation(s)
- Bernd Schmeck
- FORSYS Junior Research Group, Systems Biology of Lung Inflammation, Charité-Universitätsmedizin, Berlin, Germany.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Xu F, Droemann D, Rupp J, Shen H, Wu X, Goldmann T, Hippenstiel S, Zabel P, Dalhoff K. Modulation of the inflammatory response to Streptococcus pneumoniae in a model of acute lung tissue infection. Am J Respir Cell Mol Biol 2008; 39:522-9. [PMID: 18483419 DOI: 10.1165/rcmb.2007-0328oc] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pneumoniae is the leading pathogen of community-acquired pneumonia and is a main cause of infectious deaths. However, little is known about host-pathogen interaction in human lung tissue. We tested the hypothesis that human alveolar macrophages (AMs) and alveolar epithelial cells (AECs) are important for initiating the host response against S. pneumoniae, and we evaluated the role of Toll-like receptor (TLR) 2, TLR4, and p38 mitogen-activated protein kinase (MAPK) signaling in the inflammatory response after pneumococcal infection. We established a novel model of acute S. pneumoniae infection using vital human lung specimens. In situ hybridization analysis showed that S. pneumoniae DNA was detected in 80 to 90% of AMs and 15 to 30% of AECs after in vitro infection accompanied by increased expression of inflammatory cytokines. Enhanced phosphorylation of p38 MAPK and increased TLR2 and 4 mRNA expression were observed in infected lung tissue. Thirty to fifty percent of AMs and 10 to 20% of AECs showed evidence of apoptosis 24 hours after pneumococcal infection. After macrophage deactivation with Clodronate/liposomes, infected lung tissue exhibited a significantly decreased release of inflammatory mediators. Inhibition of p38 MAPK signaling markedly reduced inflammatory cytokine release from human lungs, whereas TLR2 blockade revealed only minor effects. AMs are central resident immune cells during S. pneumoniae infection and are the main source of early proinflammatory cytokine release. p38 MAPK holds a major role in pathogen-induced pulmonary cytokine release and is a potential molecular target to modulate overwhelming lung inflammation.
Collapse
Affiliation(s)
- Feng Xu
- Medical Clinic III, Campus Lübeck, University of Schleswig-Holstein, Lübeck, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Subcellular expression pattern and role of IL-15 in pneumococci induced lung epithelial apoptosis. Histochem Cell Biol 2008; 130:165-76. [PMID: 18365236 DOI: 10.1007/s00418-008-0414-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2008] [Indexed: 10/22/2022]
Abstract
Streptococcus pneumoniae is the leading causative agent of community-acquired pneumonia. Induction of apoptosis in pulmonary epithelial cells by bacteria during pneumonia might be harmful to the host. Interleukin-15 (IL-15) has been demonstrated as an effective inhibitor of apoptosis and is expressed in lung epithelium on the mRNA and protein level. Therefore, we characterized the sub-cellular expression pattern of the short and long IL-15 isoforms in lung epithelial cells in vitro as well as its role in pneumococci-related lung epithelial cell apoptosis. We found an expression pattern for both IL-15 signal peptides in the pulmonary epithelial cell lines A549 and Beas-2B. Moreover, a strong co-localization of IL-15 and IL-15Ralpha was detected on cell surfaces. Compared to pro-inflammatory cytokine stimulation, neither IL-15 nor its trimeric receptor complex was up-regulated after pneumococcal infection. However, overexpression of IL-15 isoforms revealed IL-15LSP and IL-15Vkl as inhibitors of pneumococci induced apoptosis in pulmonary epithelial cells. Thus, IL-15 may act as an anti-apoptotic molecule in pneumococci infection, thereby suggesting IL-15 as a benefical cytokine in pulmonary host defense against infection.
Collapse
|
46
|
Bootsma HJ, Egmont-Petersen M, Hermans PWM. Analysis of the in vitro transcriptional response of human pharyngeal epithelial cells to adherent Streptococcus pneumoniae: evidence for a distinct response to encapsulated strains. Infect Immun 2007; 75:5489-99. [PMID: 17709418 PMCID: PMC2168309 DOI: 10.1128/iai.01823-06] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection of the human host by Streptococcus pneumoniae begins with colonization of the nasopharynx, which is mediated by the adherence of bacteria to the respiratory epithelium. Several studies have indicated an important role for the pneumococcal capsule in this process. Here, we used microarrays to characterize the in vitro transcriptional response of human pharyngeal epithelial Detroit 562 cells to the adherence of serotype 2 encapsulated strain D39, serotype 19F encapsulated strain G54, serotype 4 encapsulated strain TIGR4, and their nonencapsulated derivatives (Deltacps). In total, 322 genes were found to be upregulated in response to adherent pneumococci. Twenty-two genes were commonly induced, including those encoding several cytokines (e.g., interleukin 1beta [IL-1beta] and IL-6), chemokines (e.g., IL-8 and CXCL1/2), and transcriptional regulators (e.g., FOS), consistent with an innate immune response mediated by Toll-like receptor signaling. Interestingly, 85% of genes were induced specifically by one or more encapsulated strains, suggestive of a capsule-dependent response. Importantly, purified capsular polysaccharides alone had no effect. Over a third of these loci encoded products predicted to be involved in transcriptional regulation and signal transduction, in particular mitogen-activated protein kinase signaling pathways. Real-time PCR of a subset of 10 genes confirmed the microarray data and showed a time-dependent upregulation of, especially, innate immunity genes. The downregulation of epithelial genes was most pronounced upon adherence of D39Deltacps, as 68% of the 161 genes identified were repressed only by this nonencapsulated strain. In conclusion, we identified a subset of host genes specifically induced by encapsulated strains during in vitro adherence and have demonstrated the complexity of interactions occurring during the initial stages of pneumococcal infection.
Collapse
Affiliation(s)
- Hester J Bootsma
- Laboratory of Pediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, P.O. Box 9101 (Route 224), 6500 HB Nijmegen, The Netherlands
| | | | | |
Collapse
|
47
|
García-Suárez MDM, Flórez N, Astudillo A, Vázquez F, Villaverde R, Fabrizio K, Pirofski LA, Méndez FJ. The role of pneumolysin in mediating lung damage in a lethal pneumococcal pneumonia murine model. Respir Res 2007; 8:3. [PMID: 17257395 PMCID: PMC1790890 DOI: 10.1186/1465-9921-8-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Accepted: 01/26/2007] [Indexed: 01/28/2023] Open
Abstract
Background Intranasal inoculation of Streptococcus pneumoniae D39 serotype 2 causes fatal pneumonia in mice. The cytotoxic and inflammatory properties of pneumolysin (PLY) have been implicated in the pathogenesis of pneumococcal pneumonia. Methods To examine the role of PLY in this experimental model we performed ELISA assays for PLY quantification. The distribution patterns of PLY and apoptosis were established by immunohistochemical detection of PLY, caspase-9 activity and TUNEL assay on tissue sections from mice lungs at various times, and the results were quantified with image analysis. Inflammatory and apoptotic cells were also quantified on lung tissue sections from antibody treated mice. Results In bronchoalveolar lavages (BAL), total PLY was found at sublytic concentrations which were located in alveolar macrophages and leukocytes. The bronchoalveolar epithelium was PLY-positive, while the vascular endothelium was not PLY reactive. The pattern and extension of cellular apoptosis was similar. Anti-PLY antibody treatment decreased the lung damage and the number of apoptotic and inflammatory cells in lung tissues. Conclusion The data strongly suggest that in vivo lung injury could be due to the pro-apoptotic and pro-inflammatory activity of PLY, rather than its cytotoxic activity. PLY at sublytic concentrations induces lethal inflammation in lung tissues and is involved in host cell apoptosis, whose effects are important to pathogen survival.
Collapse
Affiliation(s)
- María del Mar García-Suárez
- Área de Microbiología, Departamento de Biología Funcional, Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo; 33006 Oviedo, Asturias, Spain
| | - Noelia Flórez
- Área de Microbiología, Departamento de Biología Funcional, Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo; 33006 Oviedo, Asturias, Spain
| | - Aurora Astudillo
- Laboratorio de Anatomía Patológica, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo; 33006 Oviedo, Asturias, Spain
| | - Fernando Vázquez
- Área de Microbiología, Departamento de Biología Funcional, Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo; 33006 Oviedo, Asturias, Spain
| | - Roberto Villaverde
- Área de Microbiología, Departamento de Biología Funcional, Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo; 33006 Oviedo, Asturias, Spain
| | - Kevin Fabrizio
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
| | - Liise-Anne Pirofski
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, 1300 Morris Park Avenue, Bronx, New York 10461, USA
| | - Francisco J Méndez
- Área de Microbiología, Departamento de Biología Funcional, Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo; 33006 Oviedo, Asturias, Spain
| |
Collapse
|
48
|
N'Guessan PD, Etouem MO, Schmeck B, Hocke AC, Scharf S, Vardarova K, Opitz B, Flieger A, Suttorp N, Hippenstiel S. Legionella pneumophila-induced PKCα-, MAPK-, and NF-κB-dependent COX-2 expression in human lung epithelium. Am J Physiol Lung Cell Mol Physiol 2007; 292:L267-77. [PMID: 17012371 DOI: 10.1152/ajplung.00100.2006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Legionella pneumophila causes community- and hospital-acquired pneumonia. Lung airway and alveolar epithelial cells comprise an important barrier against airborne pathogens. Cyclooxygenase (COX) and microsomal PGE2synthase-1 (mPGES-1)-derived prostaglandins like prostaglandin E2(PGE2) are considered as important regulators of lung function. Herein we tested the hypothesis that L. pneumophila induced COX-2 and mPGES-1-dependent PGE2production in pulmonary epithelial cells. Legionella induced the release of PGE2in primary human small airway epithelial cells and A549 cells. This was accompanied by an increased expression of COX-2 and mPGES-1 as well as an increased PLA2activity in infected cells. Deletion of the type IV secretion system Dot/Icm did not impair Legionella-related COX-2 expression or PGE2release in A549 cells. L. pneumophila induced the degradation of IκBα and activated NF-κB. Inhibition of IKK blocked L. pneumophila-induced PGE2release and COX-2 expression. We noted activation of p38 and p42/44 MAP kinase in Legionella-infected A549 cells. Moreover, membrane translocation and activation of PKCα was observed in infected cells. PKCα and p38 and p42/44 MAP kinase inhibitors reduced PGE2release and COX-2 expression. In summary, PKCα and p38 and p42/44 MAP kinase controlled COX-2 expression and subsequent PGE2release by Legionella-infected lung epithelial cells. These pathways may significantly contribute to the host response in Legionnaires' disease.
Collapse
Affiliation(s)
- Philippe Dje N'Guessan
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Schreiber T, Swanson PE, Chang KC, Davis CC, Dunne WM, Karl IE, Reinhart K, Hotchkiss RS. BOTH GRAM-NEGATIVE AND GRAM-POSITIVE EXPERIMENTAL PNEUMONIA INDUCE PROFOUND LYMPHOCYTE BUT NOT RESPIRATORY EPITHELIAL CELL APOPTOSIS. Shock 2006; 26:271-6. [PMID: 16912652 DOI: 10.1097/01.shk0000225856.32260.0d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To determine whether and by which pathway (via the death receptor or mitochondrial mediated pathway) lymphocyte apoptosis occurs in pneumonia and to determine if increased bronchial epithelial cell apoptosis occurs in pneumonia. Prospective randomized study in a university research laboratory. Male C57BL/6 mice (n = 30). Animals received an intratracheal injection of Streptococcus pneumoniae or Pseudomonas aeruginosa to induce gram-positive or gram-negative pneumonia, respectively and were killed 24, 30, or 48 h later. Presence of pneumonia was confirmed via gross visual examination of lungs and by histology. Lymphocyte apoptosis in spleen and thymus was analyzed by flow cytometry for active caspases 3, 8, and 9 and by immunohistochemical (IHC) staining for active caspase 3 and DNA strand breaks. Respiratory epithelial cell apoptosis was assessed by IHC. Histologically, pneumonia was present in all bacteria-treated animals but none in sham-treated mice. Extensive lymphocyte apoptosis in spleen and thymus was documented by characteristic morphological changes on hematoxylin and eosin staining and by IHC staining in both S. pneumonia and P. aeruginosa infection. Flow cytometry confirmed IHC and showed apoptotic lymphocytes positive for active caspases 3, 8, and 9 in both thymi and spleens in both infections. In contrast to the extensive lymphocyte apoptosis, only rare scattered apoptotic changes were seen in respiratory epithelial or endothelial cells in pneumonia due to either organism. Increased lymphocyte but not bronchial cell apoptosis occurs in both gram-positive and gram-negative pneumonia and probably involves both the extrinsic and intrinsic pathway.
Collapse
Affiliation(s)
- Torsten Schreiber
- Department of Anesthesiology, Washington University School of Medicine, St Louis, MO, USA.
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Marriott HM, Dockrell DH. Streptococcus pneumoniae: the role of apoptosis in host defense and pathogenesis. Int J Biochem Cell Biol 2006; 38:1848-54. [PMID: 16844403 DOI: 10.1016/j.biocel.2006.06.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 05/30/2006] [Accepted: 06/05/2006] [Indexed: 01/29/2023]
Abstract
Programmed cell death or apoptosis is a recognised feature of infection with Streptococcus pneumoniae, and is observed during pneumococcal meningitis and pneumonia. The cholesterol-dependent cytolysin, pneumolysin, is a major trigger of apoptosis in the brain in association with pneumococcal production of hydrogen peroxide. Pneumococcal cell wall is also an important stimulus for apoptosis. Microbial factors and host factors combine in causing apoptosis in the brain, with hippocampal neurons being particularly susceptible. In pulmonary infection epithelial cell apoptosis contributes to tissue injury but macrophage apoptosis may benefit the host, aiding microbial killing and downregulating the inflammatory response. During sepsis lymphocyte apoptosis may be harmful to the host while dendritic cell apoptosis may limit the generation of an adaptive immune response during infection. Apoptosis induction may be harmful or potentially beneficial during pneumococcal infection and understanding its function in each setting is essential to allow specific therapeutic intervention.
Collapse
Affiliation(s)
- Helen M Marriott
- Division of Genomic Medicine, F-Floor, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | | |
Collapse
|