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Eating the Enemy: Mycoplasma Strategies to Evade Neutrophil Extracellular Traps (NETs) Promoting Bacterial Nucleotides Uptake and Inflammatory Damage. Int J Mol Sci 2022; 23:ijms232315030. [PMID: 36499356 PMCID: PMC9740415 DOI: 10.3390/ijms232315030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Neutrophils are effector cells involved in the innate immune response against infection; they kill infectious agents in the intracellular compartment (phagocytosis) or in the extracellular milieu (degranulation). Moreover, neutrophils release neutrophil extracellular traps (NETs), complex structures composed of a scaffold of decondensed DNA associated with histones and antimicrobial compounds; NETs entrap infectious agents, preventing their spread and promoting their clearance. NET formation is triggered by microbial compounds, but many microorganisms have evolved several strategies for NET evasion. In addition, the dysregulated production of NETs is associated with chronic inflammatory diseases. Mycoplasmas are reduced genome bacteria, able to induce chronic infections with recurrent inflammatory symptoms. Mycoplasmas' parasitic lifestyle relies on metabolite uptake from the host. Mycoplasmas induce NET release, but their surface or secreted nucleases digest the NETs' DNA scaffold, allowing them to escape from entrapment and providing essential nucleotide precursors, thus promoting the infection. The presence of Mycoplasma species has been associated with chronic inflammatory disorders, such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, Crohn's disease, and cancer. The persistence of mycoplasma infection and prolonged NET release may contribute to the onset of chronic inflammatory diseases and needs further investigation and insights.
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2
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Fisunov GY, Pobeguts OV, Ladygina VG, Zubov AI, Galyamina MA, Kovalchuk SI, Ziganshin RK, Evsyutina DV, Matyushkina DS, Butenko IO, Bukato ON, Veselovsky VA, Semashko TA, Klimina KM, Levina GA, Barhatova OI, Rakovskaya IV. Thymidine utilisation pathway is a novel phenotypic switch of Mycoplasma hominis. J Med Microbiol 2022; 71. [PMID: 35037614 PMCID: PMC8895549 DOI: 10.1099/jmm.0.001468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Introduction. Mycoplasma hominis is a bacterium belonging to the class Mollicutes. It causes acute and chronic infections of the urogenital tract. The main features of this bacterium are an absence of cell wall and a reduced genome size (517-622 protein-encoding genes). Previously, we have isolated morphologically unknown M. hominis colonies called micro-colonies (MCs) from the serum of patients with inflammatory urogenital tract infection.Hypothesis. MCs are functionally different from the typical colonies (TCs) in terms of metabolism and cell division.Aim. To determine the physiological differences between MCs and TCs of M. hominis and elucidate the pathways of formation and growth of MCs by a comparative proteomic analysis of these two morphological forms.Methodology. LC-MS proteomic analysis of TCs and MCs using an Ultimate 3000 RSLC nanoHPLC system connected to a QExactive Plus mass spectrometer.Results. The study of the proteomic profiles of M. hominis colonies allowed us to reconstruct their energy metabolism pathways. In addition to the already known pentose phosphate and arginine deamination pathways, M. hominis can utilise ribose phosphate and deoxyribose phosphate formed by nucleoside catabolism as energy sources. Comparative proteomic HPLC-MS analysis revealed that the proteomic profiles of TCs and MCs were different. We assume that MC cells preferably utilised deoxyribonucleosides, particularly thymidine, as an energy source rather than arginine or ribonucleosides. Utilisation of deoxyribonucleosides is less efficient as compared with that of ribonucleosides and arginine in terms of energy production. Thymidine phosphorylase DeoA is one of the key enzymes of deoxyribonucleosides utilisation. We obtained a DeoA overexpressing mutant that exhibited a phenotype similar to that of MCs, which confirmed our hypothesis.Conclusion. In addition to the two known pathways for energy production (arginine deamination and the pentose phosphate pathway) M. hominis can use deoxyribonucleosides and ribonucleosides. MC cells demonstrate a reorganisation of energy metabolism: unlike TC cells, they preferably utilise deoxyribonucleosides, particularly thymidine, as an energy source rather than arginine or ribonucleosides. Thus MC cells enter a state of energy starvation, which helps them to survive under stress, and in particular, to be resistant to antibiotics.
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Affiliation(s)
- Gleb Yu Fisunov
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Olga V Pobeguts
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Valentina G Ladygina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Alexandr I Zubov
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Mariya A Galyamina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Sergey I Kovalchuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Rustam K Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Daria V Evsyutina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Daria S Matyushkina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Ivan O Butenko
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Olga N Bukato
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Vladimir A Veselovsky
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Tatiana A Semashko
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia
| | - Ksenia M Klimina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Centre of Physical-Chemical Medicine, Moscow, Russia.,Department of Biotechnology, Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia
| | - Galina A Levina
- Gamaleya National Research Center of Epidemiology and Microbiology, Moscow, Russia
| | - Olga I Barhatova
- Gamaleya National Research Center of Epidemiology and Microbiology, Moscow, Russia
| | - Irina V Rakovskaya
- Gamaleya National Research Center of Epidemiology and Microbiology, Moscow, Russia
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3
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Henrich B, Hammerlage S, Scharf S, Haberhausen D, Fürnkranz U, Köhrer K, Peitzmann L, Fiori PL, Spergser J, Pfeffer K, Dilthey AT. Characterisation of mobile genetic elements in Mycoplasma hominis with the description of ICEHo-II, a variant mycoplasma integrative and conjugative element. Mob DNA 2020; 11:30. [PMID: 33292499 PMCID: PMC7648426 DOI: 10.1186/s13100-020-00225-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/22/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Mobile genetic elements are found in genomes throughout the microbial world, mediating genome plasticity and important prokaryotic phenotypes. Even the cell wall-less mycoplasmas, which are known to harbour a minimal set of genes, seem to accumulate mobile genetic elements. In Mycoplasma hominis, a facultative pathogen of the human urogenital tract and an inherently very heterogeneous species, four different MGE-classes had been detected until now: insertion sequence ISMhom-1, prophage MHoV-1, a tetracycline resistance mediating transposon, and ICEHo, a species-specific variant of a mycoplasma integrative and conjugative element encoding a T4SS secretion system (termed MICE). RESULTS To characterize the prevalence of these MGEs, genomes of 23 M. hominis isolates were assembled using whole genome sequencing and bioinformatically analysed for the presence of mobile genetic elements. In addition to the previously described MGEs, a new ICEHo variant was found, which we designate ICEHo-II. Of 15 ICEHo-II genes, five are common MICE genes; eight are unique to ICEHo-II; and two represent a duplication of a gene also present in ICEHo-I. In 150 M. hominis isolates and based on a screening PCR, prevalence of ICEHo-I was 40.7%; of ICEHo-II, 28.7%; and of both elements, 15.3%. Activity of ICEHo-I and -II was demonstrated by detection of circularized extrachromosomal forms of the elements through PCR and subsequent Sanger sequencing. CONCLUSIONS Nanopore sequencing enabled the identification of mobile genetic elements and of ICEHo-II, a novel MICE element of M. hominis, whose phenotypic impact and potential impact on pathogenicity can now be elucidated.
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Affiliation(s)
- Birgit Henrich
- Institute of Med. Microbiology and Hospital Hygiene of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany.
| | - Stephanie Hammerlage
- Institute of Med. Microbiology and Hospital Hygiene of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Sebastian Scharf
- Institute of Med. Microbiology and Hospital Hygiene of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany.,Department of Haematology, Oncology and Clinical Immunology, Medical Faculty, University of Duesseldorf, Duesseldorf, Germany
| | - Diana Haberhausen
- Institute of Med. Microbiology and Hospital Hygiene of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Ursula Fürnkranz
- Institute for Specific Prophylaxis and Tropical Medicine, Centre for Pathophysiology, Immunology and Infectiology, Medical University of Vienna, Vienna, Austria
| | - Karl Köhrer
- Biological and Medical Research Centre (BMFZ) of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Lena Peitzmann
- Biological and Medical Research Centre (BMFZ) of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Pier Luigi Fiori
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Joachim Spergser
- Institute of Microbiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Klaus Pfeffer
- Institute of Med. Microbiology and Hospital Hygiene of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Alexander T Dilthey
- Institute of Med. Microbiology and Hospital Hygiene of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany.,Institute of Medical Statistics and Computational Biology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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4
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Cacciotto C, Dessì D, Cubeddu T, Cocco AR, Pisano A, Tore G, Fiori PL, Rappelli P, Pittau M, Alberti A. MHO_0730 as a Surface-Exposed Calcium-Dependent Nuclease of Mycoplasma hominis Promoting Neutrophil Extracellular Trap Formation and Escape. J Infect Dis 2020; 220:1999-2008. [PMID: 31420650 DOI: 10.1093/infdis/jiz406] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 08/08/2019] [Indexed: 12/22/2022] Open
Abstract
Mycoplasma lipoproteins play a relevant role in pathogenicity and directly interact with the host immune system. Among human mycoplasmas, Mycoplasma hominis is described as a commensal bacterium that can be associated with a number of genital and extragenital conditions. Mechanisms of M. hominis pathogenicity are still largely obscure, and only a limited number of proteins have been associated with virulence. The current study focused on investigating the role of MHO_0730 as a virulence factor and demonstrated that MHO_0730 is a surface lipoprotein, potentially expressed in vivo during natural infection, acting both as a nuclease with its amino acidic portion and as a potent inducer of Neutrophil extracellular trapsosis with its N-terminal lipid moiety. Evidence for M. hominis neutrophil extracellular trap escape is also presented. Results highlight the relevance of MHO_0730 in promoting infection and modulation and evasion of innate immunity and provide additional knowledge on M. hominis virulence and survival in the host.
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Affiliation(s)
- Carla Cacciotto
- Department of Veterinary Medicine, University of Sassari, Italy
| | - Daniele Dessì
- Department of Biomedical Sciences, University of Sassari, Italy.,Mediterranean Center for Disease Control, University of Sassari, Italy
| | - Tiziana Cubeddu
- Department of Veterinary Medicine, University of Sassari, Italy
| | - Anna Rita Cocco
- Department of Biomedical Sciences, University of Sassari, Italy
| | - Andrea Pisano
- Department of Veterinary Medicine, University of Sassari, Italy
| | - Gessica Tore
- Department of Veterinary Medicine, University of Sassari, Italy
| | - Pier Luigi Fiori
- Department of Biomedical Sciences, University of Sassari, Italy.,Mediterranean Center for Disease Control, University of Sassari, Italy
| | - Paola Rappelli
- Department of Biomedical Sciences, University of Sassari, Italy.,Mediterranean Center for Disease Control, University of Sassari, Italy
| | - Marco Pittau
- Department of Veterinary Medicine, University of Sassari, Italy.,Mediterranean Center for Disease Control, University of Sassari, Italy
| | - Alberto Alberti
- Department of Veterinary Medicine, University of Sassari, Italy.,Mediterranean Center for Disease Control, University of Sassari, Italy
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5
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Blötz C, Singh N, Dumke R, Stülke J. Characterization of an Immunoglobulin Binding Protein (IbpM) From Mycoplasma pneumoniae. Front Microbiol 2020; 11:685. [PMID: 32373096 PMCID: PMC7176901 DOI: 10.3389/fmicb.2020.00685] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 03/24/2020] [Indexed: 01/30/2023] Open
Abstract
Bacteria evolved many ways to invade, colonize and survive in the host tissue. Such complex infection strategies of other bacteria are not present in the cell-wall less Mycoplasmas. Due to their strongly reduced genomes, these bacteria have only a minimal metabolism. Mycoplasma pneumoniae is a pathogenic bacterium using its virulence repertoire very efficiently, infecting the human lung. M. pneumoniae can cause a variety of conditions including fever, inflammation, atypical pneumoniae, and even death. Due to its strongly reduced metabolism, M. pneumoniae is dependent on nutrients from the host and aims to persist as long as possible, resulting in chronic diseases. Mycoplasmas evolved strategies to subvert the host immune system which involve proteins fending off immunoglobulins (Igs). In this study, we investigated the role of MPN400 as the putative factor responsible for Ig-binding and host immune evasion. MPN400 is a cell-surface localized protein which binds strongly to human IgG, IgA, and IgM. We therefore named the protein MPN400 immunoglobulin binding protein of Mycoplasma (IbpM). A strain devoid of IbpM is slightly compromised in cytotoxicity. Taken together, our study indicates that M. pneumoniae uses a refined mechanism for immune evasion.
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Affiliation(s)
- Cedric Blötz
- Department of General Microbiology, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Neil Singh
- Department of General Microbiology, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Roger Dumke
- Medical Faculty Carl Gustav Carus, Institute of Medical Microbiology and Hygiene, Technical University Dresden, Dresden, Germany
| | - Jörg Stülke
- Department of General Microbiology, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
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6
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Rideau F, Le Roy C, Sagné E, Renaudin H, Pereyre S, Henrich B, Dordet-Frisoni E, Citti C, Lartigue C, Bébéar C. Random transposon insertion in the Mycoplasma hominis minimal genome. Sci Rep 2019; 9:13554. [PMID: 31537861 PMCID: PMC6753208 DOI: 10.1038/s41598-019-49919-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 08/30/2019] [Indexed: 11/09/2022] Open
Abstract
Mycoplasma hominis is an opportunistic human pathogen associated with genital and neonatal infections. Until this study, the lack of a reliable transformation method for the genetic manipulation of M. hominis hindered the investigation of the pathogenicity and the peculiar arginine-based metabolism of this bacterium. A genomic analysis of 20 different M. hominis strains revealed a number of putative restriction-modification systems in this species. Despite the presence of these systems, a reproducible polyethylene glycol (PEG)-mediated transformation protocol was successfully developed in this study for three different strains: two clinical isolates and the M132 reference strain. Transformants were generated by transposon mutagenesis with an efficiency of approximately 10-9 transformants/cell/µg plasmid and were shown to carry single or multiple mini-transposons randomly inserted within their genomes. One M132-mutant was observed to carry a single-copy transposon inserted within the gene encoding P75, a protein potentially involved in adhesion. However, no difference in adhesion was observed in cell-assays between this mutant and the M132 parent strain. Whole genome sequencing of mutants carrying multiple copies of the transposon further revealed the occurrence of genomic rearrangements. Overall, this is the first time that genetically modified strains of M. hominis have been obtained by random mutagenesis using a mini-transposon conferring resistance to tetracycline.
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Affiliation(s)
- Fabien Rideau
- University of Bordeaux, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France.,INRA, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France
| | - Chloé Le Roy
- University of Bordeaux, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France.,INRA, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France
| | - Eveline Sagné
- IHAP, Université de Toulouse, INRA, ENVT, Toulouse, France
| | - Hélène Renaudin
- University of Bordeaux, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France.,INRA, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France
| | - Sabine Pereyre
- University of Bordeaux, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France.,INRA, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France
| | - Birgit Henrich
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich Heine University, Düsseldorf, Germany
| | | | | | - Carole Lartigue
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, Gironde, France. .,University of Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, F-33140 Villenave d'Ornon, Gironde, France.
| | - Cécile Bébéar
- University of Bordeaux, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France. .,INRA, USC-EA3671 Mycoplasmal and Chlamydial Infections in Humans, Bordeaux, France.
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7
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Christodoulides A, Gupta N, Yacoubian V, Maithel N, Parker J, Kelesidis T. The Role of Lipoproteins in Mycoplasma-Mediated Immunomodulation. Front Microbiol 2018; 9:1682. [PMID: 30108558 PMCID: PMC6080569 DOI: 10.3389/fmicb.2018.01682] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 07/05/2018] [Indexed: 01/16/2023] Open
Abstract
Mycoplasma infections, such as walking pneumonia or pelvic inflammatory diseases, are a major threat to public health. Despite their relatively small physical and genomic size, mycoplasmas are known to elicit strong host immune responses, generally inflammatory, while also being able to evade the immune system. The mycoplasma membrane is composed of approximately two-thirds protein and one-third lipid and contains several lipoproteins that are known to regulate host immune responses. Herein, the immunomodulatory effects of mycoplasma lipoproteins are reviewed. A better understanding of the immunomodulatory effects, both activating and evasive, of Mycoplasma surface lipoproteins will contribute to understanding mechanisms potentially relevant to mycoplasma disease vaccine development and treatment.
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Affiliation(s)
- Alexei Christodoulides
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Neha Gupta
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Vahe Yacoubian
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Neil Maithel
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jordan Parker
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Theodoros Kelesidis
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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8
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Henrich B, Kretzmer F, Deenen R, Köhrer K. Validation of a novel Mho microarray for a comprehensive characterisation of the Mycoplasma hominis action in HeLa cell infection. PLoS One 2017; 12:e0181383. [PMID: 28753664 PMCID: PMC5533444 DOI: 10.1371/journal.pone.0181383] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/29/2017] [Indexed: 12/30/2022] Open
Abstract
Mycoplasma hominis is the second smallest facultative pathogen of the human urogenital tract. With less than 600 protein-encoding genes, it represents an ideal model organism for the study of host-pathogen interactions. For a comprehensive characterisation of the M. hominis action in infection a customized Mho microarray, which was based on two genome sequences (PG21 and LBD-4), was designed to analyze the dynamics of the mycoplasma transcriptome during infection and validated for M. hominis strain FBG. RNA preparation was evaluated and adapted to ensure the highest recovery of mycoplasmal mRNAs from in vitro HeLa cell infection assays. Following cRNA hybridization, the read-out strategy of the hybridization results was optimized and confirmed by RT-PCR. A statistically robust infection assay with M. hominis strain FBG enabled the identification of differentially regulated key effector molecules such as critical cytoadhesins (4 h post infection (pI)), invasins (48 h pI) and proteins associated with establishing chronic infection of the host (336 h pI). Of the 294 differentially regulated genes (>2-fold) 128 (43.5%) encoded hypothetical proteins, including lipoproteins that seem to play a central role as virulence factors at each stage of infection: P75 as a novel cytoadhesin candidate, which is also differentially upregulated in chronic infection; the MHO_2100 protein, a postulated invasin and the MHO_730-protein, a novel ecto-nuclease and domain of an ABC transporter, the function of which in chronic infection has still to be elucidated. Implementation of the M. hominis microarray strategy led to a comprehensive identification of to date unknown candidates for virulence factors at relevant stages of host cell infection.
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Affiliation(s)
- Birgit Henrich
- Institute of Medical Microbiology and Hospital Hygiene, Medical Faculty of Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
- * E-mail:
| | - Freya Kretzmer
- Institute of Medical Microbiology and Hospital Hygiene, Medical Faculty of Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
- Biological and Medical Research Centre (BMFZ), Medical Faculty of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - René Deenen
- Biological and Medical Research Centre (BMFZ), Medical Faculty of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Karl Köhrer
- Biological and Medical Research Centre (BMFZ), Medical Faculty of the Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
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9
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Interaction of Mycoplasma hominis PG21 with Human Dendritic Cells: Interleukin-23-Inducing Mycoplasmal Lipoproteins and Inflammasome Activation of the Cell. J Bacteriol 2017; 199:JB.00213-17. [PMID: 28559291 DOI: 10.1128/jb.00213-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/18/2017] [Indexed: 11/20/2022] Open
Abstract
Mycoplasma hominis lacks a cell wall, and lipoproteins anchored to the extracellular side of the plasma membrane are in direct contact with the host components. A Triton X-114 extract of M. hominis enriched with lipoproteins was shown to stimulate the production of interleukin-23 (IL-23) by human dendritic cells (hDCs). The inflammasome activation of the host cell has never been reported upon M. hominis infection. We studied here the interaction between M. hominis PG21 and hDCs by analyzing both the inflammation-inducing mycoplasmal lipoproteins and the inflammasome activation of the host cell. IL-23-inducing lipoproteins were determined using a sequential extraction strategy with two nondenaturing detergents, Sarkosyl and Triton X-114, followed by SDS-PAGE separation and mass spectrometry identification. The activation of the hDC inflammasome was assessed using PCR array and enzyme-linked immunosorbent assay (ELISA). We defined a list of 24 lipoproteins that could induce the secretion of IL-23 by hDCs, 5 with a molecular mass between 20 and 35 kDa and 19 with a molecular mass between 40 and 100 kDa. Among them, lipoprotein MHO_4720 was identified as potentially bioactive, and a synthetic lipopeptide corresponding to the N-terminal part of the lipoprotein was subsequently shown to induce IL-23 release by hDCs. Regarding the hDC innate immune response, inflammasome activation with caspase-dependent production of IL-1β was observed. After 24 h of coincubation of hDCs with M. hominis, downregulation of the NLRP3-encoding gene and of the adaptor PYCARD-encoding gene was noticed. Overall, this study provides insight into both protagonists of the interaction of M. hominis and hDCs.IMPORTANCEMycoplasma hominis is a human urogenital pathogen involved in gynecologic and opportunistic infections. M. hominis lacks a cell wall, and its membrane contains many lipoproteins that are anchored to the extracellular side of the plasma membrane. In the present study, we focused on the interaction between M. hominis and human dendritic cells and examined both sides of the interaction, the mycoplasmal lipoproteins involved in the activation of the host cell and the immune response of the cell. On the mycoplasmal side, we showed for the first time that M. hominis lipoproteins with high molecular mass were potentially bioactive. On the cell side, we reported an activation of the inflammasome, which is involved in the innate immune response.
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10
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Dubrana MP, Guéguéniat J, Bertin C, Duret S, Arricau-Bouvery N, Claverol S, Lartigue C, Blanchard A, Renaudin J, Béven L. Proteolytic Post-Translational Processing of Adhesins in a Pathogenic Bacterium. J Mol Biol 2017; 429:1889-1902. [PMID: 28501585 DOI: 10.1016/j.jmb.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/25/2017] [Accepted: 05/04/2017] [Indexed: 11/29/2022]
Abstract
Mollicutes, including mycoplasmas and spiroplasmas, have been considered as good representatives of the « minimal cell » concept: these wall-less bacteria are small in size and possess a minimal genome and restricted metabolic capacities. However, the recent discovery of the presence of post-translational modifications unknown so far, such as the targeted processing of membrane proteins of mycoplasma pathogens for human and swine, revealed a part of the hidden complexity of these microorganisms. In this study, we show that in the phytopathogen, insect-vectored Spiroplasma citri GII-3 adhesion-related protein (ScARP) adhesins are post-translationally processed through an ATP-dependent targeted cleavage. The cleavage efficiency could be enhanced in vitro when decreasing the extracellular pH or upon the addition of polyclonal antibodies directed against ScARP repeated units, suggesting that modification of the surface charge and/or ScARP conformational changes could initiate the cleavage. The two major sites for primary cleavage are localized within predicted disordered regions and do not fit any previously reported cleavage motif; in addition, the inhibition profile and the metal ion requirements indicate that this post-translational modification involves at least one non-conventional protease. Such a proteolytic process may play a role in S. citri colonization of cells of the host insect. Furthermore, our work indicates that post-translational cleavage of adhesins represents a common feature to mollicutes colonizing distinct hosts and that processing of surface antigens could represent a way to make the most out of a minimal genome.
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Affiliation(s)
| | - Julia Guéguéniat
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Clothilde Bertin
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Sybille Duret
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | | | | | - Carole Lartigue
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Alain Blanchard
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Joël Renaudin
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Laure Béven
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France.
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