1
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Habjan E, Lepioshkin A, Charitou V, Egorova A, Kazakova E, Ho VQT, Bitter W, Makarov V, Speer A. Modulating mycobacterial envelope integrity for antibiotic synergy with benzothiazoles. Life Sci Alliance 2024; 7:e202302509. [PMID: 38744470 PMCID: PMC11094368 DOI: 10.26508/lsa.202302509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/16/2024] Open
Abstract
Developing effective tuberculosis drugs is hindered by mycobacteria's intrinsic antibiotic resistance because of their impermeable cell envelope. Using benzothiazole compounds, we aimed to increase mycobacterial cell envelope permeability and weaken the defenses of Mycobacterium marinum, serving as a model for Mycobacterium tuberculosis Initial hit, BT-08, significantly boosted ethidium bromide uptake, indicating enhanced membrane permeability. It also demonstrated efficacy in the M. marinum-zebrafish embryo infection model and M. tuberculosis-infected macrophages. Notably, BT-08 synergized with established antibiotics, including vancomycin and rifampicin. Subsequent medicinal chemistry optimization led to BT-37, a non-toxic and more potent derivative, also enhancing ethidium bromide uptake and maintaining synergy with rifampicin in infected zebrafish embryos. Mutants of M. marinum resistant to BT-37 revealed that MMAR_0407 (Rv0164) is the molecular target and that this target plays a role in the observed synergy and permeability. This study introduces novel compounds targeting a new mycobacterial vulnerability and highlights their cooperative and synergistic interactions with existing antibiotics.
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Affiliation(s)
- Eva Habjan
- https://ror.org/00q6h8f30 Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, Location VU Medical Center, Amsterdam, Netherlands
| | - Alexander Lepioshkin
- Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences (Research Centre of Biotechnology RAS), Moscow, Russia
| | - Vicky Charitou
- https://ror.org/00q6h8f30 Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, Location VU Medical Center, Amsterdam, Netherlands
| | - Anna Egorova
- Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences (Research Centre of Biotechnology RAS), Moscow, Russia
| | - Elena Kazakova
- Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences (Research Centre of Biotechnology RAS), Moscow, Russia
| | - Vien QT Ho
- https://ror.org/00q6h8f30 Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, Location VU Medical Center, Amsterdam, Netherlands
| | - Wilbert Bitter
- https://ror.org/00q6h8f30 Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, Location VU Medical Center, Amsterdam, Netherlands
| | - Vadim Makarov
- Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences (Research Centre of Biotechnology RAS), Moscow, Russia
| | - Alexander Speer
- https://ror.org/00q6h8f30 Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, Location VU Medical Center, Amsterdam, Netherlands
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2
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Le Mouëllic W, Poquet Y, Neyrolles O. Dual-action compounds unleash a one-two punch against tuberculosis. Cell Chem Biol 2024; 31:627-629. [PMID: 38640900 DOI: 10.1016/j.chembiol.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/14/2024] [Accepted: 03/18/2024] [Indexed: 04/21/2024]
Abstract
In this issue of Cell Chemical Biology, Gries et al.1 employ an innovative screening approach to identify anti-tuberculosis compounds with dual modes of action: anti-virulence against the type VII secretion system ESX-1 and enhanced ethionamide efficacy. These compounds hold promise for developing multi-target tuberculosis drugs with potential clinical applications.
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Affiliation(s)
- Wendy Le Mouëllic
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yannick Poquet
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France.
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3
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Gries R, Chhen J, van Gumpel E, Theobald SJ, Sonnenkalb L, Utpatel C, Metzen F, Koch M, Dallenga T, Djaout K, Baulard A, Dal Molin M, Rybniker J. Discovery of dual-active ethionamide boosters inhibiting the Mycobacterium tuberculosis ESX-1 secretion system. Cell Chem Biol 2024; 31:699-711.e6. [PMID: 38181799 DOI: 10.1016/j.chembiol.2023.12.007] [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: 01/17/2023] [Revised: 08/22/2023] [Accepted: 12/08/2023] [Indexed: 01/07/2024]
Abstract
Drug-resistant Mycobacterium tuberculosis (Mtb) remains a major public health concern requiring complementary approaches to standard anti-tuberculous regimens. Anti-virulence molecules or compounds that enhance the activity of antimicrobial prodrugs are promising alternatives to conventional antibiotics. Exploiting host cell-based drug discovery, we identified an oxadiazole compound (S3) that blocks the ESX-1 secretion system, a major virulence factor of Mtb. S3-treated mycobacteria showed impaired intracellular growth and a reduced ability to lyse macrophages. RNA sequencing experiments of drug-exposed bacteria revealed strong upregulation of a distinct set of genes including ethA, encoding a monooxygenase activating the anti-tuberculous prodrug ethionamide. Accordingly, we found a strong ethionamide boosting effect in S3-treated Mtb. Extensive structure-activity relationship experiments revealed that anti-virulence and ethionamide-boosting activity can be uncoupled by chemical modification of the primary hit molecule. To conclude, this series of dual-active oxadiazole compounds targets Mtb via two distinct mechanisms of action.
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Affiliation(s)
- Raphael Gries
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50931 Cologne, Germany
| | - Jason Chhen
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Edeltraud van Gumpel
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Sebastian J Theobald
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Lindsay Sonnenkalb
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany; Molecular and Experimental Mycobacteriology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Christian Utpatel
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany; Molecular and Experimental Mycobacteriology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Fabian Metzen
- Institute for Dental Research and Oral Musculoskeletal Biology, Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Manuel Koch
- Institute for Dental Research and Oral Musculoskeletal Biology, Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Tobias Dallenga
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany; Cellular Microbiology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Kamel Djaout
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Alain Baulard
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Michael Dal Molin
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Jan Rybniker
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50931 Cologne, Germany.
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4
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Stupar M, Tan L, Kerr ED, De Voss CJ, Forde BM, Schulz BL, West NP. TcrXY is an acid-sensing two-component transcriptional regulator of Mycobacterium tuberculosis required for persistent infection. Nat Commun 2024; 15:1615. [PMID: 38388565 PMCID: PMC10883919 DOI: 10.1038/s41467-024-45343-7] [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: 05/08/2023] [Accepted: 01/22/2024] [Indexed: 02/24/2024] Open
Abstract
The ability of Mycobacterium tuberculosis (Mtb) to persist in the host complicates and prolongs tuberculosis (TB) patient chemotherapy. Here we demonstrate that a neglected two-component system (TCS) of Mtb, TcrXY, is an autoregulated acid-sensing TCS that controls a functionally diverse 70-gene regulon required for bacterial persistence. Characterisation of two representatives of this regulon, Rv3706c and Rv3705A, implicate these genes as key determinants for the survival of Mtb in vivo by serving as important effectors to mitigate redox stress at acidic pH. We show that genetic silencing of the response regulator tcrX using CRISPR interference attenuates the persistence of Mtb during chronic mouse infection and improves treatment with the two front-line anti-TB drugs, rifampicin and isoniazid. We propose that targeting TcrXY signal transduction blocks the ability of Mtb to sense and respond to acid stress, resulting in a disordered program of persistence to render the organism vulnerable to existing TB chemotherapy.
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Affiliation(s)
- Miljan Stupar
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia
| | - Edward D Kerr
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia
| | - Christopher J De Voss
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia
| | - Brian M Forde
- Faculty of Medicine, UQ Centre for Clinical Research, The University of Queensland, Brisbane, Australia
| | - Benjamin L Schulz
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia
| | - Nicholas P West
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia.
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5
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Yang J, Zhang L, Qiao W, Luo Y. Mycobacterium tuberculosis: Pathogenesis and therapeutic targets. MedComm (Beijing) 2023; 4:e353. [PMID: 37674971 PMCID: PMC10477518 DOI: 10.1002/mco2.353] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 07/31/2023] [Accepted: 08/03/2023] [Indexed: 09/08/2023] Open
Abstract
Tuberculosis (TB) remains a significant public health concern in the 21st century, especially due to drug resistance, coinfection with diseases like immunodeficiency syndrome (AIDS) and coronavirus disease 2019, and the lengthy and costly treatment protocols. In this review, we summarize the pathogenesis of TB infection, therapeutic targets, and corresponding modulators, including first-line medications, current clinical trial drugs and molecules in preclinical assessment. Understanding the mechanisms of Mycobacterium tuberculosis (Mtb) infection and important biological targets can lead to innovative treatments. While most antitubercular agents target pathogen-related processes, host-directed therapy (HDT) modalities addressing immune defense, survival mechanisms, and immunopathology also hold promise. Mtb's adaptation to the human host involves manipulating host cellular mechanisms, and HDT aims to disrupt this manipulation to enhance treatment effectiveness. Our review provides valuable insights for future anti-TB drug development efforts.
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Affiliation(s)
- Jiaxing Yang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Laiying Zhang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Wenliang Qiao
- Department of Thoracic Surgery, West China HospitalSichuan UniversityChengduSichuanChina
- Lung Cancer Center, West China HospitalSichuan UniversityChengduSichuanChina
| | - Youfu Luo
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
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6
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Gries R, Dal Molin M, Chhen J, van Gumpel E, Dreyer V, Niemann S, Rybniker J. Characterization of Two Novel Inhibitors of the Mycobacterium tuberculosis Cytochrome bc1 Complex. Antimicrob Agents Chemother 2023; 67:e0025123. [PMID: 37358461 PMCID: PMC10353358 DOI: 10.1128/aac.00251-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 06/05/2023] [Indexed: 06/27/2023] Open
Abstract
Drug-resistant tuberculosis is a global health care threat calling for novel effective treatment options. Here, we report on two novel cytochrome bc1 inhibitors (MJ-22 and B6) targeting the Mycobacterium tuberculosis respiratory chain with excellent intracellular activities in human macrophages. Both hit compounds revealed very low mutation frequencies and distinct cross-resistance patterns with other advanced cytochrome bc1 inhibitors.
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Affiliation(s)
- Raphael Gries
- Department I of Internal Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
| | - Michael Dal Molin
- Department I of Internal Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Jason Chhen
- Department I of Internal Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Edeltraud van Gumpel
- Department I of Internal Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Viola Dreyer
- Molecular and Experimental Mycobacteriology, Research Center Borstel, Borstel, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Borstel, Germany
| | - Stefan Niemann
- Molecular and Experimental Mycobacteriology, Research Center Borstel, Borstel, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Borstel, Germany
| | - Jan Rybniker
- Department I of Internal Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
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7
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Toniolo C, Dhar N, McKinney JD. Uptake-independent killing of macrophages by extracellular Mycobacterium tuberculosis aggregates. EMBO J 2023; 42:e113490. [PMID: 36920246 PMCID: PMC10152147 DOI: 10.15252/embj.2023113490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 01/30/2023] [Accepted: 02/23/2023] [Indexed: 03/16/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) infection is initiated by inhalation of bacteria into lung alveoli, where they are phagocytosed by resident macrophages. Intracellular Mtb replication induces the death of the infected macrophages and the release of bacterial aggregates. Here, we show that these aggregates can evade phagocytosis by killing macrophages in a contact-dependent but uptake-independent manner. We use time-lapse fluorescence microscopy to show that contact with extracellular Mtb aggregates triggers macrophage plasma membrane perturbation, cytosolic calcium accumulation, and pyroptotic cell death. These effects depend on the Mtb ESX-1 secretion system, however, this system alone cannot induce calcium accumulation and macrophage death in the absence of the Mtb surface-exposed lipid phthiocerol dimycocerosate. Unexpectedly, we found that blocking ESX-1-mediated secretion of the EsxA/EsxB virulence factors does not eliminate the uptake-independent killing of macrophages and that the 50-kDa isoform of the ESX-1-secreted protein EspB can mediate killing in the absence of EsxA/EsxB secretion. Treatment with an ESX-1 inhibitor reduces uptake-independent killing of macrophages by Mtb aggregates, suggesting that novel therapies targeting this anti-phagocytic mechanism could prevent the propagation of extracellular bacteria within the lung.
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Affiliation(s)
- Chiara Toniolo
- School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
| | - Neeraj Dhar
- School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland.,Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - John D McKinney
- School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
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8
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Kalita E, Panda M, Rao A, Prajapati VK. Exploring the role of secretory proteins in the human infectious diseases diagnosis and therapeutics. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 133:231-269. [PMID: 36707203 DOI: 10.1016/bs.apcsb.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Secretory proteins are playing important role during the host-pathogen interaction to develop the infection or protection into the cell. Pathogens developing infectious disease to human being are taken up by host macrophages or number of immune cells, play an important role in physiological, developmental and immunological function. At the same time, infectious agents are also secreting various proteins to neutralize the resistance caused by host cells and also helping the pathogens to develop the infection. Secretory proteins (secretome) are only developed at the time of host-pathogen interaction, therefore they become very important to develop the targeted and potential therapeutic strategies. Pathogen specific secretory proteins released during interaction with host cell provide opportunity to develop point of care and rapid diagnostic kits. Proteins secreted by pathogens at the time of interaction with host cell have also been found as immunogenic in nature and numbers of vaccines have been developed to control the spread of human infectious diseases. This chapter highlights the importance of secretory proteins in the development of diagnostic and therapeutic strategies to fight against human infectious diseases.
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Affiliation(s)
- Elora Kalita
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India
| | - Mamta Panda
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India
| | - Abhishek Rao
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India.
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9
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Nisa A, Kipper FC, Panigrahy D, Tiwari S, Kupz A, Subbian S. Different modalities of host cell death and their impact on Mycobacterium tuberculosis infection. Am J Physiol Cell Physiol 2022; 323:C1444-C1474. [PMID: 36189975 PMCID: PMC9662802 DOI: 10.1152/ajpcell.00246.2022] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/16/2022] [Accepted: 09/25/2022] [Indexed: 11/22/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is the pathogen that causes tuberculosis (TB), a leading infectious disease of humans worldwide. One of the main histopathological hallmarks of TB is the formation of granulomas comprised of elaborately organized aggregates of immune cells containing the pathogen. Dissemination of Mtb from infected cells in the granulomas due to host and mycobacterial factors induces multiple cell death modalities in infected cells. Based on molecular mechanism, morphological characteristics, and signal dependency, there are two main categories of cell death: programmed and nonprogrammed. Programmed cell death (PCD), such as apoptosis and autophagy, is associated with a protective response to Mtb by keeping the bacteria encased within dead macrophages that can be readily phagocytosed by arriving in uninfected or neighboring cells. In contrast, non-PCD necrotic cell death favors the pathogen, resulting in bacterial release into the extracellular environment. Multiple types of cell death in the PCD category, including pyroptosis, necroptosis, ferroptosis, ETosis, parthanatos, and PANoptosis, may be involved in Mtb infection. Since PCD pathways are essential for host immunity to Mtb, therapeutic compounds targeting cell death signaling pathways have been experimentally tested for TB treatment. This review summarizes different modalities of Mtb-mediated host cell deaths, the molecular mechanisms underpinning host cell death during Mtb infection, and its potential implications for host immunity. In addition, targeting host cell death pathways as potential therapeutic and preventive approaches against Mtb infection is also discussed.
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Affiliation(s)
- Annuurun Nisa
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Franciele C Kipper
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Dipak Panigrahy
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Sangeeta Tiwari
- Department of Biological Sciences, Border Biomedical Research Center (BBRC), University of Texas, El Paso, Texas
| | - Andreas Kupz
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine (AITHM), James Cook University, Townsville, Queensland, Australia
| | - Selvakumar Subbian
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey
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10
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Secretory proteins of
Mycobacterium tuberculosis
and their roles in modulation of host immune responses: focus on therapeutic targets. FEBS J 2022; 289:4146-4171. [DOI: 10.1111/febs.16369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/04/2022] [Accepted: 01/21/2022] [Indexed: 12/01/2022]
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11
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Dwivedi M, Bajpai K. The chamber of secretome in Mycobacterium tuberculosis as a potential therapeutic target. Biotechnol Genet Eng Rev 2022; 39:1-44. [PMID: 35613080 DOI: 10.1080/02648725.2022.2076031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mycobacterium tuberculosis (MTB) causes one of the ancient diseases, Tuberculosis, affects people around the globe and its severity can be understood by its classification as a second infectious disease after COVID-19 and the 13th leading cause of death according to a WHO report. Despite having advanced diagnostic approaches and therapeutic strategies, unfortunately, TB is still spreading across the population due to the emergence of drug-resistance MTB and Latent TB infection (LTBI). We are seeking for effective approaches to overcome these hindrances and efficient treatment for this perilous disease. Therefore, there is an urgent need to develop drugs based on operative targeting of the bacterial system that could result in both efficient treatment and lesser emergence of MDR-TB. One such promising target could be the secretory systems and especially the Type 7 secretory system (T7SS-ESX) of Mycobacterium tuberculosis, which is crucial for the secretion of effector proteins as well as in establishing host-pathogen interactions of the tubercle bacilli. The five paralogous ESX systems (ESX-1 to EXS-5) have been observed by in silico genome analysis of MTB, among which ESX-1 and ESX-5 are substantial for virulence and mediating host cellular inflammasome. The bacterium growth and virulence can be modulated by targeting the T7SS. In the present review, we demonstrate the current status of therapeutics against MTB and focus on the function and cruciality of T7SS along with other secretory systems as a promising therapeutic target against Tuberculosis.
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Affiliation(s)
- Manish Dwivedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, India
| | - Kriti Bajpai
- Department of Biotechnology, Himachal Pradesh University, Shimla, India
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12
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Stupar M, Furness J, De Voss CJ, Tan L, West NP. Two-component sensor histidine kinases of Mycobacterium tuberculosis: beacons for niche navigation. Mol Microbiol 2022; 117:973-985. [PMID: 35338720 PMCID: PMC9321153 DOI: 10.1111/mmi.14899] [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] [Received: 12/22/2021] [Revised: 03/12/2022] [Accepted: 03/22/2022] [Indexed: 11/27/2022]
Abstract
Intracellular bacterial pathogens such as Mycobacterium tuberculosis are remarkably adept at surviving within a host, employing a variety of mechanisms to counteract host defenses and establish a protected niche. Constant surveying of the environment is key for pathogenic mycobacteria to discern their immediate location and coordinate the expression of genes necessary for adaptation. Two‐component systems efficiently perform this role, typically comprised of a transmembrane sensor kinase and a cytoplasmic response regulator. In this review, we describe the role of two‐component systems in bacterial pathogenesis, focusing predominantly on the role of sensor kinases of M. tuberculosis. We highlight important features of sensor kinases in mycobacterial infection, discuss ways in which these signaling proteins sense and respond to environments, and how this is attuned to their intracellular lifestyle. Finally, we discuss recent studies which have identified and characterized inhibitors of two‐component sensor kinases toward establishing a new strategy in anti‐mycobacterial therapy.
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Affiliation(s)
- Miljan Stupar
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Juanelle Furness
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Christopher J De Voss
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Nicholas P West
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
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13
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Mycobacterium tuberculosis EspK Has Active but Distinct Roles in the Secretion of EsxA and EspB. J Bacteriol 2022; 204:e0006022. [PMID: 35315684 DOI: 10.1128/jb.00060-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Mycobacterium tuberculosis type-7 protein secretion system ESX-1 is a major driver of its virulence. While the functions of most ESX-1 components are characterized, many others remain poorly defined. In this study, we examined the role of EspK, an ESX-1-associated protein that is thought to be dispensable for ESX-1 activity in members of the Mycobacterium tuberculosis complex. We show that EspK is needed for the timely and optimal secretion of EsxA and absolutely essential for EspB secretion in M. tuberculosis Erdman. We demonstrate that only the EsxA secretion defect can be alleviated in EspK-deficient M. tuberculosis by culturing it in media containing detergents like Tween 80 or tyloxapol. Subcellular fractionation experiments reveal EspK is exported by M. tuberculosis in an ESX-1-independent manner and localized to its cell wall. We also show a conserved W-X-G motif in EspK is important for its interaction with EspB and enabling its secretion. The same motif, however, is not important for EspK localization in the cell wall. Finally, we show EspB in EspK-deficient M. tuberculosis tends to adopt higher-order oligomeric conformations, more so than EspB in wild-type M. tuberculosis. These results suggest EspK interacts with EspB and prevents it from assembling prematurely into macromolecular complexes that are presumably too large to pass through the membrane-spanning ESX-1 translocon assembly. Collectively, our findings indicate M. tuberculosis EspK has a far more active role in ESX-1-mediated secretion than was previously appreciated and underscores the complex nature of this secretion apparatus. IMPORTANCE Mycobacterium tuberculosis uses its ESX-1 system to secrete EsxA and EspB into a host to cause disease. We show that EspK, a protein whose role in the ESX-1 machinery was thought to be nonessential, is needed by M. tuberculosis for optimal EsxA and EspB secretion. Culturing EspK-deficient M. tuberculosis with detergents alleviates EsxA but not EspB secretion defects. We also show that EspK, which is exported by M. tuberculosis in an ESX-1-independent manner to the cell wall, interacts with and prevents EspB from assembling into large structures inside the M. tuberculosis cell that are nonsecretable. Collectively, our observations demonstrate EspK is an active component of the ESX-1 secretion machinery of the tubercle bacillus.
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14
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Lata S, Mahatha AC, Mal S, Gupta UD, Kundu M, Basu J. Unravelling novel roles of the Mycobacterium tuberculosis transcription factor Rv0081 in regulation of the nucleoid-associated proteins Lsr2 and EspR, cholesterol utilization and subversion of lysosomal trafficking in macrophages. Mol Microbiol 2022; 117:1104-1120. [PMID: 35304930 DOI: 10.1111/mmi.14895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 11/30/2022]
Abstract
The transcriptional network of Mycobacterium tuberculosis is designed to enable the organism to withstand host-associated stresses and to exploit the host milieu for its own survival and multiplication. Rv0081 (MT0088) is a transcriptional regulator whose interplay with other gene regulatory proteins and role in enabling M. tuberculosis to thrive within its host is incompletely understood. M. tuberculosis utilizes cholesterol within the granuloma. We show that deletion of Rv0081 compromises the ability of M. tuberculosis to utilize cholesterol as sole carbon source, to subvert lysosomal trafficking, and to form granulomas in vitro. Rv0081 downregulates expression of the nucleoid associated repressor Lsr2, leading to increased expression of the cholesterol catabolism-linked gene kshA and genes of the cholesterol importing operon, accounting for the requirement of Rv0081 in cholesterol utilization. Further, Rv0081 activates EspR which is required for secretion of ESX-1 substrates, which in turn are involved in subversion of lysosomal traffickingof M. tuberculosisand granuloma expansion. These results provide new insight into the role of Rv0081 under conditions which resemble the environment encountered by M. tuberculosis within its host. Rv0081 emergesas a central regulator of genes linked to various pathways which are crucial for the survival of the bacterium in vivo.
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Affiliation(s)
- Suruchi Lata
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Amar Chandra Mahatha
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Soumya Mal
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Umesh D Gupta
- National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra 282004, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
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15
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Advances in Key Drug Target Identification and New Drug Development for Tuberculosis. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5099312. [PMID: 35252448 PMCID: PMC8896939 DOI: 10.1155/2022/5099312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 02/14/2022] [Indexed: 12/15/2022]
Abstract
Tuberculosis (TB) is a severe infectious disease worldwide. The increasing emergence of drug-resistant Mycobacterium tuberculosis (Mtb) has markedly hampered TB control. Therefore, there is an urgent need to develop new anti-TB drugs to treat drug-resistant TB and shorten the standard therapy. The discovery of targets of drug action will lay a theoretical foundation for new drug development. With the development of molecular biology and the success of Mtb genome sequencing, great progress has been made in the discovery of new targets and their relevant inhibitors. In this review, we summarized 45 important drug targets and 15 new drugs that are currently being tested in clinical stages and several prospective molecules that are still at the level of preclinical studies. A comprehensive understanding of the drug targets of Mtb can provide extensive insights into the development of safer and more efficient drugs and may contribute new ideas for TB control and treatment.
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16
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Multiple genetic paths including massive gene amplification allow Mycobacterium tuberculosis to overcome loss of ESX-3 secretion system substrates. Proc Natl Acad Sci U S A 2022; 119:2112608119. [PMID: 35193958 PMCID: PMC8872769 DOI: 10.1073/pnas.2112608119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2021] [Indexed: 01/18/2023] Open
Abstract
The Mycobacterium tuberculosis (Mtb) ESX-3 type VII secretion system plays a critical role in iron acquisition. Infection of mice with highly attenuated Mtb deletion mutants lacking esxG or esxH, genes encoding key ESX-3 substrates, unexpectedly yielded suppressor mutants with restored capacity to grow in vivo and in vitro in the absence of iron supplementation. Whole-genome sequencing identified two mechanisms of suppression, the disruption of a transcriptional repressor that regulates expression of an ESX-3 paralogous region encoding EsxR and EsxS, and a massive 38- to 60-fold gene amplification of this same region. These data are significant because they reveal a previously unrecognized iron acquisition regulon and inform mechanisms of Mtb chromosome evolution. Mycobacterium tuberculosis (Mtb) possesses five type VII secretion systems (T7SS), virulence determinants that include the secretion apparatus and associated secretion substrates. Mtb strains deleted for the genes encoding substrates of the ESX-3 T7SS, esxG or esxH, require iron supplementation for in vitro growth and are highly attenuated in vivo. In a subset of infected mice, suppressor mutants of esxG or esxH deletions were isolated, which enabled growth to high titers or restored virulence. Suppression was conferred by mechanisms that cause overexpression of an ESX-3 paralogous region that lacks genes for the secretion apparatus but encodes EsxR and EsxS, apparent ESX-3 orphan substrates that functionally compensate for the lack of EsxG or EsxH. The mechanisms include the disruption of a transcriptional repressor and a massive 38- to 60-fold gene amplification. These data identify an iron acquisition regulon, provide insight into T7SS, and reveal a mechanism of Mtb chromosome evolution involving “accordion-type” amplification.
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17
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Theobald SJ, Gräb J, Fritsch M, Suárez I, Eisfeld HS, Winter S, Koch M, Hölscher C, Pasparakis M, Kashkar H, Rybniker J. Gasdermin D mediates host cell death but not interleukin-1β secretion in Mycobacterium tuberculosis-infected macrophages. Cell Death Discov 2021; 7:327. [PMID: 34718331 PMCID: PMC8557205 DOI: 10.1038/s41420-021-00716-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 11/09/2022] Open
Abstract
Necrotic cell death represents a major pathogenic mechanism of Mycobacterium tuberculosis (Mtb) infection. It is increasingly evident that Mtb induces several types of regulated necrosis but how these are interconnected and linked to the release of pro-inflammatory cytokines remains unknown. Exploiting a clinical cohort of tuberculosis patients, we show here that the number and size of necrotic lesions correlates with IL-1β plasma levels as a strong indicator of inflammasome activation. Our mechanistic studies reveal that Mtb triggers mitochondrial permeability transition (mPT) and subsequently extensive macrophage necrosis, which requires activation of the NLRP3 inflammasome. NLRP3-driven mitochondrial damage is dependent on proteolytic activation of the pore-forming effector protein gasdermin D (GSDMD), which links two distinct cell death machineries. Intriguingly, GSDMD, but not the membranolytic mycobacterial ESX-1 secretion system, is dispensable for IL-1β secretion from Mtb-infected macrophages. Thus, our study dissects a novel mechanism of pathogen-induced regulated necrosis by identifying mitochondria as central regulatory hubs capable of delineating cytokine secretion and lytic cell death.
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Affiliation(s)
- Sebastian J Theobald
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Jessica Gräb
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Melanie Fritsch
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Medical Microbiology, Immunology and Hygiene (IMMIH), University of Cologne, 50935, Cologne, Germany
| | - Isabelle Suárez
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
| | - Hannah S Eisfeld
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Sandra Winter
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Maximilian Koch
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Christoph Hölscher
- Division of Infection Immunology, Research Center Borstel, 23845, Borstel, Germany.,German Center for Infection Research (DZIF), Partner Site Borstel, 23845, Borstel, Germany
| | - Manolis Pasparakis
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Genetics, University of Cologne, 50674, Cologne, Germany
| | - Hamid Kashkar
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Medical Microbiology, Immunology and Hygiene (IMMIH), University of Cologne, 50935, Cologne, Germany
| | - Jan Rybniker
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany. .,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany. .,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany.
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18
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Jia P, Zhang Y, Xu J, Zhu M, Peng S, Zhang Y, Zhao J, Li X, Mi K, Yan D, Wang Y, Yu L, Lu Y, Shi H, Cen S. IMB-BZ as an Inhibitor Targeting ESX-1 Secretion System to Control Mycobacterial Infection. J Infect Dis 2021; 225:608-616. [PMID: 34558604 DOI: 10.1093/infdis/jiab486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/23/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Resistance to anti-tuberculosis (TB) drug is a major issue in TB control, and demands the discovery of new drugs targeting virulence factor ESX-1. METHODS We first established a high-throughput screen (HTS) assay for the discovery of ESX-1 secretion inhibitors. The positive hits were then evaluated for the potency of diminishing the survival of virulent mycobacterium and reducing bacterial virulence. We further investigated the probability of inducing drug-resistance and the underlying mechanism using M-PFC. RESULTS A robust HTS assay was developed to identify small molecules that inhibit ESX-1 secretion without impairing bacterial growth in vitro. A hit named IMB-BZ specifically inhibits the secretion of CFP-10 and reduces virulence in an ESX-1-dependent manner, therefore resulting in significant reduction in intracellular and in vivo survival of mycobacteria. Blocking the CFP-10-EccCb1 interaction directly or indirectly underlies the inhibitory effect of IMB-BZ on the secretion of CFP-10. Importantly, our finding shows that the ESX-1 inhibitors pose low risk of drug resistance development by mycobacteria in vitro as compared with traditional anti-TB drug, and exhibit high potency against chronic mycobacterial infection. CONCLUSION Targeting ESX-1 may lead to the development of novel therapeutics for tuberculosis. IMB-BZ holds the potential for future development into a new anti-TB drug.
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Affiliation(s)
- Pingping Jia
- Department of Clinical Nutrition, Department of Gastrointestinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China; Department of Oncology, Capital Medical University, Beijing, 100038, China.,Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Yi Zhang
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Jian Xu
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China.,Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, China
| | - Mei Zhu
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Shize Peng
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Yongxin Zhang
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Jianyuan Zhao
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Xiaoyu Li
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Kaixia Mi
- The Institute of Microbiology of the Chinese Academy of Sciences, Beijing 100101, China
| | - Dan Yan
- Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yucheng Wang
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Liyan Yu
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Yu Lu
- Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, China
| | - Hanping Shi
- Department of Clinical Nutrition, Department of Gastrointestinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China; Department of Oncology, Capital Medical University, Beijing, 100038, China
| | - Shan Cen
- Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences, Beijing, 100050, China.,Beijing Friendship Hospital, Capital Medical University, Beijing, China
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19
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Rivera-Calzada A, Famelis N, Llorca O, Geibel S. Type VII secretion systems: structure, functions and transport models. Nat Rev Microbiol 2021; 19:567-584. [PMID: 34040228 DOI: 10.1038/s41579-021-00560-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2021] [Indexed: 02/07/2023]
Abstract
Type VII secretion systems (T7SSs) have a key role in the secretion of effector proteins in non-pathogenic mycobacteria and pathogenic mycobacteria such as Mycobacterium tuberculosis, the main causative agent of tuberculosis. Tuberculosis-causing mycobacteria, still accounting for 1.4 million deaths annually, rely on paralogous T7SSs to survive in the host and efficiently evade its immune response. Although it is still unknown how effector proteins of T7SSs cross the outer membrane of the diderm mycobacterial cell envelope, recent advances in the structural characterization of these secretion systems have revealed the intricate network of interactions of conserved components in the plasma membrane. This structural information, added to recent advances in the molecular biology and regulation of mycobacterial T7SSs as well as progress in our understanding of their secreted effector proteins, is shedding light on the inner working of the T7SS machinery. In this Review, we highlight the implications of these studies and the derived transport models, which provide new scenarios for targeting the deathly human pathogen M. tuberculosis.
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Affiliation(s)
- Angel Rivera-Calzada
- Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
| | - Nikolaos Famelis
- Institute for Molecular Infection Biology, Julius-Maximilian University of Würzburg, Würzburg, Germany.,Rudolf Virchow Center for Integrative and Translational Biomedicine, Julius-Maximilian University of Würzburg, Würzburg, Germany
| | - Oscar Llorca
- Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Sebastian Geibel
- Institute for Molecular Infection Biology, Julius-Maximilian University of Würzburg, Würzburg, Germany. .,Rudolf Virchow Center for Integrative and Translational Biomedicine, Julius-Maximilian University of Würzburg, Würzburg, Germany.
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20
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Santucci P, Greenwood DJ, Fearns A, Chen K, Jiang H, Gutierrez MG. Intracellular localisation of Mycobacterium tuberculosis affects efficacy of the antibiotic pyrazinamide. Nat Commun 2021; 12:3816. [PMID: 34155215 PMCID: PMC8217510 DOI: 10.1038/s41467-021-24127-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 05/28/2021] [Indexed: 11/09/2022] Open
Abstract
To be effective, chemotherapy against tuberculosis (TB) must kill the intracellular population of the pathogen, Mycobacterium tuberculosis. However, how host cell microenvironments affect antibiotic accumulation and efficacy remains unclear. Here, we use correlative light, electron, and ion microscopy to investigate how various microenvironments within human macrophages affect the activity of pyrazinamide (PZA), a key antibiotic against TB. We show that PZA accumulates heterogeneously among individual bacteria in multiple host cell environments. Crucially, PZA accumulation and efficacy is maximal within acidified phagosomes. Bedaquiline, another antibiotic commonly used in combined TB therapy, enhances PZA accumulation via a host cell-mediated mechanism. Thus, intracellular localisation and specific microenvironments affect PZA accumulation and efficacy. Our results may explain the potent in vivo efficacy of PZA, compared to its modest in vitro activity, and its critical contribution to TB combination chemotherapy.
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Affiliation(s)
- Pierre Santucci
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK
| | - Daniel J Greenwood
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK.,Institute of Molecular Systems Biology, ETH, Zurich, Switzerland
| | - Antony Fearns
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK
| | - Kai Chen
- School of Molecular Sciences, University of Western Australia, Perth, AU, Australia
| | - Haibo Jiang
- School of Molecular Sciences, University of Western Australia, Perth, AU, Australia. .,Department of Chemistry, The University of Hong Kong, Hong Kong, China.
| | - Maximiliano G Gutierrez
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK.
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21
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Bendre AD, Peters PJ, Kumar J. Recent Insights into the Structure and Function of Mycobacterial Membrane Proteins Facilitated by Cryo-EM. J Membr Biol 2021; 254:321-341. [PMID: 33954837 PMCID: PMC8099146 DOI: 10.1007/s00232-021-00179-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 03/23/2021] [Indexed: 12/26/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is one of the deadliest pathogens encountered by humanity. Over the decades, its characteristic membrane organization and composition have been understood. However, there is still limited structural information and mechanistic understanding of the constituent membrane proteins critical for drug discovery pipelines. Recent advances in single-particle cryo-electron microscopy and cryo-electron tomography have provided the much-needed impetus towards structure determination of several vital Mtb membrane proteins whose structures were inaccessible via X-ray crystallography and NMR. Important insights into membrane composition and organization have been gained via a combination of electron tomography and biochemical and biophysical assays. In addition, till the time of writing this review, 75 new structures of various Mtb proteins have been reported via single-particle cryo-EM. The information obtained from these structures has improved our understanding of the mechanisms of action of these proteins and the physiological pathways they are associated with. These structures have opened avenues for structure-based drug design and vaccine discovery programs that might help achieve global-TB control. This review describes the structural features of selected membrane proteins (type VII secretion systems, Rv1819c, Arabinosyltransferase, Fatty Acid Synthase, F-type ATP synthase, respiratory supercomplex, ClpP1P2 protease, ClpB disaggregase and SAM riboswitch), their involvement in physiological pathways, and possible use as a drug target. Tuberculosis is a deadly disease caused by Mycobacterium tuberculosis. The Cryo-EM and tomography have simplified the understanding of the mycobacterial membrane organization. Some proteins are located in the plasma membrane; some span the entire envelope, while some, like MspA, are located in the mycomembrane. Cryo-EM has made the study of such membrane proteins feasible.
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Affiliation(s)
- Ameya D Bendre
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University Campus, Ganeshkhind, Pune, Maharashtra, 411007, India
| | - Peter J Peters
- The Maastricht Multimodal Molecular Imaging Institute (M4I), Division of Nanoscopy, Maastricht University, Maastricht, The Netherlands
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University Campus, Ganeshkhind, Pune, Maharashtra, 411007, India.
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22
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Beckham KSH, Ritter C, Chojnowski G, Ziemianowicz DS, Mullapudi E, Rettel M, Savitski MM, Mortensen SA, Kosinski J, Wilmanns M. Structure of the mycobacterial ESX-5 type VII secretion system pore complex. SCIENCE ADVANCES 2021; 7:eabg9923. [PMID: 34172453 PMCID: PMC8232910 DOI: 10.1126/sciadv.abg9923] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/10/2021] [Indexed: 05/28/2023]
Abstract
The ESX-5 type VII secretion system is a membrane-spanning protein complex key to the virulence of mycobacterial pathogens. However, the overall architecture of the fully assembled translocation machinery and the composition of the central secretion pore have remained unknown. Here, we present the high-resolution structure of the 2.1-megadalton ESX-5 core complex. Our structure captured a dynamic, secretion-competent conformation of the pore within a well-defined transmembrane section, sandwiched between two flexible protein layers at the cytosolic entrance and the periplasmic exit. We propose that this flexibility endows the ESX-5 machinery with large conformational plasticity required to accommodate targeted protein secretion. Compared to known secretion systems, a highly dynamic state of the pore may represent a fundamental principle of bacterial secretion machineries.
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Affiliation(s)
- Katherine S H Beckham
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany
| | - Christina Ritter
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany
| | - Grzegorz Chojnowski
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany
| | - Daniel S Ziemianowicz
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany
| | - Edukondalu Mullapudi
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany
| | - Mandy Rettel
- European Molecular Biology Laboratory, Heidelberg, Germany
| | | | - Simon A Mortensen
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany
| | - Jan Kosinski
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany.
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Matthias Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607 Hamburg, Germany.
- University Hamburg Clinical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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23
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Bunduc CM, Fahrenkamp D, Wald J, Ummels R, Bitter W, Houben ENG, Marlovits TC. Structure and dynamics of a mycobacterial type VII secretion system. Nature 2021; 593:445-448. [PMID: 33981042 PMCID: PMC8131196 DOI: 10.1038/s41586-021-03517-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/06/2021] [Indexed: 11/20/2022]
Abstract
Mycobacterium tuberculosis is the cause of one of the most important infectious diseases in humans, which leads to 1.4 million deaths every year1. Specialized protein transport systems-known as type VII secretion systems (T7SSs)-are central to the virulence of this pathogen, and are also crucial for nutrient and metabolite transport across the mycobacterial cell envelope2,3. Here we present the structure of an intact T7SS inner-membrane complex of M. tuberculosis. We show how the 2.32-MDa ESX-5 assembly, which contains 165 transmembrane helices, is restructured and stabilized as a trimer of dimers by the MycP5 protease. A trimer of MycP5 caps a central periplasmic dome-like chamber that is formed by three EccB5 dimers, with the proteolytic sites of MycP5 facing towards the cavity. This chamber suggests a central secretion and processing conduit. Complexes without MycP5 show disruption of the EccB5 periplasmic assembly and increased flexibility, which highlights the importance of MycP5 for complex integrity. Beneath the EccB5-MycP5 chamber, dimers of the EccC5 ATPase assemble into three bundles of four transmembrane helices each, which together seal the potential central secretion channel. Individual cytoplasmic EccC5 domains adopt two distinctive conformations that probably reflect different secretion states. Our work suggests a previously undescribed mechanism of protein transport and provides a structural scaffold to aid in the development of drugs against this major human pathogen.
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Affiliation(s)
- Catalin M Bunduc
- Centre for Structural Systems Biology, Hamburg, Germany
- Institute of Structural and Systems Biology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Deutsches Elektron Synchrotron DESY, Hamburg, Germany
- Molecular Microbiology Section, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Dirk Fahrenkamp
- Centre for Structural Systems Biology, Hamburg, Germany
- Institute of Structural and Systems Biology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Deutsches Elektron Synchrotron DESY, Hamburg, Germany
| | - Jiri Wald
- Centre for Structural Systems Biology, Hamburg, Germany
- Institute of Structural and Systems Biology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Deutsches Elektron Synchrotron DESY, Hamburg, Germany
| | - Roy Ummels
- Department of Medical Microbiology and Infection Control, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Amsterdam, The Netherlands
| | - Wilbert Bitter
- Molecular Microbiology Section, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Medical Microbiology and Infection Control, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Amsterdam, The Netherlands
| | - Edith N G Houben
- Molecular Microbiology Section, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Thomas C Marlovits
- Centre for Structural Systems Biology, Hamburg, Germany.
- Institute of Structural and Systems Biology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
- Deutsches Elektron Synchrotron DESY, Hamburg, Germany.
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24
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Drever K, Lim ZL, Zriba S, Chen JM. Protein Synthesis and Degradation Inhibitors Potently Block Mycobacterium tuberculosis type-7 Secretion System ESX-1 Activity. ACS Infect Dis 2021; 7:273-280. [PMID: 33534536 DOI: 10.1021/acsinfecdis.0c00741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mycobacterium tuberculosis (M. tb) uses its type-7 secretion system ESX-1 to translocate key virulence effector proteins. Taking a chemical genetics approach, we demonstrate for the first time the importance of mycobacterial proteostasis to ESX-1. We show that individual treatment with inhibitors of protein synthesis (chloramphenicol and kanamycin) and protein degradation (lassomycin and bortezomib), at concentrations that only reduce M. tb growth by 50% and less, specifically block ESX-1 secretion activity in the tubercle bacillus. In contrast, the mycobacterial cell-wall synthesis inhibitor isoniazid, even at a concentration that reduces M. tb growth by 90% has no effect on ESX-1 secretion activity. We also show that chloramphenicol but not isoniazid at subinhibitory concentrations specifically attenuates ESX-1-mediated M. tb virulence in macrophages. Taken together, the results of our study identify a novel vulnerability in the ESX-1 system and offer new avenues of anti-TB drug research to neutralize this critical virulence-mediating protein secretion apparatus.
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Affiliation(s)
- Kylee Drever
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - Ze Long Lim
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
| | - Slim Zriba
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
- Vaccinology and Immunotherapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan S7N 2Z4, Canada
| | - Jeffrey M. Chen
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada
- Vaccinology and Immunotherapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan S7N 2Z4, Canada
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25
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Zn 2+ Intoxication of Mycobacterium marinum during Dictyostelium discoideum Infection Is Counteracted by Induction of the Pathogen Zn 2+ Exporter CtpC. mBio 2021; 12:mBio.01313-20. [PMID: 33531393 PMCID: PMC7858047 DOI: 10.1128/mbio.01313-20] [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] [Indexed: 12/23/2022] Open
Abstract
Microelements are essential for the function of the innate immune system. A deficiency in zinc or copper results in an increased susceptibility to bacterial infections. Macrophages use diverse strategies to restrict intracellular pathogens, including either depriving the bacteria of (micro)nutrients such as transition metals or intoxicating them via metal accumulation. Little is known about the chemical warfare between Mycobacterium marinum, a close relative of Mycobacterium tuberculosis (Mtb), and its hosts. We use the professional phagocyte Dictyostelium discoideum to investigate the role of Zn2+ during M. marinum infection. We show that M. marinum senses toxic levels of Zn2+ and responds by upregulating one of its isoforms of the Zn2+ efflux transporter CtpC. Deletion of ctpC (MMAR_1271) leads to growth inhibition in broth supplemented with Zn2+ as well as reduced intracellular growth. Both phenotypes were fully rescued by constitutive ectopic expression of the Mtb CtpC orthologue demonstrating that MMAR_1271 is the functional CtpC Zn2+ efflux transporter in M. marinum. Infection leads to the accumulation of Zn2+ inside the Mycobacterium-containing vacuole (MCV), achieved by the induction and recruitment of the D. discoideum Zn2+ efflux pumps ZntA and ZntB. In cells lacking ZntA, there is further attenuation of M. marinum growth, presumably due to a compensatory efflux of Zn2+ into the MCV, carried out by ZntB, the main Zn2+ transporter in endosomes and phagosomes. Counterintuitively, bacterial growth is also impaired in zntB KO cells, in which MCVs appear to accumulate less Zn2+ than in wild-type cells, suggesting restriction by other Zn2+-mediated mechanisms. Absence of CtpC further epistatically attenuates the intracellular proliferation of M. marinum in zntA and zntB KO cells, confirming that mycobacteria face noxious levels of Zn2+.
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26
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Monakhova N, Korduláková J, Vocat A, Egorova A, Lepioshkin A, Salina EG, Nosek J, Repková E, Zemanová J, Jurdáková H, Górová R, Roh J, Degiacomi G, Sammartino JC, Pasca MR, Cole ST, Mikušová K, Makarov V. Design and Synthesis of Pyrano[3,2- b]indolones Showing Antimycobacterial Activity. ACS Infect Dis 2021; 7:88-100. [PMID: 33352041 DOI: 10.1021/acsinfecdis.0c00622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Latent Mycobacterium tuberculosis infection presents one of the largest challenges for tuberculosis control and novel antimycobacterial drug development. A series of pyrano[3,2-b]indolone-based compounds was designed and synthesized via an original eight-step scheme. The synthesized compounds were evaluated for their in vitro activity against M. tuberculosis strains H37Rv and streptomycin-starved 18b (SS18b), representing models for replicating and nonreplicating mycobacteria, respectively. Compound 10a exhibited good activity with MIC99 values of 0.3 and 0.4 μg/mL against H37Rv and SS18b, respectively, as well as low toxicity, acceptable intracellular activity, and satisfactory metabolic stability and was selected as the lead compound for further studies. An analysis of 10a-resistant M. bovis mutants disclosed a cross-resistance with pretomanid and altered relative amounts of different forms of cofactor F420 in these strains. Complementation experiments showed that F420-dependent glucose-6-phosphate dehydrogenase and the synthesis of mature F420 were important for 10a activity. Overall these studies revealed 10a to be a prodrug that is activated by an unknown F420-dependent enzyme in mycobacteria.
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Affiliation(s)
- Natalia Monakhova
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russian Federation
| | | | - Anthony Vocat
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Anna Egorova
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russian Federation
| | - Alexander Lepioshkin
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russian Federation
| | - Elena G. Salina
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russian Federation
| | | | | | | | | | | | - Jaroslav Roh
- Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové 50005, Czech Republic
| | - Giulia Degiacomi
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Pavia 27100, Italy
| | - José Camilla Sammartino
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Pavia 27100, Italy
| | - Maria Rosalia Pasca
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Pavia 27100, Italy
| | - Stewart T. Cole
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | | | - Vadim Makarov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russian Federation
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27
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Bahuguna A, Rawat S, Rawat DS. QcrB in Mycobacterium tuberculosis: The new drug target of antitubercular agents. Med Res Rev 2021; 41:2565-2581. [PMID: 33400275 DOI: 10.1002/med.21779] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/23/2020] [Accepted: 12/12/2020] [Indexed: 11/08/2022]
Abstract
Drug-resistance in mycobacterial infections is a major global health problem that leads to high mortality and socioeconomic pressure in developing countries around the world. From finding new targets to discovering novel chemical scaffolds, there is an urgent need for the development of better approaches for the cure of tuberculosis. Recently, energy metabolism in mycobacteria, particularly the oxidative phosphorylation pathway of cellular respiration, has emerged as a novel target pathway in drug discovery. New classes of antibacterials which target oxidative phosphorylation pathway either by interacting with a protein or any step in the pathway of oxidative phosphorylation can combat dormant mycobacterial infections leading to shortening of tuberculosis chemotherapy. Adenosine triphosphate synthase is one such recently discovered target of the newly approved antitubercular drug bedaquiline. Cytochrome bcc is another new target of the antitubercular drug candidate Q203, currently in phase II clinical trial. Research suggests that b subunit of cytochrome bcc, QcrB, is the target of Q203. The review article describes the structure, function, and importance of targeting QcrB throwing light on all chemical classes of QcrB inhibitors discovered to date. An understanding of the structure and function of validated targets and their inhibitors would enable the development of new chemical entities.
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Affiliation(s)
| | - Srishti Rawat
- Department of Chemistry, University of Delhi, Delhi, India
| | - Diwan S Rawat
- Department of Chemistry, University of Delhi, Delhi, India
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28
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Velappan AB, Kesamsetty D, Datta D, Ma R, Hari N, Franzblau SG, Debnath J. 1,3-Oxazine-2-one derived dual-targeted molecules against replicating and non-replicating forms of Mycobacterium tuberculosis. Eur J Med Chem 2020; 208:112835. [PMID: 32977201 DOI: 10.1016/j.ejmech.2020.112835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/02/2020] [Accepted: 09/07/2020] [Indexed: 10/23/2022]
Abstract
The high mortality rate and increasing prevalence of resistant Mtb are the major concerns for the Tuberculosis (TB) treatment in this century. To curtail the prevalence of resistant Mtb, we have prepared 1,3-oxazine-2-one based dual targeted molecules. Compound 67 and 68 were found to be equally active against replicating and non-replicatiing form of Mtb (MICMABA 3.48 and 2.97 μg/ml; MICLORA 2.94 and 2.15 μg/ml respectively). They had found to suppress the biosynthesis of alfa, methoxy and keto-mycolate completely, as well as inhibit enzymatic activity of MenG (IC50 = 9.11 and 6.25 μg/ml respectively for H37Ra; IC50 = 11.76 and 10.88 μg/ml respectively for M smegmatis).
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Affiliation(s)
- Anand Babu Velappan
- Department of Chemistry, SCBT, SASTRA Deemed to Be University, Tamilnadu, 613401, India
| | - Dhanunjaya Kesamsetty
- Department of Chemistry, SCBT, SASTRA Deemed to Be University, Tamilnadu, 613401, India
| | - Dhrubajyoti Datta
- Department of Chemistry, Indian Institute of Science Education and Research, Pune, Maharashtra, 411008, India
| | - Rui Ma
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood St, Chicago, IL, 60612, USA
| | - Natarajan Hari
- NMR Laboratory, SCBT, SASTRA Deemed to Be University, Tamilnadu, 613401, India
| | - Scott G Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood St, Chicago, IL, 60612, USA
| | - Joy Debnath
- Department of Chemistry, SCBT, SASTRA Deemed to Be University, Tamilnadu, 613401, India.
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29
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Kim JK, Silwal P, Jo EK. Host-Pathogen Dialogues in Autophagy, Apoptosis, and Necrosis during Mycobacterial Infection. Immune Netw 2020; 20:e37. [PMID: 33163245 PMCID: PMC7609165 DOI: 10.4110/in.2020.20.e37] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is an etiologic pathogen of human tuberculosis (TB), a serious infectious disease with high morbidity and mortality. In addition, the threat of drug resistance in anti-TB therapy is of global concern. Despite this, it remains urgent to research for understanding the molecular nature of dynamic interactions between host and pathogens during TB infection. While Mtb evasion from phagolysosomal acidification is a well-known virulence mechanism, the molecular events to promote intracellular parasitism remains elusive. To combat intracellular Mtb infection, several defensive processes, including autophagy and apoptosis, are activated. In addition, Mtb-ingested phagocytes trigger inflammation, and undergo necrotic cell death, potentially harmful responses in case of uncontrolled pathological condition. In this review, we focus on Mtb evasion from phagosomal acidification, and Mtb interaction with host autophagy, apoptosis, and necrosis. Elucidation of the molecular dialogue will shed light on Mtb pathogenesis, host defense, and development of new paradigms of therapeutics.
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Affiliation(s)
- Jin Kyung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, Korea
| | - Prashanta Silwal
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, Korea
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30
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Bunduc CM, Bitter W, Houben E. Structure and Function of the Mycobacterial Type VII Secretion Systems. Annu Rev Microbiol 2020; 74:315-335. [DOI: 10.1146/annurev-micro-012420-081657] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacteria have evolved intricate secretion machineries for the successful delivery of large molecules across their cell envelopes. Such specialized secretion systems allow a variety of bacteria to thrive in specific host environments. In mycobacteria, type VII secretion systems (T7SSs) are dedicated protein transport machineries that fulfill diverse and crucial roles, ranging from metabolite uptake to immune evasion and subversion to conjugation. Since the discovery of mycobacterial T7SSs about 15 y ago, genetic, structural, and functional studies have provided insight into the roles and functioning of these secretion machineries. Here, we focus on recent advances in the elucidation of the structure and mechanism of mycobacterial T7SSs in protein secretion. As many of these systems are essential for mycobacterial growth or virulence, they provide opportunities for the development of novel therapies to combat a number of relevant mycobacterial diseases.
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Affiliation(s)
- Catalin M. Bunduc
- Section of Molecular Microbiology, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - W. Bitter
- Section of Molecular Microbiology, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
- Department of Medical Microbiology and Infection Control, Amsterdam Infection and Immunity Institute, Amsterdam University Medical Centers, 1007 MB Amsterdam, The Netherlands
| | - E.N.G. Houben
- Section of Molecular Microbiology, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
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31
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Crosskey TD, Beckham KS, Wilmanns M. The ATPases of the mycobacterial type VII secretion system: Structural and mechanistic insights into secretion. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 152:25-34. [DOI: 10.1016/j.pbiomolbio.2019.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/08/2019] [Accepted: 11/22/2019] [Indexed: 12/12/2022]
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32
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Host-Directed Therapies and Anti-Virulence Compounds to Address Anti-Microbial Resistant Tuberculosis Infection. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10082688] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Despite global efforts to contain tuberculosis (TB), the disease remains a leading cause of morbidity and mortality worldwide, further exacerbated by the increased resistance to antibiotics displayed by the tubercle bacillus Mycobacterium tuberculosis. In order to treat drug-resistant TB, alternative or complementary approaches to standard anti-TB regimens are being explored. An area of active research is represented by host-directed therapies which aim to modulate the host immune response by mitigating inflammation and by promoting the antimicrobial activity of immune cells. Additionally, compounds that reduce the virulence of M. tuberculosis, for instance by targeting the major virulence factor ESX-1, are being given increased attention by the TB research community. This review article summarizes the current state of the art in the development of these emerging therapies against TB.
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33
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Tsenova L, Singhal A. Effects of host-directed therapies on the pathology of tuberculosis. J Pathol 2020; 250:636-646. [PMID: 32108337 DOI: 10.1002/path.5407] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/12/2020] [Accepted: 02/24/2020] [Indexed: 12/15/2022]
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), has co-evolved with the human immune system and utilizes multiple strategies to persist within infected cells, to hijack several immune mechanisms, and to cause severe pathology and tissue damage in the host. This delays the efficacy of current antibiotic therapy and contributes to the evolution of multi-drug-resistant strains. These challenges led to the development of the novel approach in TB treatment that involves therapeutic targeting of host immune response to control disease pathogenesis and pathogen growth, namely, host-directed therapies (HDTs). Such HDT approaches can (1) enhance the effect of antibiotics, (2) shorten treatment duration for any clinical form of TB, (3) promote development of immunological memory that could protect against relapse, and (4) ameliorate the immunopathology including matrix destruction and fibrosis associated with TB. In this review we discuss TB-HDT candidates shown to be of clinical relevance that thus could be developed to reduce pathology, tissue damage, and subsequent impairment of pulmonary function. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Liana Tsenova
- Department of Biological Sciences, New York City College of Technology, Brooklyn, NY, USA
| | - Amit Singhal
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Vaccine and Infectious Disease Research Centre (VIDRC), Translational Health Science and Technology Institute (THSTI), Faridabad, India
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34
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Ates LS. New insights into the mycobacterial PE and PPE proteins provide a framework for future research. Mol Microbiol 2020; 113:4-21. [PMID: 31661176 PMCID: PMC7028111 DOI: 10.1111/mmi.14409] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2019] [Indexed: 12/30/2022]
Abstract
The PE and PPE proteins of Mycobacterium tuberculosis have been studied with great interest since their discovery. Named after the conserved proline (P) and glutamic acid (E) residues in their N-terminal domains, these proteins are postulated to perform wide-ranging roles in virulence and immune modulation. However, technical challenges in studying these proteins and their encoding genes have hampered the elucidation of molecular mechanisms and leave many open questions regarding the biological functions mediated by these proteins. Here, I review the shared and unique characteristics of PE and PPE proteins from a molecular perspective linking this information to their functions in mycobacterial virulence. I discuss how the different subgroups (PE_PGRS, PPE-PPW, PPE-SVP and PPE-MPTR) are defined and why this classification of paramount importance to understand the PE and PPE proteins as individuals and or groups. The goal of this MicroReview is to summarize and structure the existing information on this gene family into a simplified framework of thinking about PE and PPE proteins and genes. Thereby, I hope to provide helpful starting points in studying these genes and proteins for researchers with different backgrounds. This has particular implications for the design and monitoring of novel vaccine candidates and in understanding the evolution of the M. tuberculosis complex.
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Affiliation(s)
- Louis S. Ates
- Department of Experimental ImmunologyAmsterdam Infection & Immunity InstituteAmsterdam UMCUniversity of AmsterdamMeibergdreef 9Amsterdamthe Netherlands
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35
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Extremely Low Hit Rate in a Diverse Chemical Drug Screen Targeting Mycobacterium abscessus. Antimicrob Agents Chemother 2019; 63:AAC.01008-19. [PMID: 31427298 DOI: 10.1128/aac.01008-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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36
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Gräb J, Suárez I, van Gumpel E, Winter S, Schreiber F, Esser A, Hölscher C, Fritsch M, Herb M, Schramm M, Wachsmuth L, Pallasch C, Pasparakis M, Kashkar H, Rybniker J. Corticosteroids inhibit Mycobacterium tuberculosis-induced necrotic host cell death by abrogating mitochondrial membrane permeability transition. Nat Commun 2019; 10:688. [PMID: 30737374 PMCID: PMC6368550 DOI: 10.1038/s41467-019-08405-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 01/09/2019] [Indexed: 12/16/2022] Open
Abstract
Corticosteroids are host-directed drugs with proven beneficial effect on survival of tuberculosis (TB) patients, but their precise mechanisms of action in this disease remain largely unknown. Here we show that corticosteroids such as dexamethasone inhibit necrotic cell death of cells infected with Mycobacterium tuberculosis (Mtb) by facilitating mitogen-activated protein kinase phosphatase 1 (MKP-1)-dependent dephosphorylation of p38 MAPK. Characterization of infected mixed lineage kinase domain-like (MLKL) and tumor necrosis factor receptor 1 (TNFR1) knockout cells show that the underlying mechanism is independent from TNFα-signaling and necroptosis. Our results link corticosteroid function and p38 MAPK inhibition to abrogation of necrotic cell death mediated by mitochondrial membrane permeability transition, and open new avenues for research on novel host-directed therapies (HDT). Corticosteroids are host-directed drugs that enhance survival of tuberculosis patients through unclear mechanisms. Here, Gräb et al. show that corticosteroids inhibit necrotic death of cells infected with Mycobacterium tuberculosis by facilitating MKP-1-dependent dephosphorylation of p38 MAPK.
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Affiliation(s)
- Jessica Gräb
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Isabelle Suárez
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
| | - Edeltraud van Gumpel
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Sandra Winter
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Fynn Schreiber
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Anna Esser
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany
| | - Christoph Hölscher
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner Site Hamburg - Lübeck - Borstel - Riems, 23845, Germany
| | - Melanie Fritsch
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Medical Microbiology, Immunology and Hygiene (IMMIH), University of Cologne, 50935, Cologne, Germany
| | - Marc Herb
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Medical Microbiology, Immunology and Hygiene (IMMIH), University of Cologne, 50935, Cologne, Germany
| | - Michael Schramm
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Medical Microbiology, Immunology and Hygiene (IMMIH), University of Cologne, 50935, Cologne, Germany
| | - Laurens Wachsmuth
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
| | - Christian Pallasch
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany
| | - Manolis Pasparakis
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Genetics, University of Cologne, 50674, Cologne, Germany
| | - Hamid Kashkar
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany.,Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.,Institute for Medical Microbiology, Immunology and Hygiene (IMMIH), University of Cologne, 50935, Cologne, Germany
| | - Jan Rybniker
- Department I of Internal Medicine, University of Cologne, 50937, Cologne, Germany. .,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany. .,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany.
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37
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Mycobacterium tuberculosis virulence inhibitors discovered by Mycobacterium marinum high-throughput screening. Sci Rep 2019; 9:26. [PMID: 30631100 PMCID: PMC6328581 DOI: 10.1038/s41598-018-37176-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 12/03/2018] [Indexed: 01/08/2023] Open
Abstract
High-throughput screening facilities do not generally support biosafety level 3 organisms such as Mycobacterium tuberculosis. To discover not only antibacterials, but also virulence inhibitors with either bacterial or host cell targets, an assay monitoring lung fibroblast survival upon infection was developed and optimized for 384-plate format and robotic liquid handling. By using Mycobacterium marinum as surrogate organism, 28,000 compounds were screened at biosafety level 2 classification, resulting in 49 primary hits. Exclusion of substances with unfavourable properties and known antimicrobials resulted in 11 validated hits of which 7 had virulence inhibiting properties and one had bactericidal effect also in wild type Mycobacterium tuberculosis. This strategy to discover virulence inhibitors using a model organism in high-throughput screening can be a valuable tool for other researchers working on drug discovery against tuberculosis and other biosafety level 3 infectious agents.
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Sala C, Odermatt NT, Soler-Arnedo P, Gülen MF, von Schultz S, Benjak A, Cole ST. EspL is essential for virulence and stabilizes EspE, EspF and EspH levels in Mycobacterium tuberculosis. PLoS Pathog 2018; 14:e1007491. [PMID: 30571761 PMCID: PMC6319747 DOI: 10.1371/journal.ppat.1007491] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/04/2019] [Accepted: 11/28/2018] [Indexed: 12/03/2022] Open
Abstract
The ESX-1, type VII, secretion system represents the major virulence determinant of Mycobacterium tuberculosis, one of the most successful intracellular pathogens. Here, by combining genetic and high-throughput approaches, we show that EspL, a protein of 115 amino acids, is essential for mediating ESX-1-dependent virulence and for stabilization of EspE, EspF and EspH protein levels. Indeed, an espL knock-out mutant was unable to replicate intracellularly, secrete ESX-1 substrates or stimulate innate cytokine production. Moreover, proteomic studies detected greatly reduced amounts of EspE, EspF and EspH in the espL mutant as compared to the wild type strain, suggesting a role for EspL as a chaperone. The latter conclusion was further supported by discovering that EspL interacts with EspD, which was previously demonstrated to stabilize the ESX-1 substrates and effector proteins, EspA and EspC. Loss of EspL also leads to downregulation in M. tuberculosis of WhiB6, a redox-sensitive transcriptional activator of ESX-1 genes. Overall, our data highlight the importance of a so-far overlooked, though conserved, component of the ESX-1 secretion system and begin to delineate the role played by EspE, EspF and EspH in virulence and host-pathogen interaction. Mycobacterium tuberculosis is the etiological agent of human tuberculosis, a life-threatening disease which has seen a recrudescence in the last decades due to the spread of drug-resistant bacterial strains and to co-morbidities such as HIV and diabetes. To develop effective treatment and limit bacterial dissemination within and outside the host, it is pivotal to improve our understanding of the strategies used by the pathogen to colonize the host and subvert the immune defenses. The ESX-1 secretion system represents a key player in these processes. Here we show that the EspL protein, encoded by the ESX-1 gene cluster, is essential for bacterial virulence and for stabilizing the abundance of the EspE, EspF and EspH components of the ESX-1 system. Tubercle bacilli lacking EspL cannot multiply inside macrophages, do not secrete the major virulence factor EsxA and fail to trigger the ESX-1 dependent innate immune response. EspL is thus an important but so-far neglected contributor to ESX-1 function.
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Affiliation(s)
- Claudia Sala
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- * E-mail: (CS); (STC)
| | - Nina T. Odermatt
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Paloma Soler-Arnedo
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Muhammet F. Gülen
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sofia von Schultz
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Andrej Benjak
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Stewart T. Cole
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- * E-mail: (CS); (STC)
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Abstract
Bacterial signal transduction systems are responsible for sensing environmental cues and adjusting the cellular behaviour and/or metabolism in response to these cues. They also monitor the intracellular conditions and the status of the cell envelope and the cytoplasmic membrane and trigger various stress responses to counteract adverse changes. This surveillance involves several classes of sensor proteins: histidine kinases; chemoreceptors; membrane components of the sugar phosphotransferase system; adenylate, diadenylate and diguanylate cyclases and certain cAMP, c-di-AMP and c-di-GMP phosphodiesterases; extracytoplasmic function sigma factors and Ser/Thr/Tyr protein kinases and phosphoprotein phosphatases. We have compiled a detailed listing of sensor proteins that are encoded in the genomes of Escherichia coli, Bacillus subtilis and 10 widespread pathogens: Chlamydia trachomatis, Haemophilus influenzae, Helicobacter pylori, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Neisseria gonorrhoeae, Porphyromonas gingivalis, Rickettsia typhi, Streptococcus pyogenes and Treponema pallidum, and checked what, if anything, is known about their functions. This listing shows significant gaps in the understanding of which environmental and intracellular cues are perceived by these bacteria and which cellular responses are triggered by the changes in the respective parameters. A better understanding of bacterial preferences may suggest new ways to modulate the expression of virulence factors and therefore decrease the reliance on antibiotics to fight infection.
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Affiliation(s)
- Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
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Accelerating Early Antituberculosis Drug Discovery by Creating Mycobacterial Indicator Strains That Predict Mode of Action. Antimicrob Agents Chemother 2018; 62:AAC.00083-18. [PMID: 29661879 DOI: 10.1128/aac.00083-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/27/2018] [Indexed: 12/14/2022] Open
Abstract
Due to the rise of drug-resistant forms of tuberculosis, there is an urgent need for novel antibiotics to effectively combat these cases and shorten treatment regimens. Recently, drug screens using whole-cell analyses have been shown to be successful. However, current high-throughput screens focus mostly on stricto sensu life/death screening that give little qualitative information. In doing so, promising compound scaffolds or nonoptimized compounds that fail to reach inhibitory concentrations are missed. To accelerate early tuberculosis (TB) drug discovery, we performed RNA sequencing on Mycobacterium tuberculosis and Mycobacterium marinum to map the stress responses that follow upon exposure to subinhibitory concentrations of antibiotics with known targets, ciprofloxacin, ethambutol, isoniazid, streptomycin, and rifampin. The resulting data set comprises the first overview of transcriptional stress responses of mycobacteria to different antibiotics. We show that antibiotics can be distinguished based on their specific transcriptional stress fingerprint. Notably, this fingerprint was more distinctive in M. marinum We decided to use this to our advantage and continue with this model organism. A selection of diverse antibiotic stress genes was used to construct stress reporters. In total, three functional reporters were constructed to respond to DNA damage, cell wall damage, and ribosomal inhibition. Subsequently, these reporter strains were used to screen a small anti-TB compound library to predict the mode of action. In doing so, we identified the putative modes of action for three novel compounds, which confirms the utility of our approach.
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Reens AL, Crooks AL, Su CC, Nagy TA, Reens DL, Podoll JD, Edwards ME, Yu EW, Detweiler CS. A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. PLoS Pathog 2018; 14:e1007115. [PMID: 29879224 PMCID: PMC6007937 DOI: 10.1371/journal.ppat.1007115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/19/2018] [Accepted: 05/21/2018] [Indexed: 12/20/2022] Open
Abstract
Bacterial efflux pumps transport small molecules from the cytoplasm or periplasm outside the cell. Efflux pump activity is typically increased in multi-drug resistant (MDR) pathogens; chemicals that inhibit efflux pumps may have potential for antibiotic development. Using an in-cell screen, we identified three efflux pump modulators (EPMs) from a drug diversity library. The screening platform uses macrophages infected with the human Gram-negative pathogen Salmonella enterica (Salmonella) to identify small molecules that prevent bacterial replication or survival within the host environment. A secondary screen for hit compounds that increase the accumulation of an efflux pump substrate, Hoechst 33342, identified three small molecules with activity comparable to the known efflux pump inhibitor PAβN (Phe-Arg β-naphthylamide). The three putative EPMs demonstrated significant antibacterial activity against Salmonella within primary and cell culture macrophages and within a human epithelial cell line. Unlike traditional antibiotics, the three compounds did not inhibit bacterial growth in standard microbiological media. The three compounds prevented energy-dependent efflux pump activity in Salmonella and bound the AcrB subunit of the AcrAB-TolC efflux system with KDs in the micromolar range. Moreover, the EPMs display antibacterial synergy with antimicrobial peptides, a class of host innate immune defense molecules present in body fluids and cells. The EPMs also had synergistic activity with antibiotics exported by AcrAB-TolC in broth and in macrophages and inhibited efflux pump activity in MDR Gram-negative ESKAPE clinical isolates. Thus, an in-cell screening approach identified EPMs that synergize with innate immunity to kill bacteria and have potential for development as adjuvants to antibiotics.
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Affiliation(s)
- Abigail L. Reens
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Amy L. Crooks
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve, Cleveland OH, United States of America
| | - Toni A. Nagy
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - David L. Reens
- Department of Physics, University of Colorado Boulder, Boulder, CO, United States of America
- JILA, National Institutes of Standards and Technology and University of Colorado Boulder, Boulder, CO, United States of America
| | - Jessica D. Podoll
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Madeline E. Edwards
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve, Cleveland OH, United States of America
| | - Corrella S. Detweiler
- Department of Molecular, Cellular, & Developmental Biology, University of Colorado Boulder, Boulder, CO, United States of America
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Esx Paralogs Are Functionally Equivalent to ESX-1 Proteins but Are Dispensable for Virulence in Mycobacterium marinum. J Bacteriol 2018; 200:JB.00726-17. [PMID: 29555701 DOI: 10.1128/jb.00726-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/11/2018] [Indexed: 12/20/2022] Open
Abstract
Mycobacterium marinum is a nontuberculous pathogen of poikilothermic fish and an opportunistic human pathogen. Like tuberculous mycobacteria, the M. marinum M strain requires the ESX-1 (ESAT-6 system 1) secretion system for virulence in host cells. EsxB and EsxA, two major virulence factors exported by the ESX-1 system, are encoded by the esxBA genes within the ESX-1 locus. Deletion of the esxBA genes abrogates ESX-1 export and attenuates M. marinum in ex vivo and in vivo models of infection. Interestingly, there are several duplications of the esxB and esxA genes (esxB_1, esxB_2, esxA_1, esxA_2, and esxA_3) in the M. marinum M genome located outside the ESX-1 locus. We sought to understand if this region, known as ESX-6, contributes to ESX-1-mediated virulence. We found that deletion of the esxB_1 gene alone or the entire ESX-6 locus did not impact ESX-1 export or function, supporting the idea that the esxBA genes present at the ESX-1 locus are the primary contributors to ESX-1-mediated virulence. Nevertheless, overexpression of the esxB_1 locus complemented ESX-1 function in the ΔesxBA strain, signifying that the two loci are functionally equivalent. Our findings raise questions about why duplicate versions of the esxBA genes are maintained in the M. marinum M genome and how these proteins, which are functionally equivalent to virulence factors, contribute to mycobacterial biology.IMPORTANCEMycobacterium tuberculosis is the causative agent of the human disease tuberculosis (TB). There are 10.4 million cases and 1.7 million TB-associated deaths annually, making TB a leading cause of death globally. Nontuberculous mycobacteria (NTM) cause chronic human infections that are acquired from the environment. Despite differences in disease etiology, both tuberculous and NTM pathogens use the ESX-1 secretion system to cause disease. The nontubercular mycobacterial species, Mycobacterium marinum, has additional copies of specific ESX-1 genes. Our findings demonstrate that the duplicated genes do not contribute to virulence but can substitute for virulence factors in M. marinum These findings suggest that the duplicated genes may play a specific role in NTM biology.
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Abstract
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Current tuberculosis
(TB) drug development efforts are not sufficient
to end the global TB epidemic. Recent efforts have focused on the
development of whole-cell screening assays because biochemical, target-based
inhibitor screens during the last two decades have not delivered new
TB drugs. Mycobacterium tuberculosis (Mtb), the causative
agent of TB, encounters diverse microenvironments and can be found
in a variety of metabolic states in the human host. Due to the complexity
and heterogeneity of Mtb infection, no single model can fully recapitulate
the in vivo conditions in which Mtb is found in TB patients, and there
is no single “standard” screening condition to generate
hit compounds for TB drug development. However, current screening
assays have become more sophisticated as researchers attempt to mirror
the complexity of TB disease in the laboratory. In this review, we
describe efforts using surrogates and engineered strains of Mtb to
focus screens on specific targets. We explain model culture systems
ranging from carbon starvation to hypoxia, and combinations thereof,
designed to represent the microenvironment which Mtb encounters in
the human body. We outline ongoing efforts to model Mtb infection
in the lung granuloma. We assess these different models, their ability
to generate hit compounds, and needs for further TB drug development,
to provide direction for future TB drug discovery.
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Affiliation(s)
- Tianao Yuan
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11794-3400, United States
| | - Nicole S Sampson
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11794-3400, United States.,Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University , Stellenbosch 7600, South Africa
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Cole ST. Inhibiting Mycobacterium tuberculosis within and without. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0506. [PMID: 27672155 DOI: 10.1098/rstb.2015.0506] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2016] [Indexed: 01/05/2023] Open
Abstract
Tuberculosis remains a scourge of global health with shrinking treatment options due to the spread of drug-resistant strains of Mycobacterium tuberculosis Intensive efforts have been made in the past 15 years to find leads for drug development so that better, more potent drugs inhibiting new targets could be produced and thus shorten treatment duration. Initial attempts focused on repurposing drugs that had been developed for other therapeutic areas but these agents did not meet their goals in clinical trials. Attempts to find new lead compounds employing target-based screens were unsuccessful as the leads were inactive against M. tuberculosis Greater success was achieved using phenotypic screening against live tubercle bacilli and this gave rise to the drugs bedaquiline, pretomanid and delamanid, currently in phase III trials. Subsequent phenotypic screens also uncovered new leads and targets but several of these targets proved to be promiscuous and inhibited by a variety of seemingly unrelated pharmacophores. This setback sparked an interest in alternative screening approaches that mimic the disease state more accurately. Foremost among these were cell-based screens, often involving macrophages, as these should reflect the bacterium's niche in the host more faithfully. A major advantage of this approach is its ability to uncover functions that are central to infection but not necessarily required for growth in vitro For instance, inhibition of virulence functions mediated by the ESX-1 secretion system severely attenuates intracellular M. tuberculosis, preventing intercellular spread and ultimately limiting tissue damage. Cell-based screens have highlighted the druggability of energy production via the electron transport chain and cholesterol metabolism. Here, I review the scientific progress and the pipeline, but warn against over-optimism due to the lack of industrial commitment for tuberculosis drug development and other socio-economic factors.This article is part of the themed issue 'The new bacteriology'.
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Affiliation(s)
- Stewart T Cole
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland
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Queval CJ, Brosch R, Simeone R. The Macrophage: A Disputed Fortress in the Battle against Mycobacterium tuberculosis. Front Microbiol 2017; 8:2284. [PMID: 29218036 PMCID: PMC5703847 DOI: 10.3389/fmicb.2017.02284] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/06/2017] [Indexed: 01/09/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the etiological agent of human tuberculosis (TB), has plagued humans for thousands of years. TB still remains a major public health problem in our era, causing more than 4,400 deaths worldwide every day and killing more people than HIV. After inhaling Mtb-contaminated aerosols, TB primo-infection starts in the terminal lung airways, where Mtb is taken up by alveolar macrophages. Although macrophages are known as professional killers for pathogens, Mtb has adopted remarkable strategies to circumvent host defenses, building suitable conditions to survive and proliferate. Within macrophages, Mtb initially resides inside phagosomes, where its survival mostly depends on its ability to take control of phagosomal processing, through inhibition of phagolysosome biogenesis and acidification processes, and by progressively getting access to the cytosol. Bacterial access to the cytosolic space is determinant for specific immune responses and cell death programs, both required for the replication and the dissemination of Mtb. Comprehension of the molecular events governing Mtb survival within macrophages is fundamental for the improvement of vaccine-based and therapeutic strategies in order to help the host to better defend itself in the battle against the fierce invader Mtb. In this mini-review, we discuss recent research exploring how Mtb conquers and transforms the macrophage into a strategic base for its survival and dissemination as well as the associated defense strategies mounted by host.
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Affiliation(s)
| | | | - Roxane Simeone
- Unit for Integrated Mycobacterial Pathogenomics, Institut Pasteur, Paris, France
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Bown L, Srivastava SK, Piercey BM, McIsaac CK, Tahlan K. Mycobacterial Membrane Proteins QcrB and AtpE: Roles in Energetics, Antibiotic Targets, and Associated Mechanisms of Resistance. J Membr Biol 2017; 251:105-117. [DOI: 10.1007/s00232-017-9997-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 02/08/2023]
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Yates TA, Tomlinson LA, Bhaskaran K, Langan S, Thomas S, Smeeth L, Douglas IJ. Lansoprazole use and tuberculosis incidence in the United Kingdom Clinical Practice Research Datalink: A population based cohort. PLoS Med 2017; 14:e1002457. [PMID: 29161254 PMCID: PMC5697821 DOI: 10.1371/journal.pmed.1002457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 10/23/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Recent in vitro and animal studies have found the proton pump inhibitor (PPI) lansoprazole to be highly active against Mycobacterium tuberculosis. Omeprazole and pantoprazole have no activity. There is no evidence that, in clinical practice, lansoprazole can treat or prevent incident tuberculosis (TB) disease. METHODS AND FINDINGS We studied a cohort of new users of lansoprazole, omeprazole, or pantoprazole from the United Kingdom Clinical Practice Research Datalink to determine whether lansoprazole users have a lower incidence of TB disease than omeprazole or pantoprazole users. Negative control outcomes of myocardial infarction (MI) and herpes zoster were also studied. Multivariable Cox proportional hazards regression was used to adjust for potential confounding by a wide range of factors. We identified 527,364 lansoprazole initiators and 923,500 omeprazole or pantoprazole initiators. Lansoprazole users had a lower rate of TB disease (n = 86; 10.0 cases per 100,000 person years; 95% confidence interval 8.1-12.4) than omeprazole or pantoprazole users (n = 193; 15.3 cases per 100,000 person years; 95% confidence interval 13.3-17.7), with an adjusted hazard ratio (HR) of 0.68 (0.52-0.89). No association was found with MI (adjusted HR 1.04; 95% confidence interval 1.00-1.08) or herpes zoster (adjusted HR 1.03; 95% confidence interval 1.00-1.06). Limitations of this study are that we could not determine whether TB disease was due to reactivation of latent infection or a result of recent transmission, nor could we determine whether lansoprazole would have a beneficial effect if given to people presenting with TB disease. CONCLUSIONS In this study, use of the commonly prescribed and cheaply available PPI lansoprazole was associated with reduced incidence of TB disease. Given the serious problem of drug resistance and the adverse side effect profiles of many TB drugs, further investigation of lansoprazole as a potential antituberculosis agent is warranted.
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Affiliation(s)
- Tom A. Yates
- Institute for Global Health, University College London, Institute of Child Health, London, United Kingdom
| | | | | | - Sinead Langan
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Sara Thomas
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Liam Smeeth
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Ian J. Douglas
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
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Abstract
In this article, we have described several cellular pathological effects caused by the Mycobacterium tuberculosis ESX-1. The effects include induction of necrosis, NOD2 signaling, type I interferon production, and autophagy. We then attempted to suggest that these pathological effects are mediated by the cytosolic access of M. tuberculosis-derived materials as a result of the phagosome-disrupting activity of the major ESX-1 substrate ESAT-6. Such activity of ESAT-6 is most likely due to its pore-forming activity at the membrane. The amyloidogenic characteristic of ESAT-6 is reviewed here as a potential mechanism of membrane pore formation. In addition to ESAT-6, the ESX-1 substrate EspB interferes with membrane-mediated innate immune mechanisms such as efferocytosis and autophagy, most likely through its ability to bind phospholipids. Overall, the M. tuberculosis ESX-1 secretion system appears to be a specialized system for the deployment of host membrane-targeting proteins, whose primary function is to interrupt key steps in innate immune mechanisms against pathogens. Inhibitors that block the ESX-1 system or block host factors critical for ESX-1 toxicity have been identified and should represent attractive potential new antituberculosis drugs.
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Mukherjee R, Chandra Pal A, Banerjee M. Enabling faster Go/No-Go decisions through secondary screens in anti-mycobacterial drug discovery. Tuberculosis (Edinb) 2017; 106:44-52. [PMID: 28802404 DOI: 10.1016/j.tube.2017.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 03/30/2017] [Accepted: 06/28/2017] [Indexed: 10/19/2022]
Abstract
Management of tuberculosis, already a global health emergency, is becoming increasingly challenging with extensive misuse of second line drugs and their inaccessibility to eighty percent of the eligible patients. Rising statistics of antimicrobial resistance underscores the need for a set of completely new and more effective class of compounds with novel mechanisms of action that can be administered in combination to replace and shorten the present intensive six months regimen. In this review, we stress on the importance and the successes of phenotypic screening for discovery of anti-mycobacterial compound and discuss the importance of performing secondary screens and counter screens to get early estimate on compound's potentials for a successful development. We also highlight the recent advances and the related caveats in the assays that have been developed and discuss new screening modalities that can be incorporated during hit-selection to gain a quick insight into the mechanism of action, thus enabling quicker decisions in a hit triage.
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Affiliation(s)
- Raju Mukherjee
- Division of Biology, Indian Institute of Science Education and Research, Karakambadi Road, Tirupati, 517507, India.
| | - Anup Chandra Pal
- Division of Biology, Indian Institute of Science Education and Research, Karakambadi Road, Tirupati, 517507, India
| | - Mousumi Banerjee
- Indian Institute of Technology, Tirupati, Renigunta Road, Tirupati, 517506, India
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Inhibitors of Mycobacterium marinum virulence identified in a Dictyostelium discoideum host model. PLoS One 2017; 12:e0181121. [PMID: 28727774 PMCID: PMC5519057 DOI: 10.1371/journal.pone.0181121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/26/2017] [Indexed: 12/21/2022] Open
Abstract
Tuberculosis remains one of the major threats to public health worldwide. Given the prevalence of multi drug resistance (MDR) in Mycobacterium tuberculosis strains, there is a strong need to develop new anti-mycobacterial drugs with modes of action distinct from classical antibiotics. Inhibitors of mycobacterial virulence might target new molecular processes and may represent a potential new therapeutic alternative. In this study, we used a Dictyostelium discoideum host model to assess virulence of Mycobacterium marinum and to identify compounds inhibiting mycobacterial virulence. Among 9995 chemical compounds, we selected 12 inhibitors of mycobacterial virulence that do not inhibit mycobacterial growth in synthetic medium. Further analyses revealed that 8 of them perturbed functions requiring an intact mycobacterial cell wall such as sliding motility, bacterial aggregation or cell wall permeability. Chemical analogs of two compounds were analyzed. Chemical modifications altered concomitantly their effect on sliding motility and on mycobacterial virulence, suggesting that the alteration of the mycobacterial cell wall caused the loss of virulence. We characterized further one of the selected compounds and found that it inhibited the ability of mycobacteria to replicate in infected cells. Together these results identify new antimycobacterial compounds that represent new tools to unravel the molecular mechanisms controlling mycobacterial pathogenicity. The isolation of compounds with anti-virulence activity is the first step towards developing new antibacterial treatments.
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