1
|
Takeishi A, Shaban AK, Kakihana T, Takihara H, Okuda S, Osada H, Suameitria Dewi DNS, Ozeki Y, Yoshida Y, Nishiyama A, Tateishi Y, Aizu Y, Chuma Y, Onishi K, Hayashi D, Yamamoto S, Mukai T, Ato M, Thai DH, Nhi HTT, Shirai T, Shibata S, Obata F, Fujii J, Yamayoshi S, Kiso M, Matsumoto S. Genetic engineering employing MPB70 and its promoter enables efficient secretion and expression of foreign antigen in bacillus Calmette Guérin (BCG) Tokyo. Microbiol Immunol 2024; 68:130-147. [PMID: 38294180 DOI: 10.1111/1348-0421.13116] [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: 09/13/2023] [Revised: 12/12/2023] [Accepted: 12/29/2023] [Indexed: 02/01/2024]
Abstract
Vaccination is an important factor in public health. The recombinant bacillus Calmette Guérin (rBCG) vaccine, which expresses foreign antigens, is expected to be a superior vaccine against infectious diseases. Here, we report a new recombination platform in which the BCG Tokyo strain is transformed with nucleotide sequences encoding foreign protein fused with the MPB70 immunogenic protein precursor. By RNA-sequencing, mpb70 was found to be the most transcribed among all known genes of BCG Tokyo. Small oligopeptide, namely, polyhistidine tag, was able to be expressed in and secreted from rBCG through a process in which polyhistidine tag fused with intact MPB70 were transcribed by an mpb70 promoter. This methodology was applied to develop an rBCG expressing the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2. Immunoblotting images and mass spectrometry data showed that RBD was also secreted from rBCG. Sera from mice vaccinated with the rBCG showed a tendency of weak neutralizing capacity. The secretion was retained even after a freeze-drying process. The freeze-dried rBCG was administered to and recovered from mice. Recovered rBCG kept secreting RBD. Collectively, our recombination platform offers stable secretion of foreign antigens and can be applied to the development of practical rBCGs.
Collapse
Affiliation(s)
- Atsuki Takeishi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Amina K Shaban
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Taichi Kakihana
- Department of Virology, School of Medicine, Niigata University, Niigata, Japan
| | - Hayato Takihara
- Medical AI Center, School of Medicine, Niigata University, Niigata, Japan
| | - Shujiro Okuda
- Medical AI Center, School of Medicine, Niigata University, Niigata, Japan
| | - Hidekazu Osada
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- NIPPON ZENYAKU KOGYO CO., LTD, Fukushima, Japan
| | - Desak Nyoman Surya Suameitria Dewi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- Microbiology, Universitas Ciputra, Surabaya, Indonesia
| | - Yuriko Ozeki
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Yutaka Yoshida
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Akihito Nishiyama
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Yoshitaka Tateishi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Yuki Aizu
- Division of Research and Development, Japan BCG Laboratory, Tokyo, Japan
| | - Yasushi Chuma
- Division of Research and Development, Japan BCG Laboratory, Tokyo, Japan
| | - Kazuyo Onishi
- Division of Research and Development, Japan BCG Laboratory, Tokyo, Japan
| | - Daisuke Hayashi
- Division of Research and Development, Japan BCG Laboratory, Tokyo, Japan
| | - Saburo Yamamoto
- Division of Research and Development, Japan BCG Laboratory, Tokyo, Japan
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tetsu Mukai
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Manabu Ato
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Duong Huu Thai
- Institute of Vaccines and Medical Biologicals, Nha Trang, Vietnam
| | - Huynh Thi Thao Nhi
- Department of BCG production, Institute of Vaccines and Medical Biologicals, Nha Trang, Vietnam
| | - Tsuyoshi Shirai
- Department of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga, Japan
| | - Satoshi Shibata
- Department of Microbiology and Immunology, Division of Bacteriology, Faculty of Medicine, Tottori University, Tottori, Japan
| | - Fumiko Obata
- Department of Microbiology and Immunology, Division of Bacteriology, Faculty of Medicine, Tottori University, Tottori, Japan
| | - Jun Fujii
- Department of Microbiology and Immunology, Division of Bacteriology, Faculty of Medicine, Tottori University, Tottori, Japan
| | - Seiya Yamayoshi
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Maki Kiso
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Sohkichi Matsumoto
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- Department of Medical Microbiology, Faculty of Medicine, Universitas Airlangga, Surabaya, Indonesia
- Division of Research Aids, Hokkaido University Institute for Vaccine Research & Development, Sapporo, Hokkaido, Japan
| |
Collapse
|
2
|
Multiple genetic paths including massive gene amplification allow Mycobacterium tuberculosis to overcome loss of ESX-3 secretion system substrates. Proc Natl Acad Sci U S A 2022; 119:2112608119. [PMID: 35193958 PMCID: PMC8872769 DOI: 10.1073/pnas.2112608119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2021] [Indexed: 01/18/2023] Open
Abstract
The Mycobacterium tuberculosis (Mtb) ESX-3 type VII secretion system plays a critical role in iron acquisition. Infection of mice with highly attenuated Mtb deletion mutants lacking esxG or esxH, genes encoding key ESX-3 substrates, unexpectedly yielded suppressor mutants with restored capacity to grow in vivo and in vitro in the absence of iron supplementation. Whole-genome sequencing identified two mechanisms of suppression, the disruption of a transcriptional repressor that regulates expression of an ESX-3 paralogous region encoding EsxR and EsxS, and a massive 38- to 60-fold gene amplification of this same region. These data are significant because they reveal a previously unrecognized iron acquisition regulon and inform mechanisms of Mtb chromosome evolution. Mycobacterium tuberculosis (Mtb) possesses five type VII secretion systems (T7SS), virulence determinants that include the secretion apparatus and associated secretion substrates. Mtb strains deleted for the genes encoding substrates of the ESX-3 T7SS, esxG or esxH, require iron supplementation for in vitro growth and are highly attenuated in vivo. In a subset of infected mice, suppressor mutants of esxG or esxH deletions were isolated, which enabled growth to high titers or restored virulence. Suppression was conferred by mechanisms that cause overexpression of an ESX-3 paralogous region that lacks genes for the secretion apparatus but encodes EsxR and EsxS, apparent ESX-3 orphan substrates that functionally compensate for the lack of EsxG or EsxH. The mechanisms include the disruption of a transcriptional repressor and a massive 38- to 60-fold gene amplification. These data identify an iron acquisition regulon, provide insight into T7SS, and reveal a mechanism of Mtb chromosome evolution involving “accordion-type” amplification.
Collapse
|
3
|
Ehtram A, Shariq M, Ali S, Quadir N, Sheikh JA, Ahmad F, Sharma T, Ehtesham NZ, Hasnain SE. Teleological cooption of Mycobacterium tuberculosis PE/PPE proteins as porins: Role in molecular immigration and emigration. Int J Med Microbiol 2021; 311:151495. [PMID: 33730677 DOI: 10.1016/j.ijmm.2021.151495] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/01/2021] [Accepted: 03/05/2021] [Indexed: 01/09/2023] Open
Abstract
Permeation through bacterial cells for exchange or uptake of biomolecules and ions invariably depend upon the existence of pore-forming proteins (porins) in their outer membrane. Mycobacterium tuberculosis (M. tb) harbours one of the most rigid cell envelopes across bacterial genera and is devoid of the classical porins for solute transport across the cell membrane. Though canonical porins are incompatible with the evolution of permeability barrier, porin like activity has been reported from membrane preparations of pathogenic mycobacteria. This suggests a sophisticated transport mechanism that has been elusive until now, along with the protein family responsible for it. Recent evidence suggests that these slow-growing mycobacteria have co-opted some of PE/PPE family proteins as molecular transport channels, in place of porins, to facilitate uptake of nutrients required to thrive in the restrictive host environment. These reports advocate that PE/PPE proteins, due to their structural ability, have a potential role in importing small molecules to the cell's interior. This mechanism unveils how a successful pathogen overcomes its restrictive membrane's transport limitations for selective uptake of nutrients. If extrapolated to have a role in drug transport, these channels could help understand the emergence of drug resistance. Further, as these proteins are associated with the export of virulence factors, they can be exploited as novel drug targets. There remains, however, an interesting question that as the PE/PPE proteins can allow the 'import' of molecules from outside the cell, is the reverse transport also possible across the M. tb membrane. In this review, we have discussed recent evidence supporting PE/PPE's role as a specific transport channel for selective uptake of small molecule nutrients and, as possible molecular export machinery of M. tb. This newly discovered role as transmembrane channels demands further research on this enigmatic family of proteins to comprehend the pathomechanism of this very smart pathogen.
Collapse
Affiliation(s)
- Aquib Ehtram
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Mohd Shariq
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India
| | - Sabeeha Ali
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Neha Quadir
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India; Jamia Hamdard- Institute of Molecular Medicine, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Javaid A Sheikh
- Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi, 110062, India
| | - Faraz Ahmad
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India
| | - Tarina Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India; ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India
| | - Nasreen Z Ehtesham
- ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi, India.
| | - Seyed E Hasnain
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India; Dr Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, India.
| |
Collapse
|
4
|
Conserved ESX-1 Substrates EspE and EspF Are Virulence Factors That Regulate Gene Expression. Infect Immun 2020; 88:IAI.00289-20. [PMID: 32900815 DOI: 10.1128/iai.00289-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/28/2020] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium tuberculosis, the cause of human tuberculosis, and Mycobacterium marinum, a nontubercular pathogen with a broad host range, require the ESX-1 secretion system for virulence. The ESX-1 system secretes proteins which cause phagosomal lysis within the macrophage via an unknown mechanism. As reported elsewhere (R. E. Bosserman et al., Proc Natl Acad Sci U S A 114:E10772-E10781, 2017, https://doi.org/10.1073/pnas.1710167114), we recently discovered that the ESX-1 system regulates gene expression in M. marinum This finding was confirmed in M. tuberculosis in reports by C. Sala et al. (PLoS Pathog 14:e1007491, 2018, https://doi.org/10.1371/journal.ppat.1007491) and A. M. Abdallah et al. (PLoS One 14:e0211003, 2019, https://doi.org/10.1371/journal.pone.0211003). We further demonstrated that a feedback control mechanism connects protein secretion to WhiB6-dependent expression of the esx-1 genes via an unknown mechanism. Here, we connect protein secretion and gene expression by showing for the first time that specific ESX-1 substrates have dual functions inside and outside the mycobacterial cell. We demonstrate that the EspE and EspF substrates negatively control esx-1 gene expression in the M. marinum cytoplasm through the conserved WhiB6 transcription factor. We found that EspE and EspF are required for virulence and promote lytic activity independently of the major EsxA and EsxB substrates. We show that the dual functions of EspE and EspF are conserved in the orthologous proteins from M. tuberculosis Our findings support a role for EspE and EspF in virulence that is independent of the EsxA and EsxB substrates and demonstrate that ESX-1 substrates have a conserved role in regulating gene expression.
Collapse
|
5
|
Habibi P, Daniell H, Soccol CR, Grossi‐de‐Sa MF. The potential of plant systems to break the HIV-TB link. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:1868-1891. [PMID: 30908823 PMCID: PMC6737023 DOI: 10.1111/pbi.13110] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/13/2019] [Accepted: 03/21/2019] [Indexed: 06/09/2023]
Abstract
Tuberculosis (TB) and human immunodeficiency virus (HIV) can place a major burden on healthcare systems and constitute the main challenges of diagnostic and therapeutic programmes. Infection with HIV is the most common cause of Mycobacterium tuberculosis (Mtb), which can accelerate the risk of latent TB reactivation by 20-fold. Similarly, TB is considered the most relevant factor predisposing individuals to HIV infection. Thus, both pathogens can augment one another in a synergetic manner, accelerating the failure of immunological functions and resulting in subsequent death in the absence of treatment. Synergistic approaches involving the treatment of HIV as a tool to combat TB and vice versa are thus required in regions with a high burden of HIV and TB infection. In this context, plant systems are considered a promising approach for combatting HIV and TB in a resource-limited setting because plant-made drugs can be produced efficiently and inexpensively in developing countries and could be shared by the available agricultural infrastructure without the expensive requirement needed for cold chain storage and transportation. Moreover, the use of natural products from medicinal plants can eliminate the concerns associated with antiretroviral therapy (ART) and anti-TB therapy (ATT), including drug interactions, drug-related toxicity and multidrug resistance. In this review, we highlight the potential of plant system as a promising approach for the production of relevant pharmaceuticals for HIV and TB treatment. However, in the cases of HIV and TB, none of the plant-made pharmaceuticals have been approved for clinical use. Limitations in reaching these goals are discussed.
Collapse
Affiliation(s)
- Peyman Habibi
- Department of BiochemistrySchool of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Department of Bioprocess Engineering and BiotechnologyFederal University of ParanáCuritibaPRBrazil
- Embrapa Genetic Resources and BiotechnologyBrasíliaDFBrazil
| | - Henry Daniell
- Department of BiochemistrySchool of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | | | - Maria Fatima Grossi‐de‐Sa
- Embrapa Genetic Resources and BiotechnologyBrasíliaDFBrazil
- Catholic University of BrasíliaBrasíliaDFBrazil
- Post Graduation Program in BiotechnologyUniversity PotiguarNatalRNBrazil
| |
Collapse
|
6
|
Nath Y, Ray SK, Buragohain AK. Essential role of the ESX-3 associated eccD3 locus in maintaining the cell wall integrity of Mycobacterium smegmatis. Int J Med Microbiol 2018; 308:784-795. [PMID: 30257807 DOI: 10.1016/j.ijmm.2018.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/21/2018] [Accepted: 06/24/2018] [Indexed: 11/28/2022] Open
Abstract
Mycobacterial pathogens have evolved a unique secretory apparatus called the Type VII secretion system (T7SS) which comprises of five gene clusters designated as ESX1, ESX2, ESX3, ESX4, and ESX5. Of these the ESX3 T7SS plays an important role in the regulatory uptake of iron from the environment, thereby enabling the bacteria to establish successful infection in the host. However, ESX3 secretion system is conserved among all the mycobacterial species including the fast-growing nonpathogenic species M. smegmatis. Although the function of ESX3 T7SS is known to be absolutely critical for establishing infection by M. tuberculosis, its conserved nature in all the pathogenic and nonpathogenic mycobacterial species intrigues to explore the additional functional roles in Mycobacterium species through which potent targets for drugs can be identified and developed. In the present study, we investigated the possible role of EccD3, a transmembrane protein of the ESX3 T7SS in M. smegmatis by deleting the entire eccD3 gene by efficient allelic exchange method. The preliminary investigations through the creation of knockout mutant of the eccD3 gene indicate that this secretory apparatus has an important role in maintaining the cell wall integrity which was evident from the abnormal colony morphology, lack of biofilm formation and difference in cell wall permeability.
Collapse
Affiliation(s)
- Yutika Nath
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam, 784028, India.
| | - Suvendra Kumar Ray
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam, 784028, India.
| | - Alak Kumar Buragohain
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam, 784028, India; Dibrugarh University, Dibrugarh, Assam, 786004, India.
| |
Collapse
|
7
|
Uhía I, Krishnan N, Robertson BD. Characterising resuscitation promoting factor fluorescent-fusions in mycobacteria. BMC Microbiol 2018; 18:30. [PMID: 29649975 PMCID: PMC5898023 DOI: 10.1186/s12866-018-1165-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 03/15/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Resuscitation promoting factor proteins (Rpfs) are peptidoglycan glycosidases capable of resuscitating dormant mycobacteria, and have been found to play a role in the pathogenesis of tuberculosis. However, the specific roles and localisation of each of the 5 Rpfs in Mycobacterium tuberculosis remain mostly unknown. In this work our aim was to construct fluorescent fusions of M. tuberculosis Rpf proteins as tools to investigate their function. RESULTS We found that Rpf-fusions to the fluorescent protein mCherry are functional and able to promote cell growth under different conditions. However, fusions to Enhanced Green Fluorescent Protein (EGFP) were non-functional in the assays used and none were secreted into the extracellular medium, which suggests Rpfs may be secreted via the Sec pathway. No specific cellular localization was observed for either set of fusions using time-lapse video microscopy. CONCLUSIONS We present the validation and testing of five M. tuberculosis Rpfs fused to mCherry, which are functional in resuscitation assays, but do not show any specific cellular localisation under the conditions tested. Our results suggest that Rpfs are likely to be secreted via the Sec pathway. We propose that such mCherry fusions will be useful tools for the further study of Rpf localisation, individual expression, and function.
Collapse
Affiliation(s)
- Iria Uhía
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, SW7 2AZ UK
| | - Nitya Krishnan
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, SW7 2AZ UK
| | - Brian D. Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, SW7 2AZ UK
| |
Collapse
|
8
|
Comprehensive profiling of functional attributes, virulence potential and evolutionary dynamics in mycobacterial secretomes. World J Microbiol Biotechnol 2017; 34:5. [DOI: 10.1007/s11274-017-2388-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 11/30/2017] [Indexed: 11/25/2022]
|
9
|
Barthe P, Veyron-Churlet R, de Visch A, Gilleron M, Saliou JM, Tomavo S, Nigou J, Brodin P, Cohen-Gonsaud M. Mycobacterium tuberculosis LppM Displays an Original Structure and Domain Composition Linked to a Dual Localization. Structure 2016; 24:1788-1794. [DOI: 10.1016/j.str.2016.07.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/02/2016] [Accepted: 07/06/2016] [Indexed: 01/24/2023]
|
10
|
Ma J, Jung BG, Yi N, Samten B. Early Secreted Antigenic Target of 6 kDa ofMycobacterium tuberculosisStimulates Macrophage Chemoattractant Protein-1 Production by Macrophages and Its Regulation by p38 Mitogen-Activated Protein Kinases and Interleukin-4. Scand J Immunol 2016; 84:39-48. [DOI: 10.1111/sji.12447] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 05/04/2016] [Indexed: 11/29/2022]
Affiliation(s)
- J. Ma
- Department of Pulmonary Immunology; University of Texas Health Science Center at Tyler; Tyler TX USA
| | - B-G. Jung
- Department of Pulmonary Immunology; University of Texas Health Science Center at Tyler; Tyler TX USA
| | - N. Yi
- Department of Pulmonary Immunology; University of Texas Health Science Center at Tyler; Tyler TX USA
| | - B. Samten
- Department of Pulmonary Immunology; University of Texas Health Science Center at Tyler; Tyler TX USA
| |
Collapse
|
11
|
Xie X, Han M, Zhang L, Liu L, Gu Z, Yang M, Yang H. Effects of Mycobacterium tuberculosis ESAT6-CFP10 Protein on Cell Viability and Production of Nitric Oxide in Alveolar Macrophages. Jundishapur J Microbiol 2016; 9:e33264. [PMID: 27635210 PMCID: PMC5013290 DOI: 10.5812/jjm.33264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 04/06/2016] [Accepted: 05/27/2016] [Indexed: 11/16/2022] Open
Abstract
Background Mycobacterium tuberculosis is the major pathogen of tuberculosis, which affects approximately one-third of the world’s population. The 6 kDa early secreted antigenic target (ESAT6) and the 10 kDa culture filtrate protein (CFP10), which are secreted by the ESX-1 system in M. tuberculosis, can contribute to mycobacterial virulence. Objectives The aim of this study was to research the effects of M. tuberculosis ESAT6-CFP10 protein on macrophages during a host’s was first and second exposures to M. tuberculosis. Materials and Methods In this study, the ESAT6 and CFP10 genes were amplified to create a fusion gene (ESAT6-CFP10) and cloned into the pET-32a(+) and pEGFP-N1 expression vectors, respectively. The recombinant pET-32a(+)-ESAT6-CFP10 plasmid was transformed into the Escherichia coli Origami strain, and the fusion protein was expressed and confirmed by SDS-PAGE and Western blot analysis. The recombinant pEGFP-N1-ESAT6-CFP10 plasmid was transfected into rat alveolar macrophage cells (NR8383). The cell line expressing the ESAT6-CFP10 protein was selected with RT-PCR and designated as NR8383-EC. Finally, the effects of the ESAT6-CFP10 fusion protein on the NR8383 cell line, as well as on the newly constructed NR8383-EC cells, were further assessed. Results The recombinant ESAT6-CFP10 protein was expressed in E. coli and in NR8383 rat alveolar macrophages. This protein affected the proliferation and nitric oxide (NO) generation of the NR8383 and NR8383-EC cells. Although NO generation was inhibited in both cell lines, proliferation was inhibited in NR8383 while it was increased NR8383-EC. Conclusions The data indicate that ESAT6-CFP10 could support the survival of M. tuberculosis in the host through altering the host immune response. It also indicates that the host may gain some level of protection from a second exposure to M. tuberculosis, as evidenced by increased proliferation of NR8383-EC.
Collapse
Affiliation(s)
- Xiaoli Xie
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
| | - Meng Han
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
| | - Liang Zhang
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
| | - Laixing Liu
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
| | - Zuye Gu
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
| | - Mei Yang
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
| | - Hongjun Yang
- Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China
- Corresponding author: Hongjun Yang, Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Shandong, China. Tel: +86-053188978219, Fax: +86-053188608606, E-mail:
| |
Collapse
|
12
|
Shah S, Briken V. Modular Organization of the ESX-5 Secretion System in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2016; 6:49. [PMID: 27200304 PMCID: PMC4852179 DOI: 10.3389/fcimb.2016.00049] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/18/2016] [Indexed: 11/30/2022] Open
Abstract
Mycobacteria utilize type VII secretion systems (T7SS) to export many of their important virulence proteins. The T7SS encompasses five homologous secretion systems (ESX-1 to ESX-5). Most pathogenic mycobacterial species, including the human pathogen Mycobacterium tuberculosis, possess all five ESX systems. The ESX-1, -3, and -5 systems are important for virulence of mycobacteria but the molecular mechanisms of their secretion apparatus and the identity and activity of secreted effector proteins are not well characterized. The different ESX systems show similarities in gene composition due to their common phylogenetic origin but recent studies demonstrate mechanistic as well as functional variations between the systems. For example, the ESX-1 system is involved in lysis of the phagosomal membrane and phagosomal escape of the bacteria while the ESX-5 system is required for mycobacterial cell wall stability and host cell lysis. Mechanistically, the ESX-1 substrates show interdependence during secretion while the ESX-5 system may use a duplicated four-gene region (ESX-5a) as an accessory system for transport of a subset of proteins of the ESX-5 secretome. In the present review we will provide an overview of the molecular components of the T7SS and their function with a particular focus on the ESX-5 system.
Collapse
Affiliation(s)
- Swati Shah
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, MD, USA
| | - Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, MD, USA
| |
Collapse
|
13
|
Dhanda SK, Vir P, Singla D, Gupta S, Kumar S, Raghava GPS. A Web-Based Platform for Designing Vaccines against Existing and Emerging Strains of Mycobacterium tuberculosis. PLoS One 2016; 11:e0153771. [PMID: 27096425 PMCID: PMC4838326 DOI: 10.1371/journal.pone.0153771] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 04/04/2016] [Indexed: 01/08/2023] Open
Abstract
Development of an effective vaccine against drug-resistant Mycobacterium tuberculosis (Mtb) is crucial for saving millions of premature deaths every year due to tuberculosis. This paper describes a web portal developed for assisting researchers in designing vaccines against emerging Mtb strains using traditional and modern approaches. Firstly, we annotated 59 genomes of Mycobacterium species to understand similarity/dissimilarity between tuberculoid, non-tuberculoid and vaccine strains at genome level. Secondly, antigen-based vaccine candidates have been predicted in each Mtb strain. Thirdly, epitopes-based vaccine candidates were predicted/discovered in above antigen-based vaccine candidates that can stimulate all arms of immune system. Finally, a database of predicted vaccine candidates at epitopes as well at antigen level has been developed for above strains. In order to design vaccine against a newly sequenced genome of Mtb strain, server integrates three modules for identification of strain-, antigen-, epitope-specific vaccine candidates. We observed that 103522 unique peptides (9mers) had the potential to induce an antibody response and/or promiscuous binder to MHC alleles and/or have the capability to stimulate T lymphocytes. In summary, this web-portal will be useful for researchers working on designing vaccines against Mtb including drug-resistant strains. Availability: The database is available freely at http://crdd.osdd.net/raghava/mtbveb/.
Collapse
Affiliation(s)
- Sandeep Kumar Dhanda
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, 160036, India
| | - Pooja Vir
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, 160036, India
| | - Deepak Singla
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, 160036, India
| | - Sudheer Gupta
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, 160036, India
| | - Shailesh Kumar
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, 160036, India
| | - Gajendra P. S. Raghava
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, 160036, India
- * E-mail:
| |
Collapse
|
14
|
Lienard J, Movert E, Valfridsson C, Sturegård E, Carlsson F. ESX-1 exploits type I IFN-signalling to promote a regulatory macrophage phenotype refractory to IFNγ-mediated autophagy and growth restriction of intracellular mycobacteria. Cell Microbiol 2016; 18:1471-85. [PMID: 27062290 DOI: 10.1111/cmi.12594] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 03/14/2016] [Accepted: 03/16/2016] [Indexed: 12/20/2022]
Abstract
The ability of macrophages to eradicate intracellular pathogens is normally greatly enhanced by IFNγ, a cytokine produced mainly after onset of adaptive immunity. However, adaptive immunity is unable to provide sterilizing immunity against mycobacteria, suggesting that mycobacteria have evolved virulence strategies to inhibit the bactericidal effect of IFNγ-signalling in macrophages. Still, the host-pathogen interactions and cellular mechanisms responsible for this feature have remained elusive. We demonstrate that the ESX-1 type VII secretion systems of Mycobacterium tuberculosis and Mycobacterium marinum exploit type I IFN-signalling to promote an IL-12(low) /IL-10(high) regulatory macrophage phenotype characterized by secretion of IL-10, IL-27 and IL-6. This mechanism had no impact on intracellular growth in the absence of IFNγ but suppressed IFNγ-mediated autophagy and growth restriction, indicating that the regulatory phenotype extends to function. The IFNγ-refractory phenotype was partly mediated by IL-27-signalling, establishing functional relevance for this downstream cytokine. These findings identify a novel macrophage-modulating function for the ESX-1 secretion system that may contribute to suppress the efficacy of adaptive immunity and provide mechanistic insight into the antagonistic cross talk between type I IFNs and IFNγ in mycobacterial infection.
Collapse
Affiliation(s)
- Julia Lienard
- Section for Immunology, Department of Experimental Medical Science, Lund University, BMC D14, 221 84, Lund, Sweden
| | - Elin Movert
- Section for Immunology, Department of Experimental Medical Science, Lund University, BMC D14, 221 84, Lund, Sweden
| | - Christine Valfridsson
- Section for Immunology, Department of Experimental Medical Science, Lund University, BMC D14, 221 84, Lund, Sweden
| | - Erik Sturegård
- Section for Medical Microbiology, Department of Laboratory Medicine, Lund University, Jan Waldenströms gata 59, 205 02, Malmö, Sweden
| | - Fredric Carlsson
- Section for Immunology, Department of Experimental Medical Science, Lund University, BMC D14, 221 84, Lund, Sweden.
| |
Collapse
|
15
|
Tufariello JM, Chapman JR, Kerantzas CA, Wong KW, Vilchèze C, Jones CM, Cole LE, Tinaztepe E, Thompson V, Fenyö D, Niederweis M, Ueberheide B, Philips JA, Jacobs WR. Separable roles for Mycobacterium tuberculosis ESX-3 effectors in iron acquisition and virulence. Proc Natl Acad Sci U S A 2016; 113:E348-57. [PMID: 26729876 PMCID: PMC4725510 DOI: 10.1073/pnas.1523321113] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) encodes five type VII secretion systems (T7SS), designated ESX-1-ESX-5, that are critical for growth and pathogenesis. The best characterized is ESX-1, which profoundly impacts host cell interactions. In contrast, the ESX-3 T7SS is implicated in metal homeostasis, but efforts to define its function have been limited by an inability to recover deletion mutants. We overcame this impediment using medium supplemented with various iron complexes to recover mutants with deletions encompassing select genes within esx-3 or the entire operon. The esx-3 mutants were defective in uptake of siderophore-bound iron and dramatically accumulated cell-associated mycobactin siderophores. Proteomic analyses of culture filtrate revealed that secretion of EsxG and EsxH was codependent and that EsxG-EsxH also facilitated secretion of several members of the proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) protein families (named for conserved PE and PPE N-terminal motifs). Substrates that depended on EsxG-EsxH for secretion included PE5, encoded within the esx-3 locus, and the evolutionarily related PE15-PPE20 encoded outside the esx-3 locus. In vivo characterization of the mutants unexpectedly showed that the ESX-3 secretion system plays both iron-dependent and -independent roles in Mtb pathogenesis. PE5-PPE4 was found to be critical for the siderophore-mediated iron-acquisition functions of ESX-3. The importance of this iron-acquisition function was dependent upon host genotype, suggesting a role for ESX-3 secretion in counteracting host defense mechanisms that restrict iron availability. Further, we demonstrate that the ESX-3 T7SS secretes certain effectors that are important for iron uptake while additional secreted effectors modulate virulence in an iron-independent fashion.
Collapse
Affiliation(s)
- JoAnn M Tufariello
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Jessica R Chapman
- Office of Collaborative Science, New York University School of Medicine, New York, NY 10016
| | - Christopher A Kerantzas
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Ka-Wing Wong
- Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of the Ministry of Education/Health, School of Basic Medical Sciences, Fudan University, Shanghai 201508, China
| | - Catherine Vilchèze
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461; Howard Hughes Medical Institute, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Christopher M Jones
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Laura E Cole
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Emir Tinaztepe
- Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - Victor Thompson
- Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - David Fenyö
- Laboratory of Computational Proteomics, Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, NY 10016; Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Beatrix Ueberheide
- Office of Collaborative Science, New York University School of Medicine, New York, NY 10016; Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016
| | - Jennifer A Philips
- Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, NY 10016;
| | - William R Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461; Howard Hughes Medical Institute, Albert Einstein College of Medicine, Bronx, NY 10461;
| |
Collapse
|
16
|
Abstract
Most mycobacterial species are harmless saprophytes, often found in aquatic environments. A few species seem to have evolved from this pool of environmental mycobacteria into major human pathogens, such as Mycobacterium tuberculosis, the agent of tuberculosis, Mycobacterium leprae, the leprosy bacillus, and Mycobacterium ulcerans, the agent of Buruli ulcer. While the pathogenicity of M. ulcerans relates to the acquisition of a large plasmid encoding a polyketide-derived toxin, the molecular mechanisms by which M. leprae or M. tuberculosis have evolved to cause disease are complex and involve the interaction between the pathogen and the host. Here we focus on M. tuberculosis and closely related mycobacteria and discuss insights gained from recent genomic and functional studies. Comparison of M. tuberculosis genome data with sequences from nontuberculous mycobacteria, such as Mycobacterium marinum or Mycobacterium kansasii, provides a perception of the more distant evolution of M. tuberculosis, while the recently accomplished genome sequences of multiple tubercle bacilli with smooth colony morphology, named Mycobacterium canettii, have allowed the ancestral gene pool of tubercle bacilli to be estimated. The resulting findings are instrumental for our understanding of the pathogenomic evolution of tuberculosis-causing mycobacteria. Comparison of virulent and attenuated members of the M. tuberculosis complex has further contributed to identification of a specific secretion pathway, named ESX or Type VII secretion. The molecular machines involved are key elements for mycobacterial pathogenicity, strongly influencing the ability of M. tuberculosis to cope with the immune defense mounted by the host.
Collapse
|
17
|
Kumar S, Mittal E, Deore S, Kumar A, Rahman A, Krishnasastry MV. Mycobacterial tlyA gene product is localized to the cell-wall without signal sequence. Front Cell Infect Microbiol 2015; 5:60. [PMID: 26347855 PMCID: PMC4543871 DOI: 10.3389/fcimb.2015.00060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 07/31/2015] [Indexed: 01/09/2023] Open
Abstract
The mycobacterial tlyA gene product, Rv1694 (MtbTlyA), has been annotated as “hemolysin” which was re-annotated as 2′-O rRNA methyl transferase. In order to function as a hemolysin, it must reach the extracellular milieu with the help of signal sequence(s) and/or transmembrane segment(s). However, the MtbTlyA neither has classical signals sequences that signify general/Sec/Tat pathways nor transmembrane segments. Interestingly, the tlyA gene appears to be restricted to pathogenic strains such as H37Rv, M. marinum, M. leprae, than M. smegmatis, M. vaccae, M. kansasii etc., which highlights the need for a detailed investigation to understand its functions. In this study, we have provided several evidences which highlight the presence of TlyA on the surface of M. marinum (native host) and upon expression in M. smegmatis (surrogate host) and E. coli (heterologous host). The TlyA was visualized at the bacterial-surface by confocal microscopy and accessible to Proteinase K. In addition, sub-cellular fractionation has revealed the presence of TlyA in the membrane fractions and this sequestration is not dependent on TatA, TatC or SecA2 pathways. As a consequence of expression, the recombinant bacteria exhibit distinct hemolysis. Interestingly, the MtbTlyA was also detected in both membrane vesicles secreted by M. smegmatis and outer membrane vesicles secreted by E. coli. Our experimental evidences unambiguously confirm that the mycobacterial TlyA can reach the extra cellular milieu without any signal sequence. Hence, the localization of TlyA class of proteins at the bacterial surface may highlight the existence of non-classical bacterial secretion mechanisms.
Collapse
Affiliation(s)
- Santosh Kumar
- Membrane Biology, National Centre for Cell Science, Savitribai Phule Pune University Pune, India
| | - Ekansh Mittal
- Membrane Biology, National Centre for Cell Science, Savitribai Phule Pune University Pune, India
| | - Sapna Deore
- Membrane Biology, National Centre for Cell Science, Savitribai Phule Pune University Pune, India
| | - Anil Kumar
- Membrane Biology, National Centre for Cell Science, Savitribai Phule Pune University Pune, India
| | - Aejazur Rahman
- Membrane Biology, National Centre for Cell Science, Savitribai Phule Pune University Pune, India
| | - Musti V Krishnasastry
- Membrane Biology, National Centre for Cell Science, Savitribai Phule Pune University Pune, India
| |
Collapse
|
18
|
Smith VL, Jackson L, Schorey JS. Ubiquitination as a Mechanism To Transport Soluble Mycobacterial and Eukaryotic Proteins to Exosomes. THE JOURNAL OF IMMUNOLOGY 2015; 195:2722-30. [PMID: 26246139 DOI: 10.4049/jimmunol.1403186] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 07/08/2015] [Indexed: 01/06/2023]
Abstract
Exosomes are extracellular vesicles of endocytic origin that function in intercellular communication. Our previous studies indicate that exosomes released from Mycobacterium tuberculosis-infected macrophages contain soluble mycobacterial proteins. However, it was unclear how these secreted proteins were targeted to exosomes. In this study, we determined that exosome production by the murine macrophage cell line RAW264.7 requires the endosomal sorting complexes required for transport and that trafficking of mycobacterial proteins from phagocytosed bacilli to exosomes was dependent on protein ubiquitination. Moreover, soluble mycobacterial proteins, when added exogenously to RAW264.7 or human HEK293 cells, were endocytosed, ubiquitinated, and released via exosomes. This suggested that endocytosed proteins could be recycled from cells through exosomes. This hypothesis was supported using the tumor-associated protein He4, which, when endocytosed by RAW264.7 or HEK293 cells, was transported to exosomes in a ubiquitin-dependent manner. Our data suggest that ubiquitination is a modification sufficient for trafficking soluble proteins within the phagocytic/endocytic network to exosomes.
Collapse
Affiliation(s)
- Victoria L Smith
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556
| | - Liam Jackson
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556
| | - Jeffrey S Schorey
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556
| |
Collapse
|
19
|
Ahmed A, Das A, Mukhopadhyay S. Immunoregulatory functions and expression patterns of PE/PPE family members: Roles in pathogenicity and impact on anti-tuberculosis vaccine and drug design. IUBMB Life 2015; 67:414-27. [DOI: 10.1002/iub.1387] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 04/29/2015] [Indexed: 01/27/2023]
Affiliation(s)
- Asma Ahmed
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD); Hyderabad, Telengana India
| | - Arghya Das
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD); Hyderabad, Telengana India
- Manipal University; Manipal Karnataka India
| | - Sangita Mukhopadhyay
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD); Hyderabad, Telengana India
| |
Collapse
|
20
|
Structure of EspB from the ESX-1 Type VII Secretion System and Insights into its Export Mechanism. Structure 2015; 23:571-583. [DOI: 10.1016/j.str.2015.01.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/17/2014] [Accepted: 12/23/2014] [Indexed: 12/29/2022]
|
21
|
|
22
|
Pedersen ME, Vuong TT, Rønning SB, Kolset SO. Matrix metalloproteinases in fish biology and matrix turnover. Matrix Biol 2015; 44-46:86-93. [PMID: 25617492 DOI: 10.1016/j.matbio.2015.01.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/13/2015] [Accepted: 01/13/2015] [Indexed: 11/18/2022]
Abstract
Matrix metalloproteinases have important functions for tissue turnover in fish, with relevance both for the fish industry and molecular and cellular research on embryology, inflammation and tissue repair. These metalloproteinases have been studied in different fish types, subjected to both aquaculture and experimental conditions. This review highlights studies on these metalloproteinases in relation to both fish quality and health and further, the future importance of fish for basic research studies.
Collapse
Affiliation(s)
| | | | | | - Svein O Kolset
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
| |
Collapse
|
23
|
BoseDasgupta S, Pieters J. Striking the Right Balance Determines TB or Not TB. Front Immunol 2014; 5:455. [PMID: 25339950 PMCID: PMC4189424 DOI: 10.3389/fimmu.2014.00455] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/06/2014] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium tuberculosis continues to be one of the most successful pathogens on earth. Upon inhalation of M. tuberculosis by a healthy individual, the host immune system will attempt to eliminate these pathogens using a combination of immune defense strategies. These include the recruitment of macrophages and other phagocytes to the site of infection, production of cytokines that enhance the microbicidal capacity of the macrophages, as well as the activation of distinct subsets of leukocytes that work in concert to fight the infection. However, being as successful as it is, M. tuberculosis has evolved numerous strategies to subvert host immunity at virtual every level. As a consequence, one third of the world inhabitants carry M. tuberculosis, and tuberculosis continuous to cause disease in more than 8 million people with deadly consequences in well over 1 million patients each year. In this review, we discuss several of the strategies that M. tuberculosis employs to circumvent host immunity, as well as describe some of the mechanisms that the host uses to counter such subversive strategies. As for many other infectious diseases, the ultimate outcome is usually defined by the relative strength of the virulence strategies employed by the tubercle bacillus versus the arsenal of immune defense mechanisms of the infected host.
Collapse
Affiliation(s)
| | - Jean Pieters
- Biozentrum, University of Basel , Basel , Switzerland
| |
Collapse
|
24
|
Rowe HM, Withey JH, Neely MN. Zebrafish as a model for zoonotic aquatic pathogens. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 46:96-107. [PMID: 24607289 PMCID: PMC4096445 DOI: 10.1016/j.dci.2014.02.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/22/2014] [Accepted: 02/22/2014] [Indexed: 06/03/2023]
Abstract
Aquatic habitats harbor a multitude of bacterial species. Many of these bacteria can act as pathogens to aquatic species and/or non-aquatic organisms, including humans, that come into contact with contaminated water sources or colonized aquatic organisms. In many instances, the bacteria are not pathogenic to the aquatic species they colonize and are only considered pathogens when they come into contact with humans. There is a general lack of knowledge about how the environmental lifestyle of these pathogens allows them to persist, replicate and produce the necessary pathogenic mechanisms to successfully transmit to the human host and cause disease. Recently, the zebrafish infectious disease model has emerged as an ideal system for examining aquatic pathogens, both in the aquatic environment and during infection of the human host. This review will focus on how the zebrafish has been used successfully to analyze the pathogenesis of aquatic bacterial pathogens.
Collapse
Affiliation(s)
- Hannah M Rowe
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - Jeffrey H Withey
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - Melody N Neely
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI, USA.
| |
Collapse
|
25
|
Champion MM, Williams EA, Pinapati RS, Champion PAD. Correlation of phenotypic profiles using targeted proteomics identifies mycobacterial esx-1 substrates. J Proteome Res 2014; 13:5151-64. [PMID: 25106450 PMCID: PMC4227905 DOI: 10.1021/pr500484w] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
![]()
The
Esx/WXG-100 (ESAT-6/Wss) exporters are multiprotein complexes
that promote protein translocation across the cytoplasmic membrane
in a diverse range of pathogenic and nonpathogenic bacterial species.
The Esx-1 (ESAT-6 System-1) system mediates virulence factor translocation
in mycobacterial pathogens, including the human pathogen Mycobacterium
tuberculosis. Although several genes have been associated
with Esx-1-mediated transport and virulence, the contribution of individual
Esx-1 genes to export is largely undefined. A unique aspect of Esx-1
export is that several substrates require each other for export/stability.
We exploited substrate “codependency” to identify Esx-1
substrates. We simultaneously quantified changes in the levels of
13 Esx-1 proteins from both secreted and cytosolic protein fractions
generated from 16 Esx-1-deficient Mycobacterium marinum strains in a single experiment using MRM/SRM targeted mass spectrometry.
This expansion of measurable Esx-1 proteins allowed us to define statistical
rules for assigning novel substrates using phenotypic profiles of
known Esx-1 substrates. Using this approach, we identified three additional
Esx-1 substrates encoded by the esx-1 region. Our
studies begin to address how disruption of specific genes affects
several proteins in the Esx-1 complex. Overall, our findings illuminate
relationships between Esx-1 proteins and create a framework for the
identification of secreted substrates applicable to other protein
exporters and pathways.
Collapse
Affiliation(s)
- Matthew M Champion
- Department of Chemistry and Biochemistry, ‡Department of Biological Sciences, §Eck Institute for Global Health, and ∥Center for Rare and Neglected Diseases, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | | | | | | |
Collapse
|
26
|
Prozorov AA, Fedorova IA, Bekker OB, Danilenko VN. The virulence factors of Mycobacterium tuberculosis: Genetic control, new conceptions. RUSS J GENET+ 2014. [DOI: 10.1134/s1022795414080055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
27
|
Homeostasis of N-α-terminal acetylation of EsxA correlates with virulence in Mycobacterium marinum. Infect Immun 2014; 82:4572-86. [PMID: 25135684 DOI: 10.1128/iai.02153-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mycobacterial Esx-1 (ESAT-6 system 1) exporter translocates virulence factors across the cytoplasmic membrane to the cell wall, cell surface, and the bacteriological medium in vitro. The mechanisms underlying substrate targeting to distinct locations are unknown. Several Esx-1 substrates are N-α-terminally acetylated. The role of this rare modification in bacteria is unclear. We sought to identify genes required for Esx-1 substrate modification, transport, and localization. Pathogenic mycobacteria lyse Acanthamoeba castellanii in an Esx-1-dependent manner. We conducted a genetic screen to identify Mycobacterium marinum strains which failed to lyse amoebae. We identified a noncytotoxic M. marinum strain with a transposon insertion in a predicted N-α-terminal acetyltransferase not previously linked to mycobacterial pathogenesis. Disruption of this gene led to attenuation of virulence, failure to induce a type I interferon response during macrophage infection, and loss of hemolytic activity. The major Esx-1 substrates, EsxA and EsxB, were exported to the cell surface, but only low levels were released into the bacteriological medium. The balance of EsxA N-α-terminal acetylation was disrupted, resulting in a mycobacterial strain in which surface-associated EsxA was hyperacetylated. Genetic complementation completely restored Esx-1 function and the levels of N-α-terminally acetylated EsxA on the surface but restored only low levels of Esx-1 substrates in the bacteriological medium. Our results reveal a novel gene required for mycobacterial Esx-1 export. Our findings indicate that maintaining the homeostasis of Esx-1 substrate N-α-terminal acetylation is essential for Esx-1-mediated virulence. We propose an inverse correlation between EsxA acetylation and virulence.
Collapse
|
28
|
Srinivasan L, Ahlbrand S, Briken V. Interaction of Mycobacterium tuberculosis with host cell death pathways. Cold Spring Harb Perspect Med 2014; 4:cshperspect.a022459. [PMID: 24968864 DOI: 10.1101/cshperspect.a022459] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Mycobacterium tuberculosis (Mtb) has coevolved with humans for tens of thousands of years. It is thus highly adapted to its human host and has evolved multiple mechanisms to manipulate host immune responses to its advantage. One central host pathogen interaction modality is host cell death pathways. Host cell apoptosis is associated with a protective response to Mtb infection, whereas a necrotic response favors the pathogen. Consistently, Mtb inhibits host cell apoptosis signaling but promotes induction of programmed necrosis. The molecular mechanisms involved in Mtb-mediated host cell death manipulation, the consequences for host immunity, and the potential for therapeutic and preventive approaches will be discussed.
Collapse
Affiliation(s)
- Lalitha Srinivasan
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - Sarah Ahlbrand
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| |
Collapse
|
29
|
Siegrist MS, Steigedal M, Ahmad R, Mehra A, Dragset MS, Schuster BM, Philips JA, Carr SA, Rubin EJ. Mycobacterial Esx-3 requires multiple components for iron acquisition. mBio 2014; 5:e01073-14. [PMID: 24803520 PMCID: PMC4010830 DOI: 10.1128/mbio.01073-14] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 03/28/2014] [Indexed: 12/16/2022] Open
Abstract
ABSTRACT The type VII secretion systems are conserved across mycobacterial species and in many Gram-positive bacteria. While the well-characterized Esx-1 pathway is required for the virulence of pathogenic mycobacteria and conjugation in the model organism Mycobacterium smegmatis, Esx-3 contributes to mycobactin-mediated iron acquisition in these bacteria. Here we show that several Esx-3 components are individually required for function under low-iron conditions but that at least one, the membrane-bound protease MycP3 of M. smegmatis, is partially expendable. All of the esx-3 mutants tested, including the ΔmycP3ms mutant, failed to export the native Esx-3 substrates EsxHms and EsxGms to quantifiable levels, as determined by targeted mass spectrometry. Although we were able to restore low-iron growth to the esx-3 mutants by genetic complementation, we found a wide range of complementation levels for protein export. Indeed, minute quantities of extracellular EsxHms and EsxGms were sufficient for iron acquisition under our experimental conditions. The apparent separation of Esx-3 function in iron acquisition from robust EsxGms and EsxHms secretion in the ΔmycP3ms mutant and in some of the complemented esx-3 mutants compels reexamination of the structure-function relationships for type VII secretion systems. IMPORTANCE Mycobacteria have several paralogous type VII secretion systems, Esx-1 through Esx-5. Whereas Esx-1 is required for pathogenic mycobacteria to grow within an infected host, Esx-3 is essential for growth in vitro. We and others have shown that Esx-3 is required for siderophore-mediated iron acquisition. In this work, we identify individual Esx-3 components that contribute to this process. As in the Esx-1 system, most mutations that abolish Esx-3 protein export also disrupt its function. Unexpectedly, however, ultrasensitive quantitation of Esx-3 secretion by multiple-reaction-monitoring mass spectrometry (MRM-MS) revealed that very low levels of export were sufficient for iron acquisition under similar conditions. Although protein export clearly contributes to type VII function, the relationship is not absolute.
Collapse
Affiliation(s)
- M. Sloan Siegrist
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
| | | | - Rushdy Ahmad
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Alka Mehra
- Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, New York, USA
| | | | - Brian M. Schuster
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
| | - Jennifer A. Philips
- Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, New York, USA
| | - Steven A. Carr
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Eric J. Rubin
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
| |
Collapse
|
30
|
Ryndak MB, Singh KK, Peng Z, Zolla-Pazner S, Li H, Meng L, Laal S. Transcriptional profiling of Mycobacterium tuberculosis replicating ex vivo in blood from HIV- and HIV+ subjects. PLoS One 2014; 9:e94939. [PMID: 24755630 PMCID: PMC3995690 DOI: 10.1371/journal.pone.0094939] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 03/21/2014] [Indexed: 01/02/2023] Open
Abstract
Hematogenous dissemination of Mycobacterium tuberculosis (M. tb) occurs during both primary and reactivated tuberculosis (TB). Although hematogenous dissemination occurs in non-HIV TB patients, in ∼80% of these patients, TB manifests exclusively as pulmonary disease. In contrast, extrapulmonary, disseminated, and/or miliary TB is seen in 60–70% of HIV-infected TB patients, suggesting that hematogenous dissemination is likely more common in HIV+ patients. To understand M. tb adaptation to the blood environment during bacteremia, we have studied the transcriptome of M. tb replicating in human whole blood. To investigate if M. tb discriminates between the hematogenous environments of immunocompetent and immunodeficient individuals, we compared the M. tb transcriptional profiles during replication in blood from HIV- and HIV+ donors. Our results demonstrate that M. tb survives and replicates in blood from both HIV- and HIV+ donors and enhances its virulence/pathogenic potential in the hematogenous environment. The M. tb blood-specific transcriptome reflects suppression of dormancy, induction of cell-wall remodeling, alteration in mode of iron acquisition, potential evasion of immune surveillance, and enhanced expression of important virulence factors that drive active M. tb infection and dissemination. These changes are accentuated during bacterial replication in blood from HIV+ patients. Furthermore, the expression of ESAT-6, which participates in dissemination of M. tb from the lungs, is upregulated in M. tb growing in blood, especially during growth in blood from HIV+ patients. Preliminary experiments also demonstrate that ESAT-6 promotes HIV replication in U1 cells. These studies provide evidence, for the first time, that during bacteremia, M. tb can adapt to the blood environment by modifying its transcriptome in a manner indicative of an enhanced-virulence phenotype that favors active infection. Additionally, transcriptional modifications in HIV+ blood may further accentuate M. tb virulence and drive both M. tb and HIV infection.
Collapse
Affiliation(s)
- Michelle B. Ryndak
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
| | - Krishna K. Singh
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
| | - Zhengyu Peng
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Susan Zolla-Pazner
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
- Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America
| | - Hualin Li
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lu Meng
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Suman Laal
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
- Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
31
|
Jayachandran R, BoseDasgupta S, Pieters J. Surviving the macrophage: tools and tricks employed by Mycobacterium tuberculosis. Curr Top Microbiol Immunol 2014; 374:189-209. [PMID: 23154833 DOI: 10.1007/82_2012_273] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Mycobacterium tuberculosis has evolved to withstand one of the most inhospitable cells within the human body, namely the macrophage, a cell that is normally geared toward the destruction of any invading microbe. How M. tuberculosis achieves this is still incompletely understood; however, a number of mechanisms are now known that provide advantages to M. tuberculosis for its survival and proliferation inside the macrophage. While some of these mechanisms are mediated by factors released by M. tuberculosis, others rely on host components that are being hijacked to benefit survival of M. tuberculosis within the macrophage as well to avoid the generation of an effective immune response. Here, we describe several of these mechanisms, also pointing out the potential usage of this knowledge toward the development of novel strategies to treat tuberculosis. Furthermore, we attempt to put the 'macrophage niche' into context with other intracellular pathogens and discuss some of the generalities as well as specializations that M. tuberculosis employs to survive.
Collapse
Affiliation(s)
- Rajesh Jayachandran
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056, Basel, Switzerland
| | | | | |
Collapse
|
32
|
Tiwari B, Soory A, Raghunand TR. An immunomodulatory role for theMycobacterium tuberculosisregion of difference 1 locus proteins PE35 (Rv3872) and PPE68 (Rv3873). FEBS J 2014; 281:1556-70. [DOI: 10.1111/febs.12723] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/03/2013] [Accepted: 01/21/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Bhavana Tiwari
- CSIR - Centre for Cellular and Molecular Biology; Hyderabad India
| | | | | |
Collapse
|
33
|
Vordermeier M, Jones GJ, Whelan AO. DIVA reagents for bovine tuberculosis vaccines in cattle. Expert Rev Vaccines 2014; 10:1083-91. [DOI: 10.1586/erv.11.22] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
34
|
Salgame P, Yap GS, Gause WC. Effect of helminth-induced immunity on infections with microbial pathogens. Nat Immunol 2013; 14:1118-1126. [PMID: 24145791 DOI: 10.1038/ni.2736] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 09/11/2013] [Indexed: 02/06/2023]
Abstract
Helminth infections are ubiquitous worldwide and can trigger potent immune responses that differ from and potentially antagonize host protective responses to microbial pathogens. In this Review we focus on the three main killers in infectious disease-AIDS, tuberculosis and malaria-and critically assesses whether helminths adversely influence host control of these diseases. We also discuss emerging concepts for how M2 macrophages and helminth-modulated dendritic cells can potentially influence the protective immune response to concurrent infections. Finally, we present evidence advocating for more efforts to determine how and to what extent helminths interfere with the successful control of specific concurrent coinfections.
Collapse
Affiliation(s)
- Padmini Salgame
- Department of Medicine, Center for Emerging Pathogens, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - George S Yap
- Department of Medicine, Center for Immunity and Inflammation, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - William C Gause
- Department of Medicine, Center for Immunity and Inflammation, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| |
Collapse
|
35
|
The putative propeptide of MycP1 in mycobacterial type VII secretion system does not inhibit protease activity but improves protein stability. Protein Cell 2013; 4:921-31. [PMID: 24248472 DOI: 10.1007/s13238-013-3089-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 10/21/2013] [Indexed: 10/26/2022] Open
Abstract
Mycosin-1 protease (MycP1) is a serine protease anchored to the inner membrane of Mycobacterium tuberculosis, and is essential in virulence factor secretion through the ESX-1 type VII secretion system (T7SS). Bacterial physiology studies demonstrated that MycP1 plays a dual role in the regulation of ESX-1 secretion and virulence, primarily through cleavage of its secretion substrate EspB. MycP1 contains a putative N-terminal inhibitory propeptide and a catalytic triad of Asp-His-Ser, classic hallmarks of a subtilase family serine protease. The MycP1 propeptide was previously reported to be initially inactive and activated after prolonged incubation. In this study, we have determined crystal structures of MycP1 with (MycP1²⁴⁻⁴²²) and without (MycP1⁶³⁻⁴²²) the propeptide, and conducted EspB cleavage assays using the two proteins. Very high structural similarity was observed in the two crystal structures. Interestingly, protease assays demonstrated positive EspB cleavage for both proteins, indicating that the putative propeptide does not inhibit protease activity. Molecular dynamic simulations showed higher rigidity in regions guarding the entrance to the catalytic site in MycP1²⁴⁻⁴²² than in MycP1⁶³⁻⁴²², suggesting that the putative propeptide might contribute to the conformational stability of the active site cleft and surrounding regions.
Collapse
|
36
|
Chagnot C, Zorgani MA, Astruc T, Desvaux M. Proteinaceous determinants of surface colonization in bacteria: bacterial adhesion and biofilm formation from a protein secretion perspective. Front Microbiol 2013; 4:303. [PMID: 24133488 PMCID: PMC3796261 DOI: 10.3389/fmicb.2013.00303] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/22/2013] [Indexed: 01/30/2023] Open
Abstract
Bacterial colonization of biotic or abiotic surfaces results from two quite distinct physiological processes, namely bacterial adhesion and biofilm formation. Broadly speaking, a biofilm is defined as the sessile development of microbial cells. Biofilm formation arises following bacterial adhesion but not all single bacterial cells adhering reversibly or irreversibly engage inexorably into a sessile mode of growth. Among molecular determinants promoting bacterial colonization, surface proteins are the most functionally diverse active components. To be present on the bacterial cell surface, though, a protein must be secreted in the first place. Considering the close association of secreted proteins with their cognate secretion systems, the secretome (which refers both to the secretion systems and their protein substrates) is a key concept to apprehend the protein secretion and related physiological functions. The protein secretion systems are here considered in light of the differences in the cell-envelope architecture between diderm-LPS (archetypal Gram-negative), monoderm (archetypal Gram-positive) and diderm-mycolate (archetypal acid-fast) bacteria. Besides, their cognate secreted proteins engaged in the bacterial colonization process are regarded from single protein to supramolecular protein structure as well as the non-classical protein secretion. This state-of-the-art on the complement of the secretome (the secretion systems and their cognate effectors) involved in the surface colonization process in diderm-LPS and monoderm bacteria paves the way for future research directions in the field.
Collapse
Affiliation(s)
- Caroline Chagnot
- UR454 Microbiologie, INRA Saint-Genès Champanelle, France ; UR370 Qualité des Produits Animaux, INRA Saint-Genès Champanelle, France
| | | | | | | |
Collapse
|
37
|
Novel secreted antigens of Mycobacterium paratuberculosis as serodiagnostic biomarkers for Johne's disease in cattle. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1783-91. [PMID: 24089453 DOI: 10.1128/cvi.00380-13] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Johne's disease is a chronic gastroenteritis of cattle caused by Mycobacterium avium subsp. paratuberculosis that afflicts 40% of dairy herds worldwide. M. avium subsp. paratuberculosis-infected cattle can remain asymptomatic for years while transmitting the pathogen via fecal contamination and milk. Current serodiagnosis with enzyme-linked immunosorbent assays (ELISAs) fails to detect asymptomatic M. avium subsp. paratuberculosis-infected cattle due to the use of poorly defined antigens and knowledge gaps in our understanding of M. avium subsp. paratuberculosis components eliciting pathogen-specific immune responses. We set out to (i) define a subset of proteins that contain putative antigenic targets and (ii) screen these antigen pools for immunogens relevant in detecting infection. To accomplish our first objective, we captured and resolved M. avium subsp. paratuberculosis-secreted proteins using a 2-step fractionation method and reverse-phase liquid chromatography to identify 162 unique proteins, of which 66 had not been previously observed in M. avium subsp. paratuberculosis culture filtrates. Subsequent screening of M. avium subsp. paratuberculosis-secreted proteins showed four antigens, of which one or more reacted on immunoblotting with individual serum samples from 35 M. avium subsp. paratuberculosis-infected cows. Moreover, these novel antigens reacted with sera from 6 low M. avium subsp. paratuberculosis shedders and 3 fecal-culture-positive cows labeled as ELISA seronegative. The specificity of these antigens was demonstrated using negative-control sera from uninfected calves (n = 5) and uninfected cows (n = 5), which did not react to any of these antigens in immunoblotting. As three of the four antigens are novel, their characterization and incorporation into an ELISA-based format will aid in detecting asymptomatic cattle in early or subclinical stages of disease.
Collapse
|
38
|
Premkumar L, Heras B, Duprez W, Walden P, Halili M, Kurth F, Fairlie DP, Martin JL. Rv2969c, essential for optimal growth in Mycobacterium tuberculosis, is a DsbA-like enzyme that interacts with VKOR-derived peptides and has atypical features of DsbA-like disulfide oxidases. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:1981-94. [PMID: 24100317 PMCID: PMC3792642 DOI: 10.1107/s0907444913017800] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 06/28/2013] [Indexed: 12/16/2022]
Abstract
The bacterial disulfide machinery is an attractive molecular target for developing new antibacterials because it is required for the production of multiple virulence factors. The archetypal disulfide oxidase proteins in Escherichia coli (Ec) are DsbA and DsbB, which together form a functional unit: DsbA introduces disulfides into folding proteins and DsbB reoxidizes DsbA to maintain it in the active form. In Mycobacterium tuberculosis (Mtb), no DsbB homologue is encoded but a functionally similar but structurally divergent protein, MtbVKOR, has been identified. Here, the Mtb protein Rv2969c is investigated and it is shown that it is the DsbA-like partner protein of MtbVKOR. It is found that it has the characteristic redox features of a DsbA-like protein: a highly acidic catalytic cysteine, a highly oxidizing potential and a destabilizing active-site disulfide bond. Rv2969c also has peptide-oxidizing activity and recognizes peptide segments derived from the periplasmic loops of MtbVKOR. Unlike the archetypal EcDsbA enzyme, Rv2969c has little or no activity in disulfide-reducing and disulfide-isomerase assays. The crystal structure of Rv2969c reveals a canonical DsbA fold comprising a thioredoxin domain with an embedded helical domain. However, Rv2969c diverges considerably from other DsbAs, including having an additional C-terminal helix (H8) that may restrain the mobility of the catalytic helix H1. The enzyme is also characterized by a very shallow hydrophobic binding surface and a negative electrostatic surface potential surrounding the catalytic cysteine. The structure of Rv2969c was also used to model the structure of a paralogous DsbA-like domain of the Ser/Thr protein kinase PknE. Together, these results show that Rv2969c is a DsbA-like protein with unique properties and a limited substrate-binding specificity.
Collapse
Affiliation(s)
- Lakshmanane Premkumar
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - Begoña Heras
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - Wilko Duprez
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - Patricia Walden
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - Maria Halili
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - Fabian Kurth
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - David P. Fairlie
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| | - Jennifer L. Martin
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, University of Queensland, St Lucia, QLD 4067, Australia
| |
Collapse
|
39
|
Boggaram V, Gottipati KR, Wang X, Samten B. Early secreted antigenic target of 6 kDa (ESAT-6) protein of Mycobacterium tuberculosis induces interleukin-8 (IL-8) expression in lung epithelial cells via protein kinase signaling and reactive oxygen species. J Biol Chem 2013; 288:25500-25511. [PMID: 23867456 PMCID: PMC3757211 DOI: 10.1074/jbc.m112.448217] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 06/24/2013] [Indexed: 12/24/2022] Open
Abstract
Early secreted antigenic target of 6 kDa (ESAT-6) of Mycobacterium tuberculosis is critical for the virulence and pathogenicity of M. tuberculosis. IL-8, a major chemotactic cytokine for neutrophils and T lymphocytes, plays important roles in the development of lung injury. To further understand the role of ESAT-6 in lung pathology associated with tuberculosis development, we studied the effects of ESAT-6 on the regulation of IL-8 expression in lung epithelial cells. ESAT-6 induced IL-8 expression by increasing IL-8 gene transcription and mRNA stability. ESAT-6 induction of IL-8 promoter activity was dependent on nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) binding and sensitive to pharmacological inhibition of PKC and ERK and p38 MAPK pathways. ESAT-6 activated ERK and p38 MAPK phosphorylation and rapidly induced reactive oxygen species (ROS) production. Dimethylthiourea but not mannitol inhibited IL-8 induction by ESAT-6, further supporting the involvement of ROS in the induction of IL-8 expression. Exposure of mice to ESAT-6 induced localized inflammatory cell aggregate formation with characteristics of early granuloma concomitant with increased keratinocyte chemoattractant CXCL1 staining in bronchiolar and alveolar type II epithelial cells and alveolar macrophages. Our studies have identified a signal transduction pathway involving ROS, PKC, ERK, and p38 MAPKs and NF-κB and AP-1 in the ESAT-6 induction of IL-8 expression in lung epithelial cells. This has important implications for the understanding of lung innate immune responses to tuberculosis and the pathogenesis of lung injury in tuberculosis.
Collapse
MESH Headings
- Animals
- Antigens, Bacterial/metabolism
- Antigens, Bacterial/pharmacology
- Bacterial Proteins/metabolism
- Bacterial Proteins/pharmacology
- Cell Line, Tumor
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Gene Expression Regulation
- Humans
- Interleukin-8/biosynthesis
- Interleukin-8/genetics
- Lung/metabolism
- Lung/pathology
- MAP Kinase Signaling System
- Macrophages, Alveolar/metabolism
- Macrophages, Alveolar/pathology
- Mice
- Mycobacterium tuberculosis/metabolism
- NF-kappa B/genetics
- NF-kappa B/metabolism
- Promoter Regions, Genetic/genetics
- Protein Kinases/genetics
- Protein Kinases/metabolism
- Reactive Oxygen Species/metabolism
- Respiratory Mucosa/metabolism
- Respiratory Mucosa/pathology
- Transcription Factor AP-1/genetics
- Transcription Factor AP-1/metabolism
- Transcription, Genetic/genetics
- Tuberculosis, Pulmonary/genetics
- Tuberculosis, Pulmonary/metabolism
- Tuberculosis, Pulmonary/pathology
Collapse
Affiliation(s)
- Vijay Boggaram
- From the Department of Cell and Molecular Biology and the Center for Pulmonary Infectious Disease Control, University of Texas Health Science Center, Tyler, Texas 75708-3154.
| | - Koteswara R Gottipati
- From the Department of Cell and Molecular Biology and the Center for Pulmonary Infectious Disease Control, University of Texas Health Science Center, Tyler, Texas 75708-3154
| | - Xisheng Wang
- From the Department of Cell and Molecular Biology and the Center for Pulmonary Infectious Disease Control, University of Texas Health Science Center, Tyler, Texas 75708-3154
| | - Buka Samten
- From the Department of Cell and Molecular Biology and the Center for Pulmonary Infectious Disease Control, University of Texas Health Science Center, Tyler, Texas 75708-3154
| |
Collapse
|
40
|
Roy A, Bhattacharya S, Bothra AK, Sen A. A database for Mycobacterium secretome analysis: 'MycoSec' to accelerate global health research. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2013; 17:502-9. [PMID: 23952586 DOI: 10.1089/omi.2013.0015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract Members of the genus Mycobacterium are notorious for their pathogenesis. Investigations from various perspectives have identified the pathogenic strategies employed by these lethal pathogens. Secretomes are believed to play crucial roles in host cell recognition and cross-talks, in cellular attachment, and in triggering other functions related to host pathogen interactions. However, a proper idea of the mycobacterial secretomes and their mechanism of functionality still remains elusive. In the present study, we have developed a comprehensive database of potential mycobacterial secretomes (MycoSec) using pre-existing algorithms for secretome prediction for researchers interested in this particular field. The database provides a platform for retrieval and analysis of identified secretomes in all finished genomes of the family Mycobacteriaceae. The database contains valuable information regarding secretory signal peptides (Sec type), lipoprotein signal peptides (Lipo type), and Twin arginine (RR/KR) signal peptides (TAT type), prevalent in mycobacteria. Information pertaining to COG analysis, codon usage, and gene expression of the predicted secretomes has also been incorporated in the database. MycoSec promises to be a useful repertoire providing a plethora of information regarding mycobacterial secretomes and may well be a platform to speed global health research. MycoSec is freely accessible at http://www.bicnbu.in/mycosec .
Collapse
Affiliation(s)
- Ayan Roy
- 1 Bioinformatics Facility, Department of Botany, University of North Bengal , Siliguri, India
| | | | | | | |
Collapse
|
41
|
Gray TA, Krywy JA, Harold J, Palumbo MJ, Derbyshire KM. Distributive conjugal transfer in mycobacteria generates progeny with meiotic-like genome-wide mosaicism, allowing mapping of a mating identity locus. PLoS Biol 2013; 11:e1001602. [PMID: 23874149 PMCID: PMC3706393 DOI: 10.1371/journal.pbio.1001602] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 05/24/2013] [Indexed: 01/01/2023] Open
Abstract
We find that genome-wide DNA transfer by conjugation in mycobacteria affords bacteria that reproduce by binary fission the same advantages of sexual reproduction, and may explain the genomic evolution of Mycobacterium tuberculosis. Horizontal gene transfer (HGT) in bacteria generates variation and drives evolution, and conjugation is considered a major contributor as it can mediate transfer of large segments of DNA between strains and species. We previously described a novel form of chromosomal conjugation in mycobacteria that does not conform to classic oriT-based conjugation models, and whose potential evolutionary significance has not been evaluated. Here, we determined the genome sequences of 22 F1-generation transconjugants, providing the first genome-wide view of conjugal HGT in bacteria at the nucleotide level. Remarkably, mycobacterial recipients acquired multiple, large, unlinked segments of donor DNA, far exceeding expectations for any bacterial HGT event. Consequently, conjugal DNA transfer created extensive genome-wide mosaicism within individual transconjugants, which generated large-scale sibling diversity approaching that seen in meiotic recombination. We exploited these attributes to perform genome-wide mapping and introgression analyses to map a locus that determines conjugal mating identity in M. smegmatis. Distributive conjugal transfer offers a plausible mechanism for the predicted HGT events that created the genome mosaicism observed among extant Mycobacterium tuberculosis and Mycobacterium canettii species. Mycobacterial distributive conjugal transfer permits innovative genetic approaches to map phenotypic traits and confers the evolutionary benefits of sexual reproduction in an asexual organism. Bacteria reproduce by binary fission, generating two clones of the original; this restricts the genomic diversity of the population, which brings with it inherent evolutionary drawbacks. This problem can be eased by conjugation, which transfers DNA from a donor to a recipient bacterium. Understanding the potential of conjugal DNA transfer for generating genetic diversity is necessary for estimating gene flow through populations and for predicting rates of bacterial evolution. The influence of chromosomal conjugal DNA transfer on mycobacterial diversity has not been previously addressed. Here, we determine and compare the complete genome sequences of independent progeny from bacterial matings between defined donor and recipient strains of Mycobacterium smegmatis. We find the resulting hybrid bacteria to be extremely diverse blends of the parental strains, reminiscent of the genetic mixing that occurs through meiotic recombination in sexual organisms. This novel mechanism of conjugation can create genome-wide mosaicism in a single event, generating segments of donor DNA that range from small (∼0.05 kb) to large (∼250 kb), widely distributed around the recipient chromosome. We exploit this mixing by using genetic tools originally developed for finding mammalian disease genes to locate the genes that confer a donor phenotype in M. smegmatis. We speculate that similar genomic mosaicism observed in pathogenic mycobacteria arose from conjugation between ancestral progenitor strains.
Collapse
Affiliation(s)
- Todd A Gray
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America.
| | | | | | | | | |
Collapse
|
42
|
Jayachandran R, Scherr N, Pieters J. Elimination of intracellularly residing Mycobacterium tuberculosis through targeting of host and bacterial signaling mechanisms. Expert Rev Anti Infect Ther 2013; 10:1007-22. [PMID: 23106276 DOI: 10.1586/eri.12.95] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
With more than 2 billion latently infected people, TB continues to represent a serious threat to human health. According to the WHO, 1.1 million people died from TB in 2010, which is equal to approximately 3000 deaths per day. The causative agent of the disease, Mycobacterium tuberculosis, is a highly successful pathogen having evolved remarkable strategies to persist within the host. Although normally, upon phagocytosis by macrophages, bacteria are readily eliminated by lysosomes, pathogenic mycobacteria actively prevent destruction within macrophages. The strategies that pathogenic mycobacteria apply range from releasing virulence factors to manipulating host molecules resulting in the modulation of host signal transduction pathways in order to sustain their viability within the infected host. Here, we analyze the current status of how a better understanding of both the bacterial and host factors involved in virulence can be used to develop drugs that may be helpful to curb the TB epidemic.
Collapse
Affiliation(s)
- Rajesh Jayachandran
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | | | | |
Collapse
|
43
|
Wong KW, Jacobs WR. Mycobacterium tuberculosis exploits human interferon γ to stimulate macrophage extracellular trap formation and necrosis. J Infect Dis 2013; 208:109-19. [PMID: 23475311 PMCID: PMC3666134 DOI: 10.1093/infdis/jit097] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human neutrophils form extracellular traps during M. tuberculosis infection, but a similar phenomenon has not been reported in human macrophages. Here we demonstrate that M. tuberculosis induces release of extracellular traps from human macrophages. This process is regulated by elastase activity, previously shown to regulate formation of extracellular traps by neutrophils. Interestingly, formation of extracellular traps by macrophages during M. tuberculosis infection is inducible by interferon γ (IFN-γ). These traps are mainly produced by heavily infected macrophages. Accordingly, IFN-γ is found to stimulate M. tuberculosis aggregation in macrophages. Both IFN-γ–inducible events, extracellular trap formation and mycobacterial aggregation, require the ESX-1 secretion system. In addition, IFN-γ is found to enhance ESX-1–mediated macrophage necrosis. In the absence of ESX-1, IFN-γ does not restore any extracellular trap formation, mycobacterial aggregation, or macrophage necrosis. Thus, initial characterization of macrophage extracellular trap formation due to M. tuberculosis infection led to the uncovering of a novel role for IFN-γ in amplifying multiple effects of the mycobacterial ESX-1.
Collapse
Affiliation(s)
- Ka-Wing Wong
- Department of Microbiology and Immunology, Howard Hughes Medical Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | |
Collapse
|
44
|
Wong D, Chao JD, Av-Gay Y. Mycobacterium tuberculosis-secreted phosphatases: from pathogenesis to targets for TB drug development. Trends Microbiol 2013; 21:100-9. [DOI: 10.1016/j.tim.2012.09.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/10/2012] [Accepted: 09/14/2012] [Indexed: 01/02/2023]
|
45
|
Prozorov AA, Zaichikova MV, Danilenko VN. Systems of genes and proteins affecting mycobacteria virulence and their homologs participation in conjugation of Mycobacterium smegmatis. RUSS J GENET+ 2013. [DOI: 10.1134/s1022795413010092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
46
|
Albrethsen J, Agner J, Piersma SR, Højrup P, Pham TV, Weldingh K, Jimenez CR, Andersen P, Rosenkrands I. Proteomic profiling of Mycobacterium tuberculosis identifies nutrient-starvation-responsive toxin-antitoxin systems. Mol Cell Proteomics 2013; 12:1180-91. [PMID: 23345537 PMCID: PMC3650330 DOI: 10.1074/mcp.m112.018846] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In order to successfully enter the latent stage, Mycobacterium tuberculosis must adapt to conditions such as nutrient limitation and hypoxia. In vitro models that mimic latent infection are valuable tools for describing the changes in metabolism that occur when the bacterium exists in a non-growing form. We used two complementary proteomic approaches, label-free LC-MS/MS analysis and two-dimensional difference gel electrophoresis, to determine the proteome profile of extracellular proteins from M. tuberculosis cultured under nutrient starvation. Through the label-free LC-MS/MS analysis of fractionated samples, 1176 proteins were identified from culture filtrates of log phase and nutrient-starved cultures, and the protein levels of 230 proteins were increased in nutrient-starved culture filtrates, whereas those of 208 proteins were decreased. By means of Gene Ontology clustering analysis, significant differences in the overall metabolism during nutrient starvation were detected. Notably, members of the toxin–antitoxin systems were present in larger quantities in nutrient-starved cultures, supporting a role for these global modules as M. tuberculosis switches its metabolism into dormancy. Decreased abundance of proteins involved in amino acid and protein synthesis was apparent, as well as changes in the lipid metabolism. Further analysis of the dataset identified increased abundance of lipoproteins and decreased abundance of ESAT-6 family proteins. Results from the two-dimensional difference gel electrophoresis proteomics demonstrated overall agreement with the LC-MS/MS data and added complementary insights about protein degradation and modification.
Collapse
Affiliation(s)
- Jakob Albrethsen
- Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Briken V. Mycobacterium tuberculosis genes involved in regulation of host cell death. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 783:93-102. [PMID: 23468105 DOI: 10.1007/978-1-4614-6111-1_5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The topic of host cell death response upon Mycobacterium tuberculosis (Mtb) infection has been a controversial one [1]. Recent findings demonstrate that one of the important confounding factors was most likely the fact that while Mtb inhibits host cell apoptosis induction early during the infection it clearly induces a necrotic form of cell death during later infection stages [2, 3]. This bi-phasic intracellular lifestyle in regard to host cell death manipulation is emerging as a common theme shared with other facultative and obligate intracellular bacterial pathogens such as Chlamydia and Legionella [4-6]. Accordingly, the list of discovered bacterial proteins involved in host cell apoptosis inhibition is growing [7, 8]. At the same time it is clearly beneficial for the resistance of the host to overcome the bacterial apoptosis block during the early stage of the infection [9-11]. Hence, host cell components have evolved to recognize intracellular pathogens and mediate host cell apoptosis induction if necessary [12]. There have been several reviews on the various aspects of the host cell death response upon Mtb infection [1, 3, 13-15]. Thus in this chapter I will focus on the pathogen side of the equation and describe the tremendous progress that has been made in the identification and characterization of Mtb genes involved in manipulation of host cell death pathways.
Collapse
Affiliation(s)
- Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
| |
Collapse
|
48
|
Renier S, Micheau P, Talon R, Hébraud M, Desvaux M. Subcellular localization of extracytoplasmic proteins in monoderm bacteria: rational secretomics-based strategy for genomic and proteomic analyses. PLoS One 2012; 7:e42982. [PMID: 22912771 PMCID: PMC3415414 DOI: 10.1371/journal.pone.0042982] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/13/2012] [Indexed: 11/20/2022] Open
Abstract
Genome-scale prediction of subcellular localization (SCL) is not only useful for inferring protein function but also for supporting proteomic data. In line with the secretome concept, a rational and original analytical strategy mimicking the secretion steps that determine ultimate SCL was developed for Gram-positive (monoderm) bacteria. Based on the biology of protein secretion, a flowchart and decision trees were designed considering (i) membrane targeting, (ii) protein secretion systems, (iii) membrane retention, and (iv) cell-wall retention by domains or post-translocational modifications, as well as (v) incorporation to cell-surface supramolecular structures. Using Listeria monocytogenes as a case study, results were compared with known data set from SCL predictors and experimental proteomics. While in good agreement with experimental extracytoplasmic fractions, the secretomics-based method outperforms other genomic analyses, which were simply not intended to be as inclusive. Compared to all other localization predictors, this method does not only supply a static snapshot of protein SCL but also offers the full picture of the secretion process dynamics: (i) the protein routing is detailed, (ii) the number of distinct SCL and protein categories is comprehensive, (iii) the description of protein type and topology is provided, (iv) the SCL is unambiguously differentiated from the protein category, and (v) the multiple SCL and protein category are fully considered. In that sense, the secretomics-based method is much more than a SCL predictor. Besides a major step forward in genomics and proteomics of protein secretion, the secretomics-based method appears as a strategy of choice to generate in silico hypotheses for experimental testing.
Collapse
Affiliation(s)
- Sandra Renier
- INRA, UR454 Microbiology, Saint-Genès Champanelle, France
| | - Pierre Micheau
- INRA, UR454 Microbiology, Saint-Genès Champanelle, France
| | - Régine Talon
- INRA, UR454 Microbiology, Saint-Genès Champanelle, France
| | - Michel Hébraud
- INRA, UR454 Microbiology, Saint-Genès Champanelle, France
| | - Mickaël Desvaux
- INRA, UR454 Microbiology, Saint-Genès Champanelle, France
- * E-mail:
| |
Collapse
|
49
|
Mycobacterium marinum SecA2 promotes stable granulomas and induces tumor necrosis factor alpha in vivo. Infect Immun 2012; 80:3512-20. [PMID: 22851747 DOI: 10.1128/iai.00686-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
SecA2 is an ATPase present in some pathogenic Gram-positive bacteria, is required for translocation of a limited set of proteins across the cytosolic membrane, and plays an important role in virulence in several bacteria, including mycobacteria that cause diseases such as tuberculosis and leprosy. However, the mechanisms by which SecA2 affects virulence are incompletely understood. To investigate whether SecA2 modulates host immune responses in vivo, we studied Mycobacterium marinum infection in two different hosts: an established zebrafish model and a recently described mouse model. Here we show that M. marinum ΔsecA2 was attenuated for virulence in both host species and SecA2 was needed for normal granuloma numbers and for optimal tumor necrosis factor alpha response in both zebrafish and mice. M. marinum ΔsecA2 was more sensitive to SDS and had unique protrusions from its cell envelope when examined by cryo-electron tomography, suggesting that SecA2 is important for bacterial cell wall integrity. These results provide evidence that SecA2 induces granulomas and is required for bacterial modulation of the host response because it affects the mycobacterial cell envelope.
Collapse
|
50
|
Enhanced priming of adaptive immunity by Mycobacterium smegmatis mutants with high-level protein secretion. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1416-25. [PMID: 22787192 DOI: 10.1128/cvi.00131-12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mycobacteria have features that make them attractive as potential vaccine vectors. The nonpathogenic and rapidly growing Mycobacterium smegmatis can express both Mycobacterium tuberculosis antigens and heterologous antigens from other pathogens, and it has been used as a viable vector for the development of live vaccines. In order to further improve antigen-specific immunogenicity of M. smegmatis, we screened a random transposon mutant library for mutants displaying enhanced efficiency of protein secretion ("high secretors") and isolated 61 mutants showing enhanced endogenic and transgenic protein secretion. Sequence analysis identified a total of 54 genes involved in optimal secretion of insert proteins, as well as multiple independent transposon insertions localized within the same genomic loci and operons. The majority of transposon insertions occurred in genes that have no known protein secretion function. These transposon mutants were shown to prime antigen-specific CD8(+) T cell responses better than the parental strain. Specifically, upon introducing the simian immunodeficiency virus (SIV) gag gene into these transposon mutant strains, we observed that they primed SIV Gag-specific CD8(+) T cell responses significantly better than the control prime immunization in a heterologous prime/boost regimen. Our results reveal a dependence on bacterial secretion of mycobacterial and foreign antigens for the induction of antigen-specific CD8(+) T cells in vivo. The data also suggest that these M. smegmatis transposon mutants could be used as novel live attenuated vaccine strains to express foreign antigens, such as those of human immunodeficiency virus type 1 (HIV-1), and induce strong antigen-specific T cell responses.
Collapse
|