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Bronchial Epithelial Tet2 Maintains Epithelial Integrity during Acute Pseudomonas aeruginosa Pneumonia. Infect Immun 2020; 89:IAI.00603-20. [PMID: 33046509 DOI: 10.1128/iai.00603-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 10/05/2020] [Indexed: 12/23/2022] Open
Abstract
Respiratory epithelial cells are important for pulmonary innate immune responses during Pseudomonas aeruginosa infection. Tet methylcytosine dioxygenase 2 (Tet2) has been implicated in the regulation of host defense by myeloid and lymphoid cells, but whether Tet2 also contributes to epithelial responses during pneumonia is unknown. The aim of this study was to investigate the role of bronchial epithelial Tet2 in acute pneumonia caused by P. aeruginosa To this end, we crossed mice with Tet2 flanked by two Lox-P sites (Tet2fl/fl mice) with mice expressing Cre recombinase under the bronchial epithelial cell-specific Cc10 promoter (Cc10Cre mice) to generate bronchial epithelial cell-specific Tet2-deficient (Tet2fl/fl Cc10Cre ) mice. Six hours after infection with P. aeruginosa, Tet2fl/fl Cc10Cre and wild-type mice had similar bacterial loads in bronchoalveolar lavage fluid (BALF). At this time point, Tet2fl/fl Cc10Cre mice displayed reduced mRNA levels of the chemokines Cxcl1, Cxcl2, and Ccl20 in bronchial brushes. However, Cxcl1, Cxcl2, and Ccl20 protein levels and leukocyte recruitment in BALF were not different between groups. Tet2fl/fl Cc10Cre mice had increased protein levels in BALF after infection, indicating a disturbed epithelial barrier function, which was corroborated by reduced mRNA expression of tight junction protein 1 and occludin in bronchial brushes. Differences detected between Tet2fl/fl Cc10Cre and wild-type mice were no longer present at 24 h after infection. These results suggest that bronchial epithelial Tet2 contributes to maintaining epithelial integrity by enhancing intracellular connections between epithelial cells during the early phase of P. aeruginosa pneumonia.
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Metzemaekers M, Gouwy M, Proost P. Neutrophil chemoattractant receptors in health and disease: double-edged swords. Cell Mol Immunol 2020; 17:433-450. [PMID: 32238918 PMCID: PMC7192912 DOI: 10.1038/s41423-020-0412-0] [Citation(s) in RCA: 221] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/05/2020] [Indexed: 02/08/2023] Open
Abstract
Neutrophils are frontline cells of the innate immune system. These effector leukocytes are equipped with intriguing antimicrobial machinery and consequently display high cytotoxic potential. Accurate neutrophil recruitment is essential to combat microbes and to restore homeostasis, for inflammation modulation and resolution, wound healing and tissue repair. After fulfilling the appropriate effector functions, however, dampening neutrophil activation and infiltration is crucial to prevent damage to the host. In humans, chemoattractant molecules can be categorized into four biochemical families, i.e., chemotactic lipids, formyl peptides, complement anaphylatoxins and chemokines. They are critically involved in the tight regulation of neutrophil bone marrow storage and egress and in spatial and temporal neutrophil trafficking between organs. Chemoattractants function by activating dedicated heptahelical G protein-coupled receptors (GPCRs). In addition, emerging evidence suggests an important role for atypical chemoattractant receptors (ACKRs) that do not couple to G proteins in fine-tuning neutrophil migratory and functional responses. The expression levels of chemoattractant receptors are dependent on the level of neutrophil maturation and state of activation, with a pivotal modulatory role for the (inflammatory) environment. Here, we provide an overview of chemoattractant receptors expressed by neutrophils in health and disease. Depending on the (patho)physiological context, specific chemoattractant receptors may be up- or downregulated on distinct neutrophil subsets with beneficial or detrimental consequences, thus opening new windows for the identification of disease biomarkers and potential drug targets.
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Affiliation(s)
- Mieke Metzemaekers
- Laboratory of Molecular Immunology, Rega Institute, KU Leuven, Herestraat 49 bus 1042, B-3000, Leuven, Belgium
| | - Mieke Gouwy
- Laboratory of Molecular Immunology, Rega Institute, KU Leuven, Herestraat 49 bus 1042, B-3000, Leuven, Belgium
| | - Paul Proost
- Laboratory of Molecular Immunology, Rega Institute, KU Leuven, Herestraat 49 bus 1042, B-3000, Leuven, Belgium.
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Claushuis TAM, van der Donk LEH, Luitse AL, van Veen HA, van der Wel NN, van Vught LA, Roelofs JJTH, de Boer OJ, Lankelma JM, Boon L, de Vos AF, van 't Veer C, van der Poll T. Role of Peptidylarginine Deiminase 4 in Neutrophil Extracellular Trap Formation and Host Defense during Klebsiella pneumoniae-Induced Pneumonia-Derived Sepsis. THE JOURNAL OF IMMUNOLOGY 2018; 201:1241-1252. [PMID: 29987161 DOI: 10.4049/jimmunol.1800314] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/19/2018] [Indexed: 12/23/2022]
Abstract
Peptidylarginine deiminase 4 (PAD4) catalyzes citrullination of histones, an important step for neutrophil extracellular trap (NET) formation. We aimed to determine the role of PAD4 during pneumonia. Markers of NET formation were measured in lavage fluid from airways of critically ill patients. NET formation and host defense were studied during pneumonia-derived sepsis caused by Klebsiella pneumoniae in PAD4+/+ and PAD4-/- mice. Patients with pneumosepsis, compared with those with nonpulmonary disease, showed increased citrullinated histone 3 (CitH3) levels in their airways and a trend toward elevated levels of NET markers cell-free DNA and nucleosomes. During murine pneumosepsis, CitH3 levels were increased in the lungs of PAD4+/+ but not of PAD4-/- mice. Combined light and electron microscopy showed NET-like structures surrounding Klebsiella in areas of CitH3 staining in the lung; however, these were also seen in PAD4-/- mice with absent CitH3 lung staining. Moreover, cell-free DNA and nucleosome levels were mostly similar in both groups. Moreover, Klebsiella and LPS could still induce NETosis in PAD4-/- neutrophils. Both groups showed largely similar bacterial growth, lung inflammation, and organ injury. In conclusion, these data argue against a major role for PAD4 in NET formation, host defense, or organ injury during pneumonia-derived sepsis.
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Affiliation(s)
- Theodora A M Claushuis
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands;
| | - Lieve E H van der Donk
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Anna L Luitse
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Henk A van Veen
- Electron Microscopy Center Amsterdam, Department of Medical Biology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Nicole N van der Wel
- Electron Microscopy Center Amsterdam, Department of Medical Biology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Lonneke A van Vught
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Joris J T H Roelofs
- Department of Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Onno J de Boer
- Department of Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Jacqueline M Lankelma
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Louis Boon
- Bioceros, 3584 CM Utrecht, the Netherlands; and
| | - Alex F de Vos
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Cornelis van 't Veer
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Tom van der Poll
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.,Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
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Anas AA, van Lieshout MHP, Claushuis TAM, de Vos AF, Florquin S, de Boer OJ, Hou B, Van't Veer C, van der Poll T. Lung epithelial MyD88 drives early pulmonary clearance of Pseudomonas aeruginosa by a flagellin dependent mechanism. Am J Physiol Lung Cell Mol Physiol 2016; 311:L219-28. [PMID: 27288486 DOI: 10.1152/ajplung.00078.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/08/2016] [Indexed: 01/08/2023] Open
Abstract
Pseudomonas aeruginosa is a flagellated pathogen frequently causing pneumonia in hospitalized patients and sufferers of chronic lung disease. Here we investigated the role of the common Toll-like receptor (TLR) adaptor myeloid differentiation factor (MyD)88 in myeloid vs. lung epithelial cells in clearance of P. aeruginosa from the airways. Mice deficient for MyD88 in lung epithelial cells (Sftpccre-MyD88-lox mice) or myeloid cells (LysMcre-MyD88-lox mice) and bone marrow chimeric mice deficient for TLR5 (the receptor recognizing Pseudomonas flagellin) in either parenchymal or hematopoietic cells were infected with P. aeruginosa via the airways. Sftpccre-MyD88-lox mice demonstrated a reduced influx of neutrophils into the bronchoalveolar space and an impaired early antibacterial defense after infection with P. aeruginosa, whereas the response of LysMcre-MyD88-lox mice did not differ from control mice. The immune-enhancing role of epithelial MyD88 was dependent on recognition of pathogen-derived flagellin by epithelial TLR5, as demonstrated by an unaltered clearance of mutant P. aeruginosa lacking flagellin from the lungs of Sftpccre-MyD88-lox mice and an impaired bacterial clearance in bone marrow chimeric mice lacking TLR5 in parenchymal cells. These data indicate that early clearance of P. aeruginosa from the airways is dependent on flagellin-TLR5-MyD88-dependent signaling in respiratory epithelial cells.
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Affiliation(s)
- Adam A Anas
- Center of Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands;
| | - Miriam H P van Lieshout
- Center of Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Theodora A M Claushuis
- Center of Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Alex F de Vos
- Center of Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Sandrine Florquin
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Onno J de Boer
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Baidong Hou
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chaoyang District, Beijing, China; and
| | - Cornelis Van't Veer
- Center of Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Tom van der Poll
- Center of Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Lee JJ, Simborio HL, Reyes AWB, Hop HT, Arayan LT, Lee HJ, Min W, Her M, Rhee MH, Watarai M, Chang HH, Kim S. Influence of platelet-activating factor receptor (PAFR) on Brucella abortus infection: implications for manipulating the phagocytic strategy of B. abortus. BMC Microbiol 2016; 16:70. [PMID: 27098179 PMCID: PMC4839150 DOI: 10.1186/s12866-016-0685-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 04/07/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Brucella abortus is an intracellular pathogen which can infect and persist in host cells through multiple interactions. Above all, its interaction to host cell receptor is important to understand the pathogenic mechanisms of B. abortus. Accordingly, we demonstrated that platelet-activating factor receptor (PAFR) affects host cell response against B. abortus infection. RESULTS First of all, B. abortus infection to macrophage induces secretion of platelet-activating factor (PAF), which is a PAFR agonist. The stimulation of PAFR by PAF remarkably increases B. abortus uptake into macrophages. It induces Janus kinase 2 (JAK2) and p38α phosphorylation, indicating that PAFR-mediated activation of JAK2 signaling leads to enhanced uptake of B. abortus. Moreover, the dynamics of F-actin polymerization revealed that PAFR-mediated B. abortus uptake is related with the reorganization of F-actin and JAK2. Upon B. abortus phagocytosis, reduced PAFR in the membrane and subsequently increased levels of PAFR colocalization with endosomes were observed which indicate that B. abortus uptake into macrophages allowed PAFR trafficking to endosomes. CONCLUSIONS This study demonstrated that PAFR has a compelling involvement in B. abortus uptake as a promoter of phagocytosis, which is associated with JAK2 activation. Thus, our findings establish a novel insight into a receptor-related phagocytic mechanism of B. abortus.
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Affiliation(s)
- Jin Ju Lee
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-757, Republic of Korea
| | - Hannah Leah Simborio
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea
| | | | - Huynh Tan Hop
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea
| | - Lauren Togonon Arayan
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea
| | - Hu Jang Lee
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea
| | - Wongi Min
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea
| | - Moon Her
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-757, Republic of Korea
| | - Man Hee Rhee
- College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Masahisa Watarai
- Department of Veterinary Public Health, Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Hong Hee Chang
- Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, 660-701, Republic of Korea
| | - Suk Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 660-701, Republic of Korea. .,Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
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Lingaraju MC, Pathak NN, Begum J, Balaganur V, Bhat RA, Ramachandra HD, Ayanur A, Ram M, Singh V, Kumar D, Kumar D, Tandan SK. Betulinic acid attenuates lung injury by modulation of inflammatory cytokine response in experimentally-induced polymicrobial sepsis in mice. Cytokine 2014; 71:101-8. [PMID: 25277468 DOI: 10.1016/j.cyto.2014.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/07/2014] [Accepted: 09/09/2014] [Indexed: 11/27/2022]
Abstract
Sepsis commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity and mortality. Septic ALI is characterized by excessive production of proinflammatory mediators. It remained refractory to present therapies and new therapies need to be developed to improve further clinical outcomes. Betulinic acid (BA), a pentacyclic lupane group triterpenoid has been shown to have anti-inflammatory activities in many studies. However, its therapeutic efficacy in polymicrobial septic ALI is yet unknown. Therefore, we investigated the effects of BA on septic ALI using cecal ligation and puncture (CLP) model in mice. Vehicle or BA (3, 10, and 30mg/kg) was administered intraperitoneally, 3 times (0, 24 and 48h) before CLP and CLP was done on 49(th)h of the study. Survival rate was observed till 120h post CLP. Lung tissues were collected for analysis by sacrificing mice 18h post CLP. BA at 10 and 30mg/kg dose significantly reduced sepsis-induced mortality and lung injury as implied by attenuated lung histopathological changes, decreased protein and neutrophils infiltration. BA also decreased lung NF-κB expression, cytokine, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 and matrix metalloproteinase-9 levels. These evidences suggest that, the protective effects of BA on lungs are associated with defending action against inflammatory response and BA could be a potential modulatory agent of inflammation in sepsis-induced ALI.
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Affiliation(s)
- Madhu Cholenahalli Lingaraju
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Nitya Nand Pathak
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Jubeda Begum
- Division of Bacteriology and Mycology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Venkanna Balaganur
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Rafia Ahmad Bhat
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | | | - Anjaneya Ayanur
- Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Mahendra Ram
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Vishakha Singh
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Dhirendra Kumar
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Dinesh Kumar
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India
| | - Surendra Kumar Tandan
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P. 243 122, India.
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Lysine trimethylation of EF-Tu mimics platelet-activating factor to initiate Pseudomonas aeruginosa pneumonia. mBio 2013; 4:e00207-13. [PMID: 23653444 PMCID: PMC3663188 DOI: 10.1128/mbio.00207-13] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous microorganism and the most common Gram-negative bacterium associated with nosocomial pneumonia, which is a leading cause of mortality among critically ill patients. Although many virulence factors have been identified in this pathogen, little is known about the bacterial components required to initiate infection in the host. Here, we identified a unique trimethyl lysine posttranslational modification of elongation factor Tu as a previously unrecognized bacterial ligand involved in early host colonization by P. aeruginosa. This modification is carried out by a novel methyltransferase, here named elongation factor Tu-modifying enzyme, resulting in a motif that is a structural mimic of the phosphorylcholine present in platelet-activating factor. This novel motif mediates bacterial attachment to airway respiratory cells through platelet-activating factor receptor and is a major virulence factor, expression of which is a prerequisite to pneumonia in a murine model of respiratory infection. Phosphorylcholine is an interesting molecule from the microbiological and immunological point of view. It is a crucial epitope for the virulence of many important human pathogens, modulates the host immune response, and is involved in a wide number of processes ranging from allergy to inflammation. Our current work identifies a novel bacterial surface epitope structurally and functionally similar to phosphorylcholine. This novel epitope is crucial for initial colonization of the respiratory tract by Pseudomonas aeruginosa and for development of pneumonia. This opens up new targets for the development of novel drugs to prevent P. aeruginosa pneumonia, which is particularly important given the frequent emergence of multidrug-resistant strains.
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Iovino F, Brouwer MC, van de Beek D, Molema G, Bijlsma JJE. Signalling or binding: the role of the platelet-activating factor receptor in invasive pneumococcal disease. Cell Microbiol 2013; 15:870-81. [PMID: 23444839 DOI: 10.1111/cmi.12129] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/17/2013] [Accepted: 02/18/2013] [Indexed: 11/29/2022]
Abstract
Streptococcus pneumoniae (the pneumococcus) is an opportunistic human pathogen, which causes serious invasive disease such as pneumonia, bacteraemia and meningitis. The interaction of the bacteria with host receptors precedes the development of invasive disease. One host receptor implicated in pneumococcal adhesion to, invasion of and ultimately translocation of cell layers is the platelet-activating factor receptor (PAFR). PAFR is a G-protein coupled receptor which binds PAF, a potent phospholipid activator involved in many leucocyte functions, platelet aggregation and inflammation. PAFR has been proposed to bind S. pneumoniae and as such facilitate adhesion to, uptake by and transcytosis of endothelial cells leading to invasive disease. However, there is a shortage of biochemical data supporting direct interaction between PAFR and the bacteria, in addition to conflicting data on its role in development of invasive pneumococcal disease (IPD). In this review, we will discuss current literature on PAFR and S. pneumoniae and other pathogens,including data concerning human PAFR genetic variation related to IPD clinical aspects, to shed light on the importance of PAFR in IPD. Clarification of the role of this receptor in IPD development has the potential to enable the development of novel therapeutic strategies for treating pneumococcal disease by interfering with the PAFR.
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Affiliation(s)
- Federico Iovino
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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CCAAT/enhancer-binding protein δ facilitates bacterial dissemination during pneumococcal pneumonia in a platelet-activating factor receptor-dependent manner. Proc Natl Acad Sci U S A 2012; 109:9113-8. [PMID: 22615380 DOI: 10.1073/pnas.1202641109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
CCAAT/enhancer-binding protein δ (C/EBPδ) recently emerged as an essential player in the inflammatory response to bacterial infections. C/EBPδ levels increase rapidly after a proinflammatory stimulus, and increasing C/EBPδ levels seem to be indispensable for amplification of the inflammatory response. Here we aimed to elucidate the role of C/EBPδ in host defense in community-acquired pneumococcal pneumonia. We show that C/EBPδ(-/-) mice are relatively resistant to pneumococcal pneumonia, as indicated by delayed and reduced mortality, diminished outgrowth of pneumococci in lungs, and reduced dissemination of the infection. Moreover, expression of platelet-activating factor receptor (PAFR), which is known to potentiate bacterial translocation of gram-positive bacteria, was significantly reduced during infection in C/EBPδ(-/-) mice compared with WT controls. Importantly, cell stimulation experiments revealed that C/EBPδ potentiates PAFR expression induced by lipoteichoic acid and pneumococci. Thus, C/EBPδ exaggerates bacterial dissemination during Streptococcus pneumoniae-induced pulmonary infection, suggesting an important role for PAFR-dependent bacterial translocation.
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10
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Liu M, Zhu H, Li J, Garcia CC, Feng W, Kirpotina LN, Hilmer J, Tavares LP, Layton AW, Quinn MT, Bothner B, Teixeira MM, Lei B. Group A Streptococcus secreted esterase hydrolyzes platelet-activating factor to impede neutrophil recruitment and facilitate innate immune evasion. PLoS Pathog 2012; 8:e1002624. [PMID: 22496650 PMCID: PMC3320582 DOI: 10.1371/journal.ppat.1002624] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 02/21/2012] [Indexed: 11/19/2022] Open
Abstract
The innate immune system is the first line of host defense against invading organisms. Thus, pathogens have developed virulence mechanisms to evade the innate immune system. Here, we report a novel means for inhibition of neutrophil recruitment by Group A Streptococcus (GAS). Deletion of the secreted esterase gene (designated sse) in M1T1 GAS strains with (MGAS5005) and without (MGAS2221) a null covS mutation enhances neutrophil ingress to infection sites in the skin of mice. In trans expression of SsE in MGAS2221 reduces neutrophil recruitment and enhances skin invasion. The sse deletion mutant of MGAS5005 (ΔsseMGAS5005) is more efficiently cleared from skin than the parent strain. SsE hydrolyzes the sn-2 ester bond of platelet-activating factor (PAF), converting biologically active PAF into inactive lyso-PAF. KM and kcat of SsE for hydrolysis of 2-thio-PAF were similar to those of the human plasma PAF acetylhydrolase. Treatment of PAF with SsE abolishes the capacity of PAF to induce activation and chemotaxis of human neutrophils. More importantly, PAF receptor-deficient mice significantly reduce neutrophil infiltration to the site of ΔsseMGAS5005 infection. These findings identify the first secreted PAF acetylhydrolase of bacterial pathogens and support a novel GAS evasion mechanism that reduces phagocyte recruitment to sites of infection by inactivating PAF, providing a new paradigm for bacterial evasion of neutrophil responses. GAS is a major human pathogen causing a variety of infections, including pharyngitis and necrotizing fasciitis. GAS pathogenesis is mediated by a large array of secreted and cell-surface virulence factors. However, the functions of many GAS virulence factors are poorly understood. Recently, we reported that the esterase secreted by GAS (SsE) is a CovRS (the control of virulence two component regulatory system)-regulated protective antigen and is critical for spreading in the skin and systemic dissemination of GAS in a mouse model of necrotizing fasciitis. This report presents three major findings regarding the function and functional mechanism of SsE: 1) SsE contributes to GAS inhibition of neutrophil recruitment; 2) SsE is a potent PAF acetylhydrolase and the first secreted bacterial PAF acetylhydrolase identified so far; and 3) the PAF receptor significantly contributes to neutrophil recruitment in skin GAS infection. These findings support a novel mechanism for evasion of the innate immune system by GAS that may be relevant to other infections.
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Affiliation(s)
- Mengyao Liu
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Hui Zhu
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
- Department of Physiology, Harbin Medical University, Harbin, People's Republic of China
| | - Jinquan Li
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Cristiana C. Garcia
- Laboratory of Immunopharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Wenchao Feng
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Liliya N. Kirpotina
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Jonathan Hilmer
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Luciana P. Tavares
- Laboratory of Immunopharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Arthur W. Layton
- Montana Veterinary Diagnostic Laboratory, Bozeman, Montana, United States of America
| | - Mark T. Quinn
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Mauro M. Teixeira
- Laboratory of Immunopharmacology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Benfang Lei
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America
- * E-mail:
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11
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Endogenous MCP-1 promotes lung inflammation induced by LPS and LTA. Mol Immunol 2011; 48:1468-76. [DOI: 10.1016/j.molimm.2011.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 03/28/2011] [Accepted: 04/01/2011] [Indexed: 02/07/2023]
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McMaken S, Exline MC, Mehta P, Piper M, Wang Y, Fischer SN, Newland CA, Schrader CA, Balser SR, Sarkar A, Baran CP, Marsh CB, Cook CH, Phillips GS, Ali NA. Thrombospondin-1 contributes to mortality in murine sepsis through effects on innate immunity. PLoS One 2011; 6:e19654. [PMID: 21573017 PMCID: PMC3090410 DOI: 10.1371/journal.pone.0019654] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 04/13/2011] [Indexed: 01/15/2023] Open
Abstract
Background Thrombospondin-1 (TSP-1) is involved in many biological processes, including immune and tissue injury response, but its role in sepsis is unknown. Cell surface expression of TSP-1 on platelets is increased in sepsis and could activate the anti-inflammatory cytokine transforming growth factor beta (TGFβ1) affecting outcome. Because of these observations we sought to determine the importance of TSP-1 in sepsis. Methodology/Principal Findings We performed studies on TSP-1 null and wild type (WT) C57BL/6J mice to determine the importance of TSP-1 in sepsis. We utilized the cecal ligation puncture (CLP) and intraperitoneal E.coli injection (IP E.coli) models of peritoneal sepsis. Additionally, bone-marrow-derived macrophages (BMMs) were used to determine phagocytic activity. TSP-1−/− animals experienced lower mortality than WT mice after CLP. Tissue and peritoneal lavage TGFβ1 levels were unchanged between animals of each genotype. In addition, there is no difference between the levels of major innate cytokines between the two groups of animals. PLF from WT mice contained a greater bacterial load than TSP-1−/− mice after CLP. The survival advantage for TSP-1−/− animals persisted when IP E.coli injections were performed. TSP-1−/− BMMs had increased phagocytic capacity compared to WT. Conclusions TSP-1 deficiency was protective in two murine models of peritoneal sepsis, independent of TGFβ1 activation. Our studies suggest TSP-1 expression is associated with decreased phagocytosis and possibly bacterial clearance, leading to increased peritoneal inflammation and mortality in WT mice. These data support the contention that TSP-1 should be more fully explored in the human condition.
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Affiliation(s)
- Sara McMaken
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Matthew C. Exline
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Payal Mehta
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Melissa Piper
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Yijie Wang
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Sara N. Fischer
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Christie A. Newland
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Carrie A. Schrader
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Shannon R. Balser
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Anasuya Sarkar
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Christopher P. Baran
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Clay B. Marsh
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
| | - Charles H. Cook
- Department of Surgery, Ohio State University, Columbus, Ohio, United States of America
| | - Gary S. Phillips
- The Center for Biostatistics, Ohio State University, Columbus, Ohio, United States of America
| | - Naeem A. Ali
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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Hoogerwerf JJ, Leendertse M, Wieland CW, de Vos AF, de Boer JD, Florquin S, Poll TVD. Loss of Suppression of Tumorigenicity 2 (ST2) Gene Reverses Sepsis-induced Inhibition of Lung Host Defense in Mice. Am J Respir Crit Care Med 2011; 183:932-40. [DOI: 10.1164/rccm.201006-0934oc] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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