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Yi DY, Xu QY, He Y, Zheng XQ, Yang TC, Lin Y. Treponema pallidum protein Tp47 induced prostaglandin E2 to inhibit the phagocytosis in human macrophages. J Eur Acad Dermatol Venereol 2024; 38:1166-1178. [PMID: 38258964 DOI: 10.1111/jdv.19809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/09/2023] [Indexed: 01/24/2024]
Abstract
BACKGROUND During Treponema pallidum (T. pallidum) infection, the host's immune system actively engages in pursuit and elimination of T. pallidum, while T. pallidum skillfully employs various mechanisms to evade immune recognition. Macrophages exhibit incomplete clearance of T. pallidum in vitro and the underlying mechanism of how T. pallidum resists the attack of macrophage remains unclear. OBJECTIVES To investigate the effect of T. pallidum membrane protein Tp47 on the phagocytosis of macrophages. METHODS THP-1-derived macrophages were used to investigate the role of Tp47 in the secretion of Prostaglandin E2 (PGE2) in macrophages and the mechanism by which Tp47 induced the production of PGE2, as well as the impact of PGE2 on the macrophage's phagocytosis. RESULTS Tp47 (1-10 μg/mL) significantly inhibited the phagocytosis of latex beads and T. pallidum in macrophages (p ≤ 0.05). PGE2 production by macrophages could be induced by Tp47, and the phagocytic function of macrophages could be restored using PGE2 antibody. Tp47 produced PGE2 by activating the PERK/NF-κB/COX-2 pathway in macrophages. Inhibitors targeting PERK, NF-κB and COX-2, respectively, reduced the level of PGE2 and restored the phagocytic function of macrophages. CONCLUSION Tp47-induced PGE2 production via the PERK/NF-κB/COX-2 pathway contributed to macrophage phagocytosis inhibition, which potentially contributes to immune evasion during the T. pallidum infection.
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Affiliation(s)
- D-Y Yi
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Q-Y Xu
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Y He
- Department of Medical Laboratory, The Second Affiliated Hospital of Xiamen Medical College, Xiamen, China
| | - X-Q Zheng
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - T-C Yang
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Y Lin
- Center of Clinical Laboratory, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
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Panchal MH, Swindle EJ, Pell TJ, Rowan WC, Childs CE, Thompson J, Nicholas BL, Djukanovic R, Goss VM, Postle AD, Davies DE, Blume C. Membrane lipid composition of bronchial epithelial cells influences antiviral responses during rhinovirus infection. Tissue Barriers 2024:2300580. [PMID: 38179897 DOI: 10.1080/21688370.2023.2300580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/22/2023] [Indexed: 01/06/2024] Open
Abstract
Lipids and their mediators have important regulatory functions in many cellular processes, including the innate antiviral response. The aim of this study was to compare the lipid membrane composition of in vitro differentiated primary bronchial epithelial cells (PBECs) with ex vivo bronchial brushings and to establish whether any changes in the lipid membrane composition affect antiviral defense of cells from donors without and with severe asthma. Using mass spectrometry, we showed that the lipid membrane of in vitro differentiated PBECs was deprived of polyunsaturated fatty acids (PUFAs) compared to ex vivo bronchial brushings. Supplementation of the culture medium with arachidonic acid (AA) increased the PUFA-content to more closely match the ex vivo membrane profile. Rhinovirus (RV16) infection of AA-supplemented cultures from healthy donors resulted in significantly reduced viral replication while release of inflammatory mediators and prostaglandin E2 (PGE2) was significantly increased. Indomethacin, an inhibitor of prostaglandin-endoperoxide synthases, suppressed RV16-induced PGE2 release and significantly reduced CXCL-8/IL-8 release from AA-supplemented cultures indicating a link between PGE2 and CXCL8/IL-8 release. In contrast, in AA-supplemented cultures from severe asthmatic donors, viral replication was enhanced whereas PTGS2 expression and PGE2 release were unchanged and CXCL8/IL-8 was significantly reduced in response to RV16 infection. While the PTGS2/COX-2 pathway is initially pro-inflammatory, its downstream products can promote symptom resolution. Thus, reduced PGE2 release during an RV-induced severe asthma exacerbation may lead to prolonged symptoms and slower recovery. Our data highlight the importance of reflecting the in vivo lipid profile in in vitro cell cultures for mechanistic studies.
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Affiliation(s)
- Madhuriben H Panchal
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
| | - Emily J Swindle
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | | | | | - Caroline E Childs
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
- Faculty of Medicine, School of Human Development and Health, University of Southampton, Southampton, UK
| | - James Thompson
- Biomedical Imaging Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Benjamin L Nicholas
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Ratko Djukanovic
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Victoria M Goss
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
| | - Anthony D Postle
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Donna E Davies
- Faculty of Medicine, School of Clinical and Experimental Sciences, University of Southampton, Southampton, UK
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Cornelia Blume
- Southampton NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
- Faculty of Medicine, School of Human Development and Health, University of Southampton, Southampton, UK
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3
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Bedi B, Maurice NM, Ciavatta VT, Lynn KS, Yuan Z, Molina SA, Joo M, Tyor WR, Goldberg JB, Koval M, Hart CM, Sadikot RT. Peroxisome proliferator-activated receptor-γ agonists attenuate biofilm formation by Pseudomonas aeruginosa. FASEB J 2017; 31:3608-3621. [PMID: 28442545 DOI: 10.1096/fj.201700075r] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 04/11/2017] [Indexed: 12/20/2022]
Abstract
Pseudomonas aeruginosa is a significant contributor to recalcitrant multidrug-resistant infections, especially in immunocompromised and hospitalized patients. The pathogenic profile of P. aeruginosa is related to its ability to secrete a variety of virulence factors and to promote biofilm formation. Quorum sensing (QS) is a mechanism wherein P. aeruginosa secretes small diffusible molecules, specifically acyl homo serine lactones, such as N-(3-oxo-dodecanoyl)-l-homoserine lactone (3O-C12-HSL), that promote biofilm formation and virulence via interbacterial communication. Strategies that strengthen the host's ability to inhibit bacterial virulence would enhance host defenses and improve the treatment of resistant infections. We have recently shown that peroxisome proliferator-activated receptor γ (PPARγ) agonists are potent immunostimulators that play a pivotal role in host response to virulent P. aeruginosa Here, we show that QS genes in P. aeruginosa (strain PAO1) and 3O-C12-HSL attenuate PPARγ expression in bronchial epithelial cells. PAO1 and 3O-C12-HSL induce barrier derangements in bronchial epithelial cells by lowering the expression of junctional proteins, such as zonula occludens-1, occludin, and claudin-4. Expression of these proteins was restored in cells that were treated with pioglitazone, a PPARγ agonist, before infection with PAO1 and 3O-C12-HSL. Barrier function and bacterial permeation studies that have been performed in primary human epithelial cells showed that PPARγ agonists are able to restore barrier integrity and function that are disrupted by PAO1 and 3O-C12-HSL. Mechanistically, we show that these effects are dependent on the induction of paraoxonase-2, a QS hydrolyzing enzyme, that mitigates the effects of QS molecules. Importantly, our data show that pioglitazone, a PPARγ agonist, significantly inhibits biofilm formation on epithelial cells by a mechanism that is mediated via paraoxonase-2. These findings elucidate a novel role for PPARγ in host defense against P. aeruginosa Strategies that activate PPARγ can provide a therapeutic complement for treatment of resistant P. aeruginosa infections.-Bedi, B., Maurice, N. M., Ciavatta, V. T., Lynn, K. S., Yuan, Z., Molina, S. A., Joo, M., Tyor, W. R., Goldberg, J. B., Koval, M., Hart, C. M., Sadikot, R. T. Peroxisome proliferator-activated receptor-γ agonists attenuate biofilm formation by Pseudomonas aeruginosa.
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Affiliation(s)
- Brahmchetna Bedi
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA.,Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA
| | - Nicholas M Maurice
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA.,Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA
| | - Vincent T Ciavatta
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA.,Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - K Sabrina Lynn
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA
| | - Zhihong Yuan
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA.,Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA
| | - Samuel A Molina
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA.,Emory + Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University, Atlanta, Georgia, USA
| | - Myungsoo Joo
- Department of Immunology, Pusan University, Yangsan, South Korea
| | - William R Tyor
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA.,Department of Neurology, Emory University, Atlanta, Georgia, USA
| | | | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA.,Emory + Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University, Atlanta, Georgia, USA.,Department of Cell Biology, Emory University, Atlanta, Georgia, USA
| | - C Michael Hart
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA.,Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA
| | - Ruxana T Sadikot
- Atlanta Veterans Affairs Medical Center, Decatur, Georgia, USA; .,Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, Georgia, USA
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Fourie R, Ells R, Kemp G, Sebolai OM, Albertyn J, Pohl CH. Pseudomonas aeruginosa produces aspirin insensitive eicosanoids and contributes to the eicosanoid profile of polymicrobial biofilms with Candida albicans. Prostaglandins Leukot Essent Fatty Acids 2017; 117:36-46. [PMID: 28237086 DOI: 10.1016/j.plefa.2017.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/16/2016] [Accepted: 01/24/2017] [Indexed: 11/22/2022]
Abstract
The interaction of clinically relevant microorganisms is the focus of various studies, e.g. the interaction between the pathogenic yeast, Candida albicans, and the bacterium, Pseudomonas aeruginosa. During infection both release arachidonic acid, which they can transform into eicosanoids. This study evaluated the production of prostaglandin E2, prostaglandin F2α and 15-hydroxyeicosatetraenoic acid by biofilms of P. aeruginosa and C. albicans. The influence of co-incubation, acetylsalicylic acid and nordihydroguaiaretic acid on biofilm formation and eicosanoid production was evaluated. Acetylsalicylic acid decreased colony forming units of P. aeruginosa, but increased metabolic activity and eicosanoid production of the cells. In contrast to prostaglandin E2, prostaglandin F2a production by C. albicans was insensitive to acetylsalicylic acid, indicating that different enzymes are responsible for their production in this yeast. Nordihydroguaiaretic acid inhibited biofilm formation by P. aeruginosa, however co-incubation provided protection against this inhibitor. Production of these eicosanoids could affect pathogen-clearance and infection dynamics and this previously uncharacterized facet of interaction could facilitate novel therapeutic intervention against polymicrobial infection.
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Affiliation(s)
- Ruan Fourie
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Ruan Ells
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa; National Control Laboratory for Biological Products, University of the Free State, Bloemfontein, South Africa
| | - Gabré Kemp
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Olihile M Sebolai
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Jacobus Albertyn
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Carolina H Pohl
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa.
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5
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Tsao SM, Yin MC. Antioxidative and antiinflammatory activities of asiatic acid, glycyrrhizic acid, and oleanolic acid in human bronchial epithelial cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:3196-3204. [PMID: 25779760 DOI: 10.1021/acs.jafc.5b00102] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Protective effects of triterpenic acids, asiatic acid (AA), glycyrrhizic acid (GA), or oleanolic acid (OA), for two human bronchial epithelial cells, 16HBE and BEAS-2B cells, against hydrogen peroxide (H2O2) induced injury were examined. Cells were pretreated by triterpenic acid at 4 or 8 μmol/L and followed by H2O2 treatment. Results showed that H2O2 significantly upregulated both Bax and cleaved caspase-3 expression, and also downregulated Bcl-2 expression in test cells. AA at these doses retained Bcl-2 expression, but GA and OA only at 8 μmol/L reserved Bcl-2 expression. Test triterpenic acids lowered cleaved caspase-3 expression dose-dependently. H2O2 treatment lowered Na(+)-K(+)-ATPase activity and mitochondrial membrane potential in cells. Triterpenic acid pretreatments significantly maintained mitochondrial membrane potential and Na(+)-K(+)-ATPase activity. H2O2 enhanced reactive oxygen species, interleukin-6, tumor necrosis factor-α, and prostaglandin E2 levels in test cells. Three triterpenic acid treatments dose-dependently reversed these changes. H2O2 promoted the protein expression of p47(phox), gp91(phox), cyclooxygenase-2 (COX-2), mitogen-activated protein kinase, and nuclear factor-κB (NF-κB). AA, GA, or OA pretreatments dose-dependently downregulated the expression of p47(phox), COX-2, NF-κB p65, and p-p38 but only at 8 μmol/L decreased gp91(phox) expression. These results support that these triterpenic acids could protect bronchial epithelial cells to attenuate apoptotic, oxidative, and inflammatory stress.
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Affiliation(s)
- Shih-Ming Tsao
- †Institute of Medicine, Chung Shan Medical University, Taichung City, Taiwan
- ‡Sections of Infectious Diseases and Chest Medicine, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung City, Taiwan
| | - Mei-Chin Yin
- §Department of Health and Nutrition Biotechnology, Asia University, Taichung City, Taiwan
- ∥Department of Nutrition, China Medical University, Taichung City, Taiwan
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[Prostaglandins and the immune response at the intestinal submucosal level. A potential site for interference with the repeated use of paracetamol and ibuprofen at a young age?]. Arch Pediatr 2014; 22:311-9. [PMID: 25440768 DOI: 10.1016/j.arcped.2014.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 09/14/2014] [Accepted: 11/06/2014] [Indexed: 01/22/2023]
Abstract
Immune deviations have been shown to exponentially increase in young children. As a consequence, research investigating possible environmental reasons for this increase is considered a public health priority. An improved understanding of the immunity of the intestinal submucosal lamina propria has demonstrated the importance of prostaglandins (PGE2s) on its local development with general immune consequences further on. PGE2s appear at this intestinal submucosal level from the metabolism of arachidonic acid mediated by type-2 cyclooxygenases (COX2s) situated in the membranes of many immune cells. The potential risk of repeated inhibition of PGE2 synthesis at a young age has been demonstrated in experiments with animals systemically exposed to a non-steroidal anti-inflammatory drug (NSAID). The repeatedly exposed animal cannot develop tolerance to food antigens and exhibits autoimmune deviations. Acetaminophen (paracetamol) and ibuprofen are analgesic and antipyretic medications given to children either alone or in combination, most often without medical prescription. Recently, it has been demonstrated that paracetamol, like ibuprofen, also carries, besides its central action, a non-selective inhibitory action on peripheral COXs. However, this inhibitory action only relates to physiological concentrations of arachidonic acid and explains the difference in their respective anti-inflammatory effects. Since recently published data have repeatedly reported an increase of immune deviations associated with paracetamol exposure at a young age, it appears important to better understand the possible negative impact of excessive and repetitive inhibitions of the physiological synthesis of prostaglandins by COX2s in childhood during which all immune mechanisms are built up at the intestinal submucosal level. Therefore, a well-designed prospective strategy for pharmacovigilance of these COX inhibitors repeatedly given during childhood is urgently needed.
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Celecoxib improves host defense through prostaglandin inhibition during Histoplasma capsulatum infection. Mediators Inflamm 2013; 2013:950981. [PMID: 23818746 PMCID: PMC3681213 DOI: 10.1155/2013/950981] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/22/2013] [Indexed: 11/18/2022] Open
Abstract
Prostaglandins act as mediators of inflammation and, similar to cytokines, function as immune modulators during innate and adaptive immune responses. Therefore, using a pharmacological inhibitor, celecoxib, we investigated the role of prostaglandins in host defense against Histoplasma capsulatum infection in C57BL/6 mice. Our results showed that treatment with celecoxib inhibited cyclooxygenase 2, reduced the total fungal burden, and reduced the concentration of PGE2, cytokines, lymphocytes, neutrophils, and mononuclear cells in the bronchoalveolar space and lung parenchyma. In addition, celecoxib treatment increased the synthesis of nitric oxide, IFN-γ, LTB4, and the phagocytic capacity of alveolar macrophages. Moreover, celecoxib treatment increased the survival of mice after infection with a lethal inoculum of H. capsulatum. These results suggest that prostaglandins alter the host immune response and play an important role in the pathogenesis of histoplasmosis. Thus, the inhibition of prostaglandins could be a valuable immunomodulatory strategy and antifungal therapy for histoplasmosis treatment.
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PGD synthase and PGD2 in immune resposne. Mediators Inflamm 2012; 2012:503128. [PMID: 22791937 PMCID: PMC3389719 DOI: 10.1155/2012/503128] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/03/2012] [Accepted: 05/03/2012] [Indexed: 11/17/2022] Open
Abstract
PGD2 is formed from arachidonic acid by successive enzyme reactions: oxygenation of arachidonic acid to PGH2, a common precursor of various prostanoids, catalyzed by cyclooxygenase, and isomerization of PGH2 to PGD2 by PGD synthases (PGDSs). PGD2 can be either pro- or anti-inflammatory depending on disease process and etiology. The anti-inflammatory and immunomodulatory attributes of PGDS/PGD2 provide opportunities for development of novel therapeutic approaches for resistant infections and refractory inflammatory diseases. This paper highlights the role of PGD synthases and PGD2 in immune inflammatory response.
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Aronoff DM, Bergin IL, Lewis C, Goel D, O'Brien E, Peters-Golden M, Mancuso P. E-prostanoid 2 receptor signaling suppresses lung innate immunity against Streptococcus pneumoniae. Prostaglandins Other Lipid Mediat 2012; 98:23-30. [PMID: 22575745 DOI: 10.1016/j.prostaglandins.2012.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 03/22/2012] [Accepted: 03/23/2012] [Indexed: 10/28/2022]
Abstract
Pneumonia is a major global health problem. Prostaglandin (PG) E(2) is an immunomodulatory lipid with anti-inflammatory, immunosuppressive, and pro-resolving actions. Data suggest that the E-prostanoid (EP) 2 receptor mediates immunomodulatory effects of PGE(2), but the extent to which this occurs in Streptococcus pneumoniae infection is unknown. Intratracheal lung infection of C57BL/6 mice possessing (EP2(+/+)) or lacking (EP2(-/-)) the EP2 receptor was performed, as were in vitro studies of alveolar macrophage (AM) host defense functions. Bacterial clearance and survival were significantly improved in vivo in EP2(-/-) mice and it correlated with greater neutrophilic inflammation and higher lung IL-12 levels. Upon ex vivo challenge with pneumococcus, EP2(-/-)cells expressed greater amounts of TNF-α and MIP-2 than did EP2(+/+) AMs, and had improved phagocytosis, intracellular killing, and reactive oxygen intermediate generation. These data suggest that PGE(2)-EP2 signaling may provide a novel pharmacological target for treating pneumococcal pneumonia in combination with antimicrobials.
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Affiliation(s)
- David M Aronoff
- Divisions of Infectious Diseases, The University of Michigan, Ann Arbor, MI 48109-5680, United States.
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10
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Wu Q, Jiang D, Smith S, Thaikoottathil J, Martin RJ, Bowler RP, Chu HW. IL-13 dampens human airway epithelial innate immunity through induction of IL-1 receptor-associated kinase M. J Allergy Clin Immunol 2011; 129:825-833.e2. [PMID: 22154382 DOI: 10.1016/j.jaci.2011.10.043] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 09/26/2011] [Accepted: 10/31/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Impaired airway mucosal immunity can contribute to increased respiratory tract infections in asthmatic patients, but the involved molecular mechanisms have not been fully clarified. Airway epithelial cells serve as the first line of respiratory mucosal defense to eliminate inhaled pathogens through various mechanisms, including Toll-like receptor (TLR) pathways. Our previous studies suggest that impaired TLR2 function in T(H)2 cytokine-exposed airways might decrease immune responses to pathogens and subsequently exacerbate allergic inflammation. IL-1 receptor-associated kinase M (IRAK-M) negatively regulates TLR signaling. However, IRAK-M expression in airway epithelium from asthmatic patients and its functions under a T(H)2 cytokine milieu remain unclear. OBJECTIVES We sought to evaluate the role of IRAK-M in IL-13-inhibited TLR2 signaling in human airway epithelial cells. METHODS We examined IRAK-M protein expression in epithelia from asthmatic patients versus that in normal airway epithelia. Moreover, IRAK-M regulation and function in modulating innate immunity (eg, TLR2 signaling) were investigated in cultured human airway epithelial cells with or without IL-13 stimulation. RESULTS IRAK-M protein levels were increased in asthmatic airway epithelium. Furthermore, in primary human airway epithelial cells, IL-13 consistently upregulated IRAK-M expression, largely through activation of phosphoinositide 3-kinase pathway. Specifically, phosphoinositide 3-kinase activation led to c-Jun binding to human IRAK-M gene promoter and IRAK-M upregulation. Functionally, IL-13-induced IRAK-M suppressed airway epithelial TLR2 signaling activation (eg, TLR2 and human β-defensin 2), partly through inhibiting activation of nuclear factor κB. CONCLUSIONS Our data indicate that epithelial IRAK-M overexpression in T(H)2 cytokine-exposed airways inhibits TLR2 signaling, providing a novel mechanism for the increased susceptibility of infections in asthmatic patients.
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Affiliation(s)
- Qun Wu
- Department of Medicine, National Jewish Health and the University of Colorado Denver, Denver, CO 80206, USA
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11
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Schmidt LM, Belvisi MG, Bode KA, Bauer J, Schmidt C, Suchy MT, Tsikas D, Scheuerer J, Lasitschka F, Gröne HJ, Dalpke AH. Bronchial epithelial cell-derived prostaglandin E2 dampens the reactivity of dendritic cells. THE JOURNAL OF IMMUNOLOGY 2011; 186:2095-105. [PMID: 21228345 DOI: 10.4049/jimmunol.1002414] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Airway epithelial cells regulate immune reactivity of local dendritic cells (DCs), thus contributing to microenvironment homeostasis. In this study, we set out to identify factors that mediate this regulatory interaction. We show that tracheal epithelial cells secrete soluble factors that downregulate TNF-α and IL-12p40 secretion by bone marrow-derived DCs but upregulate IL-10 and arginase-1. Size exclusion chromatography identified small secreted molecules having high modulatory activity on DCs. We observed that airway tracheal epithelial cells constitutively release the lipid mediator PGE(2). Blocking the synthesis of PGs within airway epithelial cells relieved DCs from inhibition. Cyclooxygenase-2 was found to be expressed in primary tracheal epithelial cell cultures in vitro and in vivo as shown by microdissection of epithelial cells followed by real-time PCR. Paralleling these findings we observed that DCs treated with an antagonist for E-prostanoid 4 receptor as well as DCs lacking E-prostanoid 4 receptor showed reduced inhibition by airway epithelial cells with respect to secretion of proinflammatory cytokines measured by ELISA. Furthermore, PGE(2) mimicked the effects of epithelial cells on DCs. The results indicate that airway epithelial cell-derived PGE(2) contributes to the modulation of DCs under homeostatic conditions.
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Affiliation(s)
- Lotte M Schmidt
- Department of Infectious Diseases-Medical Microbiology and Hygiene, University of Heidelberg, 69120 Heidelberg, Germany
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12
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Syed MA, Joo M, Abbas Z, Rodger D, Christman J, Mehta D, Sadikot R. Expression of TREM-1 is inhibited by PGD2 and PGJ2 in macrophages. Exp Cell Res 2010; 316:3140-9. [DOI: 10.1016/j.yexcr.2010.08.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Revised: 08/02/2010] [Accepted: 08/17/2010] [Indexed: 11/26/2022]
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13
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Current Opinion in Pulmonary Medicine. Current world literature. Curr Opin Pulm Med 2009; 15:79-87. [PMID: 19077710 DOI: 10.1097/mcp.0b013e32831fb1f3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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