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Wang BB, Li YL, Tian SY, Wang HZ, Li X, Wang FH, Cai KZ. Chlamydospore dormancy and predatory activity of nematophagous fungus Duddingtonia flagrans. J Basic Microbiol 2024; 64:e2300365. [PMID: 38012466 DOI: 10.1002/jobm.202300365] [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: 06/24/2023] [Revised: 09/23/2023] [Accepted: 10/07/2023] [Indexed: 11/29/2023]
Abstract
The chlamydospores of Duddingtonia flagrans are an essential survival and reproductive structure and also an effective ingredient for the biocontrol of parasitic nematodes in livestock. In this study, entering and exiting dormancy conditions and predatory activity of the fungal chlamydospores were conducted. During this fungal growth process, the cultivation time is negatively correlated with spore germination rates. After the spores were processed by vacuum drying for 168 h, their germination rate dropped to 0.94%. In contrast, the percentage of living spores remained 54.82%, suggesting that the spores entered structural dormancy in the arid environment. Meanwhile, the efficacies of the spore against Haemonchus contortus larvae were 93.05% (0 h), 92.19% (16 h), 92.77% (96 h), and 86.45% (168 h), respectively. After dormant spores were stored at 4°C, -20°C, and 28°C (RH90 ~ 95%) for 7 days, their germination rate began to increase significantly (p < 0.05). For in vitro predation assay under the condition of 28°C (RH90 ~ 95%), the predation rate was significantly higher on the 7th day after incubation than that on the 3rd day (p < 0.05). During the period when spores were stored at room temperature for 8 months, their germination rate decreased in the first 5 months and then increased slowly to reach a peak in the 7th month. However, the reduction rate of H. contortus L3 in feces captured by spores remained above 71% for the first 7 months. These results will help us increase the end products yield and the quality of biological control of parasitic nematodes in livestock.
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Affiliation(s)
- Bo-Bo Wang
- Department of Medicine, Yan'an University, Yan'an, China
- Yan'an Key Laboratory of Zoonotic Parasitology Laboratory, Yan'an, China
| | - You-Lei Li
- Department of Medicine, Yan'an University, Yan'an, China
| | - Shu-Yue Tian
- Department of Medicine, Yan'an University, Yan'an, China
| | - Hai-Zhou Wang
- Department of Medicine, Yan'an University, Yan'an, China
| | - Xin Li
- Department of Medicine, Yan'an University, Yan'an, China
| | - Feng-Hui Wang
- Department of Medicine, Yan'an University, Yan'an, China
- Yan'an Key Laboratory of Fungi Resources Development and Biological Control, Yan'an, China
| | - Kui-Zheng Cai
- Department of Medicine, Yan'an University, Yan'an, China
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Wang G, Huang L, Zhuang S, Han F, Huang Q, Hao M, Lin G, Chen L, Shen B, Li F, Li X, Chen C, Gao Y, Mock T, Liang J. Resting cell formation in the marine diatom Thalassiosira pseudonana. THE NEW PHYTOLOGIST 2024. [PMID: 38402560 DOI: 10.1111/nph.19646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/08/2024] [Indexed: 02/26/2024]
Abstract
Resting cells represent a survival strategy employed by diatoms to endure prolonged periods of unfavourable conditions. In the oceans, many diatoms sink at the end of their blooming season and therefore need to endure cold and dark conditions in the deeper layers of the water column. How they survive these conditions is largely unknown. We conducted an integrative analysis encompassing methods from histology, physiology, biochemistry, and genetics to reveal the biological mechanism of resting-cell formation in the model diatom Thalassiosira pseudonana. Resting-cell formation was triggered by a decrease in light and temperature with subsequent catabolism of storage compounds. Resting cells were characterised by an acidic and viscous cytoplasm and altered morphology of the chloroplast ultrastructure. The formation of resting cells in T. pseudonana is an energy demanding process required for a biophysical alteration of the cytosol and chloroplasts to endure the unfavourable conditions of the deeper ocean as photosynthetic organisms. However, most resting cells (> 90%) germinate upon return to favorable growth conditions.
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Affiliation(s)
- Guangning Wang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Lu Huang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Shanshan Zhuang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Fang Han
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Qianqian Huang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Mengyuan Hao
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Guifang Lin
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Longnan Chen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Biying Shen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Feng Li
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Xuesong Li
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Changping Chen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Yahui Gao
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
- State Key Laboratory of Marine Environment Science, Xiamen University, Xiamen, 361102, Fujian, China
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia (UEA), Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Junrong Liang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
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Ncube P, Bagheri B, Goosen WJ, Miller MA, Sampson SL. Evidence, Challenges, and Knowledge Gaps Regarding Latent Tuberculosis in Animals. Microorganisms 2022; 10:microorganisms10091845. [PMID: 36144447 PMCID: PMC9503773 DOI: 10.3390/microorganisms10091845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 01/30/2023] Open
Abstract
Mycobacterium bovis and other Mycobacterium tuberculosis complex (MTBC) pathogens that cause domestic animal and wildlife tuberculosis have received considerably less attention than M. tuberculosis, the primary cause of human tuberculosis (TB). Human TB studies have shown that different stages of infection can exist, driven by host–pathogen interactions. This results in the emergence of heterogeneous subpopulations of mycobacteria in different phenotypic states, which range from actively replicating (AR) cells to viable but slowly or non-replicating (VBNR), viable but non-culturable (VBNC), and dormant mycobacteria. The VBNR, VBNC, and dormant subpopulations are believed to underlie latent tuberculosis (LTB) in humans; however, it is unclear if a similar phenomenon could be happening in animals. This review discusses the evidence, challenges, and knowledge gaps regarding LTB in animals, and possible host–pathogen differences in the MTBC strains M. tuberculosis and M. bovis during infection. We further consider models that might be adapted from human TB research to investigate how the different phenotypic states of bacteria could influence TB stages in animals. In addition, we explore potential host biomarkers and mycobacterial changes in the DosR regulon, transcriptional sigma factors, and resuscitation-promoting factors that may influence the development of LTB.
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YTHDF3 Is Involved in the Diapause Process of Bivoltine Bombyx mori Strains by Regulating the Expression of Cyp307a1 and Cyp18a1 Genes in the Ecdysone Synthesis Pathway. Biomolecules 2022; 12:biom12081127. [PMID: 36009021 PMCID: PMC9406231 DOI: 10.3390/biom12081127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/18/2022] Open
Abstract
The variable diapause features of bivoltine silkworm (Bombyx mori) strains regulated by environmental signals in the embryonic stage are closely related to epigenetics. Previously, we showed that the expression of YTHDF3 is significantly different in the pupae of the bivoltine silkworm Qiufeng developed from eggs incubated at a normal temperature (QFHT, diapause egg producer) compared to those from eggs incubated at a low temperature (QFLT, nondiapause egg producer), indicating that the expression of diapause-associated genes is regulated by the m6A modification level. However, how YTHDF3 regulates the expression of diapause-related genes remains unclear. In this study, we observed that the knockdown of B. mori YTHDF3 resulted in delayed embryo development, while the overexpression of YTHDF3 resulted in the transformation of nondiapause-destined eggs into a mixture of diapause and nondiapause eggs. Further studies showed that YTHDF3, as a reading protein, can recognize the m6A site of Cyp307a1 and Cyp18a1 genes in the ecdysone synthesis pathway (ESP), and the overexpression of YTHDF3 affects the diapause traits of the silkworm by decreasing the stabilities of mRNAs of Cyp307a1 and Cyp18a1 and inhibiting their translation. The above results demonstrate that m6A modification mediates YTHDF3 to affect the expression levels of its target genes, Cyp307a1 and Cyp18a1, in the ESP to regulate diapause in bivoltine B. mori. This is the first report of the m6A methylation regulation mechanism in diapause in B. mori and provides new experimental data for clarifying the diapause regulation network.
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Functional insights into Mycobacterium tuberculosis DevR-dependent transcriptional machinery utilizing Escherichia coli. Biochem J 2021; 478:3079-3098. [PMID: 34350952 DOI: 10.1042/bcj20210268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 11/17/2022]
Abstract
DevR/DosR response regulator is believed to participate in virulence, dormancy adaptation and antibiotic tolerance mechanisms of Mycobacterium tuberculosis by regulating the expression of the dormancy regulon. We have previously shown that the interaction of DevR with RNA polymerase is essential for the expression of DevR-regulated genes. Here, we developed a M. tuberculosis-specific in vivo transcription system to enrich our understanding of DevR-RNA polymerase interaction. This in vivo assay involves co-transforming E. coli with two plasmids that express α, β, β' and σA subunits of M. tuberculosis RNA polymerase and a third plasmid that harbors a DevR expression cassette and a GFP reporter gene under the DevR-regulated fdxA promoter. We show that DevR-dependent transcription is sponsored exclusively by M. tuberculosis RNA polymerase and regulated by α and σA subunits of M. tuberculosis RNA polymerase. Using this E. coli triple plasmid system to express mutant variants of M. tuberculosis RNA polymerase, we identified E280 residue in C-terminal domain of α and K513 and R515 residues of σA to participate in DevR-dependent transcription. In silico modeling of a ternary complex of DevR, σA domain 4 and fdxA promoter suggest an interaction of Q505, R515 and K513 residues of σA with E178 and D172 residues of DevR and E471 of σA, respectively. These findings provide us with new insights into the interactions between DevR and RNA polymerase of M. tuberculosis which can be targeted for intercepting DevR function. Finally, we demonstrate the utility of this system for screening of anti-DevR compounds.
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Campaniço A, Harjivan SG, Warner DF, Moreira R, Lopes F. Addressing Latent Tuberculosis: New Advances in Mimicking the Disease, Discovering Key Targets, and Designing Hit Compounds. Int J Mol Sci 2020; 21:ijms21228854. [PMID: 33238468 PMCID: PMC7700174 DOI: 10.3390/ijms21228854] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023] Open
Abstract
Despite being discovered and isolated more than one hundred years ago, tuberculosis (TB) remains a global public health concern arch. Our inability to eradicate this bacillus is strongly related with the growing resistance, low compliance to current drugs, and the capacity of the bacteria to coexist in a state of asymptomatic latency. This last state can be sustained for years or even decades, waiting for a breach in the immune system to become active again. Furthermore, most current therapies are not efficacious against this state, failing to completely clear the infection. Over the years, a series of experimental methods have been developed to mimic the latent state, currently used in drug discovery, both in vitro and in vivo. Most of these methods focus in one specific latency inducing factor, with only a few taking into consideration the complexity of the granuloma and the genomic and proteomic consequences of each physiological factor. A series of targets specifically involved in latency have been studied over the years with promising scaffolds being discovered and explored. Taking in account that solving the latency problem is one of the keys to eradicate the disease, herein we compile current therapies and diagnosis techniques, methods to mimic latency and new targets and compounds in the pipeline of drug discovery.
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Affiliation(s)
- André Campaniço
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.C.); (S.G.H.); (R.M.)
| | - Shrika G. Harjivan
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.C.); (S.G.H.); (R.M.)
| | - Digby F. Warner
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa;
- Department of Pathology, SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, University of Cape Town, Rondebosch 7701, South Africa
- Welcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Rondebosch 7701, South Africa
| | - Rui Moreira
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.C.); (S.G.H.); (R.M.)
| | - Francisca Lopes
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.C.); (S.G.H.); (R.M.)
- Correspondence:
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Potential therapeutic approaches for a sleeping pathogen: tuberculosis a case for bioinorganic chemistry. J Biol Inorg Chem 2020; 25:685-704. [PMID: 32676771 DOI: 10.1007/s00775-020-01803-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/30/2020] [Indexed: 12/18/2022]
Abstract
Mycobacterium tuberculosis (Mtb) has an old history as a human pathogen and still kills over one million people every year. One key feature of this bacterium is its dormancy: a phenomenon responsible for major changes in its metabolism and replication that have been associated with the need for a lengthy therapy for Mtb. This process is regulated by key heme-based sensors, particularly DosT and DevS (DosS), among other co-regulators, and also linked to nitrogen utilization (nitrate/nitrite) and stringent responses. In face of the current threat of tuberculosis, there is an urgent need to develop new therapeutic agents capable of targeting the dormant state, associated with the need for a lengthy therapy. Interestingly, many of those key proteins are indeed metallo-containing or metallo-dependent biomolecules, opening exciting bioinorganic opportunities. Here, we critically reviewed a series of small molecules targeting key proteins involved in these processes, including DosT/DevS/DevR, RegX3, MprA, MtrA, NarL, PknB, Rel, PPK, nitrate and nitrite reductases, GlnA1, aiming for new opportunities and alternative therapies. In the battle against Mycobacterium tuberculosis, new drug targets must be searched, in particular those involved in dormancy. A series of exciting cases for drug development involving metallo-containing or metallo-dependent biomolecules are reviewed, opening great opportunities for the bioinorganic chemistry community.
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8
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Hoang HH, Wang PC, Chen SC. The protective efficacy of recombinant hypoxic response protein 1 of Nocardia seriolae in largemouth bass (Micropterus salmoides). Vaccine 2020; 38:2925-2936. [PMID: 32115295 DOI: 10.1016/j.vaccine.2020.02.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/12/2020] [Accepted: 02/20/2020] [Indexed: 12/18/2022]
Abstract
Nocardia seriolae has become one of the major pathogens affecting the aquaculture industry and causes Nocardiosis, a highly devastating disease of marine and freshwater fish that leads to severe economic losses. Therefore, research efforts towards developing efficacious vaccines to control this disease are of high importance. In this study, the hypoxic response protein 1 (HRP1) cloned into pET32a vector was expressed, and produced in Escherichia coli strain BL21 (DE3). The antigenicity of purified recombinant TRX-tagged HRP (rHRP1) was analysed by western blotting using largemouth bass anti-N. seriolae sera. The results showed that largemouth bass anti-N. seriolae sera could specifically detect a 33 kDa rHRP1 protein. Further, the vaccine efficacy of rHRP1 was evaluated in a largemouth bass fish model by calculating the relative percent survival (RPS). rHRP1 incurred an RPS of 73.33% as compared to the control group. Immunological analysis showed that rHRP1 could produce significantly higher serum concentrations of anti-N. seriolae antibodies and serum lysozyme activity as compared to the control groups. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed that rHRP1 significantly enhanced the expression of immune-related genes, such as IL-12p40, IL-8, IL-1β, TNFα, IFNγ, NKEF, MHCIα, MHCIIα, CD4-1, CD8α, IgM, NF-κβ, STAT3, IRF4, RORα, and CCL20. These results indicate that rHRP1 may be a promising vaccine candidate against nocardiosis.
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Affiliation(s)
- Huy Hoa Hoang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, No. 1 Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Pei-Chi Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, No. 1 Shuefu Road, Neipu, Pingtung 91201, Taiwan; Southern Taiwan Fish Disease Centre, National Pingtung University of Science and Technology, No. 1 Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Shih-Chu Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, No. 1 Shuefu Road, Neipu, Pingtung 91201, Taiwan; Southern Taiwan Fish Disease Centre, National Pingtung University of Science and Technology, No. 1 Shuefu Road, Neipu, Pingtung 91201, Taiwan; International Degree Program of Ornamental Fish Science and Technology, International College, National Pingtung University of Science and Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan; Research Centre for Animal Biologics, National Pingtung University of Science and Technology, Pingtung, Taiwan.
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Li X, Lv X, Lin Y, Zhen J, Ruan C, Duan W, Li Y, Xie J. Role of two-component regulatory systems in intracellular survival of Mycobacterium tuberculosis. J Cell Biochem 2019; 120:12197-12207. [PMID: 31026098 DOI: 10.1002/jcb.28792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 11/06/2022]
Abstract
The typical two-component regulatory systems (TCSs), consisting of response regulator and histidine kinase, play a central role in survival of pathogenic bacteria under stress conditions such as nutrient starvation, hypoxia, and nitrosative stress. A total of 11 complete paired two-component regulatory systems have been found in Mycobacterium tuberculosis, including a few isolated kinase and regulatory genes. Increasing evidence has shown that TCSs are closely associated with multiple physiological process like intracellular persistence, pathogenicity, and metabolism. This review gives the two-component signal transduction systems in M. tuberculosis and their signal transduction roles in adaption to the environment.
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Affiliation(s)
- Xue Li
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Xi Lv
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Yanping Lin
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Junfeng Zhen
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Cao Ruan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Wei Duan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Yue Li
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Jianping Xie
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
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Modelling a Silent Epidemic: A Review of the In Vitro Models of Latent Tuberculosis. Pathogens 2018; 7:pathogens7040088. [PMID: 30445695 PMCID: PMC6313694 DOI: 10.3390/pathogens7040088] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/05/2018] [Accepted: 11/13/2018] [Indexed: 12/14/2022] Open
Abstract
Tuberculosis (TB) is the primary cause of death by a single infectious agent; responsible for around two million deaths in 2016. A major virulence factor of TB is the ability to enter a latent or Non-Replicating Persistent (NRP) state which is presumed untreatable. Approximately 1.7 billion people are latently infected with TB and on reactivation many of these infections are drug resistant. As the current treatment is ineffective and diagnosis remains poor, millions of people have the potential to reactivate into active TB disease. The immune system seeks to control the TB infection by containing the bacteria in a granuloma, where it is exposed to stressful anaerobic and nutrient deprived conditions. It is thought to be these environmental conditions that trigger the NRP state. A number of in vitro models have been developed that mimic conditions within the granuloma to a lesser or greater extent. These different models have all been utilised for the research of different characteristics of NRP Mycobacterium tuberculosis, however their disparity in approach and physiological relevance often results in inconsistencies and a lack of consensus between studies. This review provides a summation of the different NRP models and a critical analysis of their respective advantages and disadvantages relating to their physiological relevance.
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Trutneva K, Shleeva M, Nikitushkin V, Demina G, Kaprelyants A. Protein Composition of Mycobacterium smegmatis Differs Significantly Between Active Cells and Dormant Cells With Ovoid Morphology. Front Microbiol 2018; 9:2083. [PMID: 30233550 PMCID: PMC6131537 DOI: 10.3389/fmicb.2018.02083] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/14/2018] [Indexed: 01/07/2023] Open
Abstract
Mycobacteria are able to form dormant cells, which survive for a long time without multiplication. The molecular mechanisms behind prolonged survival of dormant cells are not fully described. In particular, little information is known on biochemical processes which might take place in cells under dormancy. To gain insight into this problem, Mycobacterium smegmatis cells in deep dormant state were obtained after gradual acidification of the growth medium in prolonged stationary phase followed by 1 month of storage at room temperature. Such cells were characterized by low metabolic activity, including respiration, resistance to antibiotics, and altered morphology. The protein composition of cytoplasm and membrane fractions obtained from active and dormant cells were compared by 2D electrophoresis. Almost half of the proteins found in the proteome of dormant cells were absent in that of active cells. This result differs significantly from published results obtained in other studies employing different models of mycobacterium dormancy. This discrepancy could be explained by a deeper dormancy developed in the present model. A feature of a “dormant proteome” is high representation of enzymes involved in glycolysis and defense systems that inactivate or detoxify reactive oxygen and nitrogen species, aldehydes, and oxidized lipids. Dormant mycobacteria are enriched by degradative enzymes, which could eliminate damaged molecules, or the products of such degradation could be reutilized by the cell during prolonged storage. We suggest that some enzymes in dormant cells are inactive, having been used upon transition to the dormant state, or proteins stored in dormant cells for further cell reactivation. At the same time, some proteins could be functional and play roles in maintenance of cell metabolism, albeit at a very slow rate. This study provides a clue as to which biochemical processes could be active under dormancy to ensure long-term viability of dormant mycobacteria.
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Affiliation(s)
- Kseniya Trutneva
- A.N. Bach Institute of Biochemistry, Federal Research Centre 'Fundamentals of Biotechnology' of the Russian Academy of Sciences, Moscow, Russia
| | - Margarita Shleeva
- A.N. Bach Institute of Biochemistry, Federal Research Centre 'Fundamentals of Biotechnology' of the Russian Academy of Sciences, Moscow, Russia
| | - Vadim Nikitushkin
- A.N. Bach Institute of Biochemistry, Federal Research Centre 'Fundamentals of Biotechnology' of the Russian Academy of Sciences, Moscow, Russia
| | - Galina Demina
- A.N. Bach Institute of Biochemistry, Federal Research Centre 'Fundamentals of Biotechnology' of the Russian Academy of Sciences, Moscow, Russia
| | - Arseny Kaprelyants
- A.N. Bach Institute of Biochemistry, Federal Research Centre 'Fundamentals of Biotechnology' of the Russian Academy of Sciences, Moscow, Russia
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Ravindran MS, Wenk MR. Activity-Based Lipid Esterase Profiling of M. bovis BCG at Different Metabolic States Using Tetrahydrolipstatin (THL) as Bait. Methods Mol Biol 2018; 1491:75-85. [PMID: 27778282 DOI: 10.1007/978-1-4939-6439-0_6] [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] [Indexed: 03/08/2023]
Abstract
This chapter provides a step-by-step protocol using activity-based protein profiling (ABPP) as a chemical-proteomic tool to survey the antibiotic properties of a small molecule. Here, we investigate the molecular mechanism behind the bactericidal activity of tetrahydrolipstatin (THL). ABPP relies on small molecule probes that target the active site of specific enzymes in complex proteomes. These probes in turn are equipped with a reporter tag that allows capturing, visualization, enrichment, identification, and quantification of its targets either in vitro or in situ. THL possesses bactericidal activities, but its precise spectrum of molecular targets is poorly characterized. Here, we used THL analogs functionalized to enable Huisgen-base cycloaddition, commonly known as "click chemistry," to identify target proteins after enrichment from mycobacterial cell lysates obtained from different physiological conditions.
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Affiliation(s)
- Madhu Sudhan Ravindran
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (NUS), Singapore, 117456, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Markus R Wenk
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Department of Biological Sciences, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Swiss Tropical and Public Health Institute, University of Basel, 4051, Basel, Switzerland.
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Sun C, Yang G, Yuan J, Peng X, Zhang C, Zhai X, Luo T, Bao L. Mycobacterium tuberculosis hypoxic response protein 1 (Hrp1) augments the pro-inflammatory response and enhances the survival of Mycobacterium smegmatis in murine macrophages. J Med Microbiol 2017; 66:1033-1044. [PMID: 28671529 DOI: 10.1099/jmm.0.000511] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE The DosR/DosS two-component regulatory system of Mycobacterium tuberculosis regulates the expression of numerous genes under stress conditions and is important for the long-term survival of M. tuberculosis in the host. The rv2626c gene of M. tuberculosis is one of the most strongly induced transcripts of the dormancy regulon. This study focused on the immunological effects and possible function of Rv2626c in maintaining mycobacterial survival under various stress conditions. METHODOLOGY We heterologously expressed the Rv2626c protein in Mycobacterium smegmatis by constructing a recombinant strain Ms_rv2626c. The viability of Ms_rv2626c was evaluated both in vivo and ex vivo. Different stress conditions, including acidified sodium nitrite, malachite green, low pH, SDS and lysozyme, were used to evaluate the effect of Rv2626c on bacterial resistance. An in vitro assay using a macrophage infection model was utilized to investigate the potential effect of Rv2626c to alter the immune response of host cell and its associated pathways. The effect of Rv2626c on cell necrosis was also explored. RESULTS The expression of Rv2626c-enhanced M. smegmatis survival under hypoxia and nitric oxide stress in vitro, and this enhancement was maintained within macrophages and in mouse tissues. In addition, macrophages infected with M. smegmatis expressing Rv2626c showed significantly higher interleukin-1β (IL-1β), IL-6, tumour necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression, as well as a higher level of cell necrosis, compared with the control. CONCLUSION M. tuberculosis protein Rv2626c plays a significant role in stimulating macrophages to provoke a pro-inflammatory response and in mycobacterial survival during infection.
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Affiliation(s)
- Changfeng Sun
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Guoping Yang
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Jinning Yuan
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Xuan Peng
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Chunxi Zhang
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Xiaoqian Zhai
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Tao Luo
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
| | - Lang Bao
- Laboratory of Infection and Immunity, School of Basic Medical Science, West China Centre of Medical Sciences, Sichuan University, no. 17, 3rd Section, Ren Min Nan Road, Chengdu, Sichuan 610041, PR China
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Delamanid Kills Dormant Mycobacteria In Vitro and in a Guinea Pig Model of Tuberculosis. Antimicrob Agents Chemother 2017; 61:AAC.02402-16. [PMID: 28373190 DOI: 10.1128/aac.02402-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 03/24/2017] [Indexed: 11/20/2022] Open
Abstract
Tuberculosis (TB) treatment is long and requires multiple drugs, likely due to various phenotypes of TB bacilli with variable drug susceptibilities. Drugs with broad activity are urgently needed. This study aimed to evaluate delamanid's activity against growing or dormant bacilli in vitro as well as in vivo Cultures of Mycobacterium bovis BCG Tokyo under aerobic and anaerobic conditions were used to study the activity of delamanid against growing and dormant bacilli, respectively. Delamanid exhibited significant bactericidal activity against replicating and dormant bacilli at or above concentrations of 0.016 and 0.4 mg/liter, respectively. To evaluate delamanid's antituberculosis activity in vivo, we used a guinea pig model of chronic TB infection in which the lung lesions were similar to those in human TB disease. In the guinea pig TB model, a daily dose of 100 mg delamanid/kg of body weight for 4 or 8 weeks demonstrated strong bactericidal activity against Mycobacterium tuberculosis Importantly, histological examination revealed that delamanid killed TB bacilli within hypoxic lesions of the lung. The combination regimens containing delamanid with rifampin and pyrazinamide or delamanid with levofloxacin, ethionamide, pyrazinamide, and amikacin were more effective than the standard regimen (rifampin, isoniazid, and pyrazinamide). Our data show that delamanid is effective in killing both growing and dormant bacilli in vitro and in the guinea pig TB model. Adding delamanid to current TB regimens may improve treatment outcomes, as demonstrated in recent clinical trials with pulmonary multidrug-resistant (MDR) TB patients. Delamanid may be an important drug for consideration in the construction of new regimens to shorten TB treatment duration.
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Devasundaram S, Gopalan A, Das SD, Raja A. Proteomics Analysis of Three Different Strains of Mycobacterium tuberculosis under In vitro Hypoxia and Evaluation of Hypoxia Associated Antigen's Specific Memory T Cells in Healthy Household Contacts. Front Microbiol 2016; 7:1275. [PMID: 27667981 PMCID: PMC5017210 DOI: 10.3389/fmicb.2016.01275] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 08/02/2016] [Indexed: 01/08/2023] Open
Abstract
In vitro mimicking conditions are thought to reflect the environment experienced by Mycobacterium tuberculosis inside the host granuloma. The majority of in vitro dormancy experimental models use laboratory-adapted strains H37Rv or Erdman instead of prevalent clinical strains involved during disease outbreaks. Thus, we included the most prevalent clinical strains (S7 and S10) of M. tuberculosis from south India in addition to H37Rv for our in vitro oxygen depletion (hypoxia) experimental model. Cytosolic proteins were prepared from hypoxic cultures, resolved by two-dimensional electrophoresis and protein spots were characterized by mass spectrometry. In total, 49 spots were characterized as over-expressed or newly emergent between the three strains. Two antigens (ESAT-6, Lpd) out of the 49 characterized spots were readily available in recombinant form in our lab. Hence, these two genes were overexpressed, purified and used for in vitro stimulation of whole blood collected from healthy household contacts (HHC) and active pulmonary tuberculosis patients (PTB). Multicolor flow cytometry analysis showed high levels of antigen specific CD4(+) central memory T cells in the circulation of HHC compared to PTB (p < 0.005 for ESAT-6 and p < 0.0005 for Lpd). This shows proteins that are predicted to be up regulated during in vitro hypoxia in most prevalent clinical strains would indicate possible potential immunogens. In vitro hypoxia experiments with most prevalent clinical strains would also elucidate the probable true representative antigens involved in adaptive mechanisms.
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Affiliation(s)
- Santhi Devasundaram
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR) Chennai, India
| | - Akilandeswari Gopalan
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR) Chennai, India
| | - Sulochana D Das
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR) Chennai, India
| | - Alamelu Raja
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR) Chennai, India
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Abstract
The emerging field of proteomics has contributed greatly to improving our understanding of the human pathogen Mycobacterium tuberculosis over the last two decades. In this chapter we provide a comprehensive overview of mycobacterial proteome research and highlight key findings. First, studies employing a combination of two-dimensional gel electrophoresis and mass spectrometry (MS) provided insights into the proteomic composition, initially of the whole bacillus and subsequently of subfractions, such as the cell wall, cytosol, and secreted proteins. Comparison of results obtained under various culture conditions, i.e., acidic pH, nutrient starvation, and low oxygen tension, aiming to mimic facets of the intracellular lifestyle of M. tuberculosis, provided initial clues to proteins relevant for intracellular survival and manipulation of the host cell. Further attempts were aimed at identifying the biological functions of the hypothetical M. tuberculosis proteins, which still make up a quarter of the gene products of M. tuberculosis, and at characterizing posttranslational modifications. Recent technological advances in MS have given rise to new methods such as selected reaction monitoring (SRM) and data-independent acquisition (DIA). These targeted, cutting-edge techniques combined with a public database of specific MS assays covering the entire proteome of M. tuberculosis allow the simple and reliable detection of any mycobacterial protein. Most recent studies attempt not only to identify but also to quantify absolute amounts of single proteins in the complex background of host cells without prior sample fractionation or enrichment. Finally, we will discuss the potential of proteomics to advance vaccinology, drug discovery, and biomarker identification to improve intervention and prevention measures for tuberculosis.
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Bai XJ, Liang Y, Yang YR, Feng JD, Luo ZP, Zhang JX, Wu XQ. Potential novel markers to discriminate between active and latent tuberculosis infection in Chinese individuals. Comp Immunol Microbiol Infect Dis 2015; 44:8-13. [PMID: 26851588 DOI: 10.1016/j.cimid.2015.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 11/05/2015] [Accepted: 11/06/2015] [Indexed: 01/09/2023]
Abstract
Latent tuberculosis infection (LTBI) constitutes the main reservoir for reactivation tuberculosis. The finding of potential biomarkers for differentiating between TB and LTBI is very necessary. In this study, the immunological characteristics and potential diagnostic utility of Rv2029c, Rv2628 and Rv1813c proteins were assessed. These three proteins stimulated PBMCs from ELISPOT-positive LTBI subjects produced higher levels of IFN-γ in comparison with TB patients and ELISPOT-negative healthy subjects (p<0.05). BCG vaccination and non-TB respiratory disease had little influence on the immunological responses of Rv2029c and Rv2628 proteins (p>0.05). The LTBI diagnostic performance of Rv2029c was higher than Rv2628 and Rv1813c by ROC evaluation. But Rv2628 had much higher specificity than Rv2029c in active TB patients and uninfected healthy subjects. The IgG level against Rv1813c was higher in the TB group than in LTBI and uninfected healthy subjects (p<0.05). These results suggest that T cell response to Rv2628 and antibody against Rv1813c might be applicable as biomarkers to distinguish TB from LTBI and uninfected individuals.
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Affiliation(s)
- Xue-juan Bai
- Army Tuberculosis Prevention and Control Key Laboratory, Beijng Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Institute for Tuberculosis Research, The 309th Hospital of Chinese PLA, Beijing 100091, PR China; Department of Pathology, The 309th Hospital of Chinese PLA, Beijing 100091, PR China
| | - Yan Liang
- Army Tuberculosis Prevention and Control Key Laboratory, Beijng Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Institute for Tuberculosis Research, The 309th Hospital of Chinese PLA, Beijing 100091, PR China
| | - You-rong Yang
- Army Tuberculosis Prevention and Control Key Laboratory, Beijng Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Institute for Tuberculosis Research, The 309th Hospital of Chinese PLA, Beijing 100091, PR China
| | - Jin-dong Feng
- Department of Respiratory, The 309th Hospital of Chinese PLA, Beijing 100091, PR China
| | - Zhan-peng Luo
- Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, PR China
| | - Jun-Xian Zhang
- Army Tuberculosis Prevention and Control Key Laboratory, Beijng Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Institute for Tuberculosis Research, The 309th Hospital of Chinese PLA, Beijing 100091, PR China
| | - Xue-qiong Wu
- Army Tuberculosis Prevention and Control Key Laboratory, Beijng Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Institute for Tuberculosis Research, The 309th Hospital of Chinese PLA, Beijing 100091, PR China.
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18
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Prabhavathi M, Pathakumari B, Raja A. IFN-γ/TNF-α ratio in response to immuno proteomically identified human T-cell antigens of Mycobacterium tuberculosis - The most suitable surrogate biomarker for latent TB infection. J Infect 2015; 71:238-49. [PMID: 25936741 DOI: 10.1016/j.jinf.2015.04.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/23/2015] [Accepted: 04/23/2015] [Indexed: 10/23/2022]
Abstract
The enormous reservoir of latent TB infection (LTBI) poses a major hurdle for global TB control. The existing Tuberculin skin test (TST) and IFN-γ release assays (IGRAs) are found to be suboptimal for LTBI diagnosis. Previously we had taken an immunoproteomic approach and identified 10 protein fractions (contains 16 proteins), which are solely recognized by LTBI. In a cohort of 40 pulmonary TB patients (PTB) and 35 healthy household contacts (HHC), IFN-γ and TNF-α response were measured against 16 antigens by using 1:10 diluted whole blood assay. Among all the antigens, IFN-γ response to Rv2626c has shown positivity of 88.57% in HHC and 7.5% in PTB group. IFN-γ response to combination of Rv2626c + Rv3716c has demonstrated 100% positivity in HHC and 17.5% positivity in PTB respectively. Compared to individual cytokines (i.e. IFN-γ and TNF-α), ratio of IFN-γ/TNF-α has shown promising results for diagnosis of LTBI. IFN-γ/TNF-α ratio against Rv3716c and TrxC has exhibited a positivity of 94.29% in HHC and 5% in PTB group. Accession of Rv2626c and Rv3716c may improve the diagnostic performance of existing QFT-GIT. Independent of QFT-GIT assay, ratio of IFN-γ/TNF-α in response to either Rv3716c or TrxC may acts as suitable surrogate biomarker for LTBI.
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Affiliation(s)
- Maddineni Prabhavathi
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetpet, Chennai 600 031, Tamil Nadu, India.
| | - Balaji Pathakumari
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetpet, Chennai 600 031, Tamil Nadu, India.
| | - Alamelu Raja
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR), No. 1, Mayor Sathyamoorthy Road, Chetpet, Chennai 600 031, Tamil Nadu, India.
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Feltcher ME, Gunawardena HP, Zulauf KE, Malik S, Griffin JE, Sassetti CM, Chen X, Braunstein M. Label-free Quantitative Proteomics Reveals a Role for the Mycobacterium tuberculosis SecA2 Pathway in Exporting Solute Binding Proteins and Mce Transporters to the Cell Wall. Mol Cell Proteomics 2015; 14:1501-16. [PMID: 25813378 DOI: 10.1074/mcp.m114.044685] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Indexed: 01/18/2023] Open
Abstract
Mycobacterium tuberculosis is an example of a bacterial pathogen with a specialized SecA2-dependent protein export system that contributes to its virulence. Our understanding of the mechanistic basis of SecA2-dependent export and the role(s) of the SecA2 pathway in M. tuberculosis pathogenesis has been hindered by our limited knowledge of the proteins exported by the pathway. Here, we set out to identify M. tuberculosis proteins that use the SecA2 pathway for their export from the bacterial cytoplasm to the cell wall. Using label-free quantitative proteomics involving spectral counting, we compared the cell wall and cytoplasmic proteomes of wild type M. tuberculosis to that of a ΔsecA2 mutant. This work revealed a role for the M. tuberculosis SecA2 pathway in the cell wall localization of solute binding proteins that work with ABC transporters to import solutes. Another discovery was a profound effect of SecA2 on the cell wall localization of the Mce1 and Mce4 lipid transporters, which contribute to M. tuberculosis virulence. In addition to the effects on solute binding proteins and Mce transporter export, our label-free quantitative analysis revealed an unexpected relationship between SecA2 and the hypoxia-induced DosR regulon, which is associated with M. tuberculosis latency. Nearly half of the transcriptionally controlled DosR regulon of cytoplasmic proteins were detected at higher levels in the ΔsecA2 mutant versus wild type M. tuberculosis. By increasing the list of M. tuberculosis proteins known to be affected by the SecA2 pathway, this study expands our appreciation of the types of proteins exported by this pathway and guides our understanding of the mechanism of SecA2-dependent protein export in mycobacteria. At the same time, the newly identified SecA2-dependent proteins are helpful for understanding the significance of this pathway to M. tuberculosis virulence and physiology.
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Affiliation(s)
| | - Harsha P Gunawardena
- §Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina, 27599
| | | | - Seidu Malik
- From the ‡Department of Microbiology and Immunology
| | - Jennifer E Griffin
- ¶Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Christopher M Sassetti
- ¶Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655; ‖Howard Hughes Medical Institute, Chevy Chase, Maryland, 20815
| | - Xian Chen
- §Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina, 27599;
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Schubert OT, Aebersold R. Microbial Proteome Profiling and Systems Biology: Applications to Mycobacterium tuberculosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 883:235-54. [PMID: 26621471 DOI: 10.1007/978-3-319-23603-2_13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Each year, 1.3 million people die from tuberculosis, an infectious disease caused by Mycobacterium tuberculosis. Systems biology-based strategies might significantly contribute to the knowledge-guided development of more effective vaccines and drugs to prevent and cure infectious diseases. To build models simulating the behaviour of a system in response to internal or external stimuli and to identify potential targets for therapeutic intervention, systems biology approaches require the acquisition of quantitative molecular profiles on many perturbed states. Here we review the current state of proteomic analyses in Mycobacterium tuberculosis and discuss the potential of recently emerging targeting mass spectrometry-based techniques which enable fast, sensitive and accurate protein measurements.
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Affiliation(s)
- Olga T Schubert
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland.
- Systems Biology Graduate School, Zurich, CH-8057, Switzerland.
| | - Ruedi Aebersold
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland.
- Faculty of Science, University of Zurich, Zurich, CH-8057, Switzerland.
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Cha NH, Jang HJ. Transcriptomic analysis of effects of triclosan on Mycobacterium bovis BCG. BIOCHIP JOURNAL 2014. [DOI: 10.1007/s13206-014-8302-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Ravindran MS, Rao SPS, Cheng X, Shukla A, Cazenave-Gassiot A, Yao SQ, Wenk MR. Targeting lipid esterases in mycobacteria grown under different physiological conditions using activity-based profiling with tetrahydrolipstatin (THL). Mol Cell Proteomics 2013; 13:435-48. [PMID: 24345785 DOI: 10.1074/mcp.m113.029942] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tetrahydrolipstatin (THL) is bactericidal but its precise target spectrum is poorly characterized. Here, we used a THL analog and activity-based protein profiling to identify target proteins after enrichment from whole cell lysates of Mycobacterium bovis Bacillus Calmette-Guérin cultured under replicating and non-replicating conditions. THL targets α/β-hydrolases, including many lipid esterases (LipD, G, H, I, M, N, O, V, W, and TesA). Target protein concentrations and total esterase activity correlated inversely with cellular triacylglycerol upon entry into and exit from non-replicating conditions. Cellular overexpression of lipH and tesA led to decreased THL susceptibility thus providing functional validation. Our results define the target spectrum of THL in a biological species with particularly diverse lipid metabolic pathways. We furthermore derive a conceptual approach that demonstrates the use of such THL probes for the characterization of substrate recognition by lipases and related enzymes.
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Affiliation(s)
- Madhu Sudhan Ravindran
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456
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Ayala JC, Pimienta E, Rodríguez C, Anné J, Vallín C, Milanés MT, King-Batsios E, Huygen K, Van Mellaert L. Use of Strep-tag II for rapid detection and purification of Mycobacterium tuberculosis recombinant antigens secreted by Streptomyces lividans. J Microbiol Methods 2013; 94:192-8. [DOI: 10.1016/j.mimet.2013.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 05/31/2013] [Accepted: 06/01/2013] [Indexed: 10/26/2022]
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Sivaramakrishnan S, de Montellano PRO. The DosS-DosT/DosR Mycobacterial Sensor System. BIOSENSORS 2013; 3:259-282. [PMID: 25002970 PMCID: PMC4082495 DOI: 10.3390/bios3030259] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/15/2013] [Accepted: 06/26/2013] [Indexed: 11/16/2022]
Abstract
DosS/DosR is a two-component regulatory system in which DosS, a heme-containing sensor also known as DevS, under certain conditions undergoes autophosphorylation and then transfers the phosphate to DosR, a DNA-binding protein that controls the entry of Mycobacterium tuberculosis and other mycobacteria into a latent, dormant state. DosT, a second sensor closely related to DosS, is present in M. tuberculosis and participates in the control of the dormancy response mediated by DosR. The binding of phosphorylated DosR to DNA initiates the expression of approximately fifty dormancy-linked genes. DosT is accepted to be a gas sensor that is activated in the ferrous state by the absence of an oxygen ligand or by the binding of NO or CO. DosS functions in a similar fashion as a gas sensor, but contradictory evidence has led to the suggestion that it also functions as a redox state sensor. This review focuses on the structure, biophysical properties, and function of the DosS/DosT heme sensors.
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Affiliation(s)
- Santhosh Sivaramakrishnan
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94158, USA;
| | - Paul R Ortiz de Montellano
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94158, USA;
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Singh SK, Tripathi DK, Singh PK, Sharma S, Srivastava KK. Protective and survival efficacies of Rv0160c protein in murine model of Mycobacterium tuberculosis. Appl Microbiol Biotechnol 2012; 97:5825-37. [PMID: 23104642 DOI: 10.1007/s00253-012-4493-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 10/01/2012] [Accepted: 10/02/2012] [Indexed: 12/20/2022]
Abstract
The proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) multi-gene families code for approximately 10% of the Mycobacterium tuberculosis (Mtb) genome. These proteins are thought to be virulence factors that participate in impounding the host immune responses. While some members have been studied, the functions of most PE/PPE proteins are yet to be explored. The studies presented here have specifically characterized the roles of one of the PE proteins of Mtb, Rv0160c (PE4), in mycobacterial persistence and in prophylactic efficacy. We have expressed Rv0160c in a non-pathogenic fast-growing Mycobacterium smegmatis strain and demonstrated that the protein improves the survival of mycobacteria in macrophages and in mice. The protein has also shown its effect under physiological stress of bacteria, as evidenced by elevated expression in acidic and in hypoxic conditions. In mice, the level of Rv0160c was noticeably high during the chronic stage of tuberculosis. The seroreactivity of the protein against different categories of tuberculosis patients revealed a strong B-cell humoral response in freshly infected pulmonary tuberculosis patients. In mice, it exhibited increased IL-2, TNF, and IL-6 production. The antigenic properties of the protein directed towards the protective efficacy against the Mtb challenge. All together, our findings have identified Rv0160c as an in vivo expressed immunodominant antigen which plays a crucial role in the pathogenesis of mycobacterial disease and could prove to be a good preventive antigen for tuberculosis.
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Affiliation(s)
- Susmita K Singh
- Division of Microbiology, CSIR--Central Drug Research Institute, Lucknow 226001, India
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Cho YS, Dobos KM, Prenni J, Yang H, Hess A, Rosenkrands I, Andersen P, Ryoo SW, Bai GH, Brennan MJ, Izzo A, Bielefeldt-Ohmann H, Belisle JT. Deciphering the proteome of the in vivo diagnostic reagent "purified protein derivative" from Mycobacterium tuberculosis. Proteomics 2012; 12:979-91. [PMID: 22522804 DOI: 10.1002/pmic.201100544] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Purified protein derivative (PPD) has served as a safe and effective diagnostic reagent for 60 years and is the only broadly available material to diagnose latent tuberculosis infections. This reagent is also used as a standard control for a number of in vitro immunological assays. Nevertheless, the molecular composition and specific products that contribute to the extraordinary immunological reactivity of PPD are poorly defined. Here, a proteomic approach was applied to elucidate the gene products in the U.S. Food and Drug Administration (FDA) standard PPD-S2. Many known Mycobacterium tuberculosis T-cell antigens were detected. Of significance, four heat shock proteins (HSPs) (GroES, GroEL2, HspX, and DnaK) dominated the composition of PPD. The chaperone activities and capacity of these proteins to influence immunological responses may explain the exquisite solubility and immunological potency of PPD. Spectral counting analysis of three separate PPD reagents revealed significant quantitative variances. Gross delayed-type hypersensitivity (DTH) responses in M. tuberculosis infected guinea pigs were comparable among these PPD preparations; however, detailed histopathology of the DTH lesions exposed unique differences, which may be explained by the variability observed in the presence and abundance of early secretory system (Esx) proteins. Variability in PPD reagents may explain differences in DTH responses reported among populations.
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Affiliation(s)
- Yun Sang Cho
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
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Boon C, Dick T. How Mycobacterium tuberculosis goes to sleep: the dormancy survival regulator DosR a decade later. Future Microbiol 2012; 7:513-8. [PMID: 22439727 DOI: 10.2217/fmb.12.14] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
With 2 million deaths per year, TB remains the most significant bacterial killer. The long duration of chemotherapy and the large pool of latently infected people represent challenges in disease control. To develop drugs that effectively eradicate latent infection and shorten treatment duration, the pathophysiology of the causative agent Mycobacterium tuberculosis needs to be understood. The discovery that the tubercle bacillus can develop a drug-tolerant dormant form and the identification of the underlying genetic program 10 years ago paved the way for a deeper understanding of the life of the parasite inside human lesions and for new approaches to antimycobacterial drug discovery. Here, we summarize what we have learnt since the discovery of the master regulator of dormancy, DosR, and the key gaps in our knowledge that remain. Furthermore, we discuss a possible wider clinical relevance of DosR for 'nontuberculous mycobacteria'.
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Affiliation(s)
- Calvin Boon
- Dx Assays Pte Ltd, Woodlands Central Industrial Estate, 35 Marsiling Industrial Estate Road 3, Unit 02-03/02/01, 739257, Singapore
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MprA and DosR coregulate a Mycobacterium tuberculosis virulence operon encoding Rv1813c and Rv1812c. Infect Immun 2012; 80:3018-33. [PMID: 22689819 DOI: 10.1128/iai.00520-12] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis remains a significant global pathogen, causing extensive morbidity and mortality worldwide. This bacterium persists within granulomatous lesions in a poorly characterized, nonreplicating state. The two-component signal transduction systems MprAB and DosRS-DosT (DevRS-Rv2027c) are responsive to conditions likely to be present within granulomatous lesions and mediate aspects of M. tuberculosis persistence in vitro and in vivo. Here, we describe a previously uncharacterized locus, Rv1813c-Rv1812c, that is coregulated by both MprA and DosR. We demonstrate that MprA and DosR bind to adjacent and overlapping sequences within the promoter region of Rv1813c and direct transcription from an initiation site located several hundred base pairs upstream of the Rv1813 translation start site. We further show that Rv1813c and Rv1812c are cotranscribed, and that the genomic organization of this operon is specific to M. tuberculosis and Mycobacterium bovis. Although Rv1813c is not required for survival of M. tuberculosis in vitro, including under conditions in which MprAB and DosRST signaling are activated, an M. tuberculosis ΔRv1813c mutant is attenuated in the low-dose aerosol model of murine tuberculosis, where it exhibits a lower bacterial burden, delayed time to death, and decreased ability to stimulate proinflammatory cytokines interleukin-1β (IL-1β) and IL-12. Interestingly, overcomplementation of these phenotypes is observed in the M. tuberculosis ΔRv1813c mutant expressing both Rv1813c and Rv1812c, but not Rv1813c alone, in trans. Therefore, Rv1813c and Rv1812c may represent general stress-responsive elements that are necessary for aspects of M. tuberculosis virulence and the host immune response to infection.
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Bretl DJ, Demetriadou C, Zahrt TC. Adaptation to environmental stimuli within the host: two-component signal transduction systems of Mycobacterium tuberculosis. Microbiol Mol Biol Rev 2011; 75:566-82. [PMID: 22126994 PMCID: PMC3232741 DOI: 10.1128/mmbr.05004-11] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pathogenic microorganisms encounter a variety of environmental stresses following infection of their respective hosts. Mycobacterium tuberculosis, the etiological agent of tuberculosis, is an unusual bacterial pathogen in that it is able to establish lifelong infections in individuals within granulomatous lesions that are formed following a productive immune response. Adaptation to this highly dynamic environment is thought to be mediated primarily through transcriptional reprogramming initiated in response to recognition of stimuli, including low-oxygen tension, nutrient depletion, reactive oxygen and nitrogen species, altered pH, toxic lipid moieties, cell wall/cell membrane-perturbing agents, and other environmental cues. To survive continued exposure to these potentially adverse factors, M. tuberculosis encodes a variety of regulatory factors, including 11 complete two-component signal transduction systems (TCSSs) and several orphaned response regulators (RRs) and sensor kinases (SKs). This report reviews our current knowledge of the TCSSs present in M. tuberculosis. In particular, we discuss the biochemical and functional characteristics of individual RRs and SKs, the environmental stimuli regulating their activation, the regulons controlled by the various TCSSs, and the known or postulated role(s) of individual TCSSs in the context of M. tuberculosis physiology and/or pathogenesis.
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Affiliation(s)
| | | | - Thomas C. Zahrt
- Center for Infectious Disease Research and Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226-0509
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Raspoet R, Gantois I, Devloo R, Martel A, Haesebrouck F, Pasmans F, Ducatelle R, Van Immerseel F. Salmonella Enteritidis universal stress protein (usp) gene expression is stimulated by egg white and supports oviduct colonization and egg contamination in laying hens. Vet Microbiol 2011; 153:186-90. [DOI: 10.1016/j.vetmic.2011.05.047] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/24/2011] [Accepted: 05/31/2011] [Indexed: 11/16/2022]
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Mehaffy MC, Kruh-Garcia NA, Dobos KM. Prospective on Mycobacterium tuberculosis proteomics. J Proteome Res 2011; 11:17-25. [PMID: 21988637 DOI: 10.1021/pr2008658] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, remains one of the most prevalent human pathogens in the world. Knowledge regarding the bacilli's physiology as well as its mechanisms of virulence, immunogenicity, and pathogenesis has increased greatly in the last three decades. However, the function of about one-quarter of the Mtb coding genome and the precise activity and protein networks of most of the Mtb proteins are still unknown. Protein mass spectrometry and a new interest in research toward the field of functional proteomics have given a new light to the study of this bacillus and will be the focus of this review. We will also discuss new perspectives in the proteomics field, in particular targeted mass spectrometry methods and their potential applications in TB research and discovery.
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Affiliation(s)
- M Carolina Mehaffy
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1619 Campus Delivery, Fort Collins, Colorado 80523, United States
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Farhana A, Guidry L, Srivastava A, Singh A, Hondalus MK, Steyn AJC. Reductive stress in microbes: implications for understanding Mycobacterium tuberculosis disease and persistence. Adv Microb Physiol 2011; 57:43-117. [PMID: 21078441 DOI: 10.1016/b978-0-12-381045-8.00002-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is a remarkably successful pathogen that is capable of persisting in host tissues for decades without causing disease. Years after initial infection, the bacilli may resume growth, the outcome of which is active tuberculosis (TB). In order to establish infection, resist host defences and re-emerge, Mtb must coordinate its metabolism with the in vivo environmental conditions and nutrient availability within the primary site of infection, the lung. Maintaining metabolic homeostasis for an intracellular pathogen such as Mtb requires a carefully orchestrated series of oxidation-reduction reactions, which, if unbalanced, generate oxidative or reductive stress. The importance of oxidative stress in microbial pathogenesis has been appreciated and well studied over the past several decades. However, the role of its counterpart, reductive stress, has been largely ignored. Reductive stress is defined as an aberrant increase in reducing equivalents, the magnitude and identity of which is determined by host carbon source utilisation and influenced by the presence of host-generated gases (e.g. NO, CO, O(2) and CO(2)). This increased reductive power must be dissipated for bacterial survival. To recycle reducing equivalents, microbes have evolved unique electron 'sinks' that are distinct for their particular environmental niche. In this review, we describe the specific mechanisms that some microbes have evolved to dispel reductive stress. The intention of this review is to introduce the concept of reductive stress, in tuberculosis research in particular, in the hope of stimulating new avenues of investigation.
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Affiliation(s)
- Aisha Farhana
- Department of Microbiology, University of Alabama at Birmingham, AL, USA
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Lennon JT, Jones SE. Microbial seed banks: the ecological and evolutionary implications of dormancy. Nat Rev Microbiol 2011; 9:119-30. [PMID: 21233850 DOI: 10.1038/nrmicro2504] [Citation(s) in RCA: 857] [Impact Index Per Article: 65.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dormancy is a bet-hedging strategy used by a wide range of taxa, including microorganisms. It refers to an organism's ability to enter a reversible state of low metabolic activity when faced with unfavourable environmental conditions. Dormant microorganisms generate a seed bank, which comprises individuals that are capable of being resuscitated following environmental change. In this Review, we highlight mechanisms that have evolved in microorganisms to allow them to successfully enter and exit a dormant state, and discuss the implications of microbial seed banks for evolutionary dynamics, population persistence, maintenance of biodiversity, and the stability of ecosystem processes.
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Affiliation(s)
- Jay T Lennon
- W.K. Kellogg Biological Station, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, Michigan 49060, USA.
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Nde CW, Toghrol F, Jang HJ, Bentley WE. Toxicogenomic response of Mycobacterium bovis BCG to peracetic acid and a comparative analysis of the M. bovis BCG response to three oxidative disinfectants. Appl Microbiol Biotechnol 2010; 90:277-304. [PMID: 21152916 DOI: 10.1007/s00253-010-2931-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 09/08/2010] [Accepted: 10/01/2010] [Indexed: 12/16/2022]
Abstract
Tuberculosis is a leading cause of death worldwide and infects thousands of Americans annually. Mycobacterium bovis causes tuberculosis in humans and several animal species. Peracetic acid is an approved tuberculocide in hospital and domestic environments. This study presents for the first time the transcriptomic changes in M. bovis BCG after treatment with 0.1 mM peracetic acid for 10 and 20 min. This study also presents for the first time a comparison among the transcriptomic responses of M. bovis BCG to three oxidative disinfectants: peracetic acid, sodium hypochlorite, and hydrogen peroxide after 10 min of treatment. Results indicate that arginine biosynthesis, virulence, and oxidative stress response genes were upregulated after both peracetic acid treatment times. Three DNA repair genes were downregulated after 10 and 20 min and cell wall component genes were upregulated after 20 min. The devR-devS signal transduction system was upregulated after 10 min, suggesting a role in the protection against peracetic acid treatment. Results also suggest that peracetic acid and sodium hypochlorite both induce the expression of the ctpF gene which is upregulated in hypoxic environments. Further, this study reveals that in M. bovis BCG, hydrogen peroxide and peracetic acid both induce the expression of katG involved in oxidative stress response and the mbtD and mbtI genes involved in iron regulation/virulence.
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Affiliation(s)
- Chantal W Nde
- Center for Biosystems Research, University of Maryland Biotechnology Institute, College Park, MD 20742, USA
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Kim MJ, Park KJ, Ko IJ, Kim YM, Oh JI. Different roles of DosS and DosT in the hypoxic adaptation of Mycobacteria. J Bacteriol 2010; 192:4868-75. [PMID: 20675480 PMCID: PMC2944544 DOI: 10.1128/jb.00550-10] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 07/22/2010] [Indexed: 11/20/2022] Open
Abstract
The DosS (DevS) and DosT histidine kinases form a two-component system together with the DosR (DevR) response regulator in Mycobacterium tuberculosis. DosS and DosT, which have high sequence similarity to each other over the length of their amino acid sequences, contain two GAF domains (GAF-A and GAF-B) in their N-terminal sensory domains. Complementation tests in conjunction with phylogenetic analysis showed that DevS of Mycobacterium smegmatis is more closely related to DosT than DosS. We also demonstrated in vivo that DosS and DosT of M. tuberculosis play a differential role in hypoxic adaptation. DosT responds to a decrease in oxygen tension more sensitively and strongly than DosS, which might be attributable to their different autooxidation rates. The different responsiveness of DosS and DosT to hypoxia is due to the difference in their GAF-A domains accommodating the hemes. Multiple alignment analysis of the GAF-A domains of mycobacterial DosS (DosT) homologs and subsequent site-directed mutagenesis revealed that just one substitution of E87, D90, H97, L118, or T169 of DosS with the corresponding residue of DosT is sufficient to convert DosS to DosT with regard to the responsiveness to changes in oxygen tension.
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Affiliation(s)
- Min-Ju Kim
- Department of Microbiology, Pusan National University, 609-735 Busan, South Korea, Korea Science Academy of KAIST, 614-822 Busan, South Korea, Department of Biology, Yonsei University, 120-749 Seoul, South Korea
| | - Kwang-Jin Park
- Department of Microbiology, Pusan National University, 609-735 Busan, South Korea, Korea Science Academy of KAIST, 614-822 Busan, South Korea, Department of Biology, Yonsei University, 120-749 Seoul, South Korea
| | - In-Jeong Ko
- Department of Microbiology, Pusan National University, 609-735 Busan, South Korea, Korea Science Academy of KAIST, 614-822 Busan, South Korea, Department of Biology, Yonsei University, 120-749 Seoul, South Korea
| | - Young Min Kim
- Department of Microbiology, Pusan National University, 609-735 Busan, South Korea, Korea Science Academy of KAIST, 614-822 Busan, South Korea, Department of Biology, Yonsei University, 120-749 Seoul, South Korea
| | - Jeong-Il Oh
- Department of Microbiology, Pusan National University, 609-735 Busan, South Korea, Korea Science Academy of KAIST, 614-822 Busan, South Korea, Department of Biology, Yonsei University, 120-749 Seoul, South Korea
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Chao JD, Papavinasasundaram KG, Zheng X, Chávez-Steenbock A, Wang X, Lee GQ, Av-Gay Y. Convergence of Ser/Thr and two-component signaling to coordinate expression of the dormancy regulon in Mycobacterium tuberculosis. J Biol Chem 2010; 285:29239-46. [PMID: 20630871 DOI: 10.1074/jbc.m110.132894] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transduction in Mycobacterium tuberculosis is mediated primarily by the Ser/Thr protein kinases and the two-component systems. The Ser/Thr kinase PknH has been shown to regulate growth of M. tuberculosis in a mouse model and in response to NO stress in vitro. Comparison of a pknH deletion mutant (ΔpknH) with its parental M. tuberculosis H37Rv strain using iTRAQ enabled us to quantify >700 mycobacterial proteins. Among these, members of the hypoxia- and NO-inducible dormancy (DosR) regulon were disregulated in the ΔpknH mutant. Using kinase assays, protein-protein interactions, and mass spectrometry analysis, we demonstrated that the two-component response regulator DosR is a substrate of PknH. PknH phosphorylation of DosR mapped to Thr(198) and Thr(205) on the key regulatory helix α10 involved in activation and dimerization of DosR. PknH Thr phosphorylation and DosS Asp phosphorylation of DosR cooperatively enhanced DosR binding to cognate DNA sequences. Transcriptional analysis comparing ΔpknH and parental M. tuberculosis revealed that induction of the DosR regulon was subdued in the ΔpknH mutant in response to NO. Together, these results indicate that PknH phosphorylation of DosR is required for full induction of the DosR regulon and demonstrate convergence of the two major signal transduction systems for the first time in M. tuberculosis.
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Affiliation(s)
- Joseph D Chao
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V5Z 3J5, Canada
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Shi C, Chen L, Chen Z, Zhang Y, Zhou Z, Lu J, Fu R, Wang C, Fang Z, Fan X. Enhanced protection against tuberculosis by vaccination with recombinant BCG over-expressing HspX protein. Vaccine 2010; 28:5237-44. [DOI: 10.1016/j.vaccine.2010.05.063] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 05/06/2010] [Accepted: 05/26/2010] [Indexed: 11/16/2022]
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Hingley-Wilson SM, Lougheed KEA, Ferguson K, Leiva S, Williams HD. Individual Mycobacterium tuberculosis universal stress protein homologues are dispensable in vitro. Tuberculosis (Edinb) 2010; 90:236-44. [PMID: 20541977 PMCID: PMC2914252 DOI: 10.1016/j.tube.2010.03.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 03/16/2010] [Accepted: 03/31/2010] [Indexed: 01/25/2023]
Abstract
Mycobacterium tuberculosis has 10 universal stress proteins, whose function is unknown. However, proteomic and transcriptomic analyses have shown that a number of usp genes are significantly upregulated under hypoxic conditions and in response to nitric oxide and carbon monoxide, as well as during M. tuberculosis infection of macrophage cell lines. Six of these USPs are part of the DosR regulon and this, along with their expression pattern and the phenotypes of usp mutants in other bacterial species, suggests a potential role in the persistence and/or intracellular survival of Mtb. Knock-out mutants of individual usp genes encoding the USPs Rv1996, Rv2005c, Rv2026c and Rv2028c were generated and their growth and survival under hypoxic and other stress conditions examined. Although the majority of usp genes are highly induced in hypoxic conditions, mutation did not affect the long term survival of Mtb under these conditions, or in response to a range of stress conditions chosen to represent the environmental onslaughts experienced by the bacillus during an infection, nor during infection of mouse and human - derived macrophage cell lines. The possibility remains that these USPs are functionally redundant in Mtb.
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Affiliation(s)
- S M Hingley-Wilson
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
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Gupta RK, Srivastava BS, Srivastava R. Comparative expression analysis of rpf-like genes of Mycobacterium tuberculosis H37Rv under different physiological stress and growth conditions. Microbiology (Reading) 2010; 156:2714-2722. [DOI: 10.1099/mic.0.037622-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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40
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Flores Valdez MA, Schoolnik GK. DosR-regulon genes induction in Mycobacterium bovis BCG under aerobic conditions. Tuberculosis (Edinb) 2010; 90:197-200. [PMID: 20421176 DOI: 10.1016/j.tube.2010.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 03/31/2010] [Accepted: 04/01/2010] [Indexed: 11/18/2022]
Abstract
In this report we demonstrated that under aerobic conditions, Mycobacterium bovis BCG expressing an hsp60-driven second copy of the hypoxia-related transcriptional regulator DosR increased 2-fold or greater the expression of 38 out of the 48 genes belonging to the DosR regulon, including the latency antigens Rv1733c, Rv2029, Rv2627, and Rv2628. Expression of DosR under these conditions slightly delayed in vitro growth, but did not promote a non-replicating state as opposed to microaerobic and hypoxic adaptation. Our results suggest BCG producing DosR can be cultured under standard in vitro conditions, allowing evaluation of this strain as a latency-specific vaccine candidate.
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Cell wall proteome analysis of Mycobacterium smegmatis strain MC2 155. BMC Microbiol 2010; 10:121. [PMID: 20412585 PMCID: PMC2867950 DOI: 10.1186/1471-2180-10-121] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Accepted: 04/22/2010] [Indexed: 11/10/2022] Open
Abstract
Background The usually non-pathogenic soil bacterium Mycobacterium smegmatis is commonly used as a model mycobacterial organism because it is fast growing and shares many features with pathogenic mycobacteria. Proteomic studies of M. smegmatis can shed light on mechanisms of mycobacterial growth, complex lipid metabolism, interactions with the bacterial environment and provide a tractable system for antimycobacterial drug development. The cell wall proteins are particularly interesting in this respect. The aim of this study was to construct a reference protein map for these proteins in M. smegmatis. Results A proteomic analysis approach, based on one dimensional polyacrylamide gel electrophoresis and LC-MS/MS, was used to identify and characterize the cell wall associated proteins of M. smegmatis. An enzymatic cell surface shaving method was used to determine the surface-exposed proteins. As a result, a total of 390 cell wall proteins and 63 surface-exposed proteins were identified. Further analysis of the 390 cell wall proteins provided the theoretical molecular mass and pI distributions and determined that 26 proteins are shared with the surface-exposed proteome. Detailed information about functional classification, signal peptides and number of transmembrane domains are given next to discussing the identified transcriptional regulators, transport proteins and the proteins involved in lipid metabolism and cell division. Conclusion In short, a comprehensive profile of the M. smegmatis cell wall subproteome is reported. The current research may help the identification of some valuable vaccine and drug target candidates and provide foundation for the future design of preventive, diagnostic, and therapeutic strategies against mycobacterial diseases.
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Bashir N, Kounsar F, Mukhopadhyay S, Hasnain SE. Mycobacterium tuberculosis conserved hypothetical protein rRv2626c modulates macrophage effector functions. Immunology 2010; 130:34-45. [PMID: 20201990 DOI: 10.1111/j.1365-2567.2009.03196.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Secretory proteins of Mycobacterium tuberculosis are the major immunomodulators of the host immune response. Open reading frame (ORF) Rv2626c, encoding a conserved hypothetical protein eliciting a strong humoral immune response in patients with tuberculosis (TB), was shown to be up-regulated upon infection in mice under hypoxic conditions. We now show that recombinant Rv2626c protein (rRv2626c) can bind to the surface of murine macrophages and elicit the type-1 immune response, as manifested by nitric oxide (NO) secretion and expression of inducible nitric oxide synthase (iNOS). Significant induction of pro-inflammatory cytokines [interleukin (IL)-12 and tumour necrosis factor (TNF)-alpha] was evident upon stimulation of murine macrophages, as well as peripheral blood mononuclear cells (PBMCs) isolated from patients with active TB disease, with rRv2626c. Stimulation with rRv2626c also enhanced the expression of costimulatory molecules such as B7-1, B7-2 and CD40 on murine macrophages. We further show that the production of NO and pro-inflammatory cytokines in response to rRv2626c is mediated by the transcription factor nuclear factor (NF)-kappaB, and this was further confirmed using pyrrolidine dithiocarbamate (PDTC), a specific pharmacological inhibitor of NF-kappaB. Rv2626c therefore appears to modulate macrophage effector functions by eliciting both innate and adaptive immune responses, suggesting its possible use as a vaccine candidate.
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Affiliation(s)
- Nasreena Bashir
- Department of Biochemistry, University of Hyderabad, Hyderabad, India.
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Shi C, Zhang H, Zhang T, Wang X, Bai B, Zhao Y, Zhang C, Xu Z. New Alternative Vaccine Component AgainstMycobacterium Tuberculosis- Heat Shock Protein 16.3 or its T-Cell Epitope. Scand J Immunol 2009; 70:465-74. [DOI: 10.1111/j.1365-3083.2009.02325.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Cross-reactive immunity to Mycobacterium tuberculosis DosR regulon-encoded antigens in individuals infected with environmental, nontuberculous mycobacteria. Infect Immun 2009; 77:5071-9. [PMID: 19737909 DOI: 10.1128/iai.00457-09] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis DosR regulon-encoded antigens are highly immunogenic in M. tuberculosis-infected humans and are associated with latent tuberculosis infection. We have investigated the hypothesis that infection with or exposure to nontuberculous mycobacteria (NTM) can induce cross-reactive immunity to M. tuberculosis DosR regulon-encoded antigens since responsiveness has been observed in non-M. tuberculosis-exposed but purified protein derivative-responsive individuals. M. tuberculosis DosR regulon-encoded antigen-specific T-cell responses were studied in peripheral blood mononuclear cells (PBMCs) of NTM-infected/exposed individuals. BLASTP was used to determine the presence of M. tuberculosis DosR regulon-encoded protein orthologs among environmental mycobacteria and nonmycobacteria. Significant gamma interferon production was observed in PBMCs from NTM-infected/exposed individuals in response to M. tuberculosis DosR regulon-encoded antigens. DosR regulon-encoded protein orthologs were prominently present in tuberculous and environmental mycobacteria and surprisingly also in nonmycobacteria. The ubiquitous presence of the highly conserved DosR master regulator protein Rv3133c suggests that this is a general adaptive bacterial response regulator. We report a first series of M. tuberculosis antigens to which cross-reactive immunity is induced by NTM infection/exposure. The high conservation of M. tuberculosis DosR regulon-encoded antigens most likely enables them to induce cross-reactive T-cell responses.
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Triacylglycerol utilization is required for regrowth of in vitro hypoxic nonreplicating Mycobacterium bovis bacillus Calmette-Guerin. J Bacteriol 2009; 191:5037-43. [PMID: 19525349 DOI: 10.1128/jb.00530-09] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacteria store triacylglycerols (TGs) under various stress conditions, such as hypoxia, exposure to nitric oxide, and acidic environments. These stress conditions are known to induce nonreplicating persistence in mycobacteria. The importance of TG accumulation and utilization during regrowth is not clearly understood. Here we specifically determined the levels of accumulated TG and TG lipase activity in Mycobacterium bovis bacillus Calmette-Guerin (BCG) in various different physiological states (logarithmic growth, aerated stationary phase, hypoxia-induced dormancy, and regrowth from dormancy). We found extensive accumulation and degradation of TGs in the bacilli during entry into and exit from hypoxia-induced dormancy, respectively. These processes are accompanied by dynamic appearance and disappearance of intracellular TG lipid particles. The reduction in TG levels coincides with an increase in cellular TG lipase activity in the regrowing bacilli. Tetrahydrolipstatin, an inhibitor of TG lipases, reduces total lipase activity, prevents breakdown of TGs, and blocks the growth of mycobacteria upon resuscitation with air. Our results demonstrate that utilization of TGs is essential for the regrowth of mycobacteria during their exit from the hypoxic nonreplicating state.
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Drumm JE, Mi K, Bilder P, Sun M, Lim J, Bielefeldt-Ohmann H, Basaraba R, So M, Zhu G, Tufariello JM, Izzo AA, Orme IM, Almo SC, Leyh TS, Chan J. Mycobacterium tuberculosis universal stress protein Rv2623 regulates bacillary growth by ATP-Binding: requirement for establishing chronic persistent infection. PLoS Pathog 2009; 5:e1000460. [PMID: 19478878 PMCID: PMC2682197 DOI: 10.1371/journal.ppat.1000460] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 04/30/2009] [Indexed: 01/20/2023] Open
Abstract
Tuberculous latency and reactivation play a significant role in the pathogenesis of tuberculosis, yet the mechanisms that regulate these processes remain unclear. The Mycobacterium tuberculosisuniversal stress protein (USP) homolog, rv2623, is among the most highly induced genes when the tubercle bacillus is subjected to hypoxia and nitrosative stress, conditions thought to promote latency. Induction of rv2623 also occurs when M. tuberculosis encounters conditions associated with growth arrest, such as the intracellular milieu of macrophages and in the lungs of mice with chronic tuberculosis. Therefore, we tested the hypothesis that Rv2623 regulates tuberculosis latency. We observed that an Rv2623-deficient mutant fails to establish chronic tuberculous infection in guinea pigs and mice, exhibiting a hypervirulence phenotype associated with increased bacterial burden and mortality. Consistent with this in vivo growth-regulatory role, constitutive overexpression of rv2623 attenuates mycobacterial growth in vitro. Biochemical analysis of purified Rv2623 suggested that this mycobacterial USP binds ATP, and the 2.9-Å-resolution crystal structure revealed that Rv2623 engages ATP in a novel nucleotide-binding pocket. Structure-guided mutagenesis yielded Rv2623 mutants with reduced ATP-binding capacity. Analysis of mycobacteria overexpressing these mutants revealed that the in vitro growth-inhibitory property of Rv2623 correlates with its ability to bind ATP. Together, the results indicate that i) M. tuberculosis Rv2623 regulates mycobacterial growth in vitro and in vivo, and ii) Rv2623 is required for the entry of the tubercle bacillus into the chronic phase of infection in the host; in addition, iii) Rv2623 binds ATP; and iv) the growth-regulatory attribute of this USP is dependent on its ATP-binding activity. We propose that Rv2623 may function as an ATP-dependent signaling intermediate in a pathway that promotes persistent infection. Mycobacterium tuberculosis poses serious threats to public health worldwide. The ability of this pathogen to establish in the host a clinically silent, persistent latent infection that can subsequently reactivate to cause diseases constitutes a major challenge in controlling tuberculosis. Our study showed that an M. tuberculosis mutant that is deficient in a universal stress protein (USP) designated Rv2623 fails to establish a chronic persistent infection in animal hosts. The mutant strain exhibits a hypervirulent phenotype as assessed by increased bacillary growth, pathology, and mortality in infected animals relative to the parental strain. Consistent with this in vivo growth-regulating attribute, we demonstrated that Rv2623, when expressed in mycobacteria at levels higher than that of the wild-type strain, retards bacterial growth in vitro. Using biochemical and biophysical analyses, including the Rv2623 crystal structure, we showed that this USP binds to ATP within a novel ATP-binding pocket. Through targeted mutagenesis studies, we further determined that the ability of Rv2623 to regulate bacillary growth is dependent on its ATP-binding capacity. Our data strongly suggest Rv2623 as a critical component that regulates the entry of M. tuberculosis into a chronic persistent growth phase, and therefore provide valuable insight into tuberculous dormancy and uncover new opportunities for the development of novel anti-tuberculous therapies.
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Affiliation(s)
- Joshua E. Drumm
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Kaixia Mi
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Patrick Bilder
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Physiology & Biophysics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Meihao Sun
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Jihyeon Lim
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Helle Bielefeldt-Ohmann
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Randall Basaraba
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Melvin So
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Guofeng Zhu
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - JoAnn M. Tufariello
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Angelo A. Izzo
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ian M. Orme
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Steve C. Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Physiology & Biophysics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Thomas S. Leyh
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - John Chan
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
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Kurosu M, Crick DC. MenA is a promising drug target for developing novel lead molecules to combat Mycobacterium tuberculosis. Med Chem 2009; 5:197-207. [PMID: 19275719 DOI: 10.2174/157340609787582882] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Potent inhibitors of MenA (1,4-dihydroxy-2-naphtoate prenyltrasferase) in Mycobacterium tuberculosis are identified, and are also effective in inhibiting growth of Mycobacterium tuberculosis at low concentrations. The MenA inhibitors possess common chemical structural features of (alkylamino)oalkoxyphenyl)(phenyl)methanones. Significantly, the MenA inhibitors can be synthesized in a few steps with high overall yields. The representative MenA inhibitors are highly effective in killing nonreplicating Mycobacterium tuberculosis that is evaluated by using the Wayne low oxygen model. In addition, a series of drug resistant Mycobacterium spp. are sensitive to the MenA inhibitors. The results are expected to be of significance in terms of discovering new lead compounds that can be developed into new drugs to combat unmet diseases caused by Mycobacterium tuberculosis.
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Affiliation(s)
- Michio Kurosu
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1682, USA.
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Rodríguez-Alvarez M, Mendoza-Hernández G, Encarnación S, Calva JJ, López-Vidal Y. Phenotypic differences between BCG vaccines at the proteome level. Tuberculosis (Edinb) 2009; 89:126-35. [DOI: 10.1016/j.tube.2008.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 10/28/2008] [Accepted: 12/14/2008] [Indexed: 12/01/2022]
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49
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Two-dimensional gel electrophoresis-based proteomics of mycobacteria. Methods Mol Biol 2009. [PMID: 20560054 DOI: 10.1007/978-1-59745-207-6_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Two-dimensional gel electrophoresis (2-DE) in combination with mass spectrometry (MS) is the classic proteomics approach used to monitor the dynamics of protein abundance and posttranslational modifications in biological systems. In this chapter, we provide detailed protocols for 2-DE-based proteomics of mycobacteria. Adequate standard operating procedures for mycobacterial culture, subcellular fractionation, and selective enrichment of proteins are indispensable prerequisites for targeted proteome analyses. Therefore, we also provide approved protocols for selective and efficient extraction of cytosolic, secreted, and hydrophobic plasma membrane proteins of mycobacteria, as well as for isolation of mycobacteria from infected macrophages.
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Lin MY, Ottenhoff TH. Not to wake a sleeping giant: new insights into host-pathogen interactions identify new targets for vaccination against latent Mycobacterium tuberculosis infection. Biol Chem 2008; 389:497-511. [DOI: 10.1515/bc.2008.057] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AbstractMycobacterium tuberculosisis one of the worlds' most successful and sophisticated pathogens. It is estimated that over 2 billion people today harbour latentM. tuberculosisinfection without any clinical symptoms. As most new cases of active tuberculosis (TB) arise from this (growing) number of latently infected individuals, urgent measures to control TB reactivation are required, including post-exposure/therapeutic vaccines. The current bacille Calmette-Guérin (BCG) vaccine and all new generation TB vaccines being developed and tested are essentially designed as prophylactic vaccines. Unfortunately, these vaccines are unlikely to be effective in individuals already latently infected withM. tuberculosis. Here, we argue that detailed analysis ofM. tuberculosisgenes that are switched on predominantly during latent stage infection may lead to the identification of new antigenic targets for anti-TB strategies. We will describe essential host-pathogen interactions in TB with particular emphasis on TB latency and persistent infection. Subsequently, we will focus on novel groups of late-stage specific genes, encoded amongst others by theM. tuberculosisdormancy (dosR) regulon, and summarise recent studies describing human T-cell recognition of these dormancy antigens in relation to (latent)M. tuberculosisinfection. We will discuss the possible relevance of these new classes of antigens for vaccine development against TB.
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