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Din SRU, Saeed S, Khan SU, Arbi FM, Xuefang G, Zhong M. Bacteria-driven cancer therapy: Exploring advancements and challenges. Crit Rev Oncol Hematol 2023; 191:104141. [PMID: 37742883 DOI: 10.1016/j.critrevonc.2023.104141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023] Open
Abstract
Cancer, a serious fatal disease caused by the uncontrolled growth of cells, is the biggest challenge flagging around medicine and health fields. Conventionally, various treatments-based strategies such as radiotherapy, chemotherapy, and alternative cancer therapies possess drugs that cannot reach the cancerous tissues and make them toxic to noncancerous cells. Cancer immunotherapy has made outstanding achievements in reducing the chances of cancer. Our considerable attention towards cancer-directed immune responses and the mechanisms behind which immune cells kill cancer cells have progressively been helpful in the advancement of new therapies. Among them, bacteria-based cancer immunotherapy has achieved much more attention due to smart and robust mechanisms in activating the host anti-tumor response. Moreover, bacterial-based therapy can be utilized as a single monotherapy or in combination with multiple anticancer immunotherapies to accelerate productive clinical results. Herein, we comprehensively reviewed recent advancements, challenges, and future perspectives in developing bacterial-based cancer immunotherapies.
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Affiliation(s)
- Syed Riaz Ud Din
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Sumbul Saeed
- School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
| | - Shahid Ullah Khan
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Beibei, Chongqing 400715, China; Engineering Research Center of South Upland Agriculture, Ministry of Education, Chongqing 400715, China; Women Medical and Dental College, Khyber Medical University, Peshawar, KPK 22020, Pakistan
| | - Fawad Mueen Arbi
- Quaid-e-Azam Medical College, Bahawalpur, Punjab 63100, Pakistan
| | - Guo Xuefang
- Department of Medical Microbiology, Dalian Medical University, Dalian 116044, China
| | - Mintao Zhong
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China.
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2
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Gupta KH, Nowicki C, Giurini EF, Marzo AL, Zloza A. Bacterial-Based Cancer Therapy (BBCT): Recent Advances, Current Challenges, and Future Prospects for Cancer Immunotherapy. Vaccines (Basel) 2021; 9:vaccines9121497. [PMID: 34960243 PMCID: PMC8707929 DOI: 10.3390/vaccines9121497] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 11/22/2021] [Indexed: 12/19/2022] Open
Abstract
Currently approximately 10 million people die each year due to cancer, and cancer is the cause of every sixth death worldwide. Tremendous efforts and progress have been made towards finding a cure for cancer. However, numerous challenges have been faced due to adverse effects of chemotherapy, radiotherapy, and alternative cancer therapies, including toxicity to non-cancerous cells, the inability of drugs to reach deep tumor tissue, and the persistent problem of increasing drug resistance in tumor cells. These challenges have increased the demand for the development of alternative approaches with greater selectivity and effectiveness against tumor cells. Cancer immunotherapy has made significant advancements towards eliminating cancer. Our understanding of cancer-directed immune responses and the mechanisms through which immune cells invade tumors have extensively helped us in the development of new therapies. Among immunotherapies, the application of bacteria and bacterial-based products has promising potential to be used as treatments that combat cancer. Bacterial targeting of tumors has been developed as a unique therapeutic option that meets the ongoing challenges of cancer treatment. In comparison with other cancer therapeutics, bacterial-based therapies have capabilities for suppressing cancer. Bacteria are known to accumulate and proliferate in the tumor microenvironment and initiate antitumor immune responses. We are currently well-informed regarding various methods by which bacteria can be manipulated by simple genetic engineering or synthetic bioengineering to induce the production of anti-cancer drugs. Further, bacterial-based cancer therapy (BBCT) can be either used as a monotherapy or in combination with other anticancer therapies for better clinical outcomes. Here, we review recent advances, current challenges, and prospects of bacteria and bacterial products in the development of BBCTs.
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Affiliation(s)
- Kajal H. Gupta
- Division of Hematology, Oncology, and Cell Therapy, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA; (K.H.G.); (C.N.); (E.F.G.); (A.L.M.)
- Division of Translational and Precision Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Christina Nowicki
- Division of Hematology, Oncology, and Cell Therapy, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA; (K.H.G.); (C.N.); (E.F.G.); (A.L.M.)
- Division of Translational and Precision Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Eileena F. Giurini
- Division of Hematology, Oncology, and Cell Therapy, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA; (K.H.G.); (C.N.); (E.F.G.); (A.L.M.)
- Division of Translational and Precision Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Amanda L. Marzo
- Division of Hematology, Oncology, and Cell Therapy, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA; (K.H.G.); (C.N.); (E.F.G.); (A.L.M.)
- Division of Translational and Precision Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Andrew Zloza
- Division of Hematology, Oncology, and Cell Therapy, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA; (K.H.G.); (C.N.); (E.F.G.); (A.L.M.)
- Division of Translational and Precision Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
- Correspondence:
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Protein Export via the Type III Secretion System of the Bacterial Flagellum. Biomolecules 2021; 11:biom11020186. [PMID: 33572887 PMCID: PMC7911332 DOI: 10.3390/biom11020186] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/15/2022] Open
Abstract
The bacterial flagellum and the related virulence-associated injectisome system of pathogenic bacteria utilize a type III secretion system (T3SS) to export substrate proteins across the inner membrane in a proton motive force-dependent manner. The T3SS is composed of an export gate (FliPQR/FlhA/FlhB) located in the flagellar basal body and an associated soluble ATPase complex in the cytoplasm (FliHIJ). Here, we summarise recent insights into the structure, assembly and protein secretion mechanisms of the T3SS with a focus on energy transduction and protein transport across the cytoplasmic membrane.
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4
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Lim D, Jung WC, Jeong JH, Song M. Targeted Delivery of the Mitochondrial Target Domain of Noxa to Tumor Tissue via Synthetic Secretion System in E. coli. Front Bioeng Biotechnol 2020; 8:840. [PMID: 32766235 PMCID: PMC7379172 DOI: 10.3389/fbioe.2020.00840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/30/2020] [Indexed: 01/21/2023] Open
Abstract
Targeted delivery of drugs is a key aspect of the successful treatment of serious conditions such as tumors. In the pursuit of accurate delivery with high specificity and low size limit for peptide drugs, a synthetic type 3 secretion system (T3SS) has been repurposed from a native genetic system encoded in Salmonella pathogenicity island-1 (SPI-1) with no virulence effectors. Here, we tested the potential of synthetic T3SS as drug delivery machinery for peptide-based drugs owing to its modular nature. First, the genetic system for synthetic T3SS was introduced into non-native host E. coli, which was chosen for its lack of Salmonella-driven virulence factors. Next, the mitochondrial targeting domain (MTD) of Noxa was tested as a cargo protein with anti-tumor activity. To this end, the gene encoding MTD was engineered for secretion through synthetic T3SS, thereby resulting in the tagged MTD at the N-terminus. When E. coli carrying synthetic T3SS and MTD on plasmids was administered into tumor-bearing mice, MTD with a secretion tag at the N-terminus was clearly detected in the tumor tissue after induction. Also, the tumor growth and mortality of tumor-bearing animals were mitigated by the cytotoxic activity of the delivered. Thus, this work potentiates the use of biotherapeutic bacteria for the treatment of tumors by implanting a dedicated delivery system.
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Affiliation(s)
- Daejin Lim
- Department of Microbiology, Chonnam National University Medical School, Gwangju, South Korea.,Department of Molecular Medicine (BK21plus), Chonnam National University Graduate School, Gwangju, South Korea
| | - Woong Chae Jung
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin, South Korea
| | - Jae-Ho Jeong
- Department of Microbiology, Chonnam National University Medical School, Gwangju, South Korea.,Department of Molecular Medicine (BK21plus), Chonnam National University Graduate School, Gwangju, South Korea
| | - Miryoung Song
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin, South Korea
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Felgner S, Spöring I, Pawar V, Kocijancic D, Preusse M, Falk C, Rohde M, Häussler S, Weiss S, Erhardt M. The immunogenic potential of bacterial flagella for Salmonella-mediated tumor therapy. Int J Cancer 2020; 147:448-460. [PMID: 31755108 DOI: 10.1002/ijc.32807] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/07/2019] [Accepted: 11/12/2019] [Indexed: 01/07/2023]
Abstract
Genetically engineered Salmonella Typhimurium are potent vectors for prophylactic and therapeutic measures against pathogens as well as cancer. This is based on the potent adjuvanticity that supports strong immune responses. The physiology of Salmonella is well understood. It simplifies engineering of both enhanced immune-stimulatory properties as well as safety features, thus, resulting in an appropriate balance between attenuation and efficacy for clinical applications. A major virulence factor of Salmonella is the flagellum. It is also a strong pathogen-associated molecular pattern recognized by extracellular and intracellular receptors of immune cells of the host. At the same time, it represents a serious metabolic burden. Accordingly, the bacteria evolved tight regulatory mechanisms that control flagella synthesis in vivo. Here, we systematically investigated the immunogenicity and adjuvant properties of various flagella mutants of Salmonella in vitro and in a mouse cancer model in vivo. We found that mutants lacking the flagellum-specific ATPase FliHIJ or the inner membrane ring FliF displayed the greatest stimulatory capacity and strongest antitumor effects, while remaining safe in vivo. Scanning electron microscopy revealed the presence of outer membrane vesicles in the ΔfliF and ΔfliHIJ mutants. Finally, the combination of the ΔfliF and ΔfliHIJ mutations with our previously described attenuated and immunogenic background strain SF102 displayed strong efficacy against the highly resistant cancer cell line RenCa. We thus conclude that manipulating flagella biosynthesis has great potential for the construction of highly efficacious and versatile Salmonella vector strains.
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Affiliation(s)
- Sebastian Felgner
- Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Imke Spöring
- Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Vinay Pawar
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Central Facilities for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Dino Kocijancic
- Institute of Immunology, Medical School Hannover, Hannover, Germany
| | - Matthias Preusse
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Christine Falk
- Institute of Transplant Immunology, Medical School Hannover, Hannover, Germany
| | - Manfred Rohde
- Central Facilities for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Siegfried Weiss
- Institute of Immunology, Medical School Hannover, Hannover, Germany
| | - Marc Erhardt
- Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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El Hamdaoui Y, Wu X, Clark RJ, Giribaldi J, Anangi R, Craik DJ, King GF, Dutertre S, Kaas Q, Herzig V, Nicke A. Periplasmic Expression of 4/7 α-Conotoxin TxIA Analogs in E. coli Favors Ribbon Isomer Formation - Suggestion of a Binding Mode at the α7 nAChR. Front Pharmacol 2019; 10:577. [PMID: 31214027 PMCID: PMC6554660 DOI: 10.3389/fphar.2019.00577] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/06/2019] [Indexed: 01/02/2023] Open
Abstract
Peptides derived from animal venoms provide important research tools for biochemical and pharmacological characterization of receptors, ion channels, and transporters. Some venom peptides have been developed into drugs (such as the synthetic ω-conotoxin MVIIA, ziconotide) and several are currently undergoing clinical trials for various clinical indications. Challenges in the development of peptides include their usually limited supply from natural sources, cost-intensive chemical synthesis, and potentially complicated stereoselective disulfide-bond formation in the case of disulfide-rich peptides. In particular, if extended structure–function analysis is performed or incorporation of stable isotopes for NMR studies is required, the comparatively low yields and high costs of synthesized peptides might constitute a limiting factor. Here we investigated the expression of the 4/7 α-conotoxin TxIA, a potent blocker at α3β2 and α7 nicotinic acetylcholine receptors (nAChRs), and three analogs in the form of maltose binding protein fusion proteins in Escherichia coli. Upon purification via nickel affinity chromatography and release of the toxins by protease cleavage, HPLC analysis revealed one major peak with the correct mass for all peptides. The final yield was 1–2 mg of recombinant peptide per liter of bacterial culture. Two-electrode voltage clamp analysis on oocyte-expressed nAChR subtypes demonstrated the functionality of these peptides but also revealed a 30 to 100-fold potency decrease of expressed TxIA compared to chemically synthesized TxIA. NMR spectroscopy analysis of TxIA and two of its analogs confirmed that the decreased activity was due to an alternative disulfide linkage rather than the missing C-terminal amidation, a post-translational modification that is common in α-conotoxins. All peptides preferentially formed in the ribbon conformation rather than the native globular conformation. Interestingly, in the case of the α7 nAChR, but not the α3β2 subtype, the loss of potency could be rescued by an R5D substitution. In conclusion, we demonstrate efficient expression of functional but alternatively folded ribbon TxIA variants in E. coli and provide the first structure–function analysis for a ribbon 4/7-α-conotoxin at α7 and α3β2 nAChRs. Computational analysis based on these data provide evidence for a ribbon α-conotoxin binding mode that might be exploited to design ligands with optimized selectivity.
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Affiliation(s)
- Yamina El Hamdaoui
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Xiaosa Wu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Julien Giribaldi
- CNRS, Institut des Biomolécules Max Mousseron, UMR 5247, Université de Montpellier, Montpellier, France
| | - Raveendra Anangi
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Sebastien Dutertre
- CNRS, Institut des Biomolécules Max Mousseron, UMR 5247, Université de Montpellier, Montpellier, France
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
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7
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Green CA, Kamble NS, Court EK, Bryant OJ, Hicks MG, Lennon C, Fraser GM, Wright PC, Stafford GP. Engineering the flagellar type III secretion system: improving capacity for secretion of recombinant protein. Microb Cell Fact 2019; 18:10. [PMID: 30657054 PMCID: PMC6337784 DOI: 10.1186/s12934-019-1058-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/08/2019] [Indexed: 08/26/2023] Open
Abstract
BACKGROUND Many valuable biopharmaceutical and biotechnological proteins have been produced in Escherichia coli, however these proteins are almost exclusively localised in the cytoplasm or periplasm. This presents challenges for purification, i.e. the removal of contaminating cellular constituents. One solution is secretion directly into the surrounding media, which we achieved via the 'hijack' of the flagellar type III secretion system (FT3SS). Ordinarily flagellar subunits are exported through the centre of the growing flagellum, before assembly at the tip. However, we exploit the fact that in the absence of certain flagellar components (e.g. cap proteins), monomeric flagellar proteins are secreted into the supernatant. RESULTS We report the creation and iterative improvement of an E. coli strain, by means of a modified FT3SS and a modular plasmid system, for secretion of exemplar proteins. We show that removal of the flagellin and HAP proteins (FliC and FlgKL) resulted in an optimal prototype. We next developed a high-throughput enzymatic secretion assay based on cutinase. This indicated that removal of the flagellar motor proteins, motAB (to reduce metabolic burden) and protein degradation machinery, clpX (to boost FT3SS levels intracellularly), result in high capacity secretion. We also show that a secretion construct comprising the 5'UTR and first 47 amino acidsof FliC from E. coli (but no 3'UTR) achieved the highest levels of secretion. Upon combination, we show a 24-fold improvement in secretion of a heterologous (cutinase) enzyme over the original strain. This improved strain could export a range of pharmaceutically relevant heterologous proteins [hGH, TrxA, ScFv (CH2)], achieving secreted yields of up to 0.29 mg L-1, in low cell density culture. CONCLUSIONS We have engineered an E. coli which secretes a range of recombinant proteins, through the FT3SS, to the extracellular media. With further developments, including cell culture process strategies, we envision further improvement to the secreted titre of recombinant protein, with the potential application for protein production for biotechnological purposes.
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Affiliation(s)
- Charlotte A Green
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK.,Sustainable Process Technologies, Chemical and Environmental Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nitin S Kamble
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - Elizabeth K Court
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - Owain J Bryant
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Matthew G Hicks
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - Christopher Lennon
- FUJIFILM Diosynth Biotechnologies, Belasis Avenue, Stockton-on-Tees, Billingham, TS23 1LH, UK
| | - Gillian M Fraser
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Phillip C Wright
- School of Engineering, The Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle, NE1 7RU, UK
| | - Graham P Stafford
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK.
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Habenstein B, El Mammeri N, Tolchard J, Lamon G, Tawani A, Berbon M, Loquet A. Structures of Type III Secretion System Needle Filaments. Curr Top Microbiol Immunol 2019; 427:109-131. [PMID: 31974760 DOI: 10.1007/82_2019_192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Among the Gram-negative bacterial secretion systems, type III secretion systems (T3SS) possess a unique extracellular molecular apparatus called the needle. This macromolecular protein assembly is a nanometre-size filament formed by the helical arrangement of hundreds of copies of a single, small protein, which is highly conserved between T3SSs from animal to plant bacterial pathogens. The needle filament forms a hollow tube with a channel ~20 Å in diameter that serves as a conduit for proteins secreted into the targeted host cell. In the past ten years, technical breakthroughs in biophysical techniques such as cryo-electron microscopy (cryo-EM) and solid-state NMR (SSNMR) spectroscopy have uncovered atomic resolution details about the T3SS needle assembly. Several high-resolution structures of Salmonella typhimurium and Shigella flexneri T3SS needles have been reported demonstrating a common structural fold. These structural models have been used to explain the active role of the needle in transmitting the host-cell contact signal from the tip to the base of the T3SS through conformational changes as well as during the injection of effector proteins. In this chapter, we summarize the current knowledge about the structure and the role of the T3SS needle during T3SS assembly and effector secretion.
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Affiliation(s)
- Birgit Habenstein
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France.
| | - Nadia El Mammeri
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France
| | - James Tolchard
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France
| | - Gaëlle Lamon
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France
| | - Arpita Tawani
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France
| | - Mélanie Berbon
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France
| | - Antoine Loquet
- University of Bordeaux, CNRS, UMR 5248, European Institute of Chemistry and Biology, 2 rue Robert Escarpit, Pessac, 33607, France.
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9
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Burdette LA, Leach SA, Wong HT, Tullman-Ercek D. Developing Gram-negative bacteria for the secretion of heterologous proteins. Microb Cell Fact 2018; 17:196. [PMID: 30572895 PMCID: PMC6302416 DOI: 10.1186/s12934-018-1041-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/08/2018] [Indexed: 11/10/2022] Open
Abstract
Gram-negative bacteria are attractive hosts for recombinant protein production because they are fast growing, easy to manipulate, and genetically stable in large cultures. However, the utility of these microbes would expand if they also could secrete the product at commercial scales. Secretion of biotechnologically relevant proteins into the extracellular medium increases product purity from cell culture, decreases downstream processing requirements, and reduces overall cost. Thus, researchers are devoting significant attention to engineering Gram-negative bacteria to secrete recombinant proteins to the extracellular medium. Secretion from these bacteria operates through highly specialized systems, which are able to translocate proteins from the cytosol to the extracellular medium in either one or two steps. Building on past successes, researchers continue to increase the secretion efficiency and titer through these systems in an effort to make them viable for industrial production. Efforts include modifying the secretion tags required for recombinant protein secretion, developing methods to screen or select rapidly for clones with higher titer or efficiency, and improving reliability and robustness of high titer secretion through genetic manipulations. An additional focus is the expression of secretion machineries from pathogenic bacteria in the "workhorse" of biotechnology, Escherichia coli, to reduce handling of pathogenic strains. This review will cover recent advances toward the development of high-expressing, high-secreting Gram-negative production strains.
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Affiliation(s)
- Lisa Ann Burdette
- Department of Chemical and Biomolecular Engineering, University of California-Berkeley, Berkeley, USA
- Present Address: Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208 USA
| | - Samuel Alexander Leach
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, USA
| | - Han Teng Wong
- Department of Plant and Microbial Biology, University of California-Berkeley, Berkeley, USA
- Present Address: Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208 USA
| | - Danielle Tullman-Ercek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, USA
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10
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Wagner S, Grin I, Malmsheimer S, Singh N, Torres-Vargas CE, Westerhausen S. Bacterial type III secretion systems: a complex device for the delivery of bacterial effector proteins into eukaryotic host cells. FEMS Microbiol Lett 2018; 365:5068689. [PMID: 30107569 PMCID: PMC6140923 DOI: 10.1093/femsle/fny201] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/08/2018] [Indexed: 12/21/2022] Open
Abstract
Virulence-associated type III secretion systems (T3SS) serve the injection of bacterial effector proteins into eukaryotic host cells. They are able to secrete a great diversity of substrate proteins in order to modulate host cell function, and have evolved to sense host cell contact and to inject their substrates through a translocon pore in the host cell membrane. T3SS substrates contain an N-terminal signal sequence and often a chaperone-binding domain for cognate T3SS chaperones. These signals guide the substrates to the machine where substrates are unfolded and handed over to the secretion channel formed by the transmembrane domains of the export apparatus components and by the needle filament. Secretion itself is driven by the proton motive force across the bacterial inner membrane. The needle filament measures 20-150 nm in length and is crowned by a needle tip that mediates host-cell sensing. Secretion through T3SS is a highly regulated process with early, intermediate and late substrates. A strict secretion hierarchy is required to build an injectisome capable of reaching, sensing and penetrating the host cell membrane, before host cell-acting effector proteins are deployed. Here, we review the recent progress on elucidating the assembly, structure and function of T3SS injectisomes.
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Affiliation(s)
- Samuel Wagner
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
- German Center for Infection Research (DZIF), partner-site Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Iwan Grin
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Silke Malmsheimer
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Nidhi Singh
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Claudia E Torres-Vargas
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Sibel Westerhausen
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
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Metcalf KJ, Slininger Lee MF, Jakobson CM, Tullman-Ercek D. An estimate is worth about a thousand experiments: using order-of-magnitude estimates to identify cellular engineering targets. Microb Cell Fact 2018; 17:135. [PMID: 30165868 PMCID: PMC6117934 DOI: 10.1186/s12934-018-0979-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/21/2018] [Indexed: 11/10/2022] Open
Abstract
Biotechnological processes use microbes to convert abundant molecules, such as glucose, into high-value products, such as pharmaceuticals, commodity and fine chemicals, and energy. However, from the outset of the development of a new bioprocess, it is difficult to determine the feasibility, expected yields, and targets for engineering. In this review, we describe a methodology that uses rough estimates to assess the feasibility of a process, approximate the expected product titer of a biological system, and identify variables to manipulate in order to achieve the desired performance. This methodology uses estimates from literature and biological intuition, and can be applied in the early stages of a project to help plan future engineering. We highlight recent literature examples, as well as two case studies from our own work, to demonstrate the use and power of rough estimates. Describing and predicting biological function using estimates guides the research and development phase of new bioprocesses and is a useful first step to understand and build a new microbial factory.
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Affiliation(s)
- Kevin James Metcalf
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA. .,Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA.
| | - Marilyn F Slininger Lee
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.,U.S. Army Edgewood Chemical Biological Center, Gunpowder, MD, 21010, USA
| | - Christopher Matthew Jakobson
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.,Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Danielle Tullman-Ercek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
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12
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Xu C, Zhang BZ, Lin Q, Deng J, Yu B, Arya S, Yuen KY, Huang JD. Live attenuated Salmonella typhimurium vaccines delivering SaEsxA and SaEsxB via type III secretion system confer protection against Staphylococcus aureus infection. BMC Infect Dis 2018; 18:195. [PMID: 29699491 PMCID: PMC5921394 DOI: 10.1186/s12879-018-3104-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 04/19/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Staphylococcus aureus (S. aureus) causes a wide range of infectious diseases in human and animals. The emergence of antibiotic-resistant strains demands novel strategies for prophylactic vaccine development. In this study, live attenuated S. enterica subsp. enterica serotype Typhimurium (S. Typhimurium) vaccine against S. aureus infection was developed, in which Salmonella Pathogenesis Island-1 Type 3 Secretion System (SPI-1 T3SS) was employed to deliver SaEsxA and SaEsxB, two of ESAT-6-like (Early Secreted Antigenic Target-6) virulence factors of S. aureus. METHODS Antigens SaEsxA and SaEsxB were fused with the N-terminal secretion and translocation domain of SPI-1 effector SipA. And cytosolic delivery of Staphylococcal antigens into macrophages was examined by western blot. BALB/c mice were orally immunized with S. Typhimurium-SaEsxA and S. Typhimurium-SaEsxB vaccines. Antigen-specific humoral and Th1/Th17 immune responses were examined by ELISA and ELISPOT assays 7-9 days after the 2nd booster. For ELISPOT assays, the statistical significance was determined by Student's t test. The vaccine efficacy was evaluated by lethal challenge with two S. aureus clinical isolates Newman strain and USA 300 strain. Statistical significance was determined by Log rank (Mantel-Cox) analysis. And a P value of < 0.05 was considered statistically significant. RESULTS Oral administration of S. Typhimurium-SaEsxA and S. Typhimurium-SaEsxB vaccines induced antigen-specific humoral and Th1/Th17 immune responses, which increased the survival rate for vaccinated mice when challenged with S. aureus strains. CONCLUSIONS The newly developed S. Typhimurium-based vaccines delivering SaEsxA and SaEsxB by SPI-1 T3SS could confer protection against S. aureus infection. This study provides evidence that translocation of foreign antigens via Salmonella SPI-1 T3SS into the cytosol of antigen presenting cells (APCs) could induce potent immune responses against pathogens.
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Affiliation(s)
- Chen Xu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - Bao-Zhong Zhang
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - Qiubin Lin
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - Jian Deng
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - Bin Yu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - Smriti Arya
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - Kwok-Yung Yuen
- Department of Microbiology, The University of Hong Kong, Hong Kong, SAR, China
| | - Jian-Dong Huang
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, SAR, China. .,HKU-Shenzhen Institute of Research and Innovation, Shenzhen, China. .,Shenzhen Institute of Advanced Technologies, Shenzhen, China.
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13
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Control of type III protein secretion using a minimal genetic system. Nat Commun 2017; 8:14737. [PMID: 28485369 PMCID: PMC5436071 DOI: 10.1038/ncomms14737] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/27/2017] [Indexed: 01/12/2023] Open
Abstract
Gram-negative bacteria secrete proteins using a type III secretion system (T3SS), which functions as a needle-like molecular machine. The many proteins involved in T3SS construction are tightly regulated due to its role in pathogenesis and motility. Here, starting with the 35 kb Salmonella pathogenicity island 1 (SPI-1), we eliminated internal regulation and simplified the genetics by removing or recoding genes, scrambling gene order and replacing all non-coding DNA with synthetic genetic parts. This process results in a 16 kb cluster that shares no sequence identity, regulation or organizational principles with SPI-1. Building this simplified system led to the discovery of essential roles for an internal start site (SpaO) and small RNA (InvR). Further, it can be controlled using synthetic regulatory circuits, including under SPI-1 repressing conditions. This work reveals an incredible post-transcriptional robustness in T3SS assembly and aids its control as a tool in biotechnology.
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14
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Metcalf KJ, Bevington JL, Rosales SL, Burdette LA, Valdivia E, Tullman-Ercek D. Proteins adopt functionally active conformations after type III secretion. Microb Cell Fact 2016; 15:213. [PMID: 28010734 PMCID: PMC5180411 DOI: 10.1186/s12934-016-0606-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/25/2016] [Indexed: 11/17/2022] Open
Abstract
Background Bacterial production of natively folded heterologous proteins by secretion to the extracellular space can improve protein production by simplifying purification and enabling continuous processing. In a typical bacterial protein production process, the protein of interest accumulates in the cytoplasm of the cell, requiring cellular lysis and extensive purification to separate the desired protein from other cellular constituents. The type III secretion system of Gram-negative bacteria is used to secrete proteins from the cytosol to the extracellular space in one step, but proteins must unfold during translocation, necessitating the folding of secreted proteins in the extracellular space for an efficient production process. We evaluated type III secretion as a protein production strategy by characterizing and quantifying the extent of correct folding after secretion. Results We probed correct folding by assaying the function after secretion of two enzymes—beta-lactamase and alkaline phosphatase—and one single-chain variable fragment of an antibody. Secreted proteins are correctly folded and functional after unfolding, secretion, and refolding in the extracellular space. Furthermore, structural and chemical features required for protein function, such as multimerization and disulfide bond formation, are evident in the secreted protein samples. Finally, the concentration of NaCl in the culture media affects the folding efficiency of secreted proteins in a protein-specific manner. Conclusions In the extracellular space, secreted proteins are able to fold to active conformations, which entails post-translational modifications including: folding, multimerization, acquisition of metal ion cofactors, and formation of disulfide bonds. Further, different proteins have different propensities to refold in the extracellular space and are sensitive to the chemical environment in the extracellular space. Our results reveal strategies to control the secretion and correct folding of diverse target proteins during bacterial cell culture. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0606-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kevin James Metcalf
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.,Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - James Lea Bevington
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Sandy Lisette Rosales
- Department of Nutritional Science and Toxicology, University of California, Berkeley, CA, 94720, USA
| | - Lisa Ann Burdette
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.,Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Elias Valdivia
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Danielle Tullman-Ercek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA.
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15
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Diepold A, Armitage JP. Type III secretion systems: the bacterial flagellum and the injectisome. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2015.0020. [PMID: 26370933 DOI: 10.1098/rstb.2015.0020] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The flagellum and the injectisome are two of the most complex and fascinating bacterial nanomachines. At their core, they share a type III secretion system (T3SS), a transmembrane export complex that forms the extracellular appendages, the flagellar filament and the injectisome needle. Recent advances, combining structural biology, cryo-electron tomography, molecular genetics, in vivo imaging, bioinformatics and biophysics, have greatly increased our understanding of the T3SS, especially the structure of its transmembrane and cytosolic components, the transcriptional, post-transcriptional and functional regulation and the remarkable adaptivity of the system. This review aims to integrate these new findings into our current knowledge of the evolution, function, regulation and dynamics of the T3SS, and to highlight commonalities and differences between the two systems, as well as their potential applications.
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Affiliation(s)
- Andreas Diepold
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Judith P Armitage
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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16
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Felgner S, Kocijancic D, Frahm M, Weiss S. Bacteria in Cancer Therapy: Renaissance of an Old Concept. Int J Microbiol 2016; 2016:8451728. [PMID: 27051423 PMCID: PMC4802035 DOI: 10.1155/2016/8451728] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 02/03/2016] [Accepted: 02/11/2016] [Indexed: 01/20/2023] Open
Abstract
The rising incidence of cancer cases worldwide generates an urgent need of novel treatment options. Applying bacteria may represent a valuable therapeutic variant that is intensively investigated nowadays. Interestingly, the idea to apply bacteria wittingly or unwittingly dates back to ancient times and was revived in the 19th century mainly by the pioneer William Coley. This review summarizes and compares the results of the past 150 years in bacteria mediated tumor therapy from preclinical to clinical studies. Lessons we have learned from the past provide a solid foundation on which to base future efforts. In this regard, several perspectives are discussed by which bacteria in addition to their intrinsic antitumor effect can be used as vector systems that shuttle therapeutic compounds into the tumor. Strategic solutions like these provide a sound and more apt exploitation of bacteria that may overcome limitations of conventional therapies.
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Affiliation(s)
- Sebastian Felgner
- Department of Molecular Immunology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Dino Kocijancic
- Department of Molecular Immunology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Michael Frahm
- Department of Molecular Immunology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Siegfried Weiss
- Department of Molecular Immunology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
- Institute of Immunology, Hannover Medical School, 30625 Hannover, Germany
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17
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Zhu X, Bi J, Yu J, Li X, Zhang Y, Zhangsun D, Luo S. Recombinant Expression and Characterization of α-Conotoxin LvIA in Escherichia coli. Mar Drugs 2016; 14:11. [PMID: 26742048 PMCID: PMC4728508 DOI: 10.3390/md14010011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/11/2015] [Accepted: 12/28/2015] [Indexed: 01/17/2023] Open
Abstract
α-Conotoxin LvIA is derived from Conus lividus, native to Hainan, and is the most selective inhibitor of α3β2 nicotinic acetylcholine receptors (nAChRs) known to date. In this study, an efficient approach for the production of recombinant α-Conotoxin LvIA is described. Tandem repeats of a LvIA gene fragment were constructed and fused with a KSI gene and a His6 tag in a Escherichia coli (E. coli) expression vector pET-31b(+). The recombinant plasmids were transformed into E. coli and were found to express well. The KSI-(LvIA)n-His6 fusion protein was purified by metal affinity chromatography and then cleaved with CNBr to release recombinant LvIA (rLvIA). High yields of fusion protein ranging from 100 to 500 mg/L culture were obtained. The pharmacological profile of rLvIA was determined by two-electrode voltage-clamp electrophysiology in Xenopus laevis oocytes expressing rat nAChR subtypes. The rLvIA antagonized the α3β2 nAChR subtype selectively with a nano-molar IC50. The rLvIA was analgesic in a mouse hot-plate test model of pain. Overall, this study provides an effective method to synthesize α-conotoxin LvIA in an E. coli recombinant expression system, and this approach could be useful to obtain active conopeptides in large quantity and at low cost.
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Affiliation(s)
- Xiaopeng Zhu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
- College of Horticulture and Landscapes, Hainan University, Haikou 570228, China.
- College of Marine Science, Hainan University, Haikou 570228, China.
| | - Jianpeng Bi
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Jinpeng Yu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Xiaodan Li
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Yaning Zhang
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
- College of Marine Science, Hainan University, Haikou 570228, China.
| | - Sulan Luo
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
- College of Marine Science, Hainan University, Haikou 570228, China.
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18
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More than a locomotive organelle: flagella in Escherichia coli. Appl Microbiol Biotechnol 2015; 99:8883-90. [DOI: 10.1007/s00253-015-6946-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/17/2015] [Accepted: 08/20/2015] [Indexed: 10/23/2022]
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19
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Lee PC, Rietsch A. Fueling type III secretion. Trends Microbiol 2015; 23:296-300. [PMID: 25701111 DOI: 10.1016/j.tim.2015.01.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/19/2015] [Accepted: 01/27/2015] [Indexed: 10/24/2022]
Abstract
Type III secretion systems (T3SSs) are complex nanomachines that export proteins from the bacterial cytoplasm across the cell envelope in a single step. They are at the core of the machinery used to assemble the bacterial flagellum, and the needle complex many Gram-negative pathogens use to inject effector proteins into host cells and cause disease. Several models have been put forward to explain how this export is energized, and the mechanism has been the subject of considerable debate. Here we present an overview of these models and discuss their relative merits. Recent evidence suggests that the proton motive force (pmf) is the primary energy source for type III secretion, although contribution from refolding of secreted proteins has not been ruled out. The mechanism by which the pmf is converted to protein export remains enigmatic.
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Affiliation(s)
- Pei-Chung Lee
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Arne Rietsch
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106-4960, USA.
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20
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Erhardt M, Mertens ME, Fabiani FD, Hughes KT. ATPase-independent type-III protein secretion in Salmonella enterica. PLoS Genet 2014; 10:e1004800. [PMID: 25393010 PMCID: PMC4230889 DOI: 10.1371/journal.pgen.1004800] [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: 07/06/2014] [Accepted: 10/02/2014] [Indexed: 01/06/2023] Open
Abstract
Type-III protein secretion systems are utilized by gram-negative pathogens to secrete building blocks of the bacterial flagellum, virulence effectors from the cytoplasm into host cells, and structural subunits of the needle complex. The flagellar type-III secretion apparatus utilizes both the energy of the proton motive force and ATP hydrolysis to energize substrate unfolding and translocation. We report formation of functional flagella in the absence of type-III ATPase activity by mutations that increased the proton motive force and flagellar substrate levels. We additionally show that increased proton motive force bypassed the requirement of the Salmonella pathogenicity island 1 virulence-associated type-III ATPase for secretion. Our data support a role for type-III ATPases in enhancing secretion efficiency under limited secretion substrate concentrations and reveal the dispensability of ATPase activity in the type-III protein export process.
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Affiliation(s)
- Marc Erhardt
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
- * E-mail:
| | - Max E. Mertens
- Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
| | - Florian D. Fabiani
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Kelly T. Hughes
- Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
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21
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Using transcriptional control to increase titers of secreted heterologous proteins by the type III secretion system. Appl Environ Microbiol 2014; 80:5927-34. [PMID: 25038096 DOI: 10.1128/aem.01330-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The type III secretion system (T3SS) encoded at the Salmonella pathogenicity island 1 (SPI-1) locus secretes protein directly from the cytosol to the culture media in a concerted, one-step process, bypassing the periplasm. While this approach is attractive for heterologous protein production, product titers are too low for many applications. In addition, the expression of the SPI-1 gene cluster is subject to native regulation, which requires culturing conditions that are not ideal for high-density growth. We used transcriptional control to increase the amount of protein that is secreted into the extracellular space by the T3SS of Salmonella enterica. The controlled expression of the gene encoding SPI-1 transcription factor HilA circumvents the requirement of endogenous induction conditions and allows for synthetic induction of the secretion system. This strategy increases the number of cells that express SPI-1 genes, as measured by promoter activity. In addition, protein secretion titer is sensitive to the time of addition and the concentration of inducer for the protein to be secreted and SPI-1 gene cluster. Overexpression of hilA increases secreted protein titer by >10-fold and enables recovery of up to 28±9 mg/liter of secreted protein from an 8-h culture. We also demonstrate that the protein beta-lactamase is able to adopt an active conformation after secretion, and the increase in secreted titer from hilA overexpression also correlates to increased enzyme activity in the culture supernatant.
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22
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Singer HM, Erhardt M, Hughes KT. Comparative analysis of the secretion capability of early and late flagellar type III secretion substrates. Mol Microbiol 2014; 93:505-20. [PMID: 24946091 DOI: 10.1111/mmi.12675] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2014] [Indexed: 11/28/2022]
Abstract
A remarkable feature of the flagellar-specific type III secretion system (T3SS) is the selective recognition of a few substrate proteins among the many thousand cytoplasmic proteins. Secretion substrates are divided into two specificity classes: early substrates secreted for hook-basal body (HBB) construction and late substrates secreted after HBB completion. Secretion was reported to require a disordered N-terminal secretion signal, mRNA secretion signals within the 5'-untranslated region (5'-UTR) and for late substrates, piloting proteins known as the T3S chaperones. Here, we utilized translational β-lactamase fusions to probe the secretion efficacy of the N-terminal secretion signal of fourteen secreted flagellar substrates in Salmonella enterica. We observed a surprising variety in secretion capability between flagellar proteins of the same secretory class. The peptide secretion signals of the early-type substrates FlgD, FlgF, FlgE and the late-type substrate FlgL were analysed in detail. Analysing the role of the 5'-UTR in secretion of flgB and flgE revealed that the native 5'-UTR substantially enhanced protein translation and secretion. Based on our data, we propose a multicomponent signal that drives secretion via the flagellar T3SS. Both mRNA and peptide signals are recognized by the export apparatus and together with substrate-specific chaperones allowing for targeted secretion of flagellar substrates.
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Affiliation(s)
- Hanna M Singer
- Microbiologie, Département de Médecine, Université de Fribourg, Fribourg, Switzerland
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23
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Abstract
Salmonella enterica serovar Typhimurium is a food-borne pathogen that causes severe gastroenteritis. The ability of Salmonella to cause disease depends on two type III secretion systems (T3SSs) encoded in two distinct Salmonella pathogenicity islands, 1 and 2 (SPI1 and SPI2, respectively). S. Typhimurium encodes a solo LuxR homolog, SdiA, which can detect the acyl-homoserine lactones (AHLs) produced by other bacteria and upregulate the rck operon and the srgE gene. SrgE is predicted to encode a protein of 488 residues with a coiled-coil domain between residues 345 and 382. In silico studies have provided conflicting predictions as to whether SrgE is a T3SS substrate. Therefore, in this work, we tested the hypothesis that SrgE is a T3SS effector by two methods, a β-lactamase activity assay and a split green fluorescent protein (GFP) complementation assay. SrgE with β-lactamase fused to residue 40, 100, 150, or 300 was indeed expressed and translocated into host cells, but SrgE with β-lactamase fused to residue 400 or 488 was not expressed, suggesting interference by the coiled-coil domain. Similarly, SrgE with GFP S11 fused to residue 300, but not to residue 488, was expressed and translocated into host cells. With both systems, translocation into host cells was dependent upon SPI2. A phylogenetic analysis indicated that srgE is found only within Salmonella enterica subspecies. It is found sporadically within both typhoidal and nontyphoidal serovars, although the SrgE protein sequences found within typhoidal serovars tend to cluster separately from those found in nontyphoidal serovars, suggesting functional diversification.
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24
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Analysis of factors that affect FlgM-dependent type III secretion for protein purification with Salmonella enterica serovar Typhimurium. J Bacteriol 2014; 196:2333-47. [PMID: 24706743 DOI: 10.1128/jb.01572-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The FlgM protein is secreted in response to flagellar hook-basal body secretion and can be used as a secretion signal to direct selected protein secretion via the flagellar type III secretion (T3S) system [H. M. Singer, M. Erhardt, A. M. Steiner, M. M. Zhang, D. Yoshikami, G. Bulaj, B. M. Olivera, and K. T. Hughes, mBio 3(3):e00115-12, 2012, http://dx.doi.org/10.1128/mBio.00115-12]. Conditions known to affect flagellar gene expression, FlgM stability, and flagellar T3S were tested either alone or in combination to determine their effects on levels of secreted FlgM. These conditions included mutations that affect activity of the flagellar FlhD4C2 master regulatory protein complex or the FlgM T3S chaperone σ(28), the removal of Salmonella pathogenicity island 1 (Spi1), the removal of flagellar late secretion substrates that could compete with FlgM for secretion, and changes in the ionic strength of the growth medium. Conditions that enhanced FlgM secretion were combined in order to maximize levels of secreted FlgM. An optimized FlgM secretion strain was used to secrete and isolate otherwise difficult-to-produce proteins and peptides fused to the C terminus of FlgM. These include cysteine-rich, hydrophobic peptides (conotoxins δ-SVIE and MrVIA), nodule-specific, cysteine-rich antimicrobial peptides (NCR), and a malaria surface antigen domain of apical membrane antigen AMA-1.
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25
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Sermadiras I, Revell J, Linley JE, Sandercock A, Ravn P. Recombinant expression and in vitro characterisation of active Huwentoxin-IV. PLoS One 2013; 8:e83202. [PMID: 24324842 PMCID: PMC3855799 DOI: 10.1371/journal.pone.0083202] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/31/2013] [Indexed: 02/06/2023] Open
Abstract
Huwentoxin-IV (HwTx-IV) is a 35-residue neurotoxin peptide with potential application as a novel analgesic. It is a member of the inhibitory cystine knot (ICK) peptide family, characterised by a compact globular structure maintained by three intramolecular disulfide bonds. Here we describe a novel strategy for producing non-tagged, fully folded ICK-toxin in a bacterial system. HwTx-IV was expressed as a cleavable fusion to small ubiquitin-related modifier (SUMO) in the cytoplasm of the SHuffle T7 Express lysY Escherichia coli strain, which allows cytosolic disulfide bond formation. Purification by IMAC with selective elution of monomeric SUMO fusion followed by proteolytic cleavage and polishing chromatographic steps yielded pure homogeneous toxin. Recombinant HwTx-IV is produced with a C-terminal acid, whereas the native peptide is C-terminally amidated. HwTx-IV(acid) inhibited Nav1.7 in a dose dependent manner (IC50 = 463-727 nM). In comparison to HwTx-IV(amide) (IC50 = 11 ± 3 nM), the carboxylate was ~50 fold less potent on Nav1.7, which highlights the impact of the C-terminus. As the amide bond of an additional amino acid may mimic the carboxamide, we expressed the glycine-extended analogue HwTx-IV(G36)(acid) in the SUMO/SHuffle system. The peptide was approximately three fold more potent on Nav1.7 in comparison to HwTx-IV(acid) (IC50 = 190 nM). In conclusion, we have established a novel system for expression and purification of fully folded and active HwTx-IV(acid) in bacteria, which could be applicable to other structurally complex and cysteine rich peptides. Furthermore, we discovered that glycine extension of HwTx-IV(acid) restores some of the potency of the native carboxamide. This finding may also apply to other C-terminally amidated peptides produced recombinantly.
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Affiliation(s)
- Isabelle Sermadiras
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
- * E-mail:
| | - Jefferson Revell
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
| | - John E. Linley
- Neuroscience in vitro Biology, Research, MedImmune, Cambridge, United Kingdom
| | - Alan Sandercock
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
| | - Peter Ravn
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
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Heel T, Vogel GF, Lammirato A, Schneider R, Auer B. FlgM as a secretion moiety for the development of an inducible type III secretion system. PLoS One 2013; 8:e59034. [PMID: 23554966 PMCID: PMC3595227 DOI: 10.1371/journal.pone.0059034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 02/11/2013] [Indexed: 11/18/2022] Open
Abstract
Regulation and assembly of the flagellar type III secretion system is one of the most investigated and best understood regulational cascades in molecular biology. Depending on the host organism, flagellar morphogenesis requires the interplay of more than 50 genes. Direct secretion of heterologous proteins to the supernatant is appealing due to protection against cellular proteases and simplified downstream processing. As Escherichia coli currently remains the predominant host organism used for recombinant prokaryotic protein expression, the generation of a strain that exhibits inducible flagellar secretion would be highly desirable for biotechnological applications. Here, we report the first engineered Escherichia coli mutant strain featuring flagellar morphogenesis upon addition of an external inducer. Using FlgM as a sensor for direct secretion in combination with this novel strain may represent a potent tool for significant improvements in future engineering of an inducible type III secretion for heterologous proteins.
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Affiliation(s)
- Thomas Heel
- Institute of Biochemistry, University of Innsbruck, Innsbruck, Austria.
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More than motility: Salmonella flagella contribute to overriding friction and facilitating colony hydration during swarming. J Bacteriol 2012; 195:919-29. [PMID: 23264575 DOI: 10.1128/jb.02064-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We show in this study that Salmonella cells, which do not upregulate flagellar gene expression during swarming, also do not increase flagellar numbers per μm of cell length as determined by systematic counting of both flagellar filaments and hooks. Instead, doubling of the average length of a swarmer cell by suppression of cell division effectively doubles the number of flagella per cell. The highest agar concentration at which Salmonella cells swarmed increased from the normal 0.5% to 1%, either when flagella were overproduced or when expression of the FliL protein was enhanced in conjunction with stator proteins MotAB. We surmise that bacteria use the resulting increase in motor power to overcome the higher friction associated with harder agar. Higher flagellar numbers also suppress the swarming defect of mutants with changes in the chemotaxis pathway that were previously shown to be defective in hydrating their colonies. Here we show that the swarming defect of these mutants can also be suppressed by application of osmolytes to the surface of swarm agar. The "dry" colony morphology displayed by che mutants was also observed with other mutants that do not actively rotate their flagella. The flagellum/motor thus participates in two functions critical for swarming, enabling hydration and overriding surface friction. We consider some ideas for how the flagellum might help attract water to the agar surface, where there is no free water.
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de Marco A. Recent contributions in the field of the recombinant expression of disulfide bonded proteins in bacteria. Microb Cell Fact 2012; 11:129. [PMID: 22978724 PMCID: PMC3462667 DOI: 10.1186/1475-2859-11-129] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 09/13/2012] [Indexed: 12/03/2022] Open
Abstract
The production of heterologous disulfide bonded proteins in bacteria remains a biotechnological challenge. A rapid literature survey results in the identification of some interesting proposals, such as the option of producing functional proteins in the cytoplasm in the presence of sulfhydryl oxidases and isomerases. Furthermore, an ever-increasing number of applications refers to recombinant proteins displayed at the bacterial surface. Time will tell whether these developments will lead to universally accepted laboratory protocols.
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