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Yang C, Cui C, Deng F. The mntH gene of Burkholderia cenocepacia influences motility and quorum sensing to control virulence. Braz J Microbiol 2024:10.1007/s42770-024-01506-8. [PMID: 39230636 DOI: 10.1007/s42770-024-01506-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 08/25/2024] [Indexed: 09/05/2024] Open
Abstract
Quorum sensing (QS) signals widely exist in bacteria to control biological functions in response to populations of cells. Burkholderia cenocepacia, an important opportunistic pathogen in patients with cystic fibrosis (CF), is commonly found in the environment and mostly utilizes the N-acylhomoserine lactone (AHL) and cis-2-dodecenoic acid (BDSF) QS systems to control biological functions. Our previous study illuminated the detailed mechanism by which B.cenocepacia integrates BDSF and cyclic diguanosine monophosphate (c-di-GMP) signals to control virulence. Here, we employed Tn5 transposon mutagenesis to identify genes related to the BDSF QS system. One of the most significantly attenuated mutants had an insertion in the mntH gene. Here, we showed that MntH (Bcam0836), a manganese transport protein, controls QS-regulated phenotypes, including motility, biofilm formation and virulence. We also found that. BDSF production was attenuated at both the gene and signaling levels in the Bcam0836 mutant, and that Bcam0836 influenced the expression of some genes regulated by the BDSF receptor RpfR and the downstream regulator GtrR. These results show that the manganese transport protein. MntH modulates a subset of genes and functions regulated by the QS system in B. cenocepacia.
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Affiliation(s)
- Chunxi Yang
- Institute of Clinical Medicine, Jiangxi Provincial People's Hospital, The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, 330006, China.
| | - Chaoyu Cui
- Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, Jiangxi, 330045, China
| | - Fengyi Deng
- Institute of Clinical Medicine, Jiangxi Provincial People's Hospital, The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, 330006, China
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Shmarina G, Pukhalskaya D, Shmarin V, Semykin S, Avakyan L, Krasovsky S, Goryainova A, Kostyuk S, Zinchenko R, Kashirskaya N. Burkholderia cepacia in cystic fibrosis children and adolescents: overall survival and immune alterations. Front Cell Infect Microbiol 2024; 14:1374318. [PMID: 39011515 PMCID: PMC11246859 DOI: 10.3389/fcimb.2024.1374318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 06/18/2024] [Indexed: 07/17/2024] Open
Abstract
Background In current literature there are only scarce data on the host inflammatory response during Burkholderia cepacia complex (Bcc) persistence. The primary objective of the present research was to carry out cross-sectional analyses of biomarkers and evaluate disease progression in cystic fibrosis (CF) patients with chronic Bcc infection and pathogen-free ones. The secondary aim was to assess prospectively overall survival of the study participants during up to 8 years of follow-up. Methods The study included 116 paediatric patients with CF; 47 CF patients were chronically infected with Bcc, and 69 individuals were Bcc free. Plasma and sputum biomarkers (neutrophil elastase, MMP-8, MMP-9, MMP-12, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, IL-22, IL-23, IL-17, IFN-γ, TGFβ1, TNF-α) were analysed using commercially available kits. Besides, inhibitory effect of dexamethasone on proliferative response of PHA-stimulated peripheral blood lymphocytes had been assessed. Results Bcc infected patients did not differ from Bcc free ones in demographic and clinical parameters, but demonstrated an increased rate of glucose metabolism disturbances and survival disadvantage during prolong follow-up period. Biomarkers analyses revealed elevated TNF-α and reduced IL-17F levels in sputum samples of Bcc infected patients. These patients also demonstrated improvement of peripheral blood lymphocyte sensitivity to steroid treatment and reduction in plasma pro-inflammatory (IL-17F and IL-18) and anti-inflammatory (TGFβ1 and IL-10) cytokine concentrations. Conclusions Reduction in IL-17F levels may have several important consequences including increase in steroid sensitivity and glycemic control disturbances. Further investigations are needed to clarify the role of IL-17 cytokines in CF complication development. Low plasma TGFβ1 and IL-10 levels in Bcc infected group may be a sign of subverted activity of regulatory T cells. Such immune alterations may be one of the factors contributing to the development of the cepacia syndrome.
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Affiliation(s)
- Galina Shmarina
- Research Centre for Medical Genetics, Moscow, Russia
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
| | | | - Vassiliy Shmarin
- Research Centre for Medical Genetics, Moscow, Russia
- First Moscow State Medical University, Moscow, Russia
| | - Sergey Semykin
- Russian Clinical Children's Hospital, a separate structural unit of the Russian National Research Medical University, Moscow, Russia
| | - Lusine Avakyan
- Russian Clinical Children's Hospital, a separate structural unit of the Russian National Research Medical University, Moscow, Russia
| | | | - Anastasia Goryainova
- Russian Clinical Children's Hospital, a separate structural unit of the Russian National Research Medical University, Moscow, Russia
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Loeven NA, Reuven AD, McGee AP, Dabi C, Mwaura BW, Bliska JB. A Type VI Secretion System in Burkholderia Species cenocepacia and orbicola Triggers Distinct Macrophage Death Pathways Independent of the Pyrin Inflammasome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.28.559184. [PMID: 38826213 PMCID: PMC11142134 DOI: 10.1101/2023.09.28.559184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
The Burkholderia cepacia complex contains opportunistic pathogens that cause chronic infections and inflammation in lungs of people with cystic fibrosis. Two closely related species within this complex are Burkholderia cenocepacia and the recently classified Burkholderia orbicola. B. cenocepacia and B. orbicola encode a type VI secretion system and the effector TecA, which is detected by the pyrin/caspase-1 inflammasome, and triggers macrophage inflammatory death. In our earlier study the pyrin inflammasome was dispensable for lung inflammation in mice infected with B. orbicola AU1054, indicating this species activates an alternative pathway of macrophage inflammatory death. Notably, B. cenocepacia J2315 and K56-2 can damage macrophage phagosomes and K56-2 triggers activation of the caspase-11 inflammasome, which detects cytosolic LPS. Here we investigated inflammatory cell death in pyrin-deficient ( Mefv -/- ) mouse macrophages infected with B. cenocepacia J2315 or K56-2 or B. orbicola AU1054 or PC184. Macrophage inflammatory death was measured by cleavage of gasdermin D protein, release of cytokines IL-1α and IL-1β and plasma membrane rupture. Findings suggest that J2315 and K56-2 are detected by the caspase-11 inflammasome in Mefv -/- macrophages, resulting in IL-1β release. In contrast, inflammasome activation is not detected in Mefv -/- macrophages infected with AU1054 or PC184. Instead, AU1054 triggers an alternative macrophage inflammatory death pathway that requires TecA and results in plasma membrane rupture and IL-1α release. Amino acid variation between TecA isoforms in B. cenocepacia and B. orbicola may explain how the latter species triggers a non-inflammasome macrophage death pathway.
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Price CE, Valls RA, Ramsey AR, Loeven NA, Jones JT, Barrack KE, Schwartzman JD, Royce DB, Cramer RA, Madan JC, Ross BD, Bliska J, O'Toole GA. Intestinal Bacteroides modulates inflammation, systemic cytokines, and microbial ecology via propionate in a mouse model of cystic fibrosis. mBio 2024; 15:e0314423. [PMID: 38179971 PMCID: PMC10865972 DOI: 10.1128/mbio.03144-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 12/01/2023] [Indexed: 01/06/2024] Open
Abstract
Persons with cystic fibrosis (CF), starting in early life, show intestinal microbiome dysbiosis characterized in part by a decreased relative abundance of the genus Bacteroides. Bacteroides is a major producer of the intestinal short chain fatty acid propionate. We demonstrate here that cystic fibrosis transmembrane conductance regulator-defective (CFTR-/-) Caco-2 intestinal epithelial cells are responsive to the anti-inflammatory effects of propionate. Furthermore, Bacteroides isolates inhibit the IL-1β-induced inflammatory response of CFTR-/- Caco-2 intestinal epithelial cells and do so in a propionate-dependent manner. The introduction of Bacteroides-supplemented stool from infants with cystic fibrosis into the gut of CftrF508del mice results in higher propionate in the stool as well as the reduction in several systemic pro-inflammatory cytokines. Bacteroides supplementation also reduced the fecal relative abundance of Escherichia coli, indicating a potential interaction between these two microbes, consistent with previous clinical studies. For a Bacteroides propionate mutant in the mouse model, pro-inflammatory cytokine KC is higher in the airway and serum compared with the wild-type (WT) strain, with no significant difference in the absolute abundance of these two strains. Taken together, our data indicate the potential multiple roles of Bacteroides-derived propionate in the modulation of systemic and airway inflammation and mediating the intestinal ecology of infants and children with CF. The roles of Bacteroides and the propionate it produces may help explain the observed gut-lung axis in CF and could guide the development of probiotics to mitigate systemic and airway inflammation for persons with CF.IMPORTANCEThe composition of the gut microbiome in persons with CF is correlated with lung health outcomes, a phenomenon referred to as the gut-lung axis. Here, we demonstrate that the intestinal microbe Bacteroides decreases inflammation through the production of the short-chain fatty acid propionate. Supplementing the levels of Bacteroides in an animal model of CF is associated with reduced systemic inflammation and reduction in the relative abundance of the opportunistically pathogenic group Escherichia/Shigella in the gut. Taken together, these data demonstrate a key role for Bacteroides and microbially produced propionate in modulating inflammation, gut microbial ecology, and the gut-lung axis in cystic fibrosis. These data support the role of Bacteroides as a potential probiotic in CF.
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Affiliation(s)
- Courtney E. Price
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Rebecca A. Valls
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Alexis R. Ramsey
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Nicole A. Loeven
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Jane T. Jones
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Kaitlyn E. Barrack
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | | | - Darlene B. Royce
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Juliette C. Madan
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Hanove, USA
| | - Benjamin D. Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - James Bliska
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - George A. O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
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Reuven AD, Mwaura BW, Bliska JB. ExoS Effector in Pseudomonas aeruginosa Hyperactive Type III Secretion System Mutant Promotes Enhanced Plasma Membrane Rupture in Neutrophils. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.24.577040. [PMID: 38328038 PMCID: PMC10849719 DOI: 10.1101/2024.01.24.577040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for a large percentage of airway infections that cause morbidity and mortality in immunocompromised patients, especially those with cystic fibrosis (CF). One important P. aeruginosa virulence factor is a type III secretion system (T3SS) that translocates effectors into host cells. ExoS is a T3SS effector with ADP ribosyltransferase (ADPRT) activity. The ADPRT activity of ExoS promotes P. aeruginosa virulence by inhibiting phagocytosis and limiting the oxidative burst in neutrophils. The P. aeruginosa T3SS also translocates flagellin, which can activate the NLRC4 inflammasome, resulting in: 1) gasdermin-D (GSDMD) pores, release of IL-1β and pyroptosis; and 2) histone 3 citrullination (CitH3) and decondensation and expansion of nuclear DNA into the cytosol. However, recent studies with the P. aeruginosa laboratory strain PAO1 indicate that ExoS ADPRT activity inhibits activation of the NLRC4 inflammasome in neutrophils. Here, an ExoS+ CF clinical isolate of P. aeruginosa with a hyperactive T3SS was identified. Variants of the hyperactive T3SS mutant or PAO1 were used to infect neutrophils from C57BL/6 mice or mice engineered to have a CF genotype or a defect in inflammasome assembly. Responses to NLRC4 inflammasome assembly or ExoS ADPRT activity were assayed, results of which were found to be similar for C57BL/6 or CF neutrophils. The hyperactive T3SS mutant had enhanced resistance to neutrophil killing, like previously identified hypervirulent P. aeruginosa isolates. ExoS ADPRT activity in the hyperactive T3SS mutant regulated inflammasome and nuclear DNA decondensation responses like PAO1 but promoted enhanced CitH3 and plasma membrane rupture (PMR). Glycine supplementation inhibited PMR caused by the hyperactive T3SS mutant, suggesting ninjurin-1 is required for this process. These results identify enhanced neutrophil PMR as a pathogenic activity of ExoS ADPRT in a hypervirulent P. aeruginosa isolate.
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Affiliation(s)
- Arianna D. Reuven
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Bethany W. Mwaura
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - James B. Bliska
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
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Malik HS, Magnotti F, Loeven NA, Delgado JM, Kettenbach AN, Henry T, Bliska JB. Phosphoprotein phosphatase activity positively regulates oligomeric pyrin to trigger inflammasome assembly in phagocytes. mBio 2023; 14:e0206623. [PMID: 37787552 PMCID: PMC10653879 DOI: 10.1128/mbio.02066-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 10/04/2023] Open
Abstract
IMPORTANCE Pyrin, a unique cytosolic receptor, initiates inflammatory responses against RhoA-inactivating bacterial toxins and effectors like Yersinia's YopE and YopT. Understanding pyrin regulation is crucial due to its association with dysregulated inflammatory responses, including Familial Mediterranean Fever (FMF), linked to pyrin gene mutations. FMF mutations historically acted as a defense mechanism against plague. Negative regulation of pyrin through PKN phosphorylation is well established, with Yersinia using the YopM effector to promote pyrin phosphorylation and counteract its activity. This study highlights the importance of phosphoprotein phosphatase activity in positively regulating pyrin inflammasome assembly in phagocytic cells of humans and mice. Oligomeric murine pyrin has S205 phosphorylated before inflammasome assembly, and this study implicates the dephosphorylation of murine pyrin S205 by two catalytic subunits of PP2A in macrophages. These findings offer insights for investigating the regulation of oligomeric pyrin and the balance of kinase and phosphatase activity in pyrin-associated infectious and autoinflammatory diseases.
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Affiliation(s)
- Haleema S. Malik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Flora Magnotti
- CIRI, Centre International de Recherche en Infectiologie, Inserm U111, Université Claude Bernard Lyon, CNRS, UMR5308, ENS de Lyon, Univ Lyon, Lyon, France
| | - Nicole A. Loeven
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jose M. Delgado
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arminja N. Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Dartmouth Cancer Center, Lebanon, New Hampshire, USA
| | - Thomas Henry
- CIRI, Centre International de Recherche en Infectiologie, Inserm U111, Université Claude Bernard Lyon, CNRS, UMR5308, ENS de Lyon, Univ Lyon, Lyon, France
| | - James B. Bliska
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Fu J, Shan J, Cui Y, Yan C, Wang Q, Han J, Cao G. Metabolic disorder and intestinal microflora dysbiosis in chronic inflammatory demyelinating polyradiculoneuropathy. Cell Biosci 2023; 13:6. [PMID: 36627678 PMCID: PMC9832664 DOI: 10.1186/s13578-023-00956-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare acquired immune-mediated neuropathy. Although microbial infection is potentially a contributing factor, a causative link between CIDP and microbial infection remains unclear. There is also no definitive biomarker for CIDP diagnostics and therapies. The present study aimed to characterize the serum metabolic profile and gut microbiome structure in CIDP. METHODS Targeted metabolomics profiling of serum, using liquid chromatography-mass spectrometry, and metagenomics sequencing of stool samples from a cohort of CIDP and non-CIDP subjects were performed to evaluate serum metabolic profiles and gut microbiome structure in CIDP subjects relative to healthy controls. RESULTS Metabolome data revealed that the bile acids profile was perturbed in CIDP with bile acids and arachidonic acid enriched significantly in CIDP versus non-CIDP controls. Metagenome data revealed that opportunistic pathogens, such as Klebsiella pneumonia and Megamonas funiformis, and genes involved in bacterial infection were notably more abundant in CIDP subjects, while gut microbes related to biotransformation of secondary bile acids were abnormal in CIDP versus non-CIDP subjects. Correlation analysis revealed that changes in secondary bile acids were associated with altered gut microbes, including Bacteroides ovatus, Bacteroides caccae, and Ruminococcus gnavus. CONCLUSION Bile acids and arachidonic acid metabolism were disturbed in CIDP subjects and might be affected by the dysbiosis of gut microbial flora. These findings suggest that the combination of bile acids and arachidonic acid could be used as a CIDP biomarker and that modulation of gut microbiota might impact the clinical course of CIDP.
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Affiliation(s)
- Jiafang Fu
- grid.452422.70000 0004 0604 7301Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, First Affiliated Hospital of Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117 China ,Key Lab for Rare & Uncommon Diseases of Shandong Province, Jinan, 250117 China ,grid.410587.fNHC Key Laboratory of Biotechnology Drugs, Shandong Academy of Medical Sciences, Jinan, 250117 China
| | - Jingli Shan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Yazhou Cui
- grid.452422.70000 0004 0604 7301Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, First Affiliated Hospital of Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117 China ,Key Lab for Rare & Uncommon Diseases of Shandong Province, Jinan, 250117 China ,grid.410587.fNHC Key Laboratory of Biotechnology Drugs, Shandong Academy of Medical Sciences, Jinan, 250117 China
| | - Chuanzhu Yan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China ,Department of Central Laboratory and Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao, 266035 China ,grid.27255.370000 0004 1761 1174Brain Science Research Institute, Shandong University, Jinan, 250012 China
| | - Qinzhou Wang
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Jinxiang Han
- grid.452422.70000 0004 0604 7301Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, First Affiliated Hospital of Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117 China ,Key Lab for Rare & Uncommon Diseases of Shandong Province, Jinan, 250117 China ,grid.410587.fNHC Key Laboratory of Biotechnology Drugs, Shandong Academy of Medical Sciences, Jinan, 250117 China
| | - Guangxiang Cao
- grid.452422.70000 0004 0604 7301Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, First Affiliated Hospital of Shandong First Medical University, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117 China ,Key Lab for Rare & Uncommon Diseases of Shandong Province, Jinan, 250117 China ,grid.410587.fNHC Key Laboratory of Biotechnology Drugs, Shandong Academy of Medical Sciences, Jinan, 250117 China
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Wang Y, Zeng M, Xia L, Valerie Olovo C, Su Z, Zhang Y. Bacterial strategies for immune systems - Role of the type VI secretion system. Int Immunopharmacol 2023; 114:109550. [PMID: 36525796 DOI: 10.1016/j.intimp.2022.109550] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/09/2022] [Accepted: 12/02/2022] [Indexed: 12/15/2022]
Abstract
The process of host infection by bacteria is complicated. Bacterial infections strongly induce the host immune system, which necessitates a robust clearance of the infection. However, bacteria have over time developed strategies that enable their evasion of attacks by the host immune system. One such strategy is the type VI secretion system (T6SS), a special needle-like secretion system that is widespread in Gram-negative bacteria and is responsible for delivering effector proteins into the external bacterial environment or directly into the host cell cytosol. Bacterial T6SS and its secreted effector proteins play an important role in the interaction between bacteria and host immune system. They also serve as antigens that are employed in the development of vaccines for clinical trials as well as future vaccine candidates. This review focuses mainly on aspects of T6SS effectors that impact the strength of the host immune system, including inflammation, autophagy, and apoptosis (silent programmed cell death). The T6SS-based vaccines are also described.
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Affiliation(s)
- Yurou Wang
- Institute for Medical Immunology of Jiangsu University, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212013, China; Department of Biochemistry and Molecular Biology, Jiangsu University School of Medicine, Zhenjiang, Jiangsu 212013, China
| | - Minmin Zeng
- Department of Biochemistry and Molecular Biology, Jiangsu University School of Medicine, Zhenjiang, Jiangsu 212013, China
| | - Lin Xia
- Department of Laboratory Medicine, Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China; International Genome Center, Jiangsu University, Zhenjiang 212013, China
| | - Chinasa Valerie Olovo
- Department of Biochemistry and Molecular Biology, Jiangsu University School of Medicine, Zhenjiang, Jiangsu 212013, China
| | - Zhaoliang Su
- Institute for Medical Immunology of Jiangsu University, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212013, China; International Genome Center, Jiangsu University, Zhenjiang 212013, China
| | - Ying Zhang
- Institute for Medical Immunology of Jiangsu University, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212013, China; Department of Biochemistry and Molecular Biology, Jiangsu University School of Medicine, Zhenjiang, Jiangsu 212013, China.
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Li J, Hu WW, Qu GX, Li XR, Xiang Y, Jiang P, Luo JQ, He WH, Jin YJ, Shi Q. Characterization of a Type VI Secretion System vgrG2 Gene in the Pathogenicity of Burkholderia thailandensis BPM. Front Microbiol 2022; 12:811343. [PMID: 35069514 PMCID: PMC8767068 DOI: 10.3389/fmicb.2021.811343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022] Open
Abstract
Burkholderia thailandensis is a clinically underestimated conditional pathogen in the genus Burkholderia, the pathogenicity of the infection caused by B. thailandensis remains poorly understood. According to previous studies, Type-VI secretion system (T6SS) is a protein secreting device widely existing in Gram-negative bacilli. Valine-glycine repeat protein G (VgrG) is not only an important component of T6SS, but also a virulence factor of many Gram-negative bacilli. In one of our previous studies, a unique T6SS vgrG gene (vgrG2 gene) was present in a virulent B. thailandensis strain BPM (BPM), but not in the relatively avirulent B. thailandensis strain E264 (E264). Meanwhile, transcriptome analysis of BPM and E264 showed that the vgrG2 gene was strongly expressed in BPM, but not in E264. Therefore, we identified the function of the vgrG2 gene by constructing the mutant and complemented strains in this study. In vitro, the vgrG2 gene was observed to be involved in the interactions with host cells. The animal model experiment showed that the deletion of vgrG2 gene significantly led to the decrease in the lethality of BPM and impaired its ability to trigger host immune response. In conclusion, our study provides a new perspective for studying the pathogenicity of B. thailandensis and lays the foundation for discovering the potential T6SS effectors.
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Affiliation(s)
- Jin Li
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Wei-Wei Hu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guo-Xin Qu
- Department of Orthopedic Surgery, The First Affiliated Hospital of Hainan Medical University, Hainan, China
| | - Xiao-Rong Li
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Yi Xiang
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Peng Jiang
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Jiang-Qiao Luo
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Wen-Huan He
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Yu-Jia Jin
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Qiong Shi
- M.O.E. Key Laboratory of Laboratory Medicine Diagnostics, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
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