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D'Elia JA, Weinrauch LA. Gated Calcium Ion Channel and Mutation Mechanisms in Multidrug-Resistant Tuberculosis. Int J Mol Sci 2023; 24:ijms24119670. [PMID: 37298620 DOI: 10.3390/ijms24119670] [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: 02/28/2023] [Revised: 05/16/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
A wide spectrum of Gram-positive/Gram-negative bacteria has been found resistant to a wide spectrum of antibiotics in the United States of America during the past decade. Drug-resistant tuberculosis is not yet a major threat in North/South America, Europe, and the Middle East. However, the migration of populations in times of drought, famine, and hostilities may increase the global reach of this ancient pathogen. Given an increased spread from China and India to African countries, drug-resistant Mycobacterium tuberculosis has become an emerging topic of concern for Europe and North America. Due to the dangers associated with the spread of pathogens among different populations, the World Health Organization continues to expand healthcare advisories for therapeutic approaches for both stationary and migrating populations. As much of the literature focuses on endemic to pandemic viruses, we remain concerned that other treatable communicable diseases may be ignored. One such disease is multidrug-resistant tuberculosis. We focus on molecular mechanisms that this pathogen relies upon for the development of multidrug resistance via gene mutation and the evolutionary development of new enzyme and calcium channels.
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Affiliation(s)
- John A D'Elia
- Kidney/Hypertension Section, E P Joslin Research Laboratory, Joslin Diabetes Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Larry A Weinrauch
- Kidney/Hypertension Section, E P Joslin Research Laboratory, Joslin Diabetes Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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2
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Sankey N, Merrick H, Singh P, Rogers J, Reddi A, Hartson SD, Mitra A. Role of the Mycobacterium tuberculosis ESX-4 Secretion System in Heme Iron Utilization and Pore Formation by PPE Proteins. mSphere 2023; 8:e0057322. [PMID: 36749044 PMCID: PMC10117145 DOI: 10.1128/msphere.00573-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/16/2023] [Indexed: 02/08/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is transmitted through aerosols and primarily colonizes within the lung. The World Health Organization estimates that Mtb kills ~1.4 million people every year. A key aspect that makes Mtb such a successful pathogen is its ability to overcome iron limitation mounted by the host immune response. In our previous studies, we have shown that Mtb can utilize iron from heme, the largest source of iron in the human host, and that it uses two redundant heme utilization pathways. In this study, we show that the ESX-4 type VII secretion system (T7SS) is necessary for extracellular heme uptake into the Mtb cell through both heme utilization pathways. ESX-4 influences the secretion of the culture filtrate proteins Rv0125 and Rv1085c, which are also necessary for efficient heme utilization. We also discovered that deletion of the alternative sigma factor SigM significantly reduced Mtb heme utilization through both pathways and predict that SigM is a global positive regulator of core heme utilization genes of both pathways. Finally, we present the first direct evidence that some mycobacterial PPE (proline-proline-glutamate motif) proteins of the PPE protein family are pore-forming membrane proteins. Altogether, we identified core components of both Mtb Heme utilization pathways that were previously unknown and identified a novel channel-forming membrane protein of Mtb. IMPORTANCE M. tuberculosis (Mtb) is completely dependent on iron acquisition in the host to cause disease. The largest source of iron for Mtb in the human host is heme. Here, we show that the ancestral ESX-4 type VII secretion system is required for the efficient utilization of heme as a source of iron, which is an essential nutrient. This is another biological function identified for ESX-4 in Mtb, whose contribution to Mtb physiology is poorly understood. A most exciting finding is that some mycobacterial PPE (proline-proline-glutamate motif) proteins that have been implicated in the nutrient acquisition are membrane proteins that can form channels in a lipid bilayer. These observations have far-reaching implications because they support an emerging theme that PPE proteins can function as channel proteins in the outer mycomembrane for nutrient acquisition. Mtb has evolved a heme uptake system that is drastically different from all other known bacterial heme acquisition systems.
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Affiliation(s)
- November Sankey
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Haley Merrick
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Padam Singh
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Janet Rogers
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Amit Reddi
- School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Steven D. Hartson
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Avishek Mitra
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
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FtsEX-independent control of RipA-mediated cell separation in Corynebacteriales. Proc Natl Acad Sci U S A 2022; 119:e2214599119. [PMID: 36469781 PMCID: PMC9897464 DOI: 10.1073/pnas.2214599119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The bacterial cell wall is a multi-layered mesh, whose major component is peptidoglycan (PG), a sugar polymer cross-linked by short peptide stems. During cell division, a careful balance of PG synthesis and degradation, precisely coordinated both in time and space, is necessary to prevent uncontrolled destruction of the cell wall. In Corynebacteriales, the D,L endopeptidase RipA has emerged as a major PG hydrolase for cell separation, and RipA defaults have major implications for virulence of the human pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae. However, the precise mechanisms by which RipA mediates cell separation remain elusive. Here we report phylogenetic, biochemical, and structural analysis of the Corynebacterium glutamicum homologue of RipA, Cg1735. The crystal structures of full-length Cg1735 in two different crystal forms revealed the C-terminal NlpC/P60 catalytic domain obtruded by its N-terminal conserved coiled-coil domain, which locks the enzyme in an autoinhibited state. We show that this autoinhibition is relieved by the extracellular core domain of the transmembrane septal protein Cg1604. The crystal structure of Cg1604 revealed a (β/α) protein with an overall topology similar to that of receiver domains from response regulator proteins. The atomic model of the Cg1735-Cg1604 complex, based on bioinformatical and mutational analysis, indicates that a conserved, distal-membrane helical insertion in Cg1604 is responsible for Cg1735 activation. The reported data provide important insights into how intracellular cell division signal(s), yet to be identified, control PG hydrolysis during RipA-mediated cell separation in Corynebacteriales.
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Poulton NC, Rock JM. Unraveling the mechanisms of intrinsic drug resistance in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:997283. [PMID: 36325467 PMCID: PMC9618640 DOI: 10.3389/fcimb.2022.997283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/30/2022] [Indexed: 02/03/2023] Open
Abstract
Tuberculosis (TB) is among the most difficult infections to treat, requiring several months of multidrug therapy to produce a durable cure. The reasons necessitating long treatment times are complex and multifactorial. However, one major difficulty of treating TB is the resistance of the infecting bacterium, Mycobacterium tuberculosis (Mtb), to many distinct classes of antimicrobials. This review will focus on the major gaps in our understanding of intrinsic drug resistance in Mtb and how functional and chemical-genetics can help close those gaps. A better understanding of intrinsic drug resistance will help lay the foundation for strategies to disarm and circumvent these mechanisms to develop more potent antitubercular therapies.
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5
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Llorca MG, Martínez-Espinosa RM. Assessment of Haloferax mediterranei Genome in Search of Copper-Molecular Machinery With Potential Applications for Bioremediation. Front Microbiol 2022; 13:895296. [PMID: 35783429 PMCID: PMC9240420 DOI: 10.3389/fmicb.2022.895296] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
Heavy metals are essential micronutrients at low concentrations, serving as cofactors for relevant microbial enzymes (i.e., respiratory nitrate and nitrite reductases NADH dehydrogenase-2, amine oxidase, etc.), but they become harmful cellular intoxicants at significant low concentrations compared to other chemical compounds. The increasing need to incorporate bioremediation in the removal of heavy metals and other contaminants from wastewaters has led extremophiles to the spotlight of research. The haloarchaeon Haloferax mediterranei has promising physiological characteristics regarding bioremediation. However, little is known about how haloarchaea manage to resist high concentrations of heavy metals in the environment. The aim of this work is to develop bioinformatics research as the first step for further omics-based studies to shed light on copper metabolism in haloarchaea by analyzing H. mediterranei genome (strain ATCC 33500). To reach this aim, genome and protein databases have been consulted, and copper-related genes have been identified. BLAST analysis has been carried out to find similarities between copper resistance genes described from other microorganisms and H. mediterranei genes. Plausible copper importer genes, genes coding for siderophores, and copper exporters belonging to P1B-type ATPase group have been found apart from genes encoding copper chaperones, metal-responsive transcriptional regulators, and several proteins belonging to the cupredoxin superfamily: nitrite reductase, nitrous oxide reductases, cytochrome c oxidases, multicopper oxidases, and small blue copper proteins from the amicyanin/pseudoazurin families as halocyanins. As the presence of heavy metals causes oxidative stress, genes coding for proteins involved in antioxidant mechanisms have been also explored: thioredoxin, glutaredoxin, peroxiredoxin, catalase, and γ-glutamylcysteine as an analog of glutathione. Bioinformatic-based analysis of H. mediterranei genome has revealed a set of genes involved in copper metabolism that could be of interest for bioremediation purposes. The analysis of genes involved in antioxidative mechanisms against heavy metals makes it possible to infer the capability of H. mediterranei to synthesize inorganic polyphosphate granules against oxidative stress.
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Affiliation(s)
- Marina García Llorca
- Biochemistry and Molecular Biology Division, Department of Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Alicante, Spain
| | - Rosa María Martínez-Espinosa
- Biochemistry and Molecular Biology Division, Department of Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Alicante, Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Alicante, Spain
- *Correspondence: Rosa María Martínez-Espinosa,
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Borah P, Deb PK, Venugopala KN, Al-Shar'i NA, Singh V, Deka S, Srivastava A, Tiwari V, Mailavaram RP. Tuberculosis: An Update on Pathophysiology, Molecular Mechanisms of Drug Resistance, Newer Anti-TB Drugs, Treatment Regimens and Host- Directed Therapies. Curr Top Med Chem 2021; 21:547-570. [PMID: 33319660 DOI: 10.2174/1568026621999201211200447] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/16/2020] [Accepted: 11/19/2020] [Indexed: 11/22/2022]
Abstract
Human tuberculosis (TB) is primarily caused by Mycobacterium tuberculosis (Mtb) that inhabits inside and amidst immune cells of the host with adapted physiology to regulate interdependent cellular functions with intact pathogenic potential. The complexity of this disease is attributed to various factors such as the reactivation of latent TB form after prolonged persistence, disease progression specifically in immunocompromised patients, advent of multi- and extensivelydrug resistant (MDR and XDR) Mtb strains, adverse effects of tailor-made regimens, and drug-drug interactions among anti-TB drugs and anti-HIV therapies. Thus, there is a compelling demand for newer anti-TB drugs or regimens to overcome these obstacles. Considerable multifaceted transformations in the current TB methodologies and molecular interventions underpinning hostpathogen interactions and drug resistance mechanisms may assist to overcome the emerging drug resistance. Evidently, recent scientific and clinical advances have revolutionised the diagnosis, prevention, and treatment of all forms of the disease. This review sheds light on the current understanding of the pathogenesis of TB disease, molecular mechanisms of drug-resistance, progress on the development of novel or repurposed anti-TB drugs and regimens, host-directed therapies, with particular emphasis on underlying knowledge gaps and prospective for futuristic TB control programs.
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Affiliation(s)
- Pobitra Borah
- Pratiksha Institute of Pharmaceutical Sciences, Chandrapur Road, Panikhaiti, Guwahati-26, Assam, India
| | - Pran K Deb
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Philadelphia University, PO Box 1, Amman 19392, Jordan
| | - Katharigatta N Venugopala
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Nizar A Al-Shar'i
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, P.O. Box 3030, Irbid, 22110, Jordan
| | - Vinayak Singh
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, 7701, South Africa
| | - Satyendra Deka
- Pratiksha Institute of Pharmaceutical Sciences, Chandrapur Road, Panikhaiti, Guwahati-26, Assam, India
| | - Amavya Srivastava
- Neuroscience and Pain Research Lab, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, 221 005, India
| | - Vinod Tiwari
- Neuroscience and Pain Research Lab, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, 221 005, India
| | - Raghu P Mailavaram
- Department of Pharmaceutical Chemistry, Shri Vishnu College of Pharmacy, Vishnupur, Bhimavaram - 534 202, West Godavari Dist., Andhra Pradesh, India
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7
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Ehtram A, Shariq M, Ali S, Quadir N, Sheikh JA, Ahmad F, Sharma T, Ehtesham NZ, Hasnain SE. Teleological cooption of Mycobacterium tuberculosis PE/PPE proteins as porins: Role in molecular immigration and emigration. Int J Med Microbiol 2021; 311:151495. [PMID: 33730677 DOI: 10.1016/j.ijmm.2021.151495] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/01/2021] [Accepted: 03/05/2021] [Indexed: 01/09/2023] Open
Abstract
Permeation through bacterial cells for exchange or uptake of biomolecules and ions invariably depend upon the existence of pore-forming proteins (porins) in their outer membrane. Mycobacterium tuberculosis (M. tb) harbours one of the most rigid cell envelopes across bacterial genera and is devoid of the classical porins for solute transport across the cell membrane. Though canonical porins are incompatible with the evolution of permeability barrier, porin like activity has been reported from membrane preparations of pathogenic mycobacteria. This suggests a sophisticated transport mechanism that has been elusive until now, along with the protein family responsible for it. Recent evidence suggests that these slow-growing mycobacteria have co-opted some of PE/PPE family proteins as molecular transport channels, in place of porins, to facilitate uptake of nutrients required to thrive in the restrictive host environment. These reports advocate that PE/PPE proteins, due to their structural ability, have a potential role in importing small molecules to the cell's interior. This mechanism unveils how a successful pathogen overcomes its restrictive membrane's transport limitations for selective uptake of nutrients. If extrapolated to have a role in drug transport, these channels could help understand the emergence of drug resistance. Further, as these proteins are associated with the export of virulence factors, they can be exploited as novel drug targets. There remains, however, an interesting question that as the PE/PPE proteins can allow the 'import' of molecules from outside the cell, is the reverse transport also possible across the M. tb membrane. In this review, we have discussed recent evidence supporting PE/PPE's role as a specific transport channel for selective uptake of small molecule nutrients and, as possible molecular export machinery of M. tb. This newly discovered role as transmembrane channels demands further research on this enigmatic family of proteins to comprehend the pathomechanism of this very smart pathogen.
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Affiliation(s)
- Aquib Ehtram
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Mohd Shariq
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India
| | - Sabeeha Ali
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Neha Quadir
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India; Jamia Hamdard- Institute of Molecular Medicine, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Javaid A Sheikh
- Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi, 110062, India
| | - Faraz Ahmad
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India
| | - Tarina Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India; ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India
| | - Nasreen Z Ehtesham
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India.
| | - Seyed E Hasnain
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India; Dr Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, India.
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8
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Swain SS, Sharma D, Hussain T, Pati S. Molecular mechanisms of underlying genetic factors and associated mutations for drug resistance in Mycobacterium tuberculosis. Emerg Microbes Infect 2021; 9:1651-1663. [PMID: 32573374 PMCID: PMC7473167 DOI: 10.1080/22221751.2020.1785334] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nowadays, drug-resistant tuberculosis (DR-TB) and co-infected tuberculosis (CI-TB) strains are the leading cause for the enhancement of long-term morbidity and unpredicted mortality rates from this ghoulish acid fast-bacterium infection, globally. Unfortunately, the lack of/ample lethargic towards the development of compelling anti-TB regimens with a large-scale prevalence rate is a great challenge towards control of the pandemic situation. Indeed, the recent improvement in genomic studies for early diagnosis and understanding the mechanisms of drug resistance, as well as the identification of newer drug targets is quite remarkable and promising. Mainly, identification of such genetic factors, chromosomal mutations and associated pathways gives new ray of hope in current anti-TB drug discovery. This focused review provides molecular insights into the updated drug resistance mechanisms with encoded bacilli genetic factors as a novel target and potential source of development with screened-out newer anti-TB agents towards the control of MDR-TB soon.
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Affiliation(s)
- Shasank S Swain
- Division of Microbiology and NCDs, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Divakar Sharma
- CRF, Mass Spectrometry Laboratory, Kusuma School of Biological Sciences (KSBS), Indian Institute of Technology-Delhi (IIT-D), Delhi, India
| | - Tahziba Hussain
- Division of Microbiology and NCDs, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sanghamitra Pati
- Division of Public Health and Research, ICMR-Regional Medical Research Centre, Bhubaneswar, India
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9
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Pore-forming Esx proteins mediate toxin secretion by Mycobacterium tuberculosis. Nat Commun 2021; 12:394. [PMID: 33452244 PMCID: PMC7810871 DOI: 10.1038/s41467-020-20533-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 11/25/2020] [Indexed: 01/29/2023] Open
Abstract
Mycobacterium tuberculosis secretes the tuberculosis necrotizing toxin (TNT) to kill host cells. Here, we show that the WXG100 proteins EsxE and EsxF are essential for TNT secretion. EsxE and EsxF form a water-soluble heterodimer (EsxEF) that assembles into oligomers and long filaments, binds to membranes, and forms stable membrane-spanning channels. Electron microscopy of EsxEF reveals mainly pentameric structures with a central pore. Mutations of both WXG motifs and of a GXW motif do not affect dimerization, but abolish pore formation, membrane deformation and TNT secretion. The WXG/GXW mutants are locked in conformations with altered thermostability and solvent exposure, indicating that the WXG/GXW motifs are molecular switches controlling membrane interaction and pore formation. EsxF is accessible on the bacterial cell surface, suggesting that EsxEF form an outer membrane channel for toxin export. Thus, our study reveals a protein secretion mechanism in bacteria that relies on pore formation by small WXG proteins.
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10
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Goossens SN, Sampson SL, Van Rie A. Mechanisms of Drug-Induced Tolerance in Mycobacterium tuberculosis. Clin Microbiol Rev 2020; 34:e00141-20. [PMID: 33055230 PMCID: PMC7566895 DOI: 10.1128/cmr.00141-20] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Successful treatment of tuberculosis (TB) can be hampered by Mycobacterium tuberculosis populations that are temporarily able to survive antibiotic pressure in the absence of drug resistance-conferring mutations, a phenomenon termed drug tolerance. We summarize findings on M. tuberculosis tolerance published in the past 20 years. Key M. tuberculosis responses to drug pressure are reduced growth rates, metabolic shifting, and the promotion of efflux pump activity. Metabolic shifts upon drug pressure mainly occur in M. tuberculosis's lipid metabolism and redox homeostasis, with reduced tricarboxylic acid cycle activity in favor of lipid anabolism. Increased lipid anabolism plays a role in cell wall thickening, which reduces sensitivity to most TB drugs. In addition to these general mechanisms, drug-specific mechanisms have been described. Upon isoniazid exposure, M. tuberculosis reprograms several pathways associated with mycolic acid biosynthesis. Upon rifampicin exposure, M. tuberculosis upregulates the expression of its drug target rpoB Upon bedaquiline exposure, ATP synthesis is stimulated, and the transcription factors Rv0324 and Rv0880 are activated. A better understanding of M. tuberculosis's responses to drug pressure will be important for the development of novel agents that prevent the development of drug tolerance following treatment initiation. Such agents could then contribute to novel TB treatment-shortening strategies.
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Affiliation(s)
- Sander N Goossens
- Family Medicine and Population Health (FAMPOP), Faculty of Medicine and Health Sciences, University of Antwerp, Wilrijk, Belgium
| | - Samantha L Sampson
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Annelies Van Rie
- Family Medicine and Population Health (FAMPOP), Faculty of Medicine and Health Sciences, University of Antwerp, Wilrijk, Belgium
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Rahmat Ullah S, Majid M, Rashid MI, Mehmood K, Andleeb S. Immunoinformatics Driven Prediction of Multiepitopic Vaccine Against Klebsiella pneumoniae and Mycobacterium tuberculosis Coinfection and Its Validation via In Silico Expression. Int J Pept Res Ther 2020; 27:987-999. [PMID: 33281529 PMCID: PMC7703501 DOI: 10.1007/s10989-020-10144-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2020] [Indexed: 01/20/2023]
Abstract
Klebsiella pneumoniae and Mycobacterium tuberculosis coinfection is one of the most lethal combinations that has been becoming frequent yet, not diagnosed and reported properly. Due to the simultaneous occurrence of both infections, diagnosis is delayed leading to inadequate treatments and mortality. With the rise of MDR Klebsiella and Mycobacterium, a prophylactic and an immunotherapeutic vaccine has to be entailed for preemptive and adroit therapeutic approach. In this study, we aim to implement reverse vaccinology approach that encompasses a comprehensive evaluation of vital aspects of the pathogens to explore immunogenic epitopes against Omp A of Klebsiella and Rv1698, Rv1973 of Mtb that may help in vaccine development. The designed multi-epitopic vaccine was assessed for antigenicity, allergenicity and various physiochemical parameters. Molecular docking and simulations were executed to assess the immunogenicity and complex stability of the vaccine. The final multi-epitopic vaccine is validated to be highly immunogenic and can serve as a valuable proactive remedy for subject pathogens.
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Affiliation(s)
- Sidra Rahmat Ullah
- Department of Industrial Biotechnology, Atta ur Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Mahnoor Majid
- Department of Industrial Biotechnology, Atta ur Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Muhammad Ibrahim Rashid
- Department of Industrial Biotechnology, Atta ur Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad, Pakistan
- Institute of Basic Medical Sciences, Khyber Medical University (KMU), Peshawar, Pakistan
| | - Khalid Mehmood
- Department of Pharmaceutics, College of Pharmacy, Kingdom of Saudi Arabia, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Saadia Andleeb
- Department of Industrial Biotechnology, Atta ur Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad, Pakistan
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12
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Barbero AM, Trotta A, Genoula M, Pino REHD, Estermann MA, Celano J, Fuentes F, García VE, Balboa L, Barrionuevo P, Pasquinelli V. SLAMF1 signaling induces Mycobacterium tuberculosis uptake leading to endolysosomal maturation in human macrophages. J Leukoc Biol 2020; 109:257-273. [PMID: 32991756 DOI: 10.1002/jlb.4ma0820-655rr] [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: 03/15/2020] [Revised: 08/19/2020] [Accepted: 09/02/2020] [Indexed: 01/18/2023] Open
Abstract
Tuberculosis dates back to ancient times but it is not a problem of the past. Each year, millions of people die from tuberculosis. After inhalation of infectious droplet nuclei, Mycobacterium tuberculosis reaches the lungs where it can manipulate the immune system and survive within host macrophages, establishing a persistent infection. The signaling lymphocytic activation molecule family member 1 (SLAMF1) is a self-ligand receptor that can internalize gram-negative bacteria and regulate macrophages' phagosomal functions. In tuberculosis, SLAMF1 promotes Th1-protective responses. In this work, we studied the role of SLAMF1 on macrophages' functions during M. tuberculosis infection. Our results showed that both M. tuberculosis and IFN-γ stimulation induce SLAMF1 expression in macrophages from healthy donor and Tohoku Hospital Pediatrcs-1 cells. Costimulation through SLAMF1 with an agonistic antibody resulted in an enhanced internalization of M. tuberculosis by macrophages. Interestingly, we found that SLAMF1 interacts with M. tuberculosis and colocalizes with the bacteria and with early and late endosomes/lysosomes markers (EEA1 and LAMP2), suggesting that SLAMF1 recognize M. tuberculosis and participate in the endolysosomal maturation process. Notably, increased levels of SLAMF1 were detected in CD14 cells from pleural effusions of tuberculosis patients, indicating that SLAMF1 might have an active function at the site of infection. Taken together, our results provide evidence that SLAMF1 improves the uptake of M. tuberculosis by human monocyte-derived macrophages.
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Affiliation(s)
- Angela María Barbero
- Center for Basic and Applied Research (CIBA), National University of the Northwest of the Province of Buenos Aires (UNNOBA), B6000DNE, Buenos Aires, Argentina.,Center for Research and Transfers of the Northwest of the Province of Buenos Aires (CIT NOBA), UNNOBA-National University of San Antonio de Areco (UNSAdA) - National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - Aldana Trotta
- Institute of Experimental Medicine (CONICET-National Academy of Medicine), C1425ASU, Buenos Aires, Argentina
| | - Melanie Genoula
- Institute of Experimental Medicine (CONICET-National Academy of Medicine), C1425ASU, Buenos Aires, Argentina
| | - Rodrigo Emanuel Hernández Del Pino
- Center for Basic and Applied Research (CIBA), National University of the Northwest of the Province of Buenos Aires (UNNOBA), B6000DNE, Buenos Aires, Argentina.,Center for Research and Transfers of the Northwest of the Province of Buenos Aires (CIT NOBA), UNNOBA-National University of San Antonio de Areco (UNSAdA) - National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - Martín Andrés Estermann
- Center for Basic and Applied Research (CIBA), National University of the Northwest of the Province of Buenos Aires (UNNOBA), B6000DNE, Buenos Aires, Argentina.,Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Victoria, Clayton, Australia
| | - Josefina Celano
- Center for Basic and Applied Research (CIBA), National University of the Northwest of the Province of Buenos Aires (UNNOBA), B6000DNE, Buenos Aires, Argentina
| | - Federico Fuentes
- Institute of Experimental Medicine (CONICET-National Academy of Medicine), C1425ASU, Buenos Aires, Argentina
| | - Verónica Edith García
- CONICET-University of Buenos Aires, Institute of Biological Chemistry of Exact and Natural Sciences (IQUIBICEN), C1428EHA, Buenos Aires, Argentina.,University of Buenos Aires, School of Sciences, Department of Biological Chemistry, C1428EHA, Buenos Aires, Argentina
| | - Luciana Balboa
- Institute of Experimental Medicine (CONICET-National Academy of Medicine), C1425ASU, Buenos Aires, Argentina
| | - Paula Barrionuevo
- Institute of Experimental Medicine (CONICET-National Academy of Medicine), C1425ASU, Buenos Aires, Argentina
| | - Virginia Pasquinelli
- Center for Basic and Applied Research (CIBA), National University of the Northwest of the Province of Buenos Aires (UNNOBA), B6000DNE, Buenos Aires, Argentina.,Center for Research and Transfers of the Northwest of the Province of Buenos Aires (CIT NOBA), UNNOBA-National University of San Antonio de Areco (UNSAdA) - National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
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13
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Metal center ion effects on photoinactivating rapidly growing mycobacteria using water-soluble tetra-cationic porphyrins. Biometals 2020; 33:269-282. [PMID: 32980947 DOI: 10.1007/s10534-020-00251-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/16/2020] [Indexed: 12/18/2022]
Abstract
Rapidly growing mycobacteria (RGM) are pathogens that belong to the mycobacteriaceae family and responsible for causing mycobacterioses, which are infections of opportunistic nature and with increasing incidence rates in the world population. This work evaluated the use of six water-soluble cationic porphyrins as photosensitizers for the antimicrobial photodynamic therapy (aPDT) of four RGM strains: Mycolicibacterium fortuitum, Mycolicibacterium smeagmatis, Mycobacteroides abscessus subs. Abscessus, and Mycobacteroides abscessus subsp. massiliense. Experiments were conducted with an adequate concentration of photosensitizer under white-light irradiation conditions over 90 min and the results showed that porphyrins 1 and 2 (M = 2H or ZnII ion) were the most effective and significantly reduced the concentration of viable mycobacteria. The present work shows the result is dependent on the metal-center ion coordinated in the cationic porphyrin core. Moreover, we showed by atomic force microscopy (AFM) the possible membrane photodamage caused by reactive oxygen species and analyzed the morphology and adhesive force properties. Tetra-positively charged and water-soluble metalloporphyrins may be promising antimycobacterial aPDT agents with potential applications in medical clinical cases and bioremediation.
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14
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Rv2037c, a stress induced conserved hypothetical protein of Mycobacterium tuberculosis, is a phospholipase: Role in cell wall modulation and intracellular survival. Int J Biol Macromol 2020; 153:817-835. [DOI: 10.1016/j.ijbiomac.2020.03.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 02/08/2023]
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15
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Abstract
The control of tuberculosis (TB) is hampered by the emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) strains, defined as resistant to at least isoniazid and rifampin, the two bactericidal drugs essential for the treatment of the disease. Due to the worldwide estimate of almost half a million incident cases of MDR/rifampin-resistant TB, it is important to continuously update the knowledge on the mechanisms involved in the development of this phenomenon. Clinical, biological and microbiological reasons account for the generation of resistance, including: (i) nonadherence of patients to their therapy, and/or errors of physicians in therapy management, (ii) complexity and poor vascularization of granulomatous lesions, which obstruct drug distribution to some sites, resulting in resistance development, (iii) intrinsic drug resistance of tubercle bacilli, (iv) formation of non-replicating, drug-tolerant bacilli inside the granulomas, (v) development of mutations in Mtb genes, which are the most important molecular mechanisms of resistance. This review provides a comprehensive overview of these issues, and releases up-dated information on the therapeutic strategies recently endorsed and recommended by the World Health Organization to facilitate the clinical and microbiological management of drug-resistant TB at the global level, with attention also to the most recent diagnostic methods.
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16
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Mycobacterium tuberculosis Rv0191 is an efflux pump of major facilitator superfamily transporter regulated by Rv1353c. Arch Biochem Biophys 2019; 667:59-66. [DOI: 10.1016/j.abb.2019.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 02/06/2023]
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17
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D'Elia JA, Weinrauch LA. Calcium Ion Channels: Roles in Infection and Sepsis Mechanisms of Calcium Channel Blocker Benefits in Immunocompromised Patients at Risk for Infection. Int J Mol Sci 2018; 19:E2465. [PMID: 30134544 PMCID: PMC6164603 DOI: 10.3390/ijms19092465] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 01/08/2023] Open
Abstract
Immunosuppression may occur for a number of reasons related to an individual's frailty, debility, disease or from therapeutic iatrogenic intervention or misadventure. A large percentage of morbidity and mortality in immunodeficient populations is related to an inadequate response to infectious agents with slow response to antibiotics, enhancements of antibiotic resistance in populations, and markedly increased prevalence of acute inflammatory response, septic and infection related death. Given known relationships between intracellular calcium ion concentrations and cytotoxicity and cellular death, we looked at currently available data linking blockade of calcium ion channels and potential decrease in expression of sepsis among immunosuppressed patients. Notable are relationships between calcium, calcium channel, vitamin D mechanisms associated with sepsis and demonstration of antibiotic-resistant pathogens that may utilize channels sensitive to calcium channel blocker. We note that sepsis shock syndrome represents loss of regulation of inflammatory response to infection and that vitamin D, parathyroid hormone, fibroblast growth factor, and klotho interact with sepsis defense mechanisms in which movement of calcium and phosphorus are part of the process. Given these observations we consider that further investigation of the effect of relatively inexpensive calcium channel blockade agents of infections in immunosuppressed populations might be worthwhile.
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Affiliation(s)
- John A D'Elia
- E P Joslin Research Laboratory, Kidney and Hypertension Section, Joslin Diabetes Center, Department of Medicine, Mount Auburn Hospital, Harvard Medical School, Boston and Cambridge, 521 Mount Auburn Street Watertown, MA 02472, USA. jd'
| | - Larry A Weinrauch
- E P Joslin Research Laboratory, Kidney and Hypertension Section, Joslin Diabetes Center, Department of Medicine, Mount Auburn Hospital, Harvard Medical School, Boston and Cambridge, 521 Mount Auburn Street Watertown, MA 02472, USA.
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18
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Issa H, Huc-Claustre E, Reddad T, Bonadé Bottino N, Tropis M, Houssin C, Daffé M, Bayan N, Dautin N. Click-chemistry approach to study mycoloylated proteins: Evidence for PorB and PorC porins mycoloylation in Corynebacterium glutamicum. PLoS One 2017; 12:e0171955. [PMID: 28199365 PMCID: PMC5310785 DOI: 10.1371/journal.pone.0171955] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/27/2017] [Indexed: 01/23/2023] Open
Abstract
Protein mycoloylation is a recently identified, new form of protein acylation. This post-translational modification consists in the covalent attachment of mycolic acids residues to serine. Mycolic acids are long chain, α-branched, β-hydroxylated fatty acids that are exclusively found in the cell envelope of Corynebacteriales, a bacterial order that includes important genera such as Mycobacterium, Nocardia or Corynebacterium. So far, only 3 mycoloylated proteins have been identified: PorA, PorH and ProtX from C. glutamicum. Whereas the identity and function of ProtX is unknown, PorH and PorA associate to form a membrane channel, the activity of which is dependent upon PorA mycoloylation. However, the exact role of mycoloylation and the generality of this phenomenon are still unknown. In particular, the identity of other mycoloylated proteins, if any, needs to be determined together with establishing whether such modification occurs in Corynebacteriales genera other than Corynebacterium. Here, we tested whether a metabolic labeling and click-chemistry approach could be used to detect mycoloylated proteins. Using a fatty acid alkyne analogue, we could indeed label PorA, PorH and ProtX and determine ProtX mycoloylation site. Importantly, we also show that two other porins from C. glutamicum, PorB and PorC are mycoloylated.
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Affiliation(s)
- Hanane Issa
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
- Holy Spirit University of Kaslik (USEK), Jounieh, Mount Lebanon, Lebanon
| | | | - Thamila Reddad
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Nolwenn Bonadé Bottino
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Maryelle Tropis
- Institute of Pharmacology and Structural Biology (IPBS), UMR 5089, France
| | - Christine Houssin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Mamadou Daffé
- Institute of Pharmacology and Structural Biology (IPBS), UMR 5089, France
| | - Nicolas Bayan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Nathalie Dautin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
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Rana A, Thakur S, Bhardwaj N, Kumar D, Akhter Y. Excavating the surface-associated and secretory proteome of Mycobacterium leprae for identifying vaccines and diagnostic markers relevant immunodominant epitopes. Pathog Dis 2016; 74:ftw110. [PMID: 27856491 DOI: 10.1093/femspd/ftw110] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/13/2016] [Accepted: 11/13/2016] [Indexed: 02/03/2023] Open
Abstract
For centuries, Mycobacterium leprae, etiological agent of leprosy, has been afflicting mankind regardless of extensive use of live-attenuated vaccines and antibiotics. Surface-associated and secretory proteins (SASPs) are attractive targets against bacteria. We have integrated biological knowledge with computational approaches and present a proteome-wide identification of SASPs. We also performed computational assignment of immunodominant epitopes as coordinates of prospective antigenic candidates in most important class of SASPs, the outer membrane proteins (OMPs). Exploiting the known protein sequence and structural characteristics shared by the SASPs from bacteria, 17 lipoproteins, 11 secretory and 19 novel OMPs (including 4 essential proteins) were identified in M. leprae As OMPs represent the most exposed antigens on the cell surface, their immunoinformatics analysis showed that the identified 19 OMPs harbor T-cell MHC class I epitopes and class II epitopes against HLA-DR alleles (54), while 15 OMPs present potential T-cell class II epitopes against HLA-DQ alleles (6) and 7 OMPs possess T-cell class II epitopes against HLA-DP alleles (5) of humans. Additionally, 11 M. leprae OMPs were found to have B-cell epitopes and these may be considered as prime candidates for the development of new immunotherapeutics against M. leprae.
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Affiliation(s)
- Aarti Rana
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh-176206, India
| | - Shweta Thakur
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh-176206, India
| | - Nupur Bhardwaj
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh-176206, India
| | - Devender Kumar
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh-176206, India
| | - Yusuf Akhter
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh-176206, India
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20
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Nguyen L. Antibiotic resistance mechanisms in M. tuberculosis: an update. Arch Toxicol 2016; 90:1585-604. [PMID: 27161440 DOI: 10.1007/s00204-016-1727-6] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/27/2016] [Indexed: 12/16/2022]
Abstract
Treatment of tuberculosis (TB) has been a therapeutic challenge because of not only the naturally high resistance level of Mycobacterium tuberculosis to antibiotics but also the newly acquired mutations that confer further resistance. Currently standardized regimens require patients to daily ingest up to four drugs under direct observation of a healthcare worker for a period of 6-9 months. Although they are quite effective in treating drug susceptible TB, these lengthy treatments often lead to patient non-adherence, which catalyzes for the emergence of M. tuberculosis strains that are increasingly resistant to the few available anti-TB drugs. The rapid evolution of M. tuberculosis, from mono-drug-resistant to multiple drug-resistant, extensively drug-resistant and most recently totally drug-resistant strains, is threatening to make TB once again an untreatable disease if new therapeutic options do not soon become available. Here, I discuss the molecular mechanisms by which M. tuberculosis confers its profound resistance to antibiotics. This knowledge may help in developing novel strategies for weakening drug resistance, thus enhancing the potency of available antibiotics against both drug susceptible and resistant M. tuberculosis strains.
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Affiliation(s)
- Liem Nguyen
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
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21
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Sha S, Shi X, Xu L, Wen J, Xin Y, Ma Y. Viability, morphology, and proteome of Mycobacterium smegmatis MSMEG_0319 knockout strain. Proteomics 2016; 16:1090-9. [PMID: 26833451 DOI: 10.1002/pmic.201500054] [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: 02/03/2015] [Revised: 11/13/2015] [Accepted: 01/26/2016] [Indexed: 11/06/2022]
Abstract
Mycobacterium tuberculosis Rv0228, a membrane protein, is predicted as a drug target through computational methods. MSMEG_0319 (MS0319) in Mycobacterium smegmatis mc(2) 155 is the ortholog of Rv0228. To study the effect of MS0319 protein on M. smegmatis, an MS0319 gene knockout strain (ΔMS0319) was generated via a homologous recombination technique in this study. The results showed that the lack of MS0319 protein in mc(2) 155 cells led to the loss of viability at nonpermissive temperature. Scanning electron microscopy and transmission electron microscopy observations showed drastic changes in cellular shape especially cell wall disruption in ΔMS0319 cells. Proteomic analysis of ΔMS0319 cells through LC-MS/MS revealed that 462 proteins had changes in their expressions by lacking MS0319 protein. The M. tuberculosis orthologs of these 462 proteins were found through BLASTp search and functional clustering and metabolic pathway enrichment were performed on the orthologs. The results revealed that most of them were enzymes involved in metabolism of carbohydrates and amino acids, indicating that Rv0228 played an important role in cellular metabolism. All these results suggested Rv0228 as a potential target for development of antituberculosis drugs.
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Affiliation(s)
- Shanshan Sha
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, P. R. China
| | - Xiaoxia Shi
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, P. R. China
| | - Liming Xu
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, P. R. China
| | - Jiabin Wen
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, P. R. China
| | - Yi Xin
- Department of Biotechnology, Dalian Medical University, Dalian, P. R. China
| | - Yufang Ma
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, P. R. China
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22
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Abstract
Copper (Cu) is a trace element essential for the growth and development of almost all organisms, including bacteria. However, Cu overload in most systems is toxic. Studies show Cu accumulates in macrophage phagosomes infected with bacteria, suggesting Cu provides an innate immune mechanism to combat invading pathogens. To counteract the host-supplied Cu, increasing evidence suggests that bacteria have evolved Cu resistance mechanisms to facilitate their pathogenesis. In particular, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has evolved multiple pathways to respond to Cu. Here, we summarize what is currently known about Cu homeostasis in Mtb and discuss potential sources of Cu encountered by this and other pathogens in a mammalian host.
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Affiliation(s)
- Xiaoshan Shi
- New York University School of Medicine, Department of Microbiology, 550 First Avenue MSB 236, New York, NY 10016, USA.
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23
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The Molecular Genetics of Fluoroquinolone Resistance in Mycobacterium tuberculosis. Microbiol Spectr 2016; 2:MGM2-0009-2013. [PMID: 26104201 DOI: 10.1128/microbiolspec.mgm2-0009-2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The fluoroquinolones (FQs) are synthetic antibiotics effectively used for curing patients with multidrug-resistant tuberculosis (TB). When a multidrug-resistant strain develops resistance to the FQs, as in extensively drug-resistant strains, obtaining a cure is much more difficult, and molecular methods can help by rapidly identifying resistance-causing mutations. The only mutations proven to confer FQ resistance in M. tuberculosis occur in the FQ target, the DNA gyrase, at critical amino acids from both the gyrase A and B subunits that form the FQ binding pocket. GyrA substitutions are much more common and generally confer higher levels of resistance than those in GyrB. Molecular techniques to detect resistance mutations have suboptimal sensitivity because gyrase mutations are not detected in a variable percentage of phenotypically resistant strains. The inability to find gyrase mutations may be explained by heteroresistance: bacilli with a resistance-conferring mutation are present only in a minority of the bacterial population (>1%) and are therefore detected by the proportion method, but not in a sufficient percentage to be reliably detected by molecular techniques. Alternative FQ resistance mechanisms in other bacteria--efflux pumps, pentapeptide proteins, or enzymes that inactivate the FQs--have not yet been demonstrated in FQ-resistant M. tuberculosis but may contribute to intrinsic levels of resistance to the FQs or induced tolerance leading to more frequent gyrase mutations. Moxifloxacin is currently the best anti-TB FQ and is being tested for use with other new drugs in shorter first-line regimens to cure drug-susceptible TB.
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24
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Liu Y, Qin R, Zaat SAJ, Breukink E, Heger M. Antibacterial photodynamic therapy: overview of a promising approach to fight antibiotic-resistant bacterial infections. J Clin Transl Res 2015; 1:140-167. [PMID: 30873451 PMCID: PMC6410618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 11/22/2015] [Accepted: 12/28/2015] [Indexed: 10/28/2022] Open
Abstract
Antibacterial photodynamic therapy (APDT) has drawn increasing attention from the scientific society for its potential to effectively kill multidrug-resistant pathogenic bacteria and for its low tendency to induce drug resistance that bacteria can rapidly develop against traditional antibiotic therapy. The review summarizes the mechanism of action of APDT, the photosensitizers, the barriers to PS localization, the targets, the in vitro-, in vivo-, and clinical evidence, the current developments in terms of treating Gram-positive and Gram-negative bacteria, the limitations, as well as future perspectives. Relevance for patients: A structured overview of all important aspects of APDT is provided in the context of resistant bacterial species. The information presented is relevant and accessible for scientists as well as clinicians, whose joint effort is required to ensure that this technology benefits patients in the post-antibiotic era.
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Affiliation(s)
- Yao Liu
- Department of Membrane Biochemistry and Biophysics, Utrecht University, the Netherlands
| | - Rong Qin
- Department of Membrane Biochemistry and Biophysics, Utrecht University, the Netherlands
| | - Sebastian A. J. Zaat
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, the Netherlands
| | - Eefjan Breukink
- Department of Membrane Biochemistry and Biophysics, Utrecht University, the Netherlands
| | - Michal Heger
- Department of Membrane Biochemistry and Biophysics, Utrecht University, the Netherlands, Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, the Netherlands
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25
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Neyrolles O, Wolschendorf F, Mitra A, Niederweis M. Mycobacteria, metals, and the macrophage. Immunol Rev 2015; 264:249-63. [PMID: 25703564 DOI: 10.1111/imr.12265] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mycobacterium tuberculosis is a facultative intracellular pathogen that thrives inside host macrophages. A key trait of M. tuberculosis is to exploit and manipulate metal cation trafficking inside infected macrophages to ensure survival and replication inside the phagosome. Here, we describe the recent fascinating discoveries that the mammalian immune system responds to infections with M. tuberculosis by overloading the phagosome with copper and zinc, two metals which are essential nutrients in small quantities but are toxic in excess. M. tuberculosis has developed multi-faceted resistance mechanisms to protect itself from metal toxicity including control of uptake, sequestration inside the cell, oxidation, and efflux. The host response to infections combines this metal poisoning strategy with nutritional immunity mechanisms that deprive M. tuberculosis from metals such as iron and manganese to prevent bacterial replication. Both immune mechanisms rely on the translocation of metal transporter proteins to the phagosomal membrane during the maturation process of the phagosome. This review summarizes these recent findings and discusses how metal-targeted approaches might complement existing TB chemotherapeutic regimens with novel anti-infective therapies.
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Affiliation(s)
- Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, Univer-sité Paul Sabatier, Université de Toulouse, Toulouse, France
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26
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Garneau-Tsodikova S, Labby KJ. Mechanisms of Resistance to Aminoglycoside Antibiotics: Overview and Perspectives. MEDCHEMCOMM 2015; 7:11-27. [PMID: 26877861 DOI: 10.1039/c5md00344j] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aminoglycoside (AG) antibiotics are used to treat many Gram-negative and some Gram-positive infections and, importantly, multidrug-resistant tuberculosis. Among various bacterial species, resistance to AGs arises through a variety of intrinsic and acquired mechanisms. The bacterial cell wall serves as a natural barrier for small molecules such as AGs and may be further fortified via acquired mutations. Efflux pumps work to expel AGs from bacterial cells, and modifications here too may cause further resistance to AGs. Mutations in the ribosomal target of AGs, while rare, also contribute to resistance. Of growing clinical prominence is resistance caused by ribosome methyltransferases. By far the most widespread mechanism of resistance to AGs is the inactivation of these antibiotics by AG-modifying enzymes. We provide here an overview of these mechanisms by which bacteria become resistant to AGs and discuss their prevalence and potential for clinical relevance.
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Affiliation(s)
- Sylvie Garneau-Tsodikova
- University of Kentucky, Department of Pharmaceutical Sciences, 789 South Limestone Street, Lexington, KY, USA. ; Tel: 859-218-1686
| | - Kristin J Labby
- Beloit College, Department of Chemistry, 700 College Street, Beloit, WI, USA. ; Tel: 608-363-2273
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27
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An update on pathogenesis and management of tuberculosis with special reference to drug resistance. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2015. [DOI: 10.1016/s2222-1808(15)60912-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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28
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Mdluli K, Kaneko T, Upton A. The tuberculosis drug discovery and development pipeline and emerging drug targets. Cold Spring Harb Perspect Med 2015; 5:a021154. [PMID: 25635061 PMCID: PMC4448709 DOI: 10.1101/cshperspect.a021154] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The recent accelerated approval for use in extensively drug-resistant and multidrug-resistant-tuberculosis (MDR-TB) of two first-in-class TB drugs, bedaquiline and delamanid, has reinvigorated the TB drug discovery and development field. However, although several promising clinical development programs are ongoing to evaluate new TB drugs and regimens, the number of novel series represented is few. The global early-development pipeline is also woefully thin. To have a chance of achieving the goal of better, shorter, safer TB drug regimens with utility against drug-sensitive and drug-resistant disease, a robust and diverse global TB drug discovery pipeline is key, including innovative approaches that make use of recently acquired knowledge on the biology of TB. Fortunately, drug discovery for TB has resurged in recent years, generating compounds with varying potential for progression into developable leads. In parallel, advances have been made in understanding TB pathogenesis. It is now possible to apply the lessons learned from recent TB hit generation efforts and newly validated TB drug targets to generate the next wave of TB drug leads. Use of currently underexploited sources of chemical matter and lead-optimization strategies may also improve the efficiency of future TB drug discovery. Novel TB drug regimens with shorter treatment durations must target all subpopulations of Mycobacterium tuberculosis existing in an infection, including those responsible for the protracted TB treatment duration. This review summarizes the current TB drug development pipeline and proposes strategies for generating improved hits and leads in the discovery phase that could help achieve this goal.
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Affiliation(s)
- Khisimuzi Mdluli
- Global Alliance for TB Drug Development, New York, New York 10005
| | - Takushi Kaneko
- Global Alliance for TB Drug Development, New York, New York 10005
| | - Anna Upton
- Global Alliance for TB Drug Development, New York, New York 10005
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29
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Gupta A, Iyer BR, Chaturvedi D, Maurya SR, Mahalakshmi R. Thermodynamic, structural and functional properties of membrane protein inclusion bodies are analogous to purified counterparts: case study from bacteria and humans. RSC Adv 2015. [DOI: 10.1039/c4ra11207e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purification-free transmembrane protein inclusion body preparations for rapid and cost-effective biophysical, functional and structural studies.
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Affiliation(s)
- Ankit Gupta
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal
- India
| | - Bharat Ramasubramanian Iyer
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal
- India
| | - Deepti Chaturvedi
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal
- India
| | - Svetlana Rajkumar Maurya
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal
- India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal
- India
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30
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Yang Y, Kulka K, Montelaro RC, Reinhart TA, Sissons J, Aderem A, Ojha AK. A hydrolase of trehalose dimycolate induces nutrient influx and stress sensitivity to balance intracellular growth of Mycobacterium tuberculosis. Cell Host Microbe 2014; 15:153-63. [PMID: 24528862 DOI: 10.1016/j.chom.2014.01.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 11/26/2013] [Accepted: 01/23/2014] [Indexed: 10/25/2022]
Abstract
Chronic tuberculosis in an immunocompetent host is a consequence of the delicately balanced growth of Mycobacterium tuberculosis (Mtb) in the face of host defense mechanisms. We identify an Mtb enzyme (TdmhMtb) that hydrolyzes the mycobacterial glycolipid trehalose dimycolate and plays a critical role in balancing the intracellular growth of the pathogen. TdmhMtb is induced under nutrient-limiting conditions and remodels the Mtb envelope to increase nutrient influx but concomitantly sensitizes Mtb to stresses encountered in the host. Consistent with this, a ΔtdmhMtb mutant is more resilient to stress and grows to levels higher than those of wild-type in immunocompetent mice. By contrast, mutant growth is retarded in MyD88(-/-) mice, indicating that TdmhMtb provides a growth advantage to intracellular Mtb in an immunocompromised host. Thus, the effects and countereffects of TdmhMtb play an important role in balancing intracellular growth of Mtb in a manner that is directly responsive to host innate immunity.
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Affiliation(s)
- Yong Yang
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Kathleen Kulka
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Ronald C Montelaro
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15261, USA; Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Todd A Reinhart
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - James Sissons
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Seattle, WA 98109, USA
| | - Alan Aderem
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Seattle, WA 98109, USA
| | - Anil K Ojha
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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31
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Mycobacterial gene cuvA is required for optimal nutrient utilization and virulence. Infect Immun 2014; 82:4104-17. [PMID: 25047842 DOI: 10.1128/iai.02207-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
To persist and cause disease in the host, Mycobacterium tuberculosis must adapt to its environment during infection. Adaptations include changes in nutrient utilization and alterations in growth rate. M. tuberculosis Rv1422 is a conserved gene of unknown function that was found in a genetic screen to interact with the mce4 cholesterol uptake locus. The Rv1422 protein is phosphorylated by the M. tuberculosis Ser/Thr kinases PknA and PknB, which regulate cell growth and cell wall synthesis. Bacillus subtilis strains lacking the Rv1422 homologue yvcK grow poorly on several carbon sources, and yvcK is required for proper localization of peptidoglycan synthesis. Here we show that Mycobacterium smegmatis and M. tuberculosis strains lacking Rv1422 have growth defects in minimal medium containing limiting amounts of several different carbon sources. These strains also have morphological abnormalities, including shortened and bulging cells, suggesting a cell wall defect. In both mycobacterial species, the Rv1422 protein localizes uniquely to the growing cell pole, the site of peptidoglycan synthesis in mycobacteria. An M. tuberculosis ΔRv1422 strain is markedly attenuated for virulence in a mouse infection model, where it elicits decreased inflammation in the lungs and shows impaired bacterial persistence. These findings led us to name this gene cuvA (carbon utilization and virulence protein A) and to suggest a model in which deletion of cuvA leads to changes in nutrient uptake and/or metabolism that affect cell wall structure, morphology, and virulence. Its role in virulence suggests that CuvA may be a useful target for novel inhibitors of M. tuberculosis during infection.
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32
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Abstract
Current tuberculosis (TB) therapies take too long and the regimens are complex and subject to adverse effects and drug-drug interactions with concomitant medications. The emergence of drug-resistant TB strains exacerbates the situation. Drug discovery for TB has resurged in recent years, generating compounds (hits) with varying potential for progression into developable leads. In parallel, advances have been made in understanding TB pathogenesis. It is now possible to apply the lessons learned from recent TB hit generation efforts and newly validated TB drug targets to generate the next wave of TB drug leads. Use of currently underexploited sources of chemical matter and lead-optimization strategies may also improve the efficiency of future TB drug discovery. Novel TB drug regimens with shorter treatment durations must target all subpopulations of Mycobacterium tuberculosis existing in an infection, including those responsible for the protracted TB treatment duration. This review proposes strategies for generating improved hits and leads that could help achieve this goal.
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An outer membrane channel protein of Mycobacterium tuberculosis with exotoxin activity. Proc Natl Acad Sci U S A 2014; 111:6750-5. [PMID: 24753609 DOI: 10.1073/pnas.1400136111] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The ability to control the timing and mode of host cell death plays a pivotal role in microbial infections. Many bacteria use toxins to kill host cells and evade immune responses. Such toxins are unknown in Mycobacterium tuberculosis. Virulent M. tuberculosis strains induce necrotic cell death in macrophages by an obscure molecular mechanism. Here we show that the M. tuberculosis protein Rv3903c (channel protein with necrosis-inducing toxin, CpnT) consists of an N-terminal channel domain that is used for uptake of nutrients across the outer membrane and a secreted toxic C-terminal domain. Infection experiments revealed that CpnT is required for survival and cytotoxicity of M. tuberculosis in macrophages. Furthermore, we demonstrate that the C-terminal domain of CpnT causes necrotic cell death in eukaryotic cells. Thus, CpnT has a dual function in uptake of nutrients and induction of host cell death by M. tuberculosis.
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34
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Viveiros M, Martins M, Rodrigues L, Machado D, Couto I, Ainsa J, Amaral L. Inhibitors of mycobacterial efflux pumps as potential boosters for anti-tubercular drugs. Expert Rev Anti Infect Ther 2014; 10:983-98. [DOI: 10.1586/eri.12.89] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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35
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Argüello JM, Raimunda D, Padilla-Benavides T. Mechanisms of copper homeostasis in bacteria. Front Cell Infect Microbiol 2013; 3:73. [PMID: 24205499 PMCID: PMC3817396 DOI: 10.3389/fcimb.2013.00073] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 10/17/2013] [Indexed: 01/27/2023] Open
Abstract
Copper is an important micronutrient required as a redox co-factor in the catalytic centers of enzymes. However, free copper is a potential hazard because of its high chemical reactivity. Consequently, organisms exert a tight control on Cu(+) transport (entry-exit) and traffic through different compartments, ensuring the homeostasis required for cuproprotein synthesis and prevention of toxic effects. Recent studies based on biochemical, bioinformatics, and metalloproteomics approaches, reveal a highly regulated system of transcriptional regulators, soluble chaperones, membrane transporters, and target cuproproteins distributed in the various bacterial compartments. As a result, new questions have emerged regarding the diversity and apparent redundancies of these components, their irregular presence in different organisms, functional interactions, and resulting system architectures.
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Affiliation(s)
- José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute Worcester, MA, USA
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36
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Sung N, Back S, Jung J, Kim KH, Kim JK, Lee JH, Ra Y, Yang HC, Lim C, Cho S, Kim K, Jheon S. Inactivation of multidrug resistant (MDR)- and extensively drug resistant (XDR)-Mycobacterium tuberculosis by photodynamic therapy. Photodiagnosis Photodyn Ther 2013; 10:694-702. [PMID: 24284129 DOI: 10.1016/j.pdpdt.2013.09.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 09/02/2013] [Accepted: 09/17/2013] [Indexed: 02/04/2023]
Abstract
We investigated the effects of photodynamic therapy (PDT) on anti-tuberculosis (TB) activity by measuring inactivation rates, expressed as D-value, of MDR- and XDR-Mycobacterium tuberculosis (M. tb) clinical strains in vitro. Approximately 10(6) colony forming unit per milliliter (CFU/ml) of the bacilli were irradiated with various doses of laser light after exposure to photosensitizers. Survival of M. tb was measured by enumerating CFU in 7H10 medium to measure D-values. No inactivation of M. tb was observed when exposed to photosensitizers (radachlorin or DH-I-180-3) only or laser light only (P>0.1). Treatment with a combination of photosentizer and laser inactivated M. tb although there was a significant difference between the types of photosensitizers applied (P<0.05). Linear inactivation curves for the clinical M. tb strains were obtained up to laser doses of 30 J/cm(2) but prolonged irradiation did not linearly inactivate M. tb, yielding sigmoid PDT inactivation curves. D-values of M. tb determined from the slope of linear regression lines in PDT were not significantly different and ranged from 10.50 to 12.13 J/cm(2) with 670 nm laser irradiation at 100 mW/cm(2) of the fluency rate, except for a drug-susceptible strain among the clinical strains tested. This suggests that PDT inactivated M. tb clinical strains regardless of drug resistance levels of the bacilli. Intermittent and repeated PDT allowed acceleration of the inactivation of the bacilli as a way to avoid the sigmoid inactivation curves. In conclusion, PDT could be alternative as a new option for treatment for MDR- and XDR-tuberculosis.
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Affiliation(s)
- Nackmoon Sung
- Clinical Research Center, National Masan Tuberculosis Hospital, Gyeongnam, Republic of Korea
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37
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Sarathy JP, Lee E, Dartois V. Polyamines inhibit porin-mediated fluoroquinolone uptake in mycobacteria. PLoS One 2013; 8:e65806. [PMID: 23755283 PMCID: PMC3670895 DOI: 10.1371/journal.pone.0065806] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 04/28/2013] [Indexed: 11/19/2022] Open
Abstract
Polyamines decrease the permeability of the outer membrane of Escherichia coli to fluoroquinolones and β-lactams. In this study, we tested the effect of four polyamines (spermidine, spermine, cadaverine and putrescine) on fluoroquinolone uptake in Mycobacterium bovis BCG. Our results show that polyamines are also capable of reducing the permeability of the mycobacterial outer membrane to fluoroquinolones. Spermidine was most effective and demonstrated reversible dose- and pH-dependent inhibition of ciprofloxacin accumulation. The extent of this inhibition was demonstrated across the fluoroquinolone compound class to varying degrees. Furthermore, we have shown that the addition of spermidine increases the survival of M. bovis BCG after a 5-day exposure to ciprofloxacin by up to 25 times. The treatment of actively-replicating Mycobacterium tuberculosis with spermidine reduced ciprofloxacin accumulation by half while non-replicating nutrient-starved M. tuberculosis cultures lacked similar sensitivity to polyamines. Gene expression studies showed that several outer membrane proteins are significantly down-regulated during the shift to non-replication. Collectively, these characteristics of fluoroquinolone uptake in M. bovis BCG are consistent with facilitated transport by porin-like proteins and suggest that a reduction in intracellular uptake contributes to the phenotypic drug resistance demonstrated by M. tuberculosis in the non-replicating state.
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38
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Differential detergent extraction of mycobacterium marinum cell envelope proteins identifies an extensively modified threonine-rich outer membrane protein with channel activity. J Bacteriol 2013; 195:2050-9. [PMID: 23457249 DOI: 10.1128/jb.02236-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A striking characteristic of mycobacteria is the presence of an unusual outer membrane which forms a thick permeability barrier and provides resistance to many antibiotics. Although specialized proteins must reside in this layer, only few mycolate outer membrane (MOM) proteins have been identified to date. Their discovery is complicated by difficulties in obtaining good separation of mycobacterial inner and outer membranes. During our efforts to identify novel mycobacterial outer membrane proteins (MOMPs), we discovered that we can enrich for MOMPs using differential solubilization of mycobacterial cell envelopes. Subsequently, these different fractions were analyzed by nano liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS). This proteomic analysis confirmed that our marker proteins for inner membrane and MOM were found in their expected fractions and revealed a few interesting candidate MOMPs. A number of these putative MOMPs were further analyzed for their expression and localization in the cell envelope. One identified MOMP, MMAR_0617 of Mycobacterium marinum, was purified and demonstrated to form a large oligomeric complex. Importantly, this protein showed a clear single-channel conductance of 0.8 ± 0.1 ns upon reconstitution into artificial planar lipid bilayers. The most surprising feature of MMAR_0617 is a long C-terminal threonine-rich domain with extensive modifications. In summary, we have identified a novel mycobacterial outer membrane porin with unusual properties.
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39
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Slayden RA, Jackson M, Zucker J, Ramirez MV, Dawson CC, Crew R, Sampson NS, Thomas ST, Jamshidi N, Sisk P, Caspi R, Crick DC, McNeil MR, Pavelka MS, Niederweis M, Siroy A, Dona V, McFadden J, Boshoff H, Lew JM. Updating and curating metabolic pathways of TB. Tuberculosis (Edinb) 2013; 93:47-59. [PMID: 23375378 DOI: 10.1016/j.tube.2012.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 11/25/2012] [Indexed: 01/08/2023]
Abstract
The sequencing of complete genomes has accelerated biomedical research by providing information about the overall coding capacity of bacterial chromosomes. The original TB annotation resulted in putative functional assignment of ∼60% of the genes to specific metabolic functions, however, the other 40% of the encoded ORFs where annotated as conserved hypothetical proteins, hypothetical proteins or encoding proteins of unknown function. The TB research community is now at the beginning of the next phases of post-genomics; namely reannotation and functional characterization by targeted experimentation. Arguably, this is the most significant time for basic microbiology in recent history. To foster basic TB research, the Tuberculosis Community Annotation Project (TBCAP) jamboree exercise began the reannotation effort by providing additional information for previous annotations, and refining and substantiating the functional assignment of ORFs and genes within metabolic pathways. The overall goal of the TBCAP 2012 exercise was to gather and compile various data types and use this information with oversight from the scientific community to provide additional information to support the functional annotations of encoding genes. Another objective of this effort was to standardize the publicly accessible Mycobacterium tuberculosis reference sequence and its annotation. The greatest benefit of functional annotation information of genome sequence is that it fuels TB research for drug discovery, diagnostics, vaccine development and epidemiology.
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40
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Sarathy JP, Dartois V, Lee EJD. The role of transport mechanisms in mycobacterium tuberculosis drug resistance and tolerance. Pharmaceuticals (Basel) 2012; 5:1210-35. [PMID: 24281307 PMCID: PMC3816664 DOI: 10.3390/ph5111210] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 10/25/2012] [Accepted: 11/02/2012] [Indexed: 02/02/2023] Open
Abstract
In the fight against tuberculosis, cell wall permeation of chemotherapeutic agents remains a critical but largely unsolved question. Here we review the major mechanisms of small molecule penetration into and efflux from Mycobacterium tuberculosis and other mycobacteria, and outline how these mechanisms may contribute to the development of phenotypic drug tolerance and induction of drug resistance. M. tuberculosis is intrinsically recalcitrant to small molecule permeation thanks to its thick lipid-rich cell wall. Passive diffusion appears to account for only a fraction of total drug permeation. As in other bacterial species, influx of hydrophilic compounds is facilitated by water-filled open channels, or porins, spanning the cell wall. However, the diversity and density of M. tuberculosis porins appears lower than in enterobacteria. Besides, physiological adaptations brought about by unfavorable conditions are thought to reduce the efficacy of porins. While intracellular accumulation of selected drug classes supports the existence of hypothesized active drug influx transporters, efflux pumps contribute to the drug resistant phenotype through their natural abundance and diversity, as well as their highly inducible expression. Modulation of efflux transporter expression has been observed in phagocytosed, non-replicating persistent and multi-drug resistant bacilli. Altogether, M. tuberculosis has evolved both intrinsic properties and acquired mechanisms to increase its level of tolerance towards xenobiotic substances, by preventing or minimizing their entry. Understanding these adaptation mechanisms is critical to counteract the natural mechanisms of defense against toxic compounds and develop new classes of chemotherapeutic agents that positively exploit the influx and efflux pathways of mycobacteria.
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Affiliation(s)
- Jansy Passiflora Sarathy
- Novartis Institute for Tropical Diseases Pte Ltd, 10 Biopolis Road #05-01, Chromos, 138670, Singapore.
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41
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Houben ENG, Bestebroer J, Ummels R, Wilson L, Piersma SR, Jiménez CR, Ottenhoff THM, Luirink J, Bitter W. Composition of the type VII secretion system membrane complex. Mol Microbiol 2012; 86:472-84. [DOI: 10.1111/j.1365-2958.2012.08206.x] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2012] [Indexed: 01/04/2023]
Affiliation(s)
| | - Jovanka Bestebroer
- Department of Medical Microbiology and Infection Control; VU University Medical Center; Amsterdam; The Netherlands
| | - Roy Ummels
- Department of Medical Microbiology and Infection Control; VU University Medical Center; Amsterdam; The Netherlands
| | - Louis Wilson
- Department of Infectious Diseases; Leiden University Medical Center; Leiden; The Netherlands
| | - Sander R. Piersma
- Department of Medical Oncology; OncoProteomics Laboratory; VU University Medical Center; Amsterdam; The Netherlands
| | - Connie R. Jiménez
- Department of Medical Oncology; OncoProteomics Laboratory; VU University Medical Center; Amsterdam; The Netherlands
| | - Tom H. M. Ottenhoff
- Department of Infectious Diseases; Leiden University Medical Center; Leiden; The Netherlands
| | - Joen Luirink
- Department of Molecular Microbiology; Institute of Molecular Cell Biology; VU University Amsterdam; Amsterdam; The Netherlands
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42
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Chen JM, Uplekar S, Gordon SV, Cole ST. A point mutation in cycA partially contributes to the D-cycloserine resistance trait of Mycobacterium bovis BCG vaccine strains. PLoS One 2012; 7:e43467. [PMID: 22912881 PMCID: PMC3422274 DOI: 10.1371/journal.pone.0043467] [Citation(s) in RCA: 46] [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: 04/25/2012] [Accepted: 07/20/2012] [Indexed: 11/18/2022] Open
Abstract
In mycobacteria, CycA a D-serine, L- and D-alanine, and glycine transporter also functions in the uptake of D-cycloserine, an important second-line anti-tubercular drug. A single nucleotide polymorphism identified in the cycA gene of BCG was hypothesized to contribute to the increased resistance of Mycobacterium bovis bacillus Calmette-Guérin (BCG) to D-cycloserine compared to wild-type Mycobacterium tuberculosis or Mycobacterium bovis. Working along these lines, a merodiploid strain of BCG expressing Mycobacterium tuberculosis CycA was generated and found to exhibit increased susceptibility to D-cycloserine albeit not to the same extent as wild-type Mycobacterium tuberculosis or Mycobacterium bovis. In addition, recombinant Mycobacterium smegmatis strains expressing either Mycobacterium tuberculosis or Mycobacterium bovis CycA but not BCG CycA were rendered more susceptible to D-cycloserine. These findings support the notion that CycA-mediated uptake in BCG is impaired as a result of a single nucleotide polymorphism; however, the partial contribution of this impairment to D-cycloserine resistance suggests the involvement of additional genetic lesions in this phenotype.
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Affiliation(s)
- Jeffrey M Chen
- École Polytechnique Fédérale de Lausanne, Global Health Institute, Lausanne, Switzerland.
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43
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Rowland JL, Niederweis M. Resistance mechanisms of Mycobacterium tuberculosis against phagosomal copper overload. Tuberculosis (Edinb) 2012; 92:202-10. [PMID: 22361385 DOI: 10.1016/j.tube.2011.12.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/27/2011] [Indexed: 12/29/2022]
Abstract
Mycobacterium tuberculosis is an important bacterial pathogen with an extremely slow growth rate, an unusual outer membrane of very low permeability and a cunning ability to survive inside the human host despite a potent immune response. A key trait of M. tuberculosis is to acquire essential nutrients while still preserving its natural resistance to toxic compounds. In this regard, copper homeostasis mechanisms are particularly interesting, because copper is an important element for bacterial growth, but copper overload is toxic. In M. tuberculosis at least two enzymes require copper as a cofactor: the Cu/Zn-superoxide dismutase SodC and the cytochrome c oxidase which is essential for growth in vitro. Mutants of M. tuberculosis lacking the copper metallothionein MymT, the efflux pump CtpV and the membrane protein MctB are more susceptible to copper indicating that these proteins are part of a multipronged system to balance intracellular copper levels. Recent evidence showed that part of copper toxicity is a reversible damage of Fe-S clusters of dehydratases and the displacement of other divalent cations such as zinc and manganese as cofactors in proteins. There is accumulating evidence that macrophages use copper to poison bacteria trapped inside phagosomes. Here, we review the rapidly increasing knowledge about copper homeostasis in M. tuberculosis and contrast those with similar mechanisms in Escherichia coli. These findings reveal an intricate interplay between the host which aims to overload the phagosome with copper and M. tuberculosis which utilizes several mechanisms to reduce the toxic effects of excess copper.
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Affiliation(s)
- Jennifer L Rowland
- Department of Microbiology, University of Alabama at Birmingham, 609 Bevill Biomedical Research Building, 845 19th Street South, Birmingham, AL 35294, USA
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44
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Smith T, Wolff KA, Nguyen L. Molecular biology of drug resistance in Mycobacterium tuberculosis. Curr Top Microbiol Immunol 2012. [PMID: 23179675 DOI: 10.1007/82_2012_279] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Tuberculosis (TB) has become a curable disease, thanks to the discovery of antibiotics. However, it has remained one of the most difficult infections to treat. Most current TB regimens consist of 6-9 months of daily doses of four drugs that are highly toxic to patients. The purpose of these lengthy treatments is to completely eradicate Mycobacterium tuberculosis, notorious for its ability to resist most antibacterial agents, thereby preventing the formation of drug resistant mutants. On the contrary, the prolonged therapies have led to poor patient adherence. This, together with a severe limit of drug choices, has resulted in the emergence of strains that are increasingly resistant to the few available antibiotics. Here, we review our current understanding of molecular mechanisms underlying the profound drug resistance of M. tuberculosis. This knowledge is essential for the development of more effective antibiotics, which are not only potent against drug resistant M. tuberculosis strains but also help shorten the current treatment courses required for drug susceptible TB.
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Affiliation(s)
- Tasha Smith
- Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
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45
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Das C, Ghosh TS, Mande SS. Computational analysis of the ESX-1 region of Mycobacterium tuberculosis: insights into the mechanism of type VII secretion system. PLoS One 2011; 6:e27980. [PMID: 22140496 PMCID: PMC3227618 DOI: 10.1371/journal.pone.0027980] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 10/28/2011] [Indexed: 01/17/2023] Open
Abstract
Type VII secretion system (T7SS) is a recent discovery in bacterial secretion systems. First identified in Mycobacterium tuberculosis, this secretion system has later been reported in organisms belonging to the Actinomycetales order and even to distant phyla like Firmicutes. The genome of M. tuberculosis H37Rv contains five gene clusters that have evolved through gene duplication events and include components of the T7SS secretion machinery. These clusters are called ESAT-6 secretion system (ESX) 1 through 5. Out of these, ESX-1 has been the most widely studied region because of its pathological importance. In spite of this, the overall mechanism of protein translocation through ESX-1 secretion machinery is not clearly understood. Specifically, the structural components contributing to the translocation through the mycomembrane have not been characterized yet. In this study, we have carried out a comprehensive in silico analysis of the genes known to be involved in ESX-1 secretion pathway and identified putative proteins having high probability to be associated with this particular pathway. Our study includes analysis of phylogenetic profiles, identification of domains, transmembrane helices, 3D folds, signal peptides and prediction of protein-protein associations. Based on our analysis, we could assign probable novel functions to a few of the ESX-1 components. Additionally, we have identified a few proteins with probable role in the initial activation and formation of mycomembrane translocon of ESX-1 secretion machinery. We also propose a probable working model of T7SS involving ESX-1 secretion pathway.
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Affiliation(s)
- Chandrani Das
- Bio-sciences R& D Division, Tata Consultancy ServicesInnovation Labs, Tata Consultancy Services Ltd, Hyderabad, Andhra Pradesh, India
| | - Tarini Shankar Ghosh
- Bio-sciences R& D Division, Tata Consultancy ServicesInnovation Labs, Tata Consultancy Services Ltd, Hyderabad, Andhra Pradesh, India
| | - Sharmila S. Mande
- Bio-sciences R& D Division, Tata Consultancy ServicesInnovation Labs, Tata Consultancy Services Ltd, Hyderabad, Andhra Pradesh, India
- * E-mail:
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46
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Youm J, Saier MH. Comparative analyses of transport proteins encoded within the genomes of Mycobacterium tuberculosis and Mycobacterium leprae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:776-97. [PMID: 22179038 DOI: 10.1016/j.bbamem.2011.11.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 11/18/2011] [Accepted: 11/18/2011] [Indexed: 10/15/2022]
Abstract
The co-emergence of multidrug resistant pathogenic bacterial strains and the Human Immunodeficiency Virus pandemic has made tuberculosis a leading public health threat. The causative agent is Mycobacterium tuberculosis (Mtu), a facultative intracellular parasite. Mycobacterium leprae (Mle), a related organism that causes leprosy, is an obligate intracellular parasite. Given that different transporters are required for bacterial growth and persistence under a variety of growth conditions, we conducted comparative analyses of transport proteins encoded within the genomes of these two organisms. A minimal set of genes required for intracellular and extracellular life was identified. Drug efflux systems utilizing primary active transport mechanisms have been preferentially retained in Mle and still others preferentially lost. Transporters associated with environmental adaptation found in Mtu were mostly lost in Mle. These findings provide starting points for experimental studies that may elucidate the dependencies of pathogenesis on transport for these two pathogenic mycobacteria. They also lead to suggestions regarding transporters that function in intra- versus extra-cellular growth.
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Affiliation(s)
- Jiwon Youm
- University of California, La Jolla, CA, USA
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47
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Functional dissection of the PE domain responsible for translocation of PE_PGRS33 across the mycobacterial cell wall. PLoS One 2011; 6:e27713. [PMID: 22110736 PMCID: PMC3218021 DOI: 10.1371/journal.pone.0027713] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 10/23/2011] [Indexed: 01/13/2023] Open
Abstract
PE are peculiar exported mycobacterial proteins over-represented in pathogenic mycobacterial species. They are characterized by an N-terminal domain of about 110 amino acids (PE domain) which has been demonstrated to be responsible for their export and localization. In this paper, we characterize the PE domain of PE_PGRS33 (PERv1818c), one of the best characterized PE proteins. We constructed several mutated proteins in which portions of the PE domain were deleted or subjected to defined mutations. These proteins were expressed in different mycobacterial species and their localization was characterized. We confirmed that the PE domain is essential for PE_PGRS33 surface localization, and demonstrated that a PE domain lacking its first 30 amino acids loses its function. However, single amino acid substitutions in two regions extremely well conserved within the N-terminal domain of all PE proteins had some effect on the stability of PE_PGRS33, but not on its localization. Using Mycobacterium marinum we could show that the type VII secretion system ESX-5 is essential for PE_PGRS33 export. Moreover, in M. marinum, but not in Mycobacterium bovis BCG and in Mycobacterium tuberculosis, the PE domain of PE_PGRS33 is processed and secreted into the culture medium when expressed in the absence of the PGRS domain. Finally, using chimeric proteins in which different portions of the PERv1818c domain were fused to the N-terminus of the green fluorescent protein, we could hypothesize that the first 30 amino acids of the PE domain contain a sequence that allows protein translocation.
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Almeida Da Silva PEA, Palomino JC. Molecular basis and mechanisms of drug resistance in Mycobacterium tuberculosis: classical and new drugs. J Antimicrob Chemother 2011; 66:1417-30. [PMID: 21558086 DOI: 10.1093/jac/dkr173] [Citation(s) in RCA: 323] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Tuberculosis (TB) remains one of the leading public health problems worldwide. Declared as a global emergency in 1993 by the WHO, its control is hampered by the emergence of multidrug resistance (MDR), defined as resistance to at least rifampicin and isoniazid, two key drugs in the treatment of the disease. More recently, severe forms of drug resistance such as extensively drug-resistant (XDR) TB have been described. After the discovery of several drugs with anti-TB activity, multidrug therapy became fundamental for control of the disease. Major advances in molecular biology and the availability of new information generated after sequencing the genome of Mycobacterium tuberculosis increased our knowledge of the mechanisms of resistance to the main anti-TB drugs. Better knowledge of the mechanisms of drug resistance in TB and the molecular mechanisms involved will help us to improve current techniques for rapid detection and will also stimulate the exploration of new targets for drug activity and drug development. This article presents an updated review of the mechanisms and molecular basis of drug resistance in M. tuberculosis. It also comments on the several gaps in our current knowledge of the molecular mechanisms of drug resistance to the main classical and new anti-TB drugs and briefly discusses some implications of the development of drug resistance and fitness, transmission and pathogenicity of M. tuberculosis.
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Lougheed KE, Osborne SA, Saxty B, Whalley D, Chapman T, Bouloc N, Chugh J, Nott TJ, Patel D, Spivey VL, Kettleborough CA, Bryans JS, Taylor DL, Smerdon SJ, Buxton RS. Effective inhibitors of the essential kinase PknB and their potential as anti-mycobacterial agents. Tuberculosis (Edinb) 2011; 91:277-86. [PMID: 21482481 PMCID: PMC3158675 DOI: 10.1016/j.tube.2011.03.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 03/03/2011] [Accepted: 03/15/2011] [Indexed: 01/18/2023]
Abstract
PknB is an essential serine/threonine kinase of Mycobacterium tuberculosis with possible roles in a number of signalling pathways involved in cell division and metabolism. We screened a library of >50,000 compounds for inhibitors of the in vitro phosphorylation of GarA (Rv1827) by PknB and identified a number of inhibitors. A program of synthetic medicinal chemistry was subsequently conducted around one class of inhibitors and was successful in generating ATP competitive inhibitors with potency in the nanomolar range. Compounds in this class showed cross-reactivity with the related M. tuberculosis kinase, PknF, but not with PknG in an in vitro autophosphorylation assay. These synthesised inhibitors were able to prevent the growth of M. tuberculosis in an Alamar blue assay and in an intracellular model of infection, but only in the micromolar range. We attempted to determine if cell wall permeability was an explanation for the discrepancy between the potent in vitro compared with relatively poor in vivo activity, but found no evidence that the activity of the inhibitors could be improved by weakening the cell wall. Despite a number of drug discovery efforts attempting to develop inhibitors against PknB, it is yet to be reported that any such inhibitors prevent mycobacterial growth at submicromolar concentrations.
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Affiliation(s)
- Kathryn E.A. Lougheed
- Division of Mycobacterial Research, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Simon A. Osborne
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Barbara Saxty
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - David Whalley
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Tim Chapman
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Nathalie Bouloc
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Jasveen Chugh
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Timothy J. Nott
- Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Dony Patel
- Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Vicky L. Spivey
- Division of Mycobacterial Research, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Catherine A. Kettleborough
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Justin S. Bryans
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Debra L. Taylor
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Stephen J. Smerdon
- Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Roger S. Buxton
- Division of Mycobacterial Research, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
- Corresponding author. Tel.: +44 20 8816 2225; fax: +44 20 8906 4477.
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Banerjee S, Farhana A, Ehtesham NZ, Hasnain SE. Iron acquisition, assimilation and regulation in mycobacteria. INFECTION GENETICS AND EVOLUTION 2011; 11:825-38. [PMID: 21414421 DOI: 10.1016/j.meegid.2011.02.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 02/25/2011] [Accepted: 02/28/2011] [Indexed: 11/28/2022]
Abstract
Iron is as crucial to the pathogen as it is to the host. The tuberculosis causing bacillus, Mycobacterium tuberculosis (M.tb), is an exceptionally efficient pathogen that has evolved proficient mechanisms to sequester iron from the host despite its thick mycolate-rich outer covering and a highly impermeable membrane of phagolysosome within which it persists inside an infected host macrophage. Further, both overindulgence and moderation of iron inside a host are a threat to mycobacterial persistence. While for removing iron from the host reservoirs, mycobacteria synthesize molecules that have several times higher affinity for iron than their host counterparts, they also synthesize molecules for efficient storage of excess iron. This is supported by tightly regulated iron dependent global gene expressions. In this review we discuss the various molecules and pathways evolved by mycobacteria for an efficient iron metabolism. We also discuss the less investigated players, like iron responsive proteins and iron responsive elements in mycobacteria, and highlight the lacunae in our current understanding of iron acquisition and utilization in mycobacteria with an ultimate aim to make iron metabolism as a possible anti-mycobacterial target.
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Affiliation(s)
- Sharmistha Banerjee
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
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