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Mayura IPB, Gotoh K, Nishimura H, Nakai E, Mima T, Yamamoto Y, Yokota K, Matsushita O. Elizabethkingia anophelis, an emerging pathogen, inhibits RAW 264.7 macrophage function. Microbiol Immunol 2021; 65:317-324. [PMID: 33913521 DOI: 10.1111/1348-0421.12888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 11/27/2022]
Abstract
Elizabethkingia anophelis is a pathogen that can cause a life-threatening infection in immunocompromised patients. The first case of E. anophelis infection was reported in 2013; subsequently, an increase in its incidence has been reported globally. Additionally, a mortality rate of more than 30% was observed in the US outbreak of 2015. To date, the pathogenic mechanisms underlying E. anophelis infection, such as toxin production, remain unclear. Since tissue macrophages act as the first line of defense against pathogens, in the present study the interactions between E. anophelis and a macrophage-like cell line RAW 264.7 were examined. Although E. anophelis showed no cytotoxicity toward RAW 264.7 macrophages, the infection inhibited LPS-induced morphological changes and activation of differentiation markers for the polarization of RAW 264.7 macrophages toward an M1-like phenotype. However, when the cell contact was restricted using Transwell inserts or bacterial culture supernatants were used instead of live bacteria, no such inhibition was observed. Moreover, it was shown that E. anophelis evaded phagocytosis. Overall, the results suggest that E. anophelis infection inhibits the differentiation of RAW 264.7 macrophages to a pro-inflammatory phenotype in a contact-dependent manner.
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Affiliation(s)
- I Putu Bayu Mayura
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.,Department of Clinical Microbiology, Faculty of Medicine, Udayana University, Bali, Indonesia
| | - Kazuyoshi Gotoh
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hayato Nishimura
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Erina Nakai
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takehiko Mima
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yumiko Yamamoto
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kenji Yokota
- Graduate School of Health Science, Okayama University, Okayama, Japan
| | - Osamu Matsushita
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Sun J, LaRock DL, Skowronski EA, Kimmey JM, Olson J, Jiang Z, O'Donoghue AJ, Nizet V, LaRock CN. The Pseudomonas aeruginosa protease LasB directly activates IL-1β. EBioMedicine 2020; 60:102984. [PMID: 32979835 PMCID: PMC7511813 DOI: 10.1016/j.ebiom.2020.102984] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Pulmonary damage by Pseudomonas aeruginosa during cystic fibrosis lung infection and ventilator-associated pneumonia is mediated both by pathogen virulence factors and host inflammation. Impaired immune function due to tissue damage and inflammation, coupled with pathogen multidrug resistance, complicates the management of these deep-seated infections. Pathological inflammation during infection is driven by interleukin-1β (IL-1β), but the molecular processes involved are not fully understood. METHODS We examined IL-1β activation in a pulmonary model infection of Pseudomonas aeruginosa and in vitro using genetics, specific inhibitors, recombinant proteins, and targeted reporters of protease activity and IL-1β bioactivity. FINDINGS Caspase-family inflammasome proteases canonically regulate maturation of this proinflammatory cytokine, but we report that plasticity in IL-1β proteolytic activation allows for its direct maturation by the pseudomonal protease LasB. LasB promotes IL-1β activation, neutrophilic inflammation, and destruction of lung architecture characteristic of severe P. aeruginosa pulmonary infection. INTERPRETATION Preservation of lung function and effective immune clearance may be enhanced by selectively controlling inflammation. Discovery of this IL-1β regulatory mechanism provides a distinct target for anti-inflammatory therapeutics, such as matrix metalloprotease inhibitors that inhibit LasB and limit inflammation and pathology during P. aeruginosa pulmonary infections. FUNDING Full details are provided in the Acknowledgements section.
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Affiliation(s)
- Josh Sun
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | - Doris L LaRock
- Department of Microbiology and Immunology, Emory School of Medicine, Atlanta GA, United States
| | - Elaine A Skowronski
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | | | - Joshua Olson
- Department of Pediatrics, UC San Diego, La Jolla, CA, United States
| | - Zhenze Jiang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | - Anthony J O'Donoghue
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | - Victor Nizet
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States; Department of Pediatrics, UC San Diego, La Jolla, CA, United States
| | - Christopher N LaRock
- Department of Microbiology and Immunology, Emory School of Medicine, Atlanta GA, United States; Division of Infectious Diseases, Emory School of Medicine, Atlanta GA, United States; Antimicrobial Resistance Center, Emory University, Atlanta GA, United States.
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Antimicrobial resistance and virulence of Pseudomonas spp. among healthy animals: concern about exolysin ExlA detection. Sci Rep 2020; 10:11667. [PMID: 32669597 PMCID: PMC7363818 DOI: 10.1038/s41598-020-68575-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 06/26/2020] [Indexed: 12/25/2022] Open
Abstract
Pseudomonas is a ubiquitous genus that also causes human, animal and plant diseases. Most studies have focused on clinical P. aeruginosa strains from humans, but they are scarce on animal strains. This study was aimed to determine the occurrence of Pseudomonas spp. among faecal samples of healthy animals, and to analyse their antimicrobial resistance, and pathogenicity. Among 704 animal faecal samples analysed, 133 Pseudomonas spp. isolates (23 species) were recovered from 46 samples (6.5%), and classified in 75 different PFGE patterns. Low antimicrobial resistance levels were found, being the highest to aztreonam (50.3%). Five sequence-types (ST1648, ST1711, ST2096, ST2194, ST2252), two serotypes (O:3, O:6), and three virulotypes (analysing 15 virulence and quorum-sensing genes) were observed among the 9 P. aeruginosa strains. Type-3-Secretion System genes were absent in the six O:3-serotype strains that additionally showed high cytotoxicity and produced higher biofilm biomass, phenazine pigments and motility than PAO1 control strain. In these six strains, the exlAB locus, and other virulence genotypes (e.g. RGP69 pathogenicity island) exclusive of PA7 outliers were detected by whole genome sequencing. This is the first description of the presence of the ExlA exolysin in P. aeruginosa from healthy animals, highlighting their pathological importance.
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Sheremet AB, Nesterenko LN, Zigangirova NA. The Type Three Secretion System of Pseudomonas aeruginosa as a Target for Development of Antivirulence Drugs. MOLECULAR GENETICS, MICROBIOLOGY AND VIROLOGY 2020. [DOI: 10.3103/s0891416820010073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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FitzGerald ES, Luz NF, Jamieson AM. Competitive Cell Death Interactions in Pulmonary Infection: Host Modulation Versus Pathogen Manipulation. Front Immunol 2020; 11:814. [PMID: 32508813 PMCID: PMC7248393 DOI: 10.3389/fimmu.2020.00814] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
In the context of pulmonary infection, both hosts and pathogens have evolved a multitude of mechanisms to regulate the process of host cell death. The host aims to rapidly induce an inflammatory response at the site of infection, promote pathogen clearance, quickly resolve inflammation, and return to tissue homeostasis. The appropriate modulation of cell death in respiratory epithelial cells and pulmonary immune cells is central in the execution of all these processes. Cell death can be either inflammatory or anti-inflammatory depending on regulated cell death (RCD) modality triggered and the infection context. In addition, diverse bacterial pathogens have evolved many means to manipulate host cell death to increase bacterial survival and spread. The multitude of ways that hosts and bacteria engage in a molecular tug of war to modulate cell death dynamics during infection emphasizes its relevance in host responses and pathogen virulence at the host pathogen interface. This narrative review outlines several current lines of research characterizing bacterial pathogen manipulation of host cell death pathways in the lung. We postulate that understanding these interactions and the dynamics of intracellular and extracellular bacteria RCD manipulation, may lead to novel therapeutic approaches for the treatment of intractable respiratory infections.
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Affiliation(s)
| | | | - Amanda M. Jamieson
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, United States
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Lee JH, Jeon J, Bai F, Jin S, Wu W, Ha UH. The Pseudomonas aeruginosa HSP70-like protein DnaK induces IL-1β expression via TLR4-dependent activation of the NF-κB and JNK signaling pathways. Comp Immunol Microbiol Infect Dis 2019; 67:101373. [PMID: 31704499 DOI: 10.1016/j.cimid.2019.101373] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/12/2019] [Accepted: 10/15/2019] [Indexed: 12/18/2022]
Abstract
IL-1β expression is increased in response to P. aeruginosa infection, but the responsible proteins have not been clearly elucidated. Here, we demonstrate for the first time that IL-1β expression is induced in response to the heat shock protein 70-like protein DnaK. Treatment with recombinant DnaK (rDnaK) increased IL-1β expression in a dose- and time-dependent manner, and the release of mature IL-1β in response to rDnaK was detected to an extent similar to that stimulated by the well-known agonists, lipopolysaccharide and nigericin. rDnaK-mediated IL-1β expression was driven by the NF-κB signaling pathway. In addition, expression was controlled by the JNK signaling pathway, although these two signaling cascades act independently upon rDnaK stimulation. Finally, rDnaK-induced IL-1β expression was initiated via the action of TLR4. Taken together, the data reveal that P. aeruginosa-derived DnaK induces expression of IL-1β via TLR4-dependent activation of the NF-κB and JNK signaling pathways.
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Affiliation(s)
- Jung-Hoon Lee
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea
| | - Jisu Jeon
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, Nankai University, Tianjin 300071, China
| | - Shouguang Jin
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida 32610, USA
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, Nankai University, Tianjin 300071, China
| | - Un-Hwan Ha
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea.
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Great phenotypic and genetic variation among successive chronic Pseudomonas aeruginosa from a cystic fibrosis patient. PLoS One 2018; 13:e0204167. [PMID: 30212579 PMCID: PMC6136817 DOI: 10.1371/journal.pone.0204167] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 09/03/2018] [Indexed: 12/31/2022] Open
Abstract
Background/Objectives Different adapted Pseudomonas aeruginosa morphotypes are found during chronic infections. Relevant biological determinants in P. aeruginosa successively isolated from a cystic fibrosis (CF) patient were analyzed in this work to gain insight into P. aeruginosa heterogeneity during chronic infection. Methods Seventeen P. aeruginosa isolates collected from a patient over a 3 year period were included, 5 small colony variants (SCV) and 12 mucoids. The following analyses were performed: Pulsed-Field-Gel-Electrophoresis (PFGE)/Multilocus- sequence-typing (MLST)/serotype, antimicrobial susceptibility, growth curves, capacity to form biofilm, pigment production, elastase activity, motility; presence/expression of virulence/quorum sensing genes, and identification of resistance mechanisms. Results All isolates had closely related PFGE patterns and belonged to ST412. Important phenotypic and genotypic differences were found. SCVs were more resistant to antimicrobials than mucoid isolates. AmpC hyperproduction and efflux pump activity were detected. Seven isolates contained two integrons and nine isolates only one integron. All SCVs showed the same OprD profile, while three different profiles were identified among mucoids. No amino acid changes were found in MutL and MutS. All isolates were slow-growing, generally produced high biofilm, had reduced their toxin expression and their quorum sensing, and showed low motility. Nevertheless, statistically significant differences were found among SCV and mucoid isolates. SCVs grew faster, presented higher biofilm formation and flicA expression; but produced less pyorubin and pyocyanin, showed lower elastase activity and rhlR, algD, and lasB expression than mucoid isolates. Conclusion These results help to understand the molecular behavior of chronic P. aeruginosa isolates in CF patients.
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Hughes AJ, Knoten CA, Morris AR, Hauser AR. ASC acts in a caspase-1-independent manner to worsen acute pneumonia caused by Pseudomonas aeruginosa. J Med Microbiol 2018; 67:1168-1180. [PMID: 29957172 DOI: 10.1099/jmm.0.000782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PURPOSE Pseudomonas aeruginosa expresses a type III secretion system (T3SS) that activates the host inflammasome-mediated immune response. We examined the role of inflammasome activation in severe infection outcomes. METHODS We infected C57BL/6 (B6) mice lacking inflammasome components ASC or caspase-1/11 with a highly virulent strain of P. aeruginosa, PSE9, using a mouse model of pneumonia. We evaluated inflammasome activation in vitro by infecting bone marrow-derived macrophages (BMDMs) with PSE9 and measuring cell death and release of inflammasome-dependent cytokines IL-18 and IL-1β. A bioluminescent reporter assay was used to detect activity of caspase-1 and caspase-3/7 in BMDMs from B6 and ASC-deficient mice.Results/Key Findings. ASC-/- mice exhibited significantly improved survival relative to caspase-1/11-/- mice and B6 mice, demonstrating that ASC and caspase-1/11 play differential roles in P. aeruginosa infection. We found that ASC-/- BMDMs exhibited significantly reduced cell death relative to B6 BMDMs, while caspase-1/11-/- BMDMs were resistant to cell death. IL-18 and IL-1β were both detected from supernatants of infected B6 BMDMs, but cytokine release was abrogated in both ASC-/- and caspase-1/11-/- BMDMs. We detected a 2.5-fold increase in the activation of caspase-3/7 in PSE9-infected B6 BMDMs, but no increase in infected ASC-/- BMDMs. Cell death, cytokine release and caspase-3/7 activity were dependent on a functional T3SS. CONCLUSIONS Collectively, these results are consistent with a model whereby the T3SS apparatus of P. aeruginosa activates the caspase-1-dependent inflammasome and caspase-3/7 through an ASC-dependent mechanism. This activation may have implications for the outcomes of P. aeruginosa infections.
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Affiliation(s)
- A J Hughes
- 1Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - C A Knoten
- 1Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,†Present address: Academy for Quality and Safety Improvement, Northwestern Medicine, Chicago, IL, USA
| | - A R Morris
- 1Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - A R Hauser
- 2Department of Medicine, Division of Infectious Diseases, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,1Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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NOD-like receptor(s) and host immune responses with Pseudomonas aeruginosa infection. Inflamm Res 2018; 67:479-493. [PMID: 29353310 DOI: 10.1007/s00011-018-1132-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/12/2018] [Accepted: 01/16/2018] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION Molecular mechanisms underlying the interactions between Pseudomonas aeruginosa, the common opportunistic pathogen in cystic fibrosis individuals, and host induce a number of marked inflammatory responses and associate with complex therapeutic problems due to bacterial resistance to antibiotics in chronic stage of infection. METHODS Pseudomonas aeruginosa is recognized by number of pattern recognition receptors (PRRs); NOD-like receptors (NLRs) are a class of PRRs, which can recognize a variety of endogenous and exogenous ligands, thereby playing a critical role in innate immunity. RESULTS NLR activation initiates forming of a multi-protein complex called inflammasome that induces activation of caspase-1 and resulted in cleavage of pro-inflammatory cytokines interleukin (IL)-1β and IL-18. When the IL-1β is secreted excessively, this causes tissue damage and extensive inflammatory responses that are potentially hazardous for the host. CONCLUSIONS Recent evidence has laid out inflammasome-forming NLR far beyond inflammation. This review summarizes current knowledge regarding the various roles played by different NLRs and associated down-signals, either in recognition of P. aeruginosa or may be associated with such bacterial pathogen infection, which may relate to for the complexity of lung diseases caused by P. aeruginosa.
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Volgers C, Benedikter BJ, Grauls GE, Savelkoul PHM, Stassen FRM. Immunomodulatory role for membrane vesicles released by THP-1 macrophages and respiratory pathogens during macrophage infection. BMC Microbiol 2017; 17:216. [PMID: 29132302 PMCID: PMC5683551 DOI: 10.1186/s12866-017-1122-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 10/26/2017] [Indexed: 02/07/2023] Open
Abstract
Background During infection, inflammation is partially driven by the release of mediators which facilitate intercellular communication. Amongst these mediators are small membrane vesicles (MVs) that can be released by both host cells and Gram-negative and -positive bacteria. Bacterial membrane vesicles are known to exert immuno-modulatory and -stimulatory actions. Moreover, it has been proposed that host cell-derived vesicles, released during infection, also have immunostimulatory properties. In this study, we assessed the release and activity of host cell-derived and bacterial MVs during the first hours following infection of THP-1 macrophages with the common respiratory pathogens non-typeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Results Using a combination of flow cytometry, tunable resistive pulse sensing (TRPS)-based analysis and electron microscopy, we demonstrated that the release of MVs occurs by both host cells and bacteria during infection. MVs released during infection and bacterial culture were found to induce a strong pro-inflammatory response by naive THP-1 macrophages. Yet, these MVs were also found to induce tolerance of host cells to secondary immunogenic stimuli and to enhance bacterial adherence and the number of intracellular bacteria. Conclusions Bacterial MVs may play a dual role during infection, as they can both trigger and dampen immune responses thereby contributing to immune defence and bacterial survival.
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Affiliation(s)
- Charlotte Volgers
- Department of Medical Microbiology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre, P. Debyelaan 25, 6229, HZ, Maastricht, The Netherlands
| | - Birke J Benedikter
- Department of Medical Microbiology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre, P. Debyelaan 25, 6229, HZ, Maastricht, The Netherlands
| | - Gert E Grauls
- Department of Medical Microbiology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre, P. Debyelaan 25, 6229, HZ, Maastricht, The Netherlands
| | - Paul H M Savelkoul
- Department of Medical Microbiology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre, P. Debyelaan 25, 6229, HZ, Maastricht, The Netherlands.,Department of Medical Microbiology and Infection Control, VU University medical center, Amsterdam, The Netherlands
| | - Frank R M Stassen
- Department of Medical Microbiology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre, P. Debyelaan 25, 6229, HZ, Maastricht, The Netherlands.
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Salicylidene Acylhydrazides and Hydroxyquinolines Act as Inhibitors of Type Three Secretion Systems in Pseudomonas aeruginosa by Distinct Mechanisms. Antimicrob Agents Chemother 2017; 61:AAC.02566-16. [PMID: 28396545 DOI: 10.1128/aac.02566-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 03/23/2017] [Indexed: 12/27/2022] Open
Abstract
Type 3 secretion systems (T3SSs) are major virulence factors in Gram-negative bacteria. Pseudomonas aeruginosa expresses two T3SSs, namely, an injectisome (iT3SS) translocating effector proteins in the host cell cytosol and a flagellum (fT3SS) ensuring bacterial motility. Inhibiting these systems is an appealing therapeutic strategy for acute infections. This study examines the protective effects of the salicylidene acylhydrazide INP0341 and of the hydroxyquinoline INP1750 (previously described as T3SS inhibitors in other species) toward cytotoxic effects of P. aeruginosain vitro Both compounds reduced cell necrosis and inflammasome activation induced by reference strains or clinical isolates expressing T3SS toxins or only the translocation apparatus. INP0341 inhibited iT3SS transcriptional activation, including in strains with constitutive iT3SS expression, and reduced the total expression of toxins, suggesting it targets iT3SS gene transcription. INP1750 inhibited toxin secretion and flagellar motility and impaired the activity of the YscN ATPase from Yersinia pseudotuberculosis (homologous to the ATPase present in the basal body of P. aeruginosa iT3SS and fT3SS), suggesting that it rather targets a T3SS core constituent with high homology among iT3SS and fT3SS. This mode of action is similar to that previously described for INP1855, another hydroxyquinoline, against P. aeruginosa Thus, although acting by different mechanisms, INP0341 and INP1750 appear as useful inhibitors of the virulence of P. aeruginosa Hydroxyquinolines may have a broader spectrum of activity by the fact they act upon two virulence factors (iT3SS and fT3SS).
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Ratner D, Orning MPA, Lien E. Bacterial secretion systems and regulation of inflammasome activation. J Leukoc Biol 2016; 101:165-181. [PMID: 27810946 DOI: 10.1189/jlb.4mr0716-330r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 01/03/2023] Open
Abstract
Innate immunity is critical for host defenses against pathogens, but many bacteria display complex ways of interacting with innate immune signaling, as they may both activate and evade certain pathways. Gram-negative bacteria can exhibit specialized nanomachine secretion systems for delivery of effector proteins into mammalian cells. Bacterial types III, IV, and VI secretion systems (T3SS, T4SS, and T6SS) are known for their impact on caspase-1-activating inflammasomes, necessary for producing bioactive inflammatory cytokines IL-1β and IL-18, key participants of anti-bacterial responses. Here, we discuss how these secretion systems can mediate triggering and inhibition of inflammasome signaling. We propose that a fine balance between secretion system-mediated activation and inhibition can determine net activation of inflammasome activity and control inflammation, clearance, or spread of the infection.
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Affiliation(s)
- Dmitry Ratner
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and
| | - M Pontus A Orning
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and.,Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norges Teknisk-Naturvitenskapelige Universitet, Trondheim, Norway
| | - Egil Lien
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and .,Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norges Teknisk-Naturvitenskapelige Universitet, Trondheim, Norway
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Anantharajah A, Faure E, Buyck JM, Sundin C, Lindmark T, Mecsas J, Yahr TL, Tulkens PM, Mingeot-Leclercq MP, Guery B, Van Bambeke F. Inhibition of the Injectisome and Flagellar Type III Secretion Systems by INP1855 Impairs Pseudomonas aeruginosa Pathogenicity and Inflammasome Activation. J Infect Dis 2016; 214:1105-16. [PMID: 27412581 DOI: 10.1093/infdis/jiw295] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/06/2016] [Indexed: 11/13/2022] Open
Abstract
With the rise of multidrug resistance, Pseudomonas aeruginosa infections require alternative therapeutics. The injectisome (iT3SS) and flagellar (fT3SS) type III secretion systems are 2 virulence factors associated with poor clinical outcomes. iT3SS translocates toxins, rod, needle, or regulator proteins, and flagellin into the host cell cytoplasm and causes cytotoxicity and NLRC4-dependent inflammasome activation, which induces interleukin 1β (IL-1β) release and reduces interleukin 17 (IL-17) production and bacterial clearance. fT3SS ensures bacterial motility, attachment to the host cells, and triggers inflammation. INP1855 is an iT3SS inhibitor identified by in vitro screening, using Yersinia pseudotuberculosis Using a mouse model of P. aeruginosa pulmonary infection, we show that INP1855 improves survival after infection with an iT3SS-positive strain, reduces bacterial pathogenicity and dissemination and IL-1β secretion, and increases IL-17 secretion. INP1855 also modified the cytokine balance in mice infected with an iT3SS-negative, fT3SS-positive strain. In vitro, INP1855 impaired iT3SS and fT3SS functionality, as evidenced by a reduction in secretory activity and flagellar motility and an increase in adenosine triphosphate levels. As a result, INP1855 decreased cytotoxicity mediated by toxins and by inflammasome activation induced by both laboratory strains and clinical isolates. We conclude that INP1855 acts by dual inhibition of iT3SS and fT3SS and represents a promising therapeutic approach.
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Affiliation(s)
- Ahalieyah Anantharajah
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Emmanuel Faure
- EA7366, Host-Pathogen Translational Research Group, Faculté de Médecine, Université Lille Nord de France, Lille, France
| | - Julien M Buyck
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | | | | | - Joan Mecsas
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
| | - Timothy L Yahr
- Department of Microbiology, University of Iowa, Iowa City
| | - Paul M Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Marie-Paule Mingeot-Leclercq
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Benoît Guery
- EA7366, Host-Pathogen Translational Research Group, Faculté de Médecine, Université Lille Nord de France, Lille, France
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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