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The ESX-1 Substrate PPE68 Has a Key Function in ESX-1-Mediated Secretion in Mycobacterium marinum. mBio 2022; 13:e0281922. [PMID: 36409073 PMCID: PMC9765416 DOI: 10.1128/mbio.02819-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Mycobacteria use specialized type VII secretion systems (T7SSs) to secrete proteins across their diderm cell envelope. One of the T7SS subtypes, named ESX-1, is a major virulence determinant in pathogenic species such as Mycobacterium tuberculosis and the fish pathogen Mycobacterium marinum. ESX-1 secretes a variety of substrates, called Esx, PE, PPE, and Esp proteins, at least some of which are folded heterodimers. Investigation into the functions of these substrates is problematic, because of the intricate network of codependent secretion between several ESX-1 substrates. Here, we describe the ESX-1 substrate PPE68 as essential for secretion of the highly immunogenic substrates EsxA and EspE via the ESX-1 system in M. marinum. While secreted PPE68 is processed on the cell surface, the majority of cell-associated PPE68 of M. marinum and M. tuberculosis is present in a cytosolic complex with its PE partner and the EspG1 chaperone. Interfering with the binding of EspG1 to PPE68 blocked its export and the secretion of EsxA and EspE. In contrast, esxA was not required for the secretion of PPE68, revealing a hierarchy in codependent secretion. Remarkably, the final 10 residues of PPE68, a negatively charged domain, seem essential for EspE secretion, but not for the secretion of EsxA and of PPE68 itself. This indicates that distinctive domains of PPE68 are involved in secretion of the different ESX-1 substrates. Based on these findings, we propose a mechanistic model for the central role of PPE68 in ESX-1-mediated secretion and substrate codependence. IMPORTANCE Pathogenic mycobacteria, such Mycobacterium tuberculosis and Mycobacterium marinum, use a type VII secretion system (T7SS) subtype, called ESX-1, to mediate intracellular survival via phagosomal rupture and subsequent translocation of the mycobacterium to the host cytosol. Identifying the ESX-1 substrate that is responsible for this process is problematic because of the intricate network of codependent secretion between ESX-1 substrates. Here, we show the central role of the ESX-1 substrate PPE68 for the secretion of ESX-1 substrates in Mycobacterium marinum. Unravelling the mechanism of codependent secretion will aid the functional understanding of T7SSs and will allow the analysis of the individual roles of ESX-1 substrates in the virulence caused by the significant human pathogen Mycobacterium tuberculosis.
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Kowalewicz-Kulbat M, Locht C. Recombinant BCG to Enhance Its Immunomodulatory Activities. Vaccines (Basel) 2022; 10:827. [PMID: 35632582 PMCID: PMC9143156 DOI: 10.3390/vaccines10050827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 05/10/2022] [Accepted: 05/16/2022] [Indexed: 11/17/2022] Open
Abstract
The bacillus Calmette-Guérin (BCG) is an attenuated Mycobacterium bovis derivative that has been widely used as a live vaccine against tuberculosis for a century. In addition to its use as a tuberculosis vaccine, BCG has also been found to have utility in the prevention or treatment of unrelated diseases, including cancer. However, the protective and therapeutic efficacy of BCG against tuberculosis and other diseases is not perfect. For three decades, it has been possible to genetically modify BCG in an attempt to improve its efficacy. Various immune-modulatory molecules have been produced in recombinant BCG strains and tested for protection against tuberculosis or treatment of several cancers or inflammatory diseases. These molecules include cytokines, bacterial toxins or toxin fragments, as well as other protein and non-protein immune-modulatory molecules. The deletion of genes responsible for the immune-suppressive properties of BCG has also been explored for their effect on BCG-induced innate and adaptive immune responses. Most studies limited their investigations to the description of T cell immune responses that were modified by the genetic modifications of BCG. Some studies also reported improved protection by recombinant BCG against tuberculosis or enhanced therapeutic efficacy against various cancer forms or allergies. However, so far, these investigations have been limited to mouse models, and the prophylactic or therapeutic potential of recombinant BCG strains has not yet been illustrated in other species, including humans, with the exception of a genetically modified BCG strain that is now in late-stage clinical development as a vaccine against tuberculosis. In this review, we provide an overview of the different molecular engineering strategies adopted over the last three decades in order to enhance the immune-modulatory potential of BCG.
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Affiliation(s)
- Magdalena Kowalewicz-Kulbat
- Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237 Lodz, Poland;
| | - Camille Locht
- Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237 Lodz, Poland;
- CHU Lille, Institut Pasteur de Lille, U1019–UMR9017–CIIL–Center for Infection and Immunity of Lille, University Lille, CNRS, Inserm, F-59000 Lille, France
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Burggraaf MJ, Ates LS, Speer A, van der Kuij K, Kuijl C, Bitter W. Optimization of secretion and surface localization of heterologous OVA protein in mycobacteria by using LipY as a carrier. Microb Cell Fact 2019; 18:44. [PMID: 30841891 PMCID: PMC6402100 DOI: 10.1186/s12934-019-1093-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/25/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mycobacterium bovis Bacille Calmette-Guérin (BCG) is not only used as a vaccine against tuberculosis but also protects against leprosy and is used as part of bladder cancer treatment to induce a protective immune response. However, protection by BCG vaccination is not optimal. To improve vaccine efficacy, recombinant BCG expressing heterologous antigens has been put forward to elicit antigen-specific cellular and humoral responses. Cell surface localized or secreted antigens induce better immune responses than their cytosolic counterparts. Optimizing secretion of heterologous proteins or protein fragments holds therefore unexplored potential for improving the efficacy of recombinant BCG vaccine candidates. Secretion of heterologous antigens requires crossing the mycobacterial inner and outer membrane. Mycobacteria have specialized ESX or type VII secretion systems that enable translocation of proteins across both membranes. Probing this secretion system could therefore be a valid approach to surface localize heterologous antigens. RESULTS We show that ESX-5 substrate LipY, a lipase, can be used as a carrier for heterologous secretion of an ovalbumin fragment (OVA). LipY contains a PE domain and a lipase domain, separated by a linker region. This linker domain is processed upon secretion. Fusion of the PE and linker domains of LipY to OVA enabled ESX-5-dependent secretion of the fusion construct LipY-OVA in M. marinum, albeit with low efficiency. Subsequent random mutagenesis of LipY-OVA and screening for increased secretion resulted in mutants with improved heterologous secretion. Detailed analysis identified two mutations in OVA that improved secretion, i.e. an L280P mutation and a protein-extending frameshift mutation. Finally, deletion of the linker domain of LipY enhanced secretion of LipY-OVA, although this mutation also reduced surface association. Further analysis in wild type LipY showed that the linker domain is required for surface association. CONCLUSION We show that the ESX-5 system can be used for heterologous secretion. Furthermore, minor mutations in the substrate can enhance secretion. Especially the C-terminal region seems to be important for this. The linker domain of LipY is involved in surface association. These findings show that non-biased screening approaches aid in optimization of heterologous secretion, which can contribute to heterologous vaccine development.
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Affiliation(s)
- Maroeska J Burggraaf
- Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands
| | - Louis S Ates
- Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands.,Department of Experimental Immunology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, Netherlands
| | - Alexander Speer
- Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands
| | - Kim van der Kuij
- Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands
| | - Coen Kuijl
- Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands
| | - Wilbert Bitter
- Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, Netherlands. .,Molecular Microbiology, Vrije Universiteit Amsterdam, de Boelelaan 1105, Amsterdam, Netherlands.
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4
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Carrère-Kremer S, Blaise M, Singh VK, Alibaud L, Tuaillon E, Halloum I, van de Weerd R, Guérardel Y, Drancourt M, Takiff H, Geurtsen J, Kremer L. A new dehydratase conferring innate resistance to thiacetazone and intra-amoebal survival of Mycobacterium smegmatis. Mol Microbiol 2015; 96:1085-102. [PMID: 25754266 DOI: 10.1111/mmi.12992] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2015] [Indexed: 12/12/2022]
Abstract
Nontuberculous mycobacteria are innately resistant to most antibiotics, although the mechanisms responsible for their drug resistance remain poorly understood. They are particularly refractory to thiacetazone (TAC), a second-line antitubercular drug. Herein, we identified MSMEG_6754 as essential for the innate resistance of Mycobacterium smegmatis to TAC. Transposon-mediated and targeted disruption of MSMEG_6754 resulted in hypersusceptibility to TAC. Conversely, introduction of MSMEG_6754 into Mycobacterium tuberculosis increased resistance 100-fold. Resolution of the crystal structure of MSMEG_6754 revealed a homodimer in which each monomer comprises two hot-dog domains characteristic of dehydratase-like proteins and very similar to the HadAB complex involved in mycolic acid biosynthesis. Gene inactivation of the essential hadB dehydratase could be achieved in M. smegmatis and M. tuberculosis only when the strains carried an integrated copy of MSMEG_6754, supporting the idea that MSMEG_6754 and HadB share redundant dehydratase activity. Using M. smegmatis-Acanthamoeba co-cultures, we found that intra-amoebal growth of the MSMEG_6754 deleted strain was significantly reduced compared with the parental strain. This in vivo growth defect was fully restored upon complementation with catalytically active MSMEG_6754 or HadABC, indicating that MSMEG_6754 plays a critical role in the survival of M. smegmatis within the environmental host.
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Affiliation(s)
- Séverine Carrère-Kremer
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR 5235, Université de Montpellier, case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.,INSERM U1058, Université de Montpellier and Department of Bacteriology-Virology, CHU de Montpellier, Montpellier, 34095, France
| | - Mickael Blaise
- CARB Centre, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
| | - Vipul K Singh
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR 5235, Université de Montpellier, case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Laeticia Alibaud
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR 5235, Université de Montpellier, case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Edouard Tuaillon
- INSERM U1058, Université de Montpellier and Department of Bacteriology-Virology, CHU de Montpellier, Montpellier, 34095, France
| | - Iman Halloum
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR 5235, Université de Montpellier, case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Robert van de Weerd
- Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, 1081 BT, The Netherlands
| | - Yann Guérardel
- Unité de Glycobiologie Structurale et Fonctionnelle, CNRS UMR 8576, IFR 147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq cedex, France
| | - Michel Drancourt
- URMITE, UMR63, CNRS 7278, IRD 198, INSERM 1095, Université Aix-Marseille, Marseille, France
| | - Howard Takiff
- Laboratorio de Genética Molecular, CMBC, IVIC, Caracas, 1020A, Venezuela
| | - Jeroen Geurtsen
- Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, 1081 BT, The Netherlands
| | - Laurent Kremer
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR 5235, Université de Montpellier, case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.,INSERM, DIMNP, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
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Oh IG, Jawale C, Lee J. The B subunits of cholera and Escherichia coli heat-labile toxins enhance the immune responses in mice orally immunised with a recombinant live P-fimbrial vaccine for avian pathogenic E. coli. Acta Vet Hung 2014; 62:293-303. [PMID: 24659715 DOI: 10.1556/avet.2014.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study aimed to investigate the adjuvant effect of recombinant attenuated Salmonella expressing cholera toxin B subunit (CTB) and Escherichia coli heat-labile enterotoxin B subunit (LTB) for the P-fimbriae subunit-based vaccine of avian pathogenic E. coli (APEC) in a murine model. The PapA-specific sIgA and IgG responses were significantly enhanced after immunisation with the Salmonella-PapA vaccine in the presence of CTB or LTB. The group immunised with the Salmonella-LTB strain promoted Th1-type immunity, whereas that immunised with the Salmonella-CTB strain produced Th2-type immunity. We concluded that both Salmonella-CTB and -LTB strains can enhance the immune response to PapA, and that the LTB strain may be a more effective adjuvant for APEC vaccination, which requires higher Th1-type immunity for protection. Thus, our findings provide evidence that immunisation with an adjuvant, LTB, is one of the strategies of developing effective vaccines against P-fimbriated APEC.
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Affiliation(s)
- In-Gyeong Oh
- 1 Chonbuk National University College of Veterinary Medicine and Bio-Safety Research Institute 561-756 Jeonju South Korea
| | - Chetan Jawale
- 1 Chonbuk National University College of Veterinary Medicine and Bio-Safety Research Institute 561-756 Jeonju South Korea
| | - John Lee
- 1 Chonbuk National University College of Veterinary Medicine and Bio-Safety Research Institute 561-756 Jeonju South Korea
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6
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Protective immunity induced by a recombinant BCG vaccine encoding the cyclophilin gene of Toxoplasma gondii. Vaccine 2013; 31:6065-71. [DOI: 10.1016/j.vaccine.2013.10.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 09/14/2013] [Accepted: 10/03/2013] [Indexed: 01/18/2023]
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7
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Chaudhari AA, Lee JH. Evaluation of the adjuvant effect of Salmonella-based Escherichia coli heat-labile toxin B subunits on the efficacy of a live Salmonella-delivered avian pathogenic Escherichia coli vaccine. Avian Pathol 2013; 42:365-72. [PMID: 23815619 DOI: 10.1080/03079457.2013.811466] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The present study evaluated the adjuvant effect of live attenuated salmonella organisms expressing the heat-labile toxin of Escherichia coli B subunit (LTB) on the efficacy of an avian pathogenic Escherichia coli (APEC) vaccine. The Asd(+) (aspartate semialdehyde dehydrogenase) plasmid pMMP906 containing the LTB gene was introduced into a Salmonella enterica Typhimurium strain lacking the lon, cpxR and asd genes to generate the adjuvant strain. Live recombinant Salmonella-delivered APEC vaccine candidates were used for this study. The birds were divided into three groups: group A, non-vaccinated controls; group B, immunized with vaccine candidates only; and group C, immunized with vaccine candidates and the LTB strain. The immune responses were measured and the birds were challenged at 21 days of age with a virulent APEC strain. Group C showed a significant increase in plasma IgG and intestinal IgA levels and a significantly higher lymphocyte proliferation response compared with the other groups. Upon challenge with the virulent APEC strain, group C showed effective protection whereas group B did not. We also attempted to optimize the effective dose of the adjuvant. The birds were immunized with the vaccine candidates together with 1×10⁷ or 1×10⁸ colony-forming units of the LTB strain and were subsequently challenged at 3 weeks of age. The 1×10⁷ colony-forming units of the LTB strain showed a greater adjuvant effect with increased levels of serum IgG, intestinal IgA and a potent lymphocyte proliferation response, and yielded higher protection against challenge. Overall, the LTB strain increased the efficacy of the Salmonella -delivered APEC vaccine, indicating that vaccination for APEC along with the LTB strain appears to increase the efficacy for protection against colibacillosis in broiler chickens.
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Affiliation(s)
- Atul A Chaudhari
- College of Veterinary Medicine, Chonbuk National University, Jeonju, Republic of Korea
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8
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Protection by a recombinant Mycobacterium bovis Bacillus Calmette-Guerin vaccine expressing Shiga toxin 2 B subunit against Shiga toxin-producing Escherichia coli in mice. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1932-7. [PMID: 23035176 DOI: 10.1128/cvi.00473-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have developed a novel vaccine against Shiga toxin (Stx)-producing Escherichia coli (STEC) infection using a recombinant Mycobacterium bovis BCG (rBCG) system. Two intraperitoneal vaccinations with rBCG expressing the Stx2 B subunit (Stx2B) resulted in an increase of protective serum IgG and mucosal IgA responses to Stx2B in BALB/c mice. When orally challenged with 10(3) CFU of STEC strain B2F1 (O91: H21), the immunized mice survived statistically significantly longer than the nonvaccinated mice. We suggest that intraperitoneal immunization with rBCG expressing Stx2B would be a potential vaccine strategy for STEC.
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9
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Daleke MH, van der Woude AD, Parret AHA, Ummels R, de Groot AM, Watson D, Piersma SR, Jiménez CR, Luirink J, Bitter W, Houben ENG. Specific chaperones for the type VII protein secretion pathway. J Biol Chem 2012; 287:31939-47. [PMID: 22843727 DOI: 10.1074/jbc.m112.397596] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mycobacteria use the dedicated type VII protein secretion systems ESX-1 and ESX-5 to secrete virulence factors across their highly hydrophobic cell envelope. The substrates of these systems include the large mycobacterial PE and PPE protein families, which are named after their characteristic Pro-Glu and Pro-Pro-Glu motifs. Pathogenic mycobacteria secrete large numbers of PE/PPE proteins via the major export pathway, ESX-5. In addition, a few PE/PPE proteins have been shown to be exported by ESX-1. It is not known how ESX-1 and ESX-5 recognize their cognate PE/PPE substrates. In this work, we investigated the function of the cytosolic protein EspG(5), which is essential for ESX-5-mediated secretion in Mycobacterium marinum, but for which the role in secretion is not known. By performing protein co-purifications, we show that EspG(5) interacts with several PPE proteins and a PE/PPE complex that is secreted by ESX-5, but not with the unrelated ESX-5 substrate EsxN or with PE/PPE proteins secreted by ESX-1. Conversely, the ESX-1 paralogue EspG(1) interacted with a PE/PPE couple secreted by ESX-1, but not with PE/PPE substrates of ESX-5. Furthermore, structural analysis of the complex formed by EspG(5) and PE/PPE indicates that these proteins interact in a 1:1:1 ratio. In conclusion, our study shows that EspG(5) and EspG(1) interact specifically with PE/PPE proteins that are secreted via their own ESX systems and suggests that EspG proteins are specific chaperones for the type VII pathway.
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Affiliation(s)
- Maria H Daleke
- Department of Medical Microbiology and Infection Control, VU University Medical Center, 1081 BT Amsterdam, The Netherlands
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10
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van der Woude AD, Sarkar D, Bhatt A, Sparrius M, Raadsen SA, Boon L, Geurtsen J, van der Sar AM, Luirink J, Houben ENG, Besra GS, Bitter W. Unexpected link between lipooligosaccharide biosynthesis and surface protein release in Mycobacterium marinum. J Biol Chem 2012; 287:20417-29. [PMID: 22505711 DOI: 10.1074/jbc.m111.336461] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mycobacterial cell envelope is characterized by the presence of a highly impermeable second membrane, which is composed of mycolic acids intercalated with different unusual free lipids, such as lipooligosaccharides (LOS). Transport across this cell envelope requires a dedicated secretion system for extracellular proteins, such as PE_PGRS proteins, which are specific mycobacterial proteins with polymorphic GC-rich sequence (PGRS). In this study, we set out to identify novel components involved in the secretion of PE_PGRS proteins by screening Mycobacterium marinum transposon mutants for secretion defects. Interestingly, most mutants were not affected in secretion but in the release of PE_PGRS proteins from the cell surface. These mutants had insertions in a gene cluster associated with LOS biosynthesis. Lipid analysis of these mutants revealed a role at different stages of LOS biosynthesis for 10 novel genes. Furthermore, we show that regulatory protein WhiB4 is involved in LOS biosynthesis. The absence of the most extended LOS molecule, i.e. LOS-IV, and a concomitant accumulation of LOS-III was already sufficient to reduce the release of PE_PGRS proteins from the mycobacterial cell surface. A similar effect was observed for major surface protein EspE. These results show that the attachment of surface proteins is strongly influenced by the glycolipid composition of the mycobacterial cell envelope. Finally, we tested the virulence of a LOS-IV-deficient mutant in our zebrafish embryo infection model. This mutant showed a marked increase in virulence as compared with the wild-type strain, suggesting that LOS-IV plays a role in the modulation of mycobacterial virulence.
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Affiliation(s)
- Aniek D van der Woude
- Department of Medical Microbiology and Infection Control, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
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Functional dissection of the PE domain responsible for translocation of PE_PGRS33 across the mycobacterial cell wall. PLoS One 2011; 6:e27713. [PMID: 22110736 PMCID: PMC3218021 DOI: 10.1371/journal.pone.0027713] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 10/23/2011] [Indexed: 01/13/2023] Open
Abstract
PE are peculiar exported mycobacterial proteins over-represented in pathogenic mycobacterial species. They are characterized by an N-terminal domain of about 110 amino acids (PE domain) which has been demonstrated to be responsible for their export and localization. In this paper, we characterize the PE domain of PE_PGRS33 (PERv1818c), one of the best characterized PE proteins. We constructed several mutated proteins in which portions of the PE domain were deleted or subjected to defined mutations. These proteins were expressed in different mycobacterial species and their localization was characterized. We confirmed that the PE domain is essential for PE_PGRS33 surface localization, and demonstrated that a PE domain lacking its first 30 amino acids loses its function. However, single amino acid substitutions in two regions extremely well conserved within the N-terminal domain of all PE proteins had some effect on the stability of PE_PGRS33, but not on its localization. Using Mycobacterium marinum we could show that the type VII secretion system ESX-5 is essential for PE_PGRS33 export. Moreover, in M. marinum, but not in Mycobacterium bovis BCG and in Mycobacterium tuberculosis, the PE domain of PE_PGRS33 is processed and secreted into the culture medium when expressed in the absence of the PGRS domain. Finally, using chimeric proteins in which different portions of the PERv1818c domain were fused to the N-terminus of the green fluorescent protein, we could hypothesize that the first 30 amino acids of the PE domain contain a sequence that allows protein translocation.
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Daleke MH, Cascioferro A, de Punder K, Ummels R, Abdallah AM, van der Wel N, Peters PJ, Luirink J, Manganelli R, Bitter W. Conserved Pro-Glu (PE) and Pro-Pro-Glu (PPE) protein domains target LipY lipases of pathogenic mycobacteria to the cell surface via the ESX-5 pathway. J Biol Chem 2011; 286:19024-34. [PMID: 21471225 DOI: 10.1074/jbc.m110.204966] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The type VII secretion system ESX-5 is a major pathway for export of PE and PPE proteins in pathogenic mycobacteria. These mycobacteria-specific protein families are characterized by conserved N-terminal domains of 100 and 180 amino acids, which contain the proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) motifs after which they are named. Here we investigated secretion of the triacylglycerol lipase LipY, which in fast-growing mycobacteria contains a signal sequence, but in slow-growing species appears to have replaced the signal peptide with a PE or PPE domain. Selected LipY homologues were expressed in wild-type Mycobacterium marinum and its corresponding ESX-5 mutant, and localization of the proteins was investigated by immunoblotting and electron microscopy. Our study shows that Mycobacterium tuberculosis PE-LipY (LipY(tub)) and M. marinum PPE-LipY (LipY(mar)) are both secreted to the bacterial surface in an ESX-5-dependent fashion. After transport, the PE/PPE domains are removed by proteolytic cleavage. In contrast, Mycobacterium gilvum LipY, which has a signal sequence, is not transported to the cell surface. Furthermore, we show that LipY(tub) and LipY(mar) require their respective PE and PPE domains for ESX-5-dependent secretion. The role of the PE domain in ESX-5 secretion was confirmed in a whole cell lipase assay, in which wild-type bacteria expressing full-length LipY(tub), but not LipY(tub) lacking its PE domain, were shown to hydrolyze extracellular lipids. In conclusion, both PE and PPE domains contain a signal required for secretion of LipY by the ESX-5 system, and these domains are proteolytically removed upon translocation.
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Affiliation(s)
- Maria H Daleke
- Department of Medical Microbiology and Infection Control, VU University Medical Centre, 1081 BT Amsterdam, The Netherlands
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Stoop EJM, Schipper T, Rosendahl Huber SK, Nezhinsky AE, Verbeek FJ, Gurcha SS, Besra GS, Vandenbroucke-Grauls CMJE, Bitter W, van der Sar AM. Zebrafish embryo screen for mycobacterial genes involved in the initiation of granuloma formation reveals a newly identified ESX-1 component. Dis Model Mech 2011; 4:526-36. [PMID: 21372049 PMCID: PMC3124061 DOI: 10.1242/dmm.006676] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The hallmark of tuberculosis (TB) is the formation of granulomas, which are clusters of infected macrophages surrounded by additional macrophages, neutrophils and lymphocytes. Although it has long been thought that granulomas are beneficial for the host, there is evidence that mycobacteria also promote the formation of these structures. In this study, we aimed to identify new mycobacterial factors involved in the initial stages of granuloma formation. We exploited the zebrafish embryo Mycobacterium marinum infection model to study initiation of granuloma formation and developed an in vivo screen to select for random M. marinum mutants that were unable to induce granuloma formation efficiently. Upon screening 200 mutants, three mutants repeatedly initiated reduced granuloma formation. One of the mutants was found to be defective in the espL gene, which is located in the ESX-1 cluster. The ESX-1 cluster is disrupted in the Mycobacterium bovis BCG vaccine strain and encodes a specialized secretion system known to be important for granuloma formation and virulence. Although espL has not been implicated in protein secretion before, we observed a strong effect on the secretion of the ESX-1 substrates ESAT-6 and EspE. We conclude that our zebrafish embryo M. marinum screen is a useful tool to identify mycobacterial genes involved in the initial stages of granuloma formation and that we have identified a new component of the ESX-1 secretion system. We are confident that our approach will contribute to the knowledge of mycobacterial virulence and could be helpful for the development of new TB vaccines.
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Affiliation(s)
- Esther J M Stoop
- Department of Medical Microbiology and Infection Control, VU University Medical Center, van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
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14
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Abstract
Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases.
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15
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Recombinant Mycobacterium bovis BCG. Vaccine 2009; 27:6495-503. [PMID: 19720367 DOI: 10.1016/j.vaccine.2009.08.044] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 08/11/2009] [Accepted: 08/12/2009] [Indexed: 12/14/2022]
Abstract
The Bacillus Calmette-Guerin (BCG) is an attenuated strain of Mycobacterium bovis that has been broadly used as a vaccine against human tuberculosis. This live bacterial vaccine is able to establish a persistent infection and induces both cellular and humoral immune responses. The development of mycobacterial genetic systems to express foreign antigens and the adjuvanticity of BCG are the basis of the potential use of this attenuated mycobacterium as a recombinant vaccine. Over the years, a range of strategies has been developed to allow controlled and stable expression of viral, bacterial and parasite antigens in BCG. Herein, we review the strategies developed to express heterologous antigens in BCG and the immune response elicited by recombinant BCG constructs. In addition, the use of recombinant BCG as an immunomodulator and future perspectives of BCG as a recombinant vaccine vector are discussed.
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16
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Role of phosphatidylinositol mannosides in the interaction between mycobacteria and DC-SIGN. Infect Immun 2009; 77:4538-47. [PMID: 19651855 DOI: 10.1128/iai.01256-08] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The C-type lectin dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) is the major receptor on DCs for mycobacteria of the Mycobacterium tuberculosis complex. Recently, we have shown that although the mannose caps of the mycobacterial surface glycolipid lipoarabinomannan (ManLAM) are essential for the binding to DC-SIGN, genetic removal of these caps did not diminish the interaction of whole mycobacteria with DC-SIGN and DCs. Here we investigated the role of the structurally related glycolipids phosphatidylinositol mannosides (PIMs) as possible ligands for DC-SIGN. In a binding assay with both synthetic and natural PIMs, DC-SIGN exhibited a high affinity for hexamannosylated PIM(6), which contains terminal alpha(1-->2)-linked mannosyl residues identical to the mannose cap on ManLAM, but not for di- and tetramannosylated PIM(2) and PIM(4), respectively. To determine the role of PIM(6) in the binding of whole mycobacteria to DC-SIGN, a mutant strain of M. bovis bacillus Calmette-Guérin deficient in the production of PIM(6) (Delta pimE) was created, as well as a double knockout deficient in the production of both PIM(6) and the mannose caps on LAM (Delta pimE Delta capA). Compared to the wild-type strain, both mutant strains bound similarly well to DC-SIGN and DCs. Furthermore, the wild-type and mutant strains induced comparable levels of interleukin-10 and interleukin-12p40 when used to stimulate DCs. Hence, we conclude that, like ManLAM, PIM(6) represents a bona fide DC-SIGN ligand but that other, as-yet-unknown, ligands dominate in the interaction between mycobacteria and DCs.
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17
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Abdallah AM, Verboom T, Weerdenburg EM, Gey van Pittius NC, Mahasha PW, Jiménez C, Parra M, Cadieux N, Brennan MJ, Appelmelk BJ, Bitter W. PPE and PE_PGRS proteins ofMycobacterium marinumare transported via the type VII secretion system ESX-5. Mol Microbiol 2009; 73:329-40. [DOI: 10.1111/j.1365-2958.2009.06783.x] [Citation(s) in RCA: 216] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Ou-Yang HF, Hu XB, Ti XY, Shi JR, Li SJ, Qi HW, Wu CG. Suppression of allergic airway inflammation in a mouse model by Der p2 recombined BCG. Immunology 2008; 128:e343-52. [PMID: 19191902 DOI: 10.1111/j.1365-2567.2008.02970.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Allergic asthma is a chronic inflammatory disease mediated by T helper (Th)2 cell immune responses. Currently, immunotherapies based on both immune deviation and immune suppression, including the development of recombinant mycobacteria as immunoregulatory vaccines, are attractive treatment strategies for asthma. In our previous studies, we created a genetically recombinant form of bacille Calmette-Guerin (rBCG) that expressed Der p2 of house dust mites and established that it induced a shift from a Th2 response to a Th1 response in naive mice. However, it is unclear whether rBCG could suppress allergic airway inflammation in a mouse model. In this article we report that rBCG dramatically inhibited airway inflammation, eosinophilia, mucus production and mast cell degranulation in allergic mice. Analysis of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) levels in bronchoalveolar lavage fluid (BALF) and lung tissue revealed that the suppression was associated with a shift from a Th2 response to a Th1 response. At the same time, rBCG induced a CD4(+) CD25(+) Foxp3(+) T-cell subtype that could suppress the proliferation of Th2 effector cells in vitro in an antigen-specific manner. Moreover, suppression of CD4(+) CD25(+) T cells could be adoptively transferred. Thus, our results demonstrate that rBCG induces both generic and specific immune responses. The generic immune response is associated with a shift from a Th2 to a Th1 cytokine response, whereas the specific immune response against Der p2 appears to be related to the expansion of transforming growth factor-beta (TGF-beta)-producing CD4(+) CD25(+) Foxp3(+) regulatory T cells. rBCG can suppress asthmatic airway inflammation through both immune deviation and immune suppression and may be a feasible, efficient immunotherapy for asthma.
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Affiliation(s)
- Hai-Feng Ou-Yang
- Department of Respiratory Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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19
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da Silva Ramos Rocha A, Conceição FR, Grassmann AA, Lagranha VL, Dellagostin OA. B subunit ofEscherichia coliheat-labile enterotoxin as adjuvant of humoral immune response in recombinant BCG vaccination. Can J Microbiol 2008; 54:677-86. [DOI: 10.1139/w08-056] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The B subunit of Escherichia coli heat-labile enterotoxin (LTB), a nontoxic molecule with potent biological properties, is a powerful mucosal and parenteral adjuvant that induces a strong immune response against co-administered or coupled antigens. In this paper, the effect of LTB on the humoral immune response to recombinant BCG (rBCG) vaccination was evaluated. Isogenic mice were immunized with rBCG expressing the R1 repeat region of the P97 adhesin of Mycoplasma hyopneumoniae alone (rBCG/R1) or fused to LTB (rBCG/LTBR1). Anti-R1 systemic antibody levels (IgG1, IgG2a, IgG2b, IgG3, IgM, and IgA) were measured by ELISA using recombinant R1 as antigen. With the exception of IgM, LTB doubled the anti-R1 antibody levels in rBCG vaccination. The IgG1/IgG2a mean ratio showed that both rBCG/LTBR1 and rBCG/R1 induced a mixed Th1/Th2 immune response. Interestingly, anti-R1 serum IgA was induced only by rBCG/LTBR1. These results demonstrate that LTB has an adjuvant effect on the humoral immune response to recombinant antigens expressed in BCG.
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Affiliation(s)
- Andréa da Silva Ramos Rocha
- Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, Pelotas, RS 96010-900, Brazil
- Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
- Instituto de Biologia, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
| | - Fabricio Rochedo Conceição
- Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, Pelotas, RS 96010-900, Brazil
- Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
- Instituto de Biologia, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
| | - André Alex Grassmann
- Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, Pelotas, RS 96010-900, Brazil
- Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
- Instituto de Biologia, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
| | - Valeska Lizzi Lagranha
- Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, Pelotas, RS 96010-900, Brazil
- Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
- Instituto de Biologia, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
| | - Odir Antônio Dellagostin
- Centro de Biotecnologia, Universidade Federal de Pelotas, CP 354, Pelotas, RS 96010-900, Brazil
- Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
- Instituto de Biologia, Universidade Federal de Pelotas, Pelotas, RS 96010-900, Brazil
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20
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Meijer AH, van der Sar AM, Cunha C, Lamers GEM, Laplante MA, Kikuta H, Bitter W, Becker TS, Spaink HP. Identification and real-time imaging of a myc-expressing neutrophil population involved in inflammation and mycobacterial granuloma formation in zebrafish. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:36-49. [PMID: 17553562 DOI: 10.1016/j.dci.2007.04.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 04/05/2007] [Accepted: 04/06/2007] [Indexed: 05/15/2023]
Abstract
By enhancer trap screening we identified a transgenic zebrafish line showing leukocyte-specific YFP expression during late embryo and early larval development. Its enhancer detection insertion was mapped near a novel member of the myc proto-oncogene family, encoding transcription factors known to be important for regulating human myelopoiesis. Characterization of the zebrafish myc family showed that only this particular myc gene is strongly expressed in leukocytes. To identify the myc/YFP-expressing cell type, we re-examined specificity of described myeloid markers by multiplex fluorescent in situ hybridization, showing that lcp1 can be considered as a general leukocyte marker, csf1r as a macrophage-specific marker, and mpx and lyz as neutrophil-specific markers. Subsequent colocalization analysis defined the YFP-positive cells as a subset of the neutrophil population. Using real-time confocal imaging we demonstrate that these cells migrate to sites of inflammation and are involved in innate immune responses towards infections, including Mycobacterium marinum-induced granuloma formation.
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Affiliation(s)
- Annemarie H Meijer
- Institute of Biology, Leiden University, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
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21
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Dennehy M, Bourn W, Steele D, Williamson AL. Evaluation of recombinant BCG expressing rotavirus VP6 as an anti-rotavirus vaccine. Vaccine 2007; 25:3646-57. [PMID: 17339069 DOI: 10.1016/j.vaccine.2007.01.087] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 12/19/2006] [Accepted: 01/11/2007] [Indexed: 11/16/2022]
Abstract
Recombinant BCG expressing rotavirus VP6 was explored as an anti-rotavirus vaccine in a mouse model. Three promoters and five ribosome-binding sites were used in episomal and integrative E. coli-mycobacterium shuttle vectors to express VP6 in BCG. The VP6 gene was configured for accumulation within the BCG cytoplasm, secretion from the BCG cell or targeting to the BCG cell membrane. Vectors were assessed in terms of stability, levels of antigen production, immunogenicity and protection in mice. Gross instability occurred in episomal vectors utilizing the hsp60 promoter. However, three integrative vectors using the same expression system and two episomal vectors using inducible promoters were successfully recovered from BCG. Growth rates of the former were not detectably reduced. Growth rates of the latter were considerably reduced, implying the existence of a significant metabolic load. In the absence of selection, loss rate of these plasmids was high. VP6 production levels (0.04-1.78% of total cytoplasmic protein) were on the lower end of the range reported for other rBCG. One episomal and one integrated vaccine reduced viral shedding in intraperitoneally vaccinated mice challenged with rotavirus. Compared to controls, infection-associated faecal shedding of virus was reduced by 66% and 62%, respectively. These protective vectors differ in promoter, ribosome-binding site and antigen production level, but both link the VP6 protein to the 19kDa lipoprotein signal sequence, suggesting that transport of VP6 to the BCG membrane is important for induction of a protective immune response. Protection occurred in the absence of detectable anti-rotavirus antibody in serum or faeces, implicating cellular immunity in protection.
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Affiliation(s)
- Maureen Dennehy
- Division of Medical Virology, Department of Clinical Laboratory Sciences, Faculty of Health Sciences, University of Cape Town, and National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa.
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22
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Abdallah AM, Verboom T, Hannes F, Safi M, Strong M, Eisenberg D, Musters RJP, Vandenbroucke-Grauls CMJE, Appelmelk BJ, Luirink J, Bitter W. A specific secretion system mediates PPE41 transport in pathogenic mycobacteria. Mol Microbiol 2006; 62:667-79. [PMID: 17076665 DOI: 10.1111/j.1365-2958.2006.05409.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mycobacterial genomes contain two unique gene families, the so-called PE and PPE gene families, which are highly expanded in the pathogenic members of this genus. Here we report that one of the PPE proteins, i.e. PPE41, is secreted by pathogenic mycobacteria, both in culture and in infected macrophages. As PPE41 lacks a signal sequence a dedicated secretion system must be involved. A single gene was identified in Mycobacterium marinum that showed strongly reduced PPE41 secretion. This gene was located in a gene cluster whose predicted proteins encode components of an ESAT-6-like secretion system. This cluster, designated ESX-5, is conserved in various pathogenic mycobacteria, but not in the saprophytic species Mycobacterium smegmatis. Therefore, different regions of this cluster were introduced in M. smegmatis. Only introduction of the complete ESX-5 locus resulted in efficient secretion of heterologously expressed PPE41. This PPE secretion system is also involved in the virulence of pathogenic mycobacteria, as the ESX-5 mutant of M. marinum was affected in spreading to uninfected macrophages.
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Affiliation(s)
- Abdallah M Abdallah
- Department of Medical Microbiology and Infection Control, VU Medical Centre, Amsterdam, the Netherlands
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23
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Fingerut E, Gutter B, Goldway M, Eliahoo D, Pitcovski J. B subunit of E. coli enterotoxin as adjuvant and carrier in oral and skin vaccination. Vet Immunol Immunopathol 2006; 112:253-63. [PMID: 16701905 DOI: 10.1016/j.vetimm.2006.03.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Revised: 02/26/2006] [Accepted: 03/14/2006] [Indexed: 02/01/2023]
Abstract
Mucosal sites are one of the main natural ports of entry into the body. Stimulation of a local response by antibodies as the systemic protection may enhance the efficacy of non-living vaccines, and allow for vaccination by subunit vaccines without the need for injection. Mucosal or skin vaccination necessitates a suitable adjuvant and carrier. Escherichia coli heat-labile enterotoxin (LT) and its B subunit (LTB) have been found to be effective adjuvants. The aim of this study was to efficiently produce and purify recombinant LTB (brLTB), and examine its adjuvant and carrier properties. The gene encoding LTB was cloned and expressed in E. coli, and the product was found to have a pentameric form with the ability to bind the cell receptor, GM1 ganglioside. A one-step method for efficient purification and concentration of brLTB was developed. Both oral and intramuscular vaccination with purified brLTB yielded high antibody titers, which detected the whole toxin. In an attempt to test its adjuvant characteristics, brLTB was mixed with either BSA or a recombinant protein (rKnob of egg drop syndrome adenovirus) and delivered intramuscularly, orally or transcutaneously. The addition of brLTB significantly elevated the antibody response in groups vaccinated orally and transcutaneously, but had no influence in injected groups. Vaccination with another recombinant protein, (viral protein 2 of infectious bursal disease virus) supplemented with brLTB did not elevate the antibody response, as compared to vaccination with the antigen alone. These results demonstrate that the addition of brLTB makes oral and transcutaneous vaccination with protein antigens possible.
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Affiliation(s)
- E Fingerut
- Migal, P.O. Box 831, Kiryat Shmona 11016, Israel
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24
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Fingerut E, Gutter B, Meir R, Eliahoo D, Pitcovski J. Vaccine and adjuvant activity of recombinant subunit B of E. coli enterotoxin produced in yeast. Vaccine 2005; 23:4685-96. [PMID: 15951067 DOI: 10.1016/j.vaccine.2005.03.050] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2004] [Accepted: 03/16/2005] [Indexed: 10/25/2022]
Abstract
Escherichia coli heat-labile enterotoxin (LT) and cholera toxin (CT) have been studied intensively as vaccines against diseases caused by those bacteria and as adjuvants for mucosal vaccination. Two major problems interfere with the use of these promising adjuvants: their toxicity and the residual bacterial endotoxins mixed with the desired LT. In this study, subunit B of LT was expressed in Pichia pastoris yeast cells (yrLTB) and the recombinant protein was purified and concentrated by ion-exchange chromatography. The final yield of the recombinant protein was 5-8 mg/l induction medium. The molecule is in pentameric form and binds to GM1 gangliosides. When given orally to chickens, anti-LTB antibodies were produced, exhibiting its ability to cross the digestive system and induce an immune response. The adjuvant activity of yrLTB was proven by fusing it to viral protein 2 (VP2) of infectious bursal disease virus. Birds intramuscularly vaccinated with this molecule exhibit 70-100% protection, in a dose-response-dependent manner. This method eliminated the bacterial endotoxins and enabled the production of large quantities of LTB. Expression in a eukaryotic system allows the production of fusion proteins that require post-translational modifications. This may allow oral vaccination with a protein fused to yrLTB. The approach described in this study will enable the efficient production of a non-toxic, eukaryotically expressed enterotoxin as a vaccine against the toxin itself or as a carrier or adjuvant for foreign vaccine molecules.
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Affiliation(s)
- E Fingerut
- Migal, Immunology Department, Industrial Zone POB 831, Kiryat Shmona 11016, Israel
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25
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Dennehy M, Williamson AL. Factors influencing the immune response to foreign antigen expressed in recombinant BCG vaccines. Vaccine 2005; 23:1209-24. [PMID: 15652663 DOI: 10.1016/j.vaccine.2004.08.039] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Accepted: 08/26/2004] [Indexed: 11/30/2022]
Abstract
A wide range of recombinant BCG vaccine candidates containing foreign viral, bacterial, parasite or immunomodulatory genetic material have been developed and evaluated, primarily in animal models, for immune response to the foreign antigen. This review considers some of the factors that may influence the immunogenicity of these vaccines. The influence of levels and timing of expression of the foreign antigen and the use of targeting sequences are considered in the first section. Genetic and functional stability of rBCG is reviewed in the second section. In the last section, the influence of dose and route of immunization, strain of BCG and the animal model used are discussed.
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Affiliation(s)
- Maureen Dennehy
- The Biovac Institute, Private Bag X3, Pinelands, 7430 Cape Town, South Africa.
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26
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Bastos RG, Dellagostin OA, Barletta RG, Doster AR, Nelson E, Zuckermann F, Osorio FA. Immune response of pigs inoculated with Mycobacterium bovis BCG expressing a truncated form of GP5 and M protein of porcine reproductive and respiratory syndrome virus. Vaccine 2004; 22:467-74. [PMID: 14670329 DOI: 10.1016/s0264-410x(03)00572-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pigs were immunised with recombinant BCG (rBCG) expressing a truncated form of GP5 (lacking the first 30 NH(2)-terminal residues) (rBCGGP5) and M protein (rBCGM) of porcine reproductive and respiratory syndrome virus (PRRSV). At 30 days post-inoculation (dpi), pigs inoculated with rBCGGP5 and rBCGM developed a specific humoral immune response against the viral proteins, as detected by commercial ELISA and Western blot tests, and at 60 dpi, three out of five animals developed neutralizing antibodies with titers ranging from 1:4 to 1:8. At 67 dpi, an IFN-gamma response against BCG antigens, but not against the viral proteins, was detected by ELISPOT in inoculated pigs. Following challenge with a pathogenic strain of PRRSV, pigs inoculated with rBCG showed lower (P<0.05) temperature, viremia and virus load in bronchial lymph nodes than control animals, suggesting the establishment of partial protection against PRRSV infection.
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Affiliation(s)
- Reginaldo G Bastos
- Department of Veterinary and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
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27
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Bout D, Mévélec MN, Velge-Roussel F, Dimier-Poisson I, Lebrun M. [Vaccines on mucosal surfaces]. Arch Pediatr 2003; 10:565-70. [PMID: 12915029 DOI: 10.1016/s0929-693x(03)00180-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Tagliabue A, Cesaroni MP, Lewis DJM. Novel human vaccine strategies and the 5th Framework Programme: pushing the envelope. Vaccine 2003; 21 Suppl 2:S121-7. [PMID: 12763695 DOI: 10.1016/s0264-410x(03)00211-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mucosal vaccines could result in a great scientific and practical achievement. More than three decades of research in experimental models have shown promising results in stimulating mucosal immune responses, thus, it was expected that within a short time mucosal vaccines for human use could be achieved. Indeed this is not being the case. In the last few years, the most important oral vaccine, the anti-polio developed by Sabin in the fifties, has been progressively abandoned in developed countries to avoid the few cases of disease caused by the vaccine. Furthermore, two recently developed mucosal vaccines for human use against rotavirus diarrhoea and influenza were withdrawn after a short period in the market because of adverse reactions among the vaccinees. This controversial situation has created a difficult future for research on mucosal vaccine at the industrial level. A great help and encouragement for believers in mucosal vaccines has been given by the EU Commission through the 5th Framework Programme (5FP). At the end of the first projects of the 5FP, it is quite clear that mucosal vaccines are experiencing a real renaissance. The Euroconference/Workshop "Novel Strategies of Mucosal Immunisation through Exploitation of Mechanisms of Innate Immunity in Pathogen-Host Interaction", organised under the sponsorship of the EU Commission and reported in this special issue of Vaccine, witnesses a very creative moment of European groups involved in mucosal immunology. This conclusive paper of the issue is intended to describe a positive experience of some European scientists that have been working together in organised fashion within two EU projects. The first, defined by the acronym MUCIMM, was aimed to pave the way to tackle mucosal vaccines with different approaches, mainly that of new delivery systems and adjuvants, that of dissecting the fine mechanisms of basic mucosal responses and that of obtaining meaningful assays to measure human immune responses to mucosal vaccines. The second, the MUCADJ project, was aimed to prove that an intranasally delivered influenza vaccine induces protective levels of immunity in human adult volunteers. The results obtained demonstrate that mucosal vaccines for humans are feasible. It is interesting to note how this model of making biomedical research is flourishing, becoming an example for work organisation. At the same time it is important to underline some of the limits of this cooperative approach and it is also mandatory to spend a word of consciousness regarding the impact that the new European regulations could exert on mucosal vaccines, particularly for those based on live delivery systems. In a world where the damages caused by syringe needles are still largely visible, mucosal vaccines could represent an extremely important tool to fight infections, particularly in the large population of the most impoverished. The EU Commission will still encourage and support mucosal vaccines in the 6FP. The scientific community must decide in which direction has to proceed to avoid regulatory problems that could halt a promising tool to improve human health. The envelope has been pushed, the trip begins.
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Affiliation(s)
- Aldo Tagliabue
- The International Vaccine Institute, Seoul National University Campus, Shillim-Dong, Kwanak-Ku, Seoul, South Korea.
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29
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Dietrich G, Viret JF, Hess J. Novel vaccination strategies based on recombinant Mycobacterium bovis BCG. Int J Med Microbiol 2003; 292:441-51. [PMID: 12635927 DOI: 10.1078/1438-4221-00227] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this manuscript, we will review the utilization of Mycobacterium bovis Bacille Calmette-Guerin (BCG) as a vaccine against tuberculosis (TB) and as a carrier system for heterologous antigens. BCG is one of the most widely used vaccines. Novel techniques in genome manipulation allow the construction of virulence-attenuated recombinant (r)-BCG strains that can be employed as homologous vaccines, or as heterologous antigen delivery systems, for priming pathogen-specific immunity against infectious diseases, including TB. Several approaches are available for heterologous antigen expression and compartmentalization in BCG and recent findings show the potential to modulate and direct the immune responses induced by r-BCG strains as desired. Recent achievements in complete genome analysis of various target pathogens, combined with a better understanding of protective pathogen-specific immune responses, form the basis for the rational design of a new generation of recombinant mycobacterial vaccines against a multitude of infectious diseases.
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MESH Headings
- Animals
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- BCG Vaccine/genetics
- BCG Vaccine/immunology
- Cattle
- Communicable Disease Control
- Genetic Vectors
- Humans
- Mycobacterium bovis/genetics
- Recombination, Genetic
- Tuberculosis/prevention & control
- Tuberculosis Vaccines/immunology
- Vaccination/methods
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Vaccines, DNA/immunology
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Guido Dietrich
- Bacterial Vaccine Research, Berna Biotech Ltd., Berne, Switzerland.
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Webster DE, Gahan ME, Strugnell RA, Wesselingh SL. Advances in Oral Vaccine Delivery Options. ACTA ACUST UNITED AC 2003. [DOI: 10.2165/00137696-200301040-00002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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31
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Bastos RG, Dellagostin OA, Barletta RG, Doster AR, Nelson E, Osorio FA. Construction and immunogenicity of recombinant Mycobacterium bovis BCG expressing GP5 and M protein of porcine reproductive respiratory syndrome virus. Vaccine 2002; 21:21-9. [PMID: 12443659 DOI: 10.1016/s0264-410x(02)00443-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mycobacterium bovis BCG was used to express a truncated form of GP5 (lacking the first 30 NH(2)-terminal residues) and M protein of porcine reproductive and respiratory syndrome virus (PRRSV). The PRRSV proteins were expressed in BCG under control of the mycobacterial hsp60 gene promoter either in the mycobacterial cytoplasm (BCGGP5cyt and BCGMcyt) or as MT19-fusion proteins on the mycobacterial surface (BCGGP5surf and BCGMsurf). Mice inoculated with BCGGP5surf and BCGMsurf developed antibodies against the viral proteins at 30 days post-inoculation (dpi) as detected by ELISA and Western blot. By 60 dpi, the animals developed titer of neutralizing antibodies of 8. A PRRSV-specific gamma interferon response was also detected in splenocytes of recombinant BCG-inoculated mice at 60 and 90 dpi. These results indicate that BCG was able to express antigens of PRRSV and elicit an immune response against the viral proteins in mice.
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Affiliation(s)
- Reginaldo G Bastos
- Department of Veterinary and Biomedical Sciences, University of Nebraska at Lincoln, Lincoln, NE 68583-0905, USA
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32
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Ryan EJ, Daly LM, Mills KH. Immunomodulators and delivery systems for vaccination by mucosal routes. Trends Biotechnol 2001; 19:293-304. [PMID: 11451471 DOI: 10.1016/s0167-7799(01)01670-5] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Current paediatric immunization programmes include too many injections in the first months of life. Oral or nasal vaccine delivery eliminates the requirement for needles and can induce immunity at the site of infection. However, protein antigens are poorly immunogenic when so delivered and can induce tolerance. Novel ways to enhance immune responses to protein or polysaccharide antigens have opened up new possibilities for the design of effective mucosal vaccines. Here, we discuss the immunological principles underlying mucosal vaccine development and review the application of immunomodulatory molecules and delivery systems to the selective enhancement of protective immune responses at mucosal surfaces.
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Affiliation(s)
- E J Ryan
- Institute of Immunology, National University of Ireland, Maynooth, Co., Kildare, Ireland
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Affiliation(s)
- N Ohara
- Nagasaki University School of Dentistry, Sakamoto 1-7-1, 852-8588, Nagasaki, Japan.
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34
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Mollenkopf H, Dietrich G, Kaufmann SH. Intracellular bacteria as targets and carriers for vaccination. Biol Chem 2001; 382:521-32. [PMID: 11405217 DOI: 10.1515/bc.2001.066] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this review we discuss intracellular bacteria as targets and carriers for vaccines. For clarity and ease of comprehension, we focus on three microbes, Mycobacterium tuberculosis, Listeria monocytogenes and Salmonella, with an emphasis on tuberculosis, one of the leading causes of death from infectious disease. Novel vaccination strategies against these pathogens are currently being considered. One approach favors the use of live attenuated vaccines and vaccine carrier strains thereof, either for heterologous antigen presentation or DNA vaccine delivery. This strategy includes both the improvement of attenuated vaccine strains as well as the 'de novo' generation of attenuated variants of virulent pathogens. An alternative strategy relies on the application of subunit immunizations, either as nucleic acid vaccines or protein antigens of the pathogen. Finally, we present a short summary of the vaccination strategies against tuberculosis.
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Affiliation(s)
- H Mollenkopf
- Max-Planck-Institute for Infection Biology, Department of Immunology, Berlin, Germany
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Miyaji EN, Mazzantini RP, Dias WO, Nascimento AL, Marcovistz R, Matos DS, Raw I, Winter N, Gicquel B, Rappuoli R, Leite LC. Induction of neutralizing antibodies against diphtheria toxin by priming with recombinant Mycobacterium bovis BCG expressing CRM(197), a mutant diphtheria toxin. Infect Immun 2001; 69:869-74. [PMID: 11159980 PMCID: PMC97964 DOI: 10.1128/iai.69.2.869-874.2001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BCG, the attenuated strain of Mycobacterium bovis, has been widely used as a vaccine against tuberculosis and is thus an important candidate as a live carrier for multiple antigens. With the aim of developing a recombinant BCG (rBCG) vaccine against diphtheria, pertussis, and tetanus (DPT), we analyzed the potential of CRM(197), a mutated nontoxic derivative of diphtheria toxin, as the recombinant antigen for a BCG-based vaccine against diphtheria. Expression of CRM(197) in rBCG was achieved using Escherichia coli-mycobacterium shuttle vectors under the control of pBlaF*, an upregulated beta-lactamase promoter from Mycobacterium fortuitum. Immunization of mice with rBCG-CRM(197) elicited an anti-diphtheria toxoid antibody response, but the sera of immunized mice were not able to neutralize diphtheria toxin (DTx) activity. On the other hand, a subimmunizing dose of the conventional diphtheria-tetanus vaccine, administered in order to mimic an infection, showed that rBCG-CRM(197) was able to prime the induction of a humoral response within shorter periods. Interestingly, the antibodies produced showed neutralizing activity only when the vaccines had been given as a mixture in combination with rBCG expressing tetanus toxin fragment C (FC), suggesting an adjuvant effect of rBCG-FC on the immune response induced by rBCG-CRM(197). Isotype analysis of the anti-diphtheria toxoid antibodies induced by the combined vaccines, but not rBCG-CRM(197) alone, showed an immunoglobulin G1-dominant profile, as did the conventional vaccine. Our results show that rBCG expressing CRM(197) can elicit a neutralizing humoral response and encourage further studies on the development of a DPT vaccine with rBCG.
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Affiliation(s)
- E N Miyaji
- Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil.
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