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Abril AG, Calo-Mata P, Böhme K, Villa TG, Barros-Velázquez J, Sánchez-Pérez Á, Pazos M, Carrera M. Shotgun proteomic analyses of Pseudomonas species isolated from fish products. Food Chem 2024; 450:139342. [PMID: 38631198 DOI: 10.1016/j.foodchem.2024.139342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 03/25/2024] [Accepted: 04/09/2024] [Indexed: 04/19/2024]
Abstract
Numerous Pseudomonas species can infect aquatic animals, such as farmed rainbow trout, sea trout, sea bass, and sea bream, by causing disease or stress reactions. In aquaculture facilities, a number of Pseudomonas species have been isolated and identified as the main pathogens. The present study describes the characterization of 18 Pseudomonas strains, isolated from fish products using shotgun proteomics. The bacterial proteomes obtained were further analyzed to identify the main functional pathway proteins involved. In addition, this study revealed the presence of 1015 non-redundant peptides related to virulence factors. An additional 25 species-specific peptides were identified as putative Pseudomonas spp. biomarkers. The results constitute the largest dataset, described thus far for the rapid identification and characterization of Pseudomonas species present in edible fish; furthermore, these data can provide the basis for further research into the development of new therapies against these harmful pathogens.
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Affiliation(s)
- Ana G Abril
- Department of Food Technology, Marine Research Institute (IIM-CSIC), Spanish National Research Council (CSIC), 36208 Vigo, Spain; Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain.
| | - Pilar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain.
| | - Karola Böhme
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Tomás G Villa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
| | - Jorge Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain.
| | - Ángeles Sánchez-Pérez
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, NSW 2006, Australia
| | - Manuel Pazos
- Department of Food Technology, Marine Research Institute (IIM-CSIC), Spanish National Research Council (CSIC), 36208 Vigo, Spain.
| | - Mónica Carrera
- Department of Food Technology, Marine Research Institute (IIM-CSIC), Spanish National Research Council (CSIC), 36208 Vigo, Spain.
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2
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Abril AG, Calo-Mata P, Villa TG, Böhme K, Barros-Velázquez J, Sánchez-Pérez Á, Pazos M, Carrera M. Comprehensive shotgun proteomic characterization and virulence factors of seafood spoilage bacteria. Food Chem 2024; 448:139045. [PMID: 38537549 DOI: 10.1016/j.foodchem.2024.139045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/01/2024] [Accepted: 03/13/2024] [Indexed: 04/24/2024]
Abstract
This article summarizes the characterization, by shotgun proteomics, of 11 bacterial strains identified as responsible for seafood spoilage. A total of 4455 peptide spectrum matches, corresponding to 4299 peptides and 3817 proteins were identified. Analyses of data determined the functional pathways they are involved in. The proteins identified were integrated into a protein-protein network that involves 371 nodes and 3016 edges. Those proteins are implicated in energy pathways, peptidoglycan biosynthesis, spermidine/putrescine metabolism. An additional 773 peptides were characterized as virulence factors, that participates in bacterial pathogenesis; while 14 peptides were defined as biomarkers, as they can be used to differentiate the bacterial species present. This report represents the most extensive proteomic repository available in the field of seafood spoilage bacteria; the data substantially advances the understanding of seafood decay, as well as provides fundamental bases for the recognition of the bacteria existent in seafood that cause spoilage during food processing/storage.
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Affiliation(s)
- Ana G Abril
- Institute of Marine Research (IIM-CSIC), Department of Food Technology, Spanish National Research Council (CSIC), 36208 Vigo, Spain; Faculty of Pharmacy, University of Santiago de Compostela, Department of Microbiology and Parasitology, 15898 Santiago de Compostela, Spain.
| | - Pilar Calo-Mata
- School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, 27002 Lugo, Spain.
| | - Tomás G Villa
- Faculty of Pharmacy, University of Santiago de Compostela, Department of Microbiology and Parasitology, 15898 Santiago de Compostela, Spain.
| | - Karola Böhme
- School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, 27002 Lugo, Spain.
| | - Jorge Barros-Velázquez
- School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, 27002 Lugo, Spain.
| | - Ángeles Sánchez-Pérez
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, NSW 2006, Australia.
| | - Manuel Pazos
- Institute of Marine Research (IIM-CSIC), Department of Food Technology, Spanish National Research Council (CSIC), 36208 Vigo, Spain.
| | - Mónica Carrera
- Institute of Marine Research (IIM-CSIC), Department of Food Technology, Spanish National Research Council (CSIC), 36208 Vigo, Spain.
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3
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Guallar-Garrido S, Soldati T. Exploring host-pathogen interactions in the Dictyostelium discoideum-Mycobacterium marinum infection model of tuberculosis. Dis Model Mech 2024; 17:dmm050698. [PMID: 39037280 DOI: 10.1242/dmm.050698] [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] [Indexed: 07/23/2024] Open
Abstract
Mycobacterium tuberculosis is a pathogenic mycobacterium that causes tuberculosis. Tuberculosis is a significant global health concern that poses numerous clinical challenges, particularly in terms of finding effective treatments for patients. Throughout evolution, host immune cells have developed cell-autonomous defence strategies to restrain and eliminate mycobacteria. Concurrently, mycobacteria have evolved an array of virulence factors to counteract these host defences, resulting in a dynamic interaction between host and pathogen. Here, we review recent findings, including those arising from the use of the amoeba Dictyostelium discoideum as a model to investigate key mycobacterial infection pathways. D. discoideum serves as a scalable and genetically tractable model for human phagocytes, providing valuable insights into the intricate mechanisms of host-pathogen interactions. We also highlight certain similarities between M. tuberculosis and Mycobacterium marinum, and the use of M. marinum to more safely investigate mycobacteria in D. discoideum.
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Affiliation(s)
- Sandra Guallar-Garrido
- Department of Biochemistry, Faculty of Science, University of Geneva, 30 quai Ernest-Ansermet, Science II, 1211 Geneva-4, Switzerland
| | - Thierry Soldati
- Department of Biochemistry, Faculty of Science, University of Geneva, 30 quai Ernest-Ansermet, Science II, 1211 Geneva-4, Switzerland
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4
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Maier FI, Klinger D, Grieshober M, Noschka R, Rodriguez A, Wiese S, Forssmann WG, Ständker L, Stenger S. Lysozyme: an endogenous antimicrobial protein with potent activity against extracellular, but not intracellular Mycobacterium tuberculosis. Med Microbiol Immunol 2024; 213:9. [PMID: 38900248 PMCID: PMC11189972 DOI: 10.1007/s00430-024-00793-0] [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: 02/07/2024] [Accepted: 06/05/2024] [Indexed: 06/21/2024]
Abstract
Endogenous antimicrobial peptides (AMPs) play a key role in the host defense against pathogens. AMPs attack pathogens preferentially at the site of entry to prevent invasive infection. Mycobacterium tuberculosis (Mtb) enters its host via the airways. AMPs released into the airways are therefore likely candidates to contribute to the clearance of Mtb immediately after infection. Since lysozyme is detectable in airway secretions, we evaluated its antimicrobial activity against Mtb. We demonstrate that lysozyme inhibits the growth of extracellular Mtb, including isoniazid-resistant strains. Lysozyme also inhibited the growth of non-tuberculous mycobacteria. Even though lysozyme entered Mtb-infected human macrophages and co-localized with the pathogen we did not observe antimicrobial activity. This observation was unlikely related to the large size of lysozyme (14.74 kDa) because a smaller lysozyme-derived peptide also co-localized with Mtb without affecting the viability. To evaluate whether the activity of lysozyme against extracellular Mtb could be relevant in vivo, we incubated Mtb with fractions of human serum and screened for antimicrobial activity. After several rounds of sub-fractionation, we identified a highly active fraction-component as lysozyme by mass spectrometry. In summary, our results identify lysozyme as an antimycobacterial protein that is detectable as an active compound in human serum. Our results demonstrate that the activity of AMPs against extracellular bacilli does not predict efficacy against intracellular pathogens despite co-localization within the macrophage. Ongoing experiments are designed to unravel peptide modifications that occur in the intracellular space and interfere with the deleterious activity of lysozyme in the extracellular environment.
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Affiliation(s)
- Felix Immanuel Maier
- Institute of Medical Microbiology and Infection and Hygiene, Ulm University, Ulm, Germany
| | - David Klinger
- Institute of Medical Microbiology and Infection and Hygiene, Ulm University, Ulm, Germany
| | - Mark Grieshober
- Institute of Medical Microbiology and Infection and Hygiene, Ulm University, Ulm, Germany
| | - Reiner Noschka
- Institute of Medical Microbiology and Infection and Hygiene, Ulm University, Ulm, Germany
| | - Armando Rodriguez
- Core Facility of Functional Peptidomics, Ulm University, Meyerhoferstraße 4, 89081, Ulm, Germany
- Core Unit Mass Spectrometry and Proteomics, Ulm University, Albert Einstein Allee 23, 89081, Ulm, Germany
| | - Sebastian Wiese
- Core Unit Mass Spectrometry and Proteomics, Ulm University, Albert Einstein Allee 23, 89081, Ulm, Germany
| | | | - Ludger Ständker
- Core Facility of Functional Peptidomics, Ulm University, Meyerhoferstraße 4, 89081, Ulm, Germany
| | - Steffen Stenger
- Institute of Medical Microbiology and Infection and Hygiene, Ulm University, Ulm, Germany.
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5
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Rahlwes KC, Dias BR, Campos PC, Alvarez-Arguedas S, Shiloh MU. Pathogenicity and virulence of Mycobacterium tuberculosis. Virulence 2023; 14:2150449. [PMID: 36419223 PMCID: PMC9817126 DOI: 10.1080/21505594.2022.2150449] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, an infectious disease with one of the highest morbidity and mortality rates worldwide. Leveraging its highly evolved repertoire of non-protein and protein virulence factors, Mtb invades through the airway, subverts host immunity, establishes its survival niche, and ultimately escapes in the setting of active disease to initiate another round of infection in a naive host. In this review, we will provide a concise synopsis of the infectious life cycle of Mtb and its clinical and epidemiologic significance. We will also take stock of its virulence factors and pathogenic mechanisms that modulate host immunity and facilitate its spread. Developing a greater understanding of the interface between Mtb virulence factors and host defences will enable progress toward improved vaccines and therapeutics to prevent and treat tuberculosis.
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Affiliation(s)
- Kathryn C. Rahlwes
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Beatriz R.S. Dias
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Priscila C. Campos
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Samuel Alvarez-Arguedas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Michael U. Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA,CONTACT Michael U. Shiloh
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6
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Bigi MM, Forrellad MA, García JS, Blanco FC, Vázquez CL, Bigi F. An update on Mycobacterium tuberculosis lipoproteins. Future Microbiol 2023; 18:1381-1398. [PMID: 37962486 DOI: 10.2217/fmb-2023-0088] [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: 04/17/2023] [Accepted: 08/29/2023] [Indexed: 11/15/2023] Open
Abstract
Almost 3% of the proteins of Mycobacterium tuberculosis (M. tuberculosis), the main causative agent of human tuberculosis, are lipoproteins. These lipoproteins are characteristic of the mycobacterial cell envelope and participate in many mechanisms involved in the pathogenesis of M. tuberculosis. In this review, the authors provide an updated analysis of M. tuberculosis lipoproteins and categorize them according to their demonstrated or predicted functions, including transport of compounds to and from the cytoplasm, biosynthesis of the mycobacterial cell envelope, defense and resistance mechanisms, enzymatic activities and signaling pathways. In addition, this updated analysis revealed that at least 40% of M. tuberculosis lipoproteins are glycosylated.
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Affiliation(s)
- María M Bigi
- Instituto de Investigaciones Biomédicas, CONICET, Universidad de Buenos Aires, Paraguay 2155 (C1121ABG), Buenos Aires, Argentina
| | - Marina A Forrellad
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Argentina (INTA), N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
- Instituto de Agrobiotecnología y Biología Molecular, INTA-CONICET, N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
| | - Julia S García
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Argentina (INTA), N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
- Instituto de Agrobiotecnología y Biología Molecular, INTA-CONICET, N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
| | - Federico C Blanco
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Argentina (INTA), N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
- Instituto de Agrobiotecnología y Biología Molecular, INTA-CONICET, N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
| | - Cristina L Vázquez
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Argentina (INTA), N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
- Instituto de Agrobiotecnología y Biología Molecular, INTA-CONICET, N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
| | - Fabiana Bigi
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Argentina (INTA), N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
- Instituto de Agrobiotecnología y Biología Molecular, INTA-CONICET, N. Repetto & de los Reseros, Hurlingham (1686), Buenos Aires, Argentina
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7
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Allué-Guardia A, Garcia-Vilanova A, Schami AM, Olmo-Fontánez AM, Hicks A, Peters J, Maselli DJ, Wewers MD, Wang Y, Torrelles JB. Exposure of Mycobacterium tuberculosis to human alveolar lining fluid shows temporal and strain-specific adaptation to the lung environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559381. [PMID: 37808780 PMCID: PMC10557635 DOI: 10.1101/2023.09.27.559381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Upon infection, Mycobacterium tuberculosis ( M.tb ) reaches the alveolar space and comes in close contact with human alveolar lining fluid (ALF) for an uncertain period of time prior to its encounter with alveolar cells. We showed that homeostatic ALF hydrolytic enzymes modify the M.tb cell envelope, driving M.tb -host cell interactions. Still, the contribution of ALF during M.tb infection is poorly understood. Here, we exposed 4 M.tb strains with different levels of virulence, transmissibility, and drug resistance (DR) to physiological concentrations of human ALF for 15-min and 12-h, and performed RNA sequencing. Gene expression analysis showed a temporal and strain-specific adaptation to human ALF. Differential expression (DE) of ALF-exposed vs. unexposed M.tb revealed a total of 397 DE genes associated with lipid metabolism, cell envelope and processes, intermediary metabolism and respiration, and regulatory proteins, among others. Most DE genes were detected at 12-h post-ALF exposure, with DR- M.tb strain W-7642 having the highest number of DE genes. Interestingly, genes from the KstR2 regulon, which controls the degradation of cholesterol C and D rings, were significantly upregulated in all strains post-ALF exposure. These results indicate that M.tb -ALF contact drives initial metabolic and physiologic changes in M.tb , with potential implications in infection outcome. IMPORTANCE Tuberculosis, caused by airborne pathogen Mycobacterium tuberculosis ( M.tb ), is one of the leading causes of mortality worldwide. Upon infection, M.tb reaches the alveoli and gets in contact with human alveolar lining fluid (ALF), where ALF hydrolases modify the M.tb cell envelope driving subsequent M.tb -host cell interactions. Still, the contributions of ALF during infection are poorly understood. We exposed 4 M.tb strains to ALF for 15-min and 12-h and performed RNA sequencing, demonstrating a temporal and strain-specific adaptation of M.tb to ALF. Interestingly, genes associated with cholesterol degradation were highly upregulated in all strains. This study shows for the first time that ALF drives global metabolic changes in M.tb during the initial stages of the infection, with potential implications in disease outcome. Biologically relevant networks and common and strain-specific bacterial determinants derived from this study could be further investigated as potential therapeutic candidates.
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8
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Seshadri R, Roux S, Huber KJ, Wu D, Yu S, Udwary D, Call L, Nayfach S, Hahnke RL, Pukall R, White JR, Varghese NJ, Webb C, Palaniappan K, Reimer LC, Sardà J, Bertsch J, Mukherjee S, Reddy T, Hajek PP, Huntemann M, Chen IMA, Spunde A, Clum A, Shapiro N, Wu ZY, Zhao Z, Zhou Y, Evtushenko L, Thijs S, Stevens V, Eloe-Fadrosh EA, Mouncey NJ, Yoshikuni Y, Whitman WB, Klenk HP, Woyke T, Göker M, Kyrpides NC, Ivanova NN. Expanding the genomic encyclopedia of Actinobacteria with 824 isolate reference genomes. CELL GENOMICS 2022; 2:100213. [PMID: 36778052 PMCID: PMC9903846 DOI: 10.1016/j.xgen.2022.100213] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 07/19/2022] [Accepted: 10/16/2022] [Indexed: 11/13/2022]
Abstract
The phylum Actinobacteria includes important human pathogens like Mycobacterium tuberculosis and Corynebacterium diphtheriae and renowned producers of secondary metabolites of commercial interest, yet only a small part of its diversity is represented by sequenced genomes. Here, we present 824 actinobacterial isolate genomes in the context of a phylum-wide analysis of 6,700 genomes including public isolates and metagenome-assembled genomes (MAGs). We estimate that only 30%-50% of projected actinobacterial phylogenetic diversity possesses genomic representation via isolates and MAGs. A comparison of gene functions reveals novel determinants of host-microbe interaction as well as environment-specific adaptations such as potential antimicrobial peptides. We identify plasmids and prophages across isolates and uncover extensive prophage diversity structured mainly by host taxonomy. Analysis of >80,000 biosynthetic gene clusters reveals that horizontal gene transfer and gene loss shape secondary metabolite repertoire across taxa. Our observations illustrate the essential role of and need for high-quality isolate genome sequences.
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Affiliation(s)
- Rekha Seshadri
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Corresponding author
| | - Simon Roux
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Katharina J. Huber
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dongying Wu
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Sora Yu
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Dan Udwary
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Lee Call
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Stephen Nayfach
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Richard L. Hahnke
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Rüdiger Pukall
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | | | - Neha J. Varghese
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Cody Webb
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | | | - Lorenz C. Reimer
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Joaquim Sardà
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Jonathon Bertsch
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | | | - T.B.K. Reddy
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Patrick P. Hajek
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Marcel Huntemann
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - I-Min A. Chen
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Alex Spunde
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Alicia Clum
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Nicole Shapiro
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Zong-Yen Wu
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zhiying Zhao
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Yuguang Zhou
- China General Microbiological Culture Collection Center, Beijing, China
| | - Lyudmila Evtushenko
- Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, All-Russian Collection of Microorganisms (VKM), Pushchino, Russia
| | - Sofie Thijs
- Center for Environmental Sciences, Environmental Biology, Hasselt University, Diepenbeek, Belgium
| | - Vincent Stevens
- Center for Environmental Sciences, Environmental Biology, Hasselt University, Diepenbeek, Belgium
| | - Emiley A. Eloe-Fadrosh
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Nigel J. Mouncey
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA,Center for Advanced Bioenergy and Bioproducts Innovation, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA,Global Institution for Collaborative Research and Education, Hokkaido University, Hokkaido 060-8589, Japan
| | | | - Hans-Peter Klenk
- School of Biology, Newcastle University, Newcastle upon Tyne, UK
| | - Tanja Woyke
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Markus Göker
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany,Corresponding author
| | - Nikos C. Kyrpides
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Natalia N. Ivanova
- US Department of Energy Joint Genome Institute, Berkeley, CA, USA,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA,Corresponding author
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9
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Amaya FA, Blondel CJ, Barros-Infante MF, Rivera D, Moreno-Switt AI, Santiviago CA, Pezoa D. Identification of Type VI Secretion Systems Effector Proteins That Contribute to Interbacterial Competition in Salmonella Dublin. Front Microbiol 2022; 13:811932. [PMID: 35222335 PMCID: PMC8867033 DOI: 10.3389/fmicb.2022.811932] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/04/2022] [Indexed: 12/12/2022] Open
Abstract
The Type VI Secretion System (T6SS) is a multiprotein device that has emerged as an important fitness and virulence factor for many Gram-negative bacteria through the injection of effector proteins into prokaryotic or eukaryotic cells via a contractile mechanism. While some effector proteins specifically target bacterial or eukaryotic cells, others can target both types of cells (trans-kingdom effectors). In Salmonella, five T6SS gene clusters have been identified within pathogenicity islands SPI-6, SPI-19, SPI-20, SPI-21, and SPI-22, which are differentially distributed among serotypes. Salmonella enterica serotype Dublin (S. Dublin) is a cattle-adapted pathogen that harbors both T6SSSPI-6 and T6SSSPI-19. Interestingly, while both systems have been linked to virulence and host colonization in S. Dublin, an antibacterial activity has not been detected for T6SSSPI-6 in this serotype. In addition, there is limited information regarding the repertoire of effector proteins encoded within T6SSSPI-6 and T6SSSPI-19 gene clusters in S. Dublin. In the present study, we demonstrate that T6SSSPI-6 and T6SSSPI-19 of S. Dublin CT_02021853 contribute to interbacterial competition. Bioinformatic and comparative genomic analyses allowed us to identify genes encoding three candidate antibacterial effectors located within SPI-6 and two candidate effectors located within SPI-19. Each antibacterial effector gene is located upstream of a gene encoding a hypothetic immunity protein, thus conforming an effector/immunity (E/I) module. Of note, the genes encoding these effectors and immunity proteins are widely distributed in Salmonella genomes, suggesting a relevant role in interbacterial competition and virulence. Finally, we demonstrate that E/I modules SED_RS01930/SED_RS01935 (encoded in SPI-6), SED_RS06235/SED_RS06230, and SED_RS06335/SED_RS06340 (both encoded in SPI-19) contribute to interbacterial competition in S. Dublin CT_02021853.
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Affiliation(s)
- Fernando A. Amaya
- Laboratorio de Microbiología, Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Carlos J. Blondel
- Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | | | - Dácil Rivera
- Escuela de Medicina Veterinaria, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Andrea I. Moreno-Switt
- Escuela de Medicina Veterinaria, Facultad de Agronomía e Ingeniería Forestal, Facultad de Ciencias Biológicas y Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Initiative on Collaborative Research on Bacterial Resistance (MICROB-R), Santiago, Chile
| | - Carlos A. Santiviago
- Laboratorio de Microbiología, Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
- *Correspondence: Carlos A. Santiviago, David Pezoa,
| | - David Pezoa
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
- *Correspondence: Carlos A. Santiviago, David Pezoa,
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10
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Artuso I, Lucidi M, Visaggio D, Capecchi G, Lugli GA, Ventura M, Visca P. Genome diversity of domesticated Acinetobacter baumannii ATCC 19606 T strains. Microb Genom 2022; 8. [PMID: 35084299 PMCID: PMC8914354 DOI: 10.1099/mgen.0.000749] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Acinetobacter baumannii has emerged as an important opportunistic pathogen worldwide, being responsible for large outbreaks for nosocomial infections, primarily in intensive care units. A. baumannii ATCC 19606T is the species type strain, and a reference organism in many laboratories due to its low virulence, amenability to genetic manipulation and extensive antibiotic susceptibility. We wondered if frequent propagation of A. baumannii ATCC 19606T in different laboratories may have driven micro- and macro-evolutionary events that could determine inter-laboratory differences of genome-based data. By combining Illumina MiSeq, MinION and Sanger technologies, we generated a high-quality whole-genome sequence of A. baumannii ATCC 19606T, then performed a comparative genome analysis between A. baumannii ATCC 19606T strains from several research laboratories and a reference collection. Differences between publicly available ATCC 19606T genome sequences were observed, including SNPs, macro- and micro-deletions, and the uneven presence of a 52 kb prophage belonging to genus Vieuvirus. Two plasmids, pMAC and p1ATCC19606, were invariably detected in all tested strains. The presence of a putative replicase, a replication origin containing four 22-mer direct repeats, and a toxin-antitoxin system implicated in plasmid stability were predicted by in silico analysis of p1ATCC19606, and experimentally confirmed. This work refines the sequence, structure and functional annotation of the A. baumannii ATCC 19606T genome, and highlights some remarkable differences between domesticated strains, likely resulting from genetic drift.
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Affiliation(s)
- Irene Artuso
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Massimiliano Lucidi
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Daniela Visaggio
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy.,Santa Lucia Fundation IRCCS, Via Ardeatina 306-354, 00179 Rome, Italy
| | - Giulia Capecchi
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy
| | - Gabriele Andrea Lugli
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11a, 43124 Parma, Italy
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11a, 43124 Parma, Italy
| | - Paolo Visca
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy.,Santa Lucia Fundation IRCCS, Via Ardeatina 306-354, 00179 Rome, Italy
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11
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Deshpande NP, Riordan SM, Gorman CJ, Nielsen S, Russell TL, Correa-Ospina C, Fernando BSM, Waters SA, Castaño-Rodríguez N, Man SM, Tedla N, Wilkins MR, Kaakoush NO. Multi-omics of the esophageal microenvironment identifies signatures associated with progression of Barrett's esophagus. Genome Med 2021; 13:133. [PMID: 34412659 PMCID: PMC8375061 DOI: 10.1186/s13073-021-00951-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 08/11/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The enrichment of Gram-negative bacteria of oral origin in the esophageal microbiome has been associated with the development of metaplasia. However, to date, no study has comprehensively assessed the relationships between the esophageal microbiome and the host. METHODS Here, we examine the esophageal microenvironment in gastro-esophageal reflux disease and metaplasia using multi-omics strategies targeting the microbiome and host transcriptome, followed by targeted culture, comparative genomics, and host-microbial interaction studies of bacterial signatures of interest. RESULTS Profiling of the host transcriptome from esophageal mucosal biopsies revealed profound changes during metaplasia. Importantly, five biomarkers showed consistent longitudinal changes with disease progression from reflux disease to metaplasia. We showed for the first time that the esophageal microbiome is distinct from the salivary microbiome and the enrichment of Campylobacter species as a consistent signature in disease across two independent cohorts. Shape fitting and matrix correlation identified associations between the microbiome and host transcriptome profiles, with a novel co-exclusion relationship found between Campylobacter and napsin B aspartic peptidase. Targeted culture of Campylobacter species from the same cohort revealed a subset of isolates to have a higher capacity to survive within primary human macrophages. Comparative genomic analyses showed these isolates could be differentiated by specific genomic features, one of which was validated to be associated with intracellular fitness. Screening for these Campylobacter strain-specific signatures in shotgun metagenomics data from another cohort showed an increase in prevalence with disease progression. Comparative transcriptomic analyses of primary esophageal epithelial cells exposed to the Campylobacter isolates revealed expression changes within those infected with strains with high intracellular fitness that could explain the increased likelihood of disease progression. CONCLUSIONS We provide a comprehensive assessment of the esophageal microenvironment, identifying bacterial strain-specific signatures with high relevance to progression of metaplasia.
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Affiliation(s)
- Nandan P Deshpande
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Stephen M Riordan
- Gastrointestinal and Liver Unit, The Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - Claire J Gorman
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Shaun Nielsen
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Tonia L Russell
- Ramaciotti Centre for Genomics, UNSW Sydney, Sydney, NSW, 2052, Australia
| | | | - Bentotage S M Fernando
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Shafagh A Waters
- School of Women's and Children's Health, UNSW Sydney, Sydney, NSW, 2052, Australia
| | | | - Si Ming Man
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, 2601, Australia
| | - Nicodemus Tedla
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
- Ramaciotti Centre for Genomics, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Nadeem O Kaakoush
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2052, Australia.
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12
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Sengupta S, Nayak B, Meuli M, Sander P, Mishra S, Sonawane A. Mycobacterium tuberculosis Phosphoribosyltransferase Promotes Bacterial Survival in Macrophages by Inducing Histone Hypermethylation in Autophagy-Related Genes. Front Cell Infect Microbiol 2021; 11:676456. [PMID: 34381738 PMCID: PMC8350138 DOI: 10.3389/fcimb.2021.676456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) inhibits autophagy to promote its survival in host cells. However, the molecular mechanisms by which Mtb inhibits autophagy are poorly understood. Here, we report a previously unknown mechanism in which Mtb phosphoribosyltransferase (MtbPRT) inhibits autophagy in an mTOR, negative regulator of autophagy, independent manner by inducing histone hypermethylation (H3K9me2/3) at the Atg5 and Atg7 promoters by activating p38-MAPK- and EHMT2 methyltransferase-dependent signaling pathways. Additionally, we find that MtbPRT induces EZH2 methyltransferase-dependent H3K27me3 hypermethylation and reduces histone acetylation modifications (H3K9ac and H3K27ac) by upregulating histone deacetylase 3 to inhibit autophagy. In summary, this is the first demonstration that Mtb inhibits autophagy by inducing histone hypermethylation in autophagy-related genes to promote intracellular bacterial survival.
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Affiliation(s)
- Srabasti Sengupta
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar, India
| | - Barsa Nayak
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Michael Meuli
- Institut für Medizinische Mikrobiologie, Universität Zürich, Zurich, Switzerland
| | - Peter Sander
- Institut für Medizinische Mikrobiologie, Universität Zürich, Zurich, Switzerland
- Nationales Zentrum für Mykobakterien, Zürich, Switzerland
| | - Snehasish Mishra
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar, India
| | - Avinash Sonawane
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
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13
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Exploration of synergistic action of cell wall-degrading enzymes against Mycobacterium tuberculosis. Antimicrob Agents Chemother 2021; 65:e0065921. [PMID: 34280017 DOI: 10.1128/aac.00659-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background The major global health threat tuberculosis is caused by Mycobacterium tuberculosis (Mtb). Mtb has a complex cell envelope - a partially covalently linked composite of polysaccharides, peptidoglycan and lipids, including a mycolic acid layer - which conveys pathogenicity but also protects against antibiotics. Given previous successes in treating gram-positive and -negative infections with cell wall degrading enzymes, we investigated such approach for Mtb. Objectives (i) Development of an Mtb microtiter growth inhibition assay that allows undisturbed cell envelope formation, to overcome the invalidation of results by typical clumped Mtb-growth in surfactant-free assays. (ii) Exploring anti-Mtb potency of cell wall layer-degrading enzymes. (iii) Investigation of the concerted action of several such enzymes. Methods We inserted a bacterial luciferase-operon in an auxotrophic Mtb strain to develop a microtiter assay that allows proper evaluation of cell wall degrading anti-Mtb enzymes. We assessed growth-inhibition by enzymes (recombinant mycobacteriophage mycolic acid esterase (LysB), fungal α-amylase and human and chicken egg white lysozymes) and combinations thereof, in presence or absence of biopharmaceutically acceptable surfactant. Results Our biosafety level-2 assay identified both LysB and lysozymes as potent Mtb-inhibitors, but only in presence of surfactant. Moreover, most potent disruption of the mycolic acid hydrophobic barrier was obtained by the highly synergistic combination of LysB, α-amylase and polysorbate 80. Conclusions Synergistically acting cell wall degrading enzymes are potently inhibiting Mtb - which sets the scene for the design of specifically tailored antimycobacterial (fusion) enzymes. Airway delivery of protein therapeutics has already been established and should be studied in animal models for active TB.
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14
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McConnell MJ, Martín-Galiano AJ. Designing Multi-Antigen Vaccines Against Acinetobacter baumannii Using Systemic Approaches. Front Immunol 2021; 12:666742. [PMID: 33936107 PMCID: PMC8085427 DOI: 10.3389/fimmu.2021.666742] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Vaccines and monoclonal antibodies are promising approaches for preventing and treating infections caused by multidrug resistant Acinetobacter baumannii. However, only partial protection has been achieved with many previously tested protein antigens, which suggests that vaccines incorporating multiple antigens may be necessary in order to obtain high levels of protection. Several aspects that use the wealth of omic data available for A. baumannii have not been fully exploited for antigen identification. In this study, the use of fractionated proteomic and computational data from ~4,200 genomes increased the number of proteins potentially accessible to the humoral response to 8,824 non-redundant proteins in the A. baumannii panproteome. Among them, 59% carried predicted B-cell epitopes and T-cell epitopes recognized by two or more alleles of the HLA class II DP supertype. Potential cross-reactivity with human proteins was detected for 8.9% of antigens at the protein level and 2.7% at the B-cell epitope level. Individual antigens were associated with different infection types by genomic, transcriptomic or functional analyses. High intra-clonal genome density permitted the identification of international clone II as a “vaccitype”, in which 20% of identified antigens were specific to this clone. Network-based centrality measurements were used to identify multiple immunologic nodes. Data were formatted, unified and stored in a data warehouse database, which was subsequently used to identify synergistic antigen combinations for different vaccination strategies. This study supports the idea that integration of multi-omic data and fundamental knowledge of the pathobiology of drug-resistant bacteria can facilitate the development of effective multi-antigen vaccines against these challenging infections.
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Affiliation(s)
- Michael J McConnell
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
| | - Antonio J Martín-Galiano
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
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15
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Cestero JJ, Castanheira S, Pucciarelli MG, García-Del Portillo F. A Novel Salmonella Periplasmic Protein Controlling Cell Wall Homeostasis and Virulence. Front Microbiol 2021; 12:633701. [PMID: 33679664 PMCID: PMC7933661 DOI: 10.3389/fmicb.2021.633701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Horizontal gene transfer has shaped the evolution of Salmonella enterica as pathogen. Some functions acquired by this mechanism include enzymes involved in peptidoglycan (PG) synthesis and remodeling. Here, we report a novel serovar Typhimurium protein that is absent in non-pathogenic bacteria and bears a LprI functional domain, first reported in a Mycobacterium tuberculosis lipoprotein conferring lysozyme resistance. Based on the presence of such domain, we hypothesized a role of this S. Typhimurium protein in PG metabolism. This protein, which we named ScwA for Salmonellacell wall-related regulator-A, controls positively the levels of the murein lytic transglycosylase MltD. In addition, the levels of other enzymes that cleave bonds in the PG lattice were affected in a mutant lacking ScwA, including a soluble lytic tranglycosylase (Slt), the amidase AmiC, and a few endo- and carboxypeptidases (NlpC, PBP4, and AmpH). The scwA gene has lower G+C content than the genomic average (43.1 vs. 52.2%), supporting acquisition by horizontal transfer. ScwA is located in the periplasm, stabilized by two disulfide bridges, produced preferentially in stationary phase and down-regulated following entry of the pathogen into eukaryotic cells. ScwA deficiency, however, results in a hypervirulent phenotype in the murine typhoid model. Based on these findings, we conclude that ScwA may be exploited by S. Typhimurium to ensure cell envelope homeostasis along the infection and to prevent host overt damage. This role could be accomplished by controlling the production or stability of a reduced number of peptidoglycan hydrolases whose activities result in the release of PG fragments.
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Affiliation(s)
- Juan J Cestero
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Madrid, Spain
| | - Sónia Castanheira
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Madrid, Spain
| | - M Graciela Pucciarelli
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Madrid, Spain.,Department of Molecular Biology, Autonomous University of Madrid, Madrid, Spain.,Center for Molecular Biology "Severo Ochoa" (CBMSO)-CSIC, Madrid, Spain
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16
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Grishin AV, Karyagina AS, Vasina DV, Vasina IV, Gushchin VA, Lunin VG. Resistance to peptidoglycan-degrading enzymes. Crit Rev Microbiol 2020; 46:703-726. [PMID: 32985279 DOI: 10.1080/1040841x.2020.1825333] [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] [Indexed: 01/21/2023]
Abstract
The spread of bacterial strains resistant to commonly used antibiotics urges the development of novel antibacterial compounds. Ideally, these novel antimicrobials should be less prone to the development of resistance. Peptidoglycan-degrading enzymes are a promising class of compounds with a fundamentally different mode of action compared to traditionally used antibiotics. The difference in the mechanism of action implies differences both in the mechanisms of resistance and the chances of its emergence. To critically assess the potential of resistance development to peptidoglycan-degrading enzymes, we review the available evidence for the development of resistance to these enzymes in vitro, along with the known mechanisms of resistance to lysozyme, bacteriocins, autolysins, and phage endolysins. We conclude that genetic determinants of resistance to peptidoglycan-degrading enzymes are unlikely to readily emerge de novo. However, resistance to these enzymes would probably spread by the horizontal transfer between intrinsically resistant and susceptible species. Finally, we speculate that the higher cost of the therapeutics based on peptidoglycan degrading enzymes compared to classical antibiotics might result in less misuse, which in turn would lead to lower selective pressure, making these antibacterials less prone to resistance development.
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Affiliation(s)
- Alexander V Grishin
- N.F. Gamaleya National Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia.,All-Russia Research Institute of Agricultural Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Anna S Karyagina
- N.F. Gamaleya National Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia.,All-Russia Research Institute of Agricultural Biotechnology, Russian Academy of Sciences, Moscow, Russia.,A.N. Belozersky Institute of Physical and Chemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Daria V Vasina
- N.F. Gamaleya National Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia.,A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Irina V Vasina
- N.F. Gamaleya National Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - Vladimir A Gushchin
- N.F. Gamaleya National Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia.,Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir G Lunin
- N.F. Gamaleya National Research Center for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia.,All-Russia Research Institute of Agricultural Biotechnology, Russian Academy of Sciences, Moscow, Russia
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17
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Bickett TE, McLean J, Creissen E, Izzo L, Hagan C, Izzo AJ, Silva Angulo F, Izzo AA. Characterizing the BCG Induced Macrophage and Neutrophil Mechanisms for Defense Against Mycobacterium tuberculosis. Front Immunol 2020; 11:1202. [PMID: 32625209 PMCID: PMC7314953 DOI: 10.3389/fimmu.2020.01202] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 05/14/2020] [Indexed: 12/16/2022] Open
Abstract
The live attenuated Mycobacterium bovis strain, Bacille Calmette Guérin (BCG) is a potent innate immune stimulator. In the C57BL/6 mouse model of tuberculosis, BCG vaccination leads to a significant reduction of Mycobacterium tuberculosis burden after aerogenic infection. Our studies indicated that BCG induced protection against pulmonary tuberculosis was independent of T cells and present as early as 7 days after vaccination. This protection showed longevity, as it did not wane when conventional T cell and TNF-α deficient mice were infected 30 days post-vaccination. As BCG induced mycobacterial killing after 7 days, this study investigated the contributions of the innate immune system after BCG vaccination to better understand mechanisms required for mycobacterial killing. Subcutaneous BCG inoculation resulted in significant CD11b+F4/80+ monocyte subset recruitment into the lungs within 7 days. Further studies revealed that killing of mycobacteria was dependent on the viability of BCG, because irradiated BCG did not have the same effect. Although others have identified BCG as a facilitator of trained innate immunity, we found that BCG reduced the mycobacterial burden in the absence of mechanisms required for trained innate immunity, highlighting a role for macrophages and neutrophils for vaccine induced killing of M. tuberculosis.
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Affiliation(s)
- Thomas E Bickett
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Jennifer McLean
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Elizabeth Creissen
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Linda Izzo
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Cassidy Hagan
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Antonio J Izzo
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Fabiola Silva Angulo
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Angelo A Izzo
- Department of Microbiology Immunology and Pathology, Cell and Molecular Biology, Colorado State University, Fort Collins, CO, United States
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18
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Gene expression profiles during subclinical Mycobacterium avium subspecies paratuberculosis infection in sheep can predict disease outcome. Sci Rep 2019; 9:8245. [PMID: 31160677 PMCID: PMC6547741 DOI: 10.1038/s41598-019-44670-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 05/22/2019] [Indexed: 01/19/2023] Open
Abstract
Paratuberculosis in ruminants is caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP) however exposure does not predetermine progression to clinical disease. The pathogenesis incorporates a subclinical phase during which MAP is capable of evading host immune responses through adaptation of host cellular immune mechanisms. Presented are results of transcriptomic analysis of Merino sheep experimentally exposed to MAP and repeatedly sampled over the subclinical phase, identifying genes consistently changed over time in comparison to unexposed controls and associated with different disease outcomes. MAP exposed sheep were classified as diseased 45% (n = 9) or resilient 55% (n = 11). Significant gene expression changes were identified in the white blood cells of paucibacillary (n = 116), multibacillary (n = 98) and resilient cohorts (n = 53) compared to controls. Members of several gene families were differentially regulated, including S100 calcium binding, lysozyme function, MHC class I and class II, T cell receptor and transcription factors. The microarray findings were validated by qPCR. These differentially regulated genes are presented as putative biomarkers of MAP exposure, or of the specified disease or resilience outcomes. Further, in silico functional analysis of genes suggests that experimental MAP exposure in Merino sheep results in adaptations to cellular growth, proliferation and lipid metabolism.
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19
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Chen Y, Xiao JN, Li Y, Xiao YJ, Xiong YQ, Liu Y, Wang SJ, Ji P, Zhao GP, Shen H, Lu SH, Fan XY, Wang Y. Mycobacterial Lipoprotein Z Triggers Efficient Innate and Adaptive Immunity for Protection Against Mycobacterium tuberculosis Infection. Front Immunol 2019; 9:3190. [PMID: 30700988 PMCID: PMC6343430 DOI: 10.3389/fimmu.2018.03190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/31/2018] [Indexed: 12/28/2022] Open
Abstract
Mycobacterial lipoproteins are considered to be involved in both virulence and immunoregulatory processes during Mycobacterium tuberculosis (M.tb) infection. In our previous investigations on the immunoreactivity of more than 30 M.tb proteins in active TB patients, we identified mycobacterial lipoprotein Z (LppZ) as one of the most immune dominant antigens. How LppZ triggers immune responses is still unclear. In this study, we analyzed LppZ-mediated innate and adaptive immunity using a murine air pouch model and an M.tb infection model, respectively. We found that LppZ could not only recruit inflammatory cells but also induce the production of proinflammatory cytokines inside the pouches. LppZ could also induce strong Th1 responses following immunization and confer protection against challenge with M.tb virulent strain H37Rv at a similar level to BCG vaccination but with less pathological damage in the lungs. Furthermore, we revealed the presence of LppZ-specific functional CD4+ T cells in the lungs of the challenged mice that were capable of secreting double or triple cytokines, including IFN-γ, IL-2, and TNF-α. Our study thus demonstrates that LppZ is of strong immunogenicity during M.tb infection in both humans and mice and has the ability to trigger effective innate and cellular immunity. Considering the limitations of candidate antigens in the pipeline of TB vaccine development, LppZ-mediated immune protection against M.tb challenge in the mouse model implies its potential application in vaccine development.
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Affiliation(s)
- Yingying Chen
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Jia-Ni Xiao
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Yong Li
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Yang-Jiong Xiao
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Yan-Qing Xiong
- Key Laboratory of Medical Molecular Virology of MOE/MOH, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Ying Liu
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Shu-Jun Wang
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Ping Ji
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China
| | - Guo-Ping Zhao
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China
| | - Hao Shen
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China.,Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Shui-Hua Lu
- Key Laboratory of Medical Molecular Virology of MOE/MOH, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xiao-Yong Fan
- Key Laboratory of Medical Molecular Virology of MOE/MOH, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China.,TB Center, Shanghai Emerging and Re-emerging Infectious Disease Institute, Fudan University, Shanghai, China
| | - Ying Wang
- Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Immunology, Shanghai, China.,Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China
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20
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Heesterbeek DA, Bardoel BW, Parsons ES, Bennett I, Ruyken M, Doorduijn DJ, Gorham RD, Berends ET, Pyne AL, Hoogenboom BW, Rooijakkers SH. Bacterial killing by complement requires membrane attack complex formation via surface-bound C5 convertases. EMBO J 2019; 38:embj.201899852. [PMID: 30643019 PMCID: PMC6376327 DOI: 10.15252/embj.201899852] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 12/05/2018] [Accepted: 12/14/2018] [Indexed: 12/16/2022] Open
Abstract
The immune system kills bacteria by the formation of lytic membrane attack complexes (MACs), triggered when complement enzymes cleave C5. At present, it is not understood how the MAC perturbs the composite cell envelope of Gram-negative bacteria. Here, we show that the role of C5 convertase enzymes in MAC assembly extends beyond the cleavage of C5 into the MAC precursor C5b. Although purified MAC complexes generated from preassembled C5b6 perforate artificial lipid membranes and mammalian cells, these components lack bactericidal activity. In order to permeabilize both the bacterial outer and inner membrane and thus kill a bacterium, MACs need to be assembled locally by the C5 convertase enzymes. Our data indicate that C5b6 rapidly loses the capacity to form bactericidal pores; therefore, bacterial killing requires both in situ conversion of C5 and immediate insertion of C5b67 into the membrane. Using flow cytometry and atomic force microscopy, we show that local assembly of C5b6 at the bacterial surface is required for the efficient insertion of MAC pores into bacterial membranes. These studies provide basic molecular insights into MAC assembly and bacterial killing by the immune system.
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Affiliation(s)
- Dani Ac Heesterbeek
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Bart W Bardoel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Edward S Parsons
- London Centre for Nanotechnology, University College London, London, UK
| | - Isabel Bennett
- London Centre for Nanotechnology, University College London, London, UK
| | - Maartje Ruyken
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Dennis J Doorduijn
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Ronald D Gorham
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Evelien Tm Berends
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Alice Lb Pyne
- London Centre for Nanotechnology, University College London, London, UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London, UK.,Department of Physics and Astronomy, University College London, London, UK
| | - Suzan Hm Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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21
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Mycobacteria and their sweet proteins: An overview of protein glycosylation and lipoglycosylation in M. tuberculosis. Tuberculosis (Edinb) 2019; 115:1-13. [PMID: 30948163 DOI: 10.1016/j.tube.2019.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 12/16/2022]
Abstract
Post-translational modifications represent a key aspect of enzyme and protein regulation and function. Post-translational modifications are involved in signaling and response to stress, adaptation to changing environments, regulation of toxic and damaged proteins, proteins localization and host-pathogen interactions. Glycosylation in Mycobacterium tuberculosis (Mtb), is a post-translational modification often found in conjunction with acylation in mycobacterial proteins. Since the discovery of glycosylated proteins in the early 1980's, important advances in our understanding of the mechanisms of protein glycosylation have been made. The number of known glycosylated substrates in Mtb has grown through the years, yet many questions remain. This review will explore the current knowledge on protein glycosylation in Mtb, causative agent of Tuberculosis and number one infectious killer in the world. The mechanism and significance of this post-translational modification, as well as maturation, export and acylation of glycosylated proteins will be reviewed. We expect to provide the reader with an overall view of protein glycosylation in Mtb, as well as the significance of this post-translational modification to the physiology and host-pathogen interactions of this important pathogen. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD011081 and 10.6019/PXD011081.
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22
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El-Rami FE, Zielke RA, Wi T, Sikora AE, Unemo M. Quantitative Proteomics of the 2016 WHO Neisseria gonorrhoeae Reference Strains Surveys Vaccine Candidates and Antimicrobial Resistance Determinants. Mol Cell Proteomics 2019; 18:127-150. [PMID: 30352803 PMCID: PMC6317477 DOI: 10.1074/mcp.ra118.001125] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 10/23/2018] [Indexed: 12/27/2022] Open
Abstract
The sexually transmitted disease gonorrhea (causative agent: Neisseria gonorrhoeae) remains an urgent public health threat globally because of its reproductive health repercussions, high incidence, widespread antimicrobial resistance (AMR), and absence of a vaccine. To mine gonorrhea antigens and enhance our understanding of gonococcal AMR at the proteome level, we performed the first large-scale proteomic profiling of a diverse panel (n = 15) of gonococcal strains, including the 2016 World Health Organization (WHO) reference strains. These strains show all existing AMR profiles - established through phenotypic characterization and reference genome publication - and are intended for quality assurance in laboratory investigations. Herein, these isolates were subjected to subcellular fractionation and labeling with tandem mass tags coupled to mass spectrometry and multi-combinatorial bioinformatics. Our analyses detected 904 and 723 common proteins in cell envelope and cytoplasmic subproteomes, respectively. We identified nine novel gonorrhea vaccine candidates. Expression and conservation of new and previously selected antigens were investigated. In addition, established gonococcal AMR determinants were evaluated for the first time using quantitative proteomics. Six new proteins, WHO_F_00238, WHO_F_00635c, WHO_F_00745, WHO_F_01139, WHO_F_01144c, and WHO_F_01126, were differentially expressed in all strains, suggesting that they represent global proteomic AMR markers, indicate a predisposition toward developing or compensating gonococcal AMR, and/or act as new antimicrobial targets. Finally, phenotypic clustering based on the isolates' defined antibiograms and common differentially expressed proteins yielded seven matching clusters between established and proteome-derived AMR signatures. Together, our investigations provide a reference proteomics data bank for gonococcal vaccine and AMR research endeavors, which enables microbiological, clinical, or epidemiological projects and enhances the utility of the WHO reference strains.
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Affiliation(s)
- Fadi E El-Rami
- From the ‡Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon
| | - Ryszard A Zielke
- From the ‡Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon
| | - Teodora Wi
- §Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - Aleksandra E Sikora
- From the ‡Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon;; ¶Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon;.
| | - Magnus Unemo
- ‖World Health Organization Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections, Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
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23
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López V, Alberdi P, Fuente JDL. Common Strategies, Different Mechanisms to Infect the Host: Anaplasma and Mycobacterium. Tuberculosis (Edinb) 2018. [DOI: 10.5772/intechopen.71535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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SliC is a surface-displayed lipoprotein that is required for the anti-lysozyme strategy during Neisseria gonorrhoeae infection. PLoS Pathog 2018; 14:e1007081. [PMID: 29975784 PMCID: PMC6033465 DOI: 10.1371/journal.ppat.1007081] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/08/2018] [Indexed: 12/16/2022] Open
Abstract
Lysozymes are nearly omnipresent as the first line of immune defense against microbes in animals. They exert bactericidal action through antimicrobial peptide activity and peptidoglycan hydrolysis. Gram-negative bacteria developed several weapons to battle lysozymes, including inhibitors of c-type lysozymes in the MliC/PliC family and the Neisseria adhesin complex protein (ACP). Until the recent discovery of ACP, no proteinaceous lysozyme inhibitors were reported for the genus Neisseria, including the important human pathogen N. gonorrhoeae. Here, we describe a previously unrecognized gonococcal virulence mechanism involving a protein encoded by the open reading frame ngo1063 that acts to counteract c-type Iysozyme and provides a competitive advantage in the murine model of gonorrhea. We named this protein SliC as a surface-exposed lysozyme inhibitor of c-type lysozyme. SliC displays low overall primary sequence similarity to the MliC/PliC inhibitors, but we demonstrate that it has a parallel inhibitory mechanism. Our studies provide the first evidence that bacterial proteinaceous lysozyme inhibitors protect against host lysozyme during infection based on lack of attenuation of the ΔsliC mutant in lysozyme knock-out mice, and that the conserved residues involved in lysozyme inhibition, S83 and K103, are functionally indispensable during infection in wild type mice. Recombinant SliC completely abrogated the lytic activity of human and chicken c-type lysozymes, showing a preference towards human lysozyme with an IC50 of 1.85 μM and calculated KD value of 9.2 ± 1.9 μM. In contrast, mutated SliC bearing S83A and K103A substitutions failed to protect fluorescein-labeled cell-wall from lysozyme-mediated hydrolysis. Further, we present data revealing that SliC is a surface-displayed lipoprotein released in membrane vesicles that is expressed throughout all phases of growth, in conditions relevant to different niches of the human host, and during experimental infection of the murine genital tract. SliC is also highly conserved and expressed by diverse gonococcal isolates as well as N. meningitidis, N. lactamica, and N. weaveri. This study is the first to highlight the importance of an anti-lysozyme strategy to escape the innate immune response during N. gonorrhoeae infection. Neisseria gonorrhoeae, the etiologic agent of gonorrhea, is a clinically important pathogen due to the emergence of multi-drug resistance and the lack of a vaccine(s). During host colonization, pathogenic and commensal Neisseria inevitably encounter lysozyme, a major host innate defense factor that is abundantly present in epithelial secretions and phagocytic cells. Although Neisseria spp produce a c-type lysozyme inhibitor, the Adhesin Complex Protein, the significance of lysozyme inhibition for host colonization has not been addressed. Here we demonstrate the existence of a new c-type lysozyme inhibitor in Neisseria. We show that it is a surface-displayed lipoprotein in N. gonorrhoeae and, through its lysozyme-blocking function, plays a critical role in colonization of genital tract mucosae during infection in the female gonorrhea mouse model. We named the protein SliC as a surface-exposed lysozyme inhibitor of c-type lysozyme. Understanding the mechanisms underlying anti-lysozyme strategies may facilitate antimicrobial development.
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25
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Li F, Feng L, Jin C, Wu X, Fan L, Xiong S, Dong Y. LpqT improves mycobacteria survival in macrophages by inhibiting TLR2 mediated inflammatory cytokine expression and cell apoptosis. Tuberculosis (Edinb) 2018; 111:57-66. [PMID: 30029916 DOI: 10.1016/j.tube.2018.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/11/2018] [Accepted: 05/13/2018] [Indexed: 12/18/2022]
Abstract
Tuberculosis is a severe infectious disease caused by Mycobacterium tuberculosis (Mtb). LpqT is a lipoprotein of Mtb identified as a candidate virulence factor by a high-throughput screen searching for genes important for mycobacteria intracellular survival. To investigate its function, we constructed M. smegmatis strains deficient of LpqT or overexpressing LpqT. Wildtype or LpqT modified M. smegmatis strains were used to infect macrophages and mice, and intracellular survival of mycobacteria was measured. We found that LpqT can improve M. smegmatis survival in macrophage cell line, bone marrow derived macrophages (BMDMs), and murine lungs. This survival promoting effect is dependent on TLR2 and Myd88. Western blot analysis of M. smegmatis infected macrophages showed that LpqT suppressed M. smegmatis induced NF-κB and MAPK phosphorylation, indicating that LpqT hampered TLR2 signal activation. In consistent with this, LpqT inhibited M. smegmatis induced inflammatory cytokine expression and cell apoptosis in macrophages, thus supported mycobacteria intracellular survival.
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Affiliation(s)
- Fengge Li
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
| | - Lili Feng
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
| | - Chunyan Jin
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
| | - Xiaoyu Wu
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
| | - Lingbo Fan
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
| | - Sidong Xiong
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
| | - Yuanshu Dong
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, 199 Renai Road, SIP, Suzhou, Jiangsu, China.
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26
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Rodriguez DC, Ocampo M, Salazar LM, Patarroyo MA. Quantifying intracellular Mycobacterium tuberculosis: An essential issue for in vitro assays. Microbiologyopen 2018; 7:e00588. [PMID: 29484835 PMCID: PMC5911991 DOI: 10.1002/mbo3.588] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 12/21/2017] [Accepted: 12/28/2017] [Indexed: 12/12/2022] Open
Abstract
Many studies about intracellular microorganisms which are important regarding diseases affecting public health have been focused on the recognition of host–pathogen interactions, thereby ascertaining the mechanisms by which the pathogen invades a cell and makes it become its host. Such knowledge enables understanding the immunological response triggered by these interactions for obtaining useful information for developing vaccines and drugs. Quantitative cell infection assay protocols are indispensable regarding studies involving Mycobacterium tuberculosis, which takes the lives of more than 2 million people worldwide every year; however, sometimes these are limited by the pathogen's slow growth. Concerning such limitation, a detailed review is presented here regarding the different methods for quantifying and differentiating an intracellular pathogen, the importance of mycobacteria aggregate dissociation and multiplicity of infection (MOI) in infection assays. The methods’ differences, advantages, and disadvantages are discussed regarding intra and extracellular bacteria (on cell surface) differentiation, current problems are outlined, as are the solutions provided using fluorophores and projections made concerning quantitative infection assays.
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Affiliation(s)
- Deisy Carolina Rodriguez
- Universidad Nacional de Colombia, Bogotá, Colombia.,Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Marisol Ocampo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,Universidad del Rosario, Bogotá, Colombia
| | | | - Manuel Alfonso Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,Universidad del Rosario, Bogotá, Colombia
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27
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Zondervan NA, van Dam JCJ, Schaap PJ, Martins Dos Santos VAP, Suarez-Diez M. Regulation of Three Virulence Strategies of Mycobacterium tuberculosis: A Success Story. Int J Mol Sci 2018; 19:E347. [PMID: 29364195 PMCID: PMC5855569 DOI: 10.3390/ijms19020347] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 01/19/2018] [Accepted: 01/21/2018] [Indexed: 12/28/2022] Open
Abstract
Tuberculosis remains one of the deadliest diseases. Emergence of drug-resistant and multidrug-resistant M. tuberculosis strains makes treating tuberculosis increasingly challenging. In order to develop novel intervention strategies, detailed understanding of the molecular mechanisms behind the success of this pathogen is required. Here, we review recent literature to provide a systems level overview of the molecular and cellular components involved in divalent metal homeostasis and their role in regulating the three main virulence strategies of M. tuberculosis: immune modulation, dormancy and phagosomal rupture. We provide a visual and modular overview of these components and their regulation. Our analysis identified a single regulatory cascade for these three virulence strategies that respond to limited availability of divalent metals in the phagosome.
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Affiliation(s)
- Niels A Zondervan
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Jesse C J van Dam
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
- LifeGlimmer GmbH, Markelstrasse 38, 12163 Berlin, Germany.
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
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28
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Becker K, Haldimann K, Selchow P, Reinau LM, Dal Molin M, Sander P. Lipoprotein Glycosylation by Protein- O-Mannosyltransferase (MAB_1122c) Contributes to Low Cell Envelope Permeability and Antibiotic Resistance of Mycobacterium abscessus. Front Microbiol 2017; 8:2123. [PMID: 29163413 PMCID: PMC5673659 DOI: 10.3389/fmicb.2017.02123] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 10/18/2017] [Indexed: 12/12/2022] Open
Abstract
Lipoproteins are important components of the mycobacterial cell envelope due to their function in cell wall homeostasis and bacterial virulence. They are post-translationally modified with lipid- and glycosyl-residues in various species and interference with acylation or glycosylation leads to reduced growth and attenuated virulence in Mycobacterium tuberculosis. Lipoproteins are also expressed in the emerging and highly drug resistant pathogen Mycobacterium abscessus which frequently affects the lungs of patients with chronic pulmonary disease or cystic fibrosis. We investigated post-translational modification, acylation and glycosylation, of heterologously expressed (M. tuberculosis LppX and Mpt83) and endogenous (SodC) lipoproteins at the molecular level in M. abscessus and identified MAB_1122c as protein O-mannosyltransferase (Pmt). Both, heterologous and endogenous lipoproteins carried a characteristic lipid anchor with palmitic acid (C16), palmitoleic acid (C16:1), oleic acid (C18), or tuberculostearic acid (C19) modifications. Multiple hexose-moieties were detected in the N-terminal region of the model lipoproteins expressed in M. abscessus. Conservation of lipoprotein glycosylation in M. tuberculosis and M. abscessus was revealed and points toward the existence of an O-glycosylation motif or other regulatory mechanisms regarding this post-translational modification. Deletion of MAB_1122c prevented glycosylation and affected susceptibility to specific antibiotics which are large or target peptidoglycan synthesis and to lysozyme. Cell envelope permeability of M. abscessus Δpmt was increased and mutant bacteria showed reduced survival inside macrophages. The results provide a link between post-translational modification of lipoproteins and the permeability of the mycobacterial cell envelope which stresses the importance of lipoproteins as components of this complex structure.
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Affiliation(s)
- Katja Becker
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Klara Haldimann
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Petra Selchow
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Lukas M Reinau
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Michael Dal Molin
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Peter Sander
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland.,National Center for Mycobacteria, Zürich, Switzerland
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29
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Uribe-Querol E, Rosales C. Control of Phagocytosis by Microbial Pathogens. Front Immunol 2017; 8:1368. [PMID: 29114249 PMCID: PMC5660709 DOI: 10.3389/fimmu.2017.01368] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 10/05/2017] [Indexed: 12/17/2022] Open
Abstract
Phagocytosis is a fundamental process of cells to capture and ingest foreign particles. Small unicellular organisms such as free-living amoeba use this process to acquire food. In pluricellular organisms, phagocytosis is a universal phenomenon that all cells are able to perform (including epithelial, endothelial, fibroblasts, etc.), but some specialized cells (such as neutrophils and macrophages) perform this very efficiently and were therefore named professional phagocytes by Rabinovitch. Cells use phagocytosis to capture and clear all particles larger than 0.5 µm, including pathogenic microorganisms and cellular debris. Phagocytosis involves a series of steps from recognition of the target particle, ingestion of it in a phagosome (phagocytic vacuole), maturation of this phagosome into a phagolysosome, to the final destruction of the ingested particle in the robust antimicrobial environment of the phagolysosome. For the most part, phagocytosis is an efficient process that eliminates invading pathogens and helps maintaining homeostasis. However, several pathogens have also evolved different strategies to prevent phagocytosis from proceeding in a normal way. These pathogens have a clear advantage to perpetuate the infection and continue their replication. Here, we present an overview of the phagocytic process with emphasis on the antimicrobial elements professional phagocytes use. We also summarize the current knowledge on the microbial strategies different pathogens use to prevent phagocytosis either at the level of ingestion, phagosome formation, and maturation, and even complete escape from phagosomes.
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Affiliation(s)
- Eileen Uribe-Querol
- División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Carlos Rosales
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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30
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Humbert MV, Awanye AM, Lian LY, Derrick JP, Christodoulides M. Structure of the Neisseria Adhesin Complex Protein (ACP) and its role as a novel lysozyme inhibitor. PLoS Pathog 2017; 13:e1006448. [PMID: 28662181 PMCID: PMC5507604 DOI: 10.1371/journal.ppat.1006448] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 07/12/2017] [Accepted: 06/06/2017] [Indexed: 12/12/2022] Open
Abstract
Pathogenic and commensal Neisseria species produce an Adhesin Complex Protein, which was first characterised in Neisseria meningitidis (Nm) as a novel surface-exposed adhesin with vaccine potential. In the current study, the crystal structure of a recombinant (r)Nm-ACP Type I protein was determined to 1.4 Å resolution: the fold resembles an eight-stranded β-barrel, stabilized by a disulphide bond between the first (Cys38) and last (Cys121) β-strands. There are few main-chain hydrogen bonds linking β4-β5 and β8-β1, so the structure divides into two four-stranded anti-parallel β-sheets (β1-β4 and β5-β8). The computed surface electrostatic charge distribution showed that the β1-β4 sheet face is predominantly basic, whereas the β5-β8 sheet is apolar, apart from the loop between β4 and β5. Concentrations of rNm-ACP and rNeisseria gonorrhoeae-ACP proteins ≥0.25 μg/ml significantly inhibited by ~80–100% (P<0.05) the in vitro activity of human lysozyme (HL) over 24 h. Specificity was demonstrated by the ability of murine anti-Neisseria ACP sera to block ACP inhibition and restore HL activity. ACP expression conferred tolerance to HL activity, as demonstrated by significant 3–9 fold reductions (P<0.05) in the growth of meningococcal and gonococcal acp gene knock-out mutants in the presence of lysozyme. In addition, wild-type Neisseria lactamica treated with purified ACP-specific rabbit IgG antibodies showed similar fold reductions in bacterial growth, compared with untreated bacteria (P<0.05). Nm-ACPI is structurally similar to the MliC/PliC protein family of lysozyme inhibitors. However, Neisseria ACP proteins show <20% primary sequence similarity with these inhibitors and do not share any conserved MliC/PliC sequence motifs associated with lysozyme recognition. These observations suggest that Neisseria ACP adopts a different mode of lysozyme inhibition and that the ability of ACP to inhibit lysozyme activity could be important for host colonization by both pathogenic and commensal Neisseria organisms. Thus, ACP represents a dual target for developing Neisseria vaccines and drugs to inhibit host-pathogen interactions. The genus Neisseria contains two major human pathogens: N. meningitidis (Nm) causes meningitis and sepsis, and N. gonorrhoeae (Ng) causes the sexually transmitted disease gonorrhoea. In addition, the genus contains a larger number of commensal organisms, including N. lactamica (Nl). Common to all of these organisms is the ability to colonize exposed mucosal epithelia. Recently, we identified a novel surface-exposed adhesin in Neisseria spp., the Adhesin Complex Protein (ACP), which was capable also of generating a functional bactericidal antibody response in mice. In the current study, we have determined the crystal structure of a recombinant (r)Nm-ACP and shown that it shares structural homology to bacterial lysozyme inhibitors. We demonstrate that Neisseria ACP functions as an inhibitor of mammalian lysozyme but the mechanism appears to be different from other bacterial family lysozyme inhibitors. Expression of ACP enables Neisseria spp. to tolerate human lysozyme. We propose that ACP-mediated inhibition of lysozyme activity could be important for host colonization by both pathogenic and commensal Neisseria organisms and that ACP represents not only a target for developing Neisseria vaccines but also drugs to inhibit host-pathogen interactions.
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Affiliation(s)
- María Victoria Humbert
- Neisseria Research, Molecular Microbiology, Academic Unit of Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, University of Southampton Faculty of Medicine, Southampton, United Kingdom
| | - Amaka Marian Awanye
- Faculty of Biology, Medicine and Health, University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
| | - Lu-Yun Lian
- NMR Centre for Structural Biology, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Jeremy P. Derrick
- Faculty of Biology, Medicine and Health, University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
| | - Myron Christodoulides
- Neisseria Research, Molecular Microbiology, Academic Unit of Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, University of Southampton Faculty of Medicine, Southampton, United Kingdom
- * E-mail:
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31
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Sengupta S, Naz S, Das I, Ahad A, Padhi A, Naik SK, Ganguli G, Pattanaik KP, Raghav SK, Nandicoori VK, Sonawane A. Mycobacterium tuberculosis EsxL inhibits MHC-II expression by promoting hypermethylation in class-II transactivator loci in macrophages. J Biol Chem 2017; 292:6855-6868. [PMID: 28209712 DOI: 10.1074/jbc.m117.775205] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 02/13/2017] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis is known to modulate the host immune responses to facilitate its persistence inside the host cells. One of the key mechanisms includes repression of class-II transactivator (CIITA) and MHC-II expression in infected macrophages. However, the precise mechanism of CIITA and MHC-II down-regulation is not well studied. M. tuberculosis 6-kDa early secretory antigenic target (ESAT-6) is a known potent virulence and antigenic determinant. The M. tuberculosis genome encodes 23 such ESAT-6 family proteins. We herein report that M. tuberculosis and M. bovis bacillus Calmette-Guérin infection down-regulated the expression of CIITA/MHC-II by inducing hypermethylation in histone H3 lysine 9 (H3K9me2/3). Further, we showed that M. tuberculosis ESAT-6 family protein EsxL, encoded by Rv1198, is responsible for the down-regulation of CIITA/MHC-II by inducing H3K9me2/3. We further report that M. tuberculosis esxL induced the expression of nitric-oxide synthase, NO production, and p38 MAPK pathway, which in turn was responsible for the increased H3K9me2/3 in CIITA via up-regulation of euchromatic histone-lysine N-methyltransferase 2 (G9a). In contrast, inhibition of nitric-oxide synthase, p38 MAPK, and G9a abrogated H3K9me2/3, resulting in increased CIITA expression. A chromatin immunoprecipitation assay confirmed that hypermethylation at the promoter IV region of CIITA is mainly responsible for CIITA down-regulation and subsequent antigen presentation. We found that co-culture of macrophages infected with esxL-expressing M. smegmatis and mouse splenocytes led to down-regulation of IL-2, a key cytokine involved in T-cell proliferation. In summary, we demonstrate that M. tuberculosis EsxL inhibits antigen presentation by enhancing H3K9me2/3 at the CIITA promoter, thereby repressing its expression through NO and p38 MAPK activation.
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Affiliation(s)
- Srabasti Sengupta
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India
| | - Saba Naz
- the National Institute of Immunology, New Delhi, Delhi 110067, India, and
| | - Ishani Das
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India
| | - Abdul Ahad
- the Institute of Life Science, Nalco Square, Bhubaneswar, Orissa 751023, India
| | - Avinash Padhi
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India
| | - Sumanta Kumar Naik
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India
| | - Geetanjali Ganguli
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India
| | - Kali Prasad Pattanaik
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India
| | - Sunil Kumar Raghav
- the Institute of Life Science, Nalco Square, Bhubaneswar, Orissa 751023, India
| | | | - Avinash Sonawane
- From the School of Biotechnology, KIIT University, Bhubaneswar, Orissa 751024, India,
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Szewczyk J, Collet JF. The Journey of Lipoproteins Through the Cell: One Birthplace, Multiple Destinations. Adv Microb Physiol 2016; 69:1-50. [PMID: 27720009 DOI: 10.1016/bs.ampbs.2016.07.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Bacterial lipoproteins are a very diverse group of proteins characterized by the presence of an N-terminal lipid moiety that serves as a membrane anchor. Lipoproteins have a wide variety of crucial functions, ranging from envelope biogenesis to stress response. In Gram-negative bacteria, lipoproteins can be targeted to various destinations in the cell, including the periplasmic side of the cytoplasmic or outer membrane, the cell surface or the external milieu. The sorting mechanisms have been studied in detail in Escherichia coli, but exceptions to the rules established in this model bacterium exist in other bacteria. In this chapter, we will present the current knowledge on lipoprotein sorting in the cell. Our particular focus will be on the surface-exposed lipoproteins that appear to be much more common than previously assumed. We will discuss the different targeting strategies, provide numerous examples of surface-exposed lipoproteins and discuss the techniques used to assess their surface exposure.
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Affiliation(s)
- J Szewczyk
- WELBIO, Brussels, Belgium; de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - J-F Collet
- WELBIO, Brussels, Belgium; de Duve Institute, Université catholique de Louvain, Brussels, Belgium.
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Becker K, Sander P. Mycobacterium tuberculosis lipoproteins in virulence and immunity - fighting with a double-edged sword. FEBS Lett 2016; 590:3800-3819. [PMID: 27350117 DOI: 10.1002/1873-3468.12273] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/06/2016] [Accepted: 06/26/2016] [Indexed: 02/06/2023]
Abstract
Bacterial lipoproteins are secreted membrane-anchored proteins characterized by a lipobox motif. This lipobox motif directs post-translational modifications at the conserved cysteine through the consecutive action of three enzymes: Lgt, LspA and Lnt, which results in di- or triacylated forms. Lipoproteins are abundant in all bacteria including Mycobacterium tuberculosis and often involved in virulence and immunoregulatory processes. On the one hand, disruption of the biosynthesis pathway of lipoproteins leads to attenuation of M. tuberculosis in vivo, and mycobacteria deficient for certain lipoproteins have been assessed as attenuated live vaccine candidates. On the other hand, several mycobacterial lipoproteins form immunodominant antigens which promote an immune response. Some of these have been explored in DNA or subunit vaccination approaches against tuberculosis. The immune recognition of specific lipoproteins, however, might also benefit long-term survival of M. tuberculosis through immune modulation, while others induce protective responses. Exploiting lipoproteins as vaccines is thus a complex matter which requires deliberative investigation. The dual role of lipoproteins in the immunity to and pathogenicity of mycobacteria is discussed here.
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Affiliation(s)
- Katja Becker
- Institute of Medical Microbiology, University of Zurich, Switzerland
| | - Peter Sander
- Institute of Medical Microbiology, University of Zurich, Switzerland
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