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Protective immunity induced with a DNA vaccine encoding B- and T-cells multi-epitope SAG1, ROP16, MIC4, GRA12, M2AP, and multi-epitope ROP8 against acute and chronic toxoplasmosis in BALB/c mice. Exp Parasitol 2022; 242:108385. [PMID: 36162598 DOI: 10.1016/j.exppara.2022.108385] [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: 12/13/2021] [Revised: 09/05/2022] [Accepted: 09/19/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND T. gondii infection is characterized by a high global prevalence. Nearly, 16-40% of people have been infected by T. gondii. Although T. gondii often causes subclinical infection, it may cause severe complications in newborns with congenital infection and immunocompromised individuals. Constant attempts of scientists have made valuable findings in the development of T. gondii candidate vaccines. However, an effective vaccine has not been successfully developed yet. In this study, multi-epitope SAG1, MIC4, ROP16, M2AP, GRA12, and multi-epitope ROP8 were injected into BALB/c mice intramuscularly, as cocktailed plasmids or as single-gene plasmids to assess the immune response against chronic and acute Toxoplasma infection. METHODS BALB/c mice were immunized on days 0, 21, and 42. The immune responses of both vaccinated and control groups were evaluated using cytokine and antibody measurements, lymphocyte proliferation assay, survival time, and average number of cysts in each brain. RESULTS The results indicated that DNA vaccination using multi-epitope ROP8 and multi-epitope SAG1, ROP16, MIC4, GRA12, M2AP could elicit both cellular and humoral immune responses, and enhanced the survival time in BALB/c mice. Also, the administration of multi-epitope ROP8 plus multi-epitope SAG1, ROP16, MIC4, GRA12, M2AP could enhance the concentrations of IgG antibody, elicit a mixed IgG1/IgG2a reaction with the predominance of the IgG2a, increase the release of IFN-γ cytokine, prolonge the survival time, and reduce the brain cysts. CONCLUSIONS Here, we report that vaccination using cocktailed plasmids could induce better protective immunity compared to single plasmid for acute and chronic T. gondii infection.
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Warner RC, Chapman RC, Davis BN, Davis PH. REVIEW OF DNA VACCINE APPROACHES AGAINST THE PARASITE TOXOPLASMA GONDII. J Parasitol 2021; 107:882-903. [PMID: 34852176 DOI: 10.1645/20-157] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Toxoplasma gondii is an apicomplexan parasite that affects both humans and livestock. Transmitted to humans through ingestion, it is the second-leading cause of foodborne illness-related death. Currently, there exists no approved vaccine for humans or most livestock against the parasite. DNA vaccines, a type of subunit vaccine which uses segments of the pathogen's DNA to generate immunity, have shown varying degrees of experimental efficacy against infection caused by the parasite. This review compiles DNA vaccine efforts against Toxoplasma gondii, segmenting the analysis by parasite antigen, as well as a review of concomitant adjuvant usage. No single antigenic group was consistently more effective within in vivo trials relative to others.
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Affiliation(s)
- Rosalie C Warner
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, 68182
| | - Ryan C Chapman
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, 68182
| | - Brianna N Davis
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, 68182
| | - Paul H Davis
- Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, 68182
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3
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Genetic immunization against toxoplasmosis: A review article. Microb Pathog 2021; 155:104888. [PMID: 33930415 DOI: 10.1016/j.micpath.2021.104888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/13/2021] [Accepted: 04/13/2021] [Indexed: 11/21/2022]
Abstract
Toxoplasma gondii is a protozoan coccidian parasite belonging to Phylum Apicomplexa and is the causative agent of toxoplasmosis as a zoonotic disease around the world. It is one of the most important protozoa which is transmitted via various routes and infects several warm-blooded animals. The seroprevalence of T. gondii infection is high worldwide and leads to clinical, psychological, and economic problems. At present, available drug therapy for toxoplasmosis has severe side effects, so the development of new anti-toxoplasma drugs or effective vaccines is mandatory. Therefore, different measures have been taken for the development of anti-toxoplasmosis vaccines, and various studies have shown that DNA vaccines could be one of the most successful approaches against the intracellular parasite, T. gondii. Many of these studies have evaluated the efficacy of immunogenicity and different aspects of the DNA vaccines for toxoplasmosis including single genes or multi-gene plasmids with or without adjuvants. Most of the literature confirms that DNA vaccines containing different antigens of the toxoplasma parasite can induce suitable immune response and protection in acute or chronic toxoplasmosis. Therefore, in this review article, we aimed to discuss the current status of DNA vaccines as a new immunization method against toxoplasmosis.
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Barros M, Teixeira D, Vilanova M, Correia A, Teixeira N, Borges M. Vaccines in Congenital Toxoplasmosis: Advances and Perspectives. Front Immunol 2021; 11:621997. [PMID: 33658997 PMCID: PMC7917294 DOI: 10.3389/fimmu.2020.621997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/29/2020] [Indexed: 12/03/2022] Open
Abstract
Congenital toxoplasmosis has a high impact on human disease worldwide, inducing serious consequences from fetus to adulthood. Despite this, there are currently no human vaccines available to prevent this infection. Most vaccination studies against Toxoplasma gondii infection used animal models in which the infection was established by exogenous inoculation. Here, we review recent research on potential T. gondii vaccines using animal models in which infection was congenitally established. Endeavors in this field have so far revealed that live or subunit vaccines previously found to confer protection against extrinsically established infections can also protect, at least partially, from vertically transmitted infection. Nevertheless, there is no consensus on the more adequate immune response to protect the host and the fetus in congenital infection. Most of the vaccination studies rely on the assessment of maternal systemic immune responses, quantification of parasitic loads in the fetuses, and survival indexes and/or brain parasitic burden in the neonates. More research must be carried out not only to explore new vaccines but also to further study the nature of the elicited immune protection at the maternal-fetal interface. Particularly, the cellular and molecular effector mechanisms at the maternal-fetal interface induced by immunization remain poorly characterized. Deeper knowledge on the immune response at this specific location will certainly help to refine the vaccine-induced immunity and, consequently, to provide the most effective and safest protection against T. gondii vertical infection.
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Affiliation(s)
- Mariana Barros
- Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Daniela Teixeira
- Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Manuel Vilanova
- Immunobiology Group, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.,Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Alexandra Correia
- Immunobiology Group, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.,Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Natercia Teixeira
- Applied Molecular Biosciences Unit/Rede de Química e Tecnologia (UCIBIO/REQUIMTE), Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Margarida Borges
- Applied Molecular Biosciences Unit/Rede de Química e Tecnologia (UCIBIO/REQUIMTE), Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
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Dodangeh S, Fasihi-Ramandi M, Daryani A, Valadan R, Asgarian-Omran H, Hosseininejad Z, Nayeri Chegeni T, Pagheh AS, Javidnia J, Sarvi S. Protective efficacy by a novel multi-epitope vaccine, including MIC3, ROP8, and SAG1, against acute Toxoplasma gondii infection in BALB/c mice. Microb Pathog 2021; 153:104764. [PMID: 33548480 DOI: 10.1016/j.micpath.2021.104764] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/21/2020] [Accepted: 01/24/2021] [Indexed: 10/22/2022]
Abstract
Toxoplasma gondii is an intracellular apicomplexan parasite, which can cause a serious infectious disease in pregnant women and immunocompromised individuals. Therefore, the development of a polyvalent vaccine consisting of all stages of the parasite life cycle using the epitopes from tachyzoites, bradyzoites, and sporozoites is likely to be required for complete protective immunity. In this study, we designed protein vaccine candidate based on the prediction of specific epitopes (i.e., B cell and T cell) from three Toxoplasma gondii antigens. The MRS protein (MIC3: 30-180, ROP8: 85-185, and SAG1: 85-235) was expressed in Escherichia coli, and purification was performed using a HisTrap HP column and then we evaluated immunogenicity and protective property in BALB/c mice. Seventy-two mice were randomly divided into six groups, including three vaccinations (i.e., MRS, MRS-Freund, and MRS-Calcium Phosphate Nanoparticles (MRS-CaPNs)) and three control (i.e., Phosphate-buffered saline, Freund, and CaPNs) groups. All groups were immunized three times via subcutaneous injection within three-week intervals. In the vaccination groups, the BALB/c mice were injected with 20 μg of MRS protein for the first time and 10 μg of MRS for the next two times. Antibodies, cytokines, and splenocytes proliferation in the immunized mice were assayed using the enzyme-linked immunosorbent assay. Protective efficacy was analyzed by challenging the immunized mice with T. gondii of RH strain. Antibody, cytokine, and lymphocyte proliferation assays showed that the mice immunized with MRS induced stronger humoral and T helper type 1 cell-mediated immune responses, compared to the control mice. However, co-immunization with adjuvants (i.e., Freund and CaNPs) resulted in impaired immune responses. Effective protection against the parasite achieved an increase in survival time in the immunized mice, especially in the MRS-CaNPs group. The obtained results of the present study demonstrated that multi-epitope protein vaccination, MRS, is a potential strategy against toxoplasmosis infection. In addition, the vaccine co-delivered with CaPNs could provide an important key for vaccine candidate to control T. gondii infection.
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Affiliation(s)
- Samira Dodangeh
- Department of Medical Parasitology and Mycology, Children Growth Research Center, Research Institute for Prevention of Non-Communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran; Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahdi Fasihi-Ramandi
- Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ahmad Daryani
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Reza Valadan
- Immunogenetics Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Hossein Asgarian-Omran
- Immunogenetics Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Zahra Hosseininejad
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Tooran Nayeri Chegeni
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abdol Sattar Pagheh
- Infectious Disease Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Javad Javidnia
- Department of Medical Mycology, Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran.
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Protective immunity induced by a DNA vaccine cocktail expressing TgSAG1, TgROP2, and the genetic adjuvant HBsAg against Toxoplasma gondii infection. Microb Pathog 2020; 147:104441. [PMID: 32781100 DOI: 10.1016/j.micpath.2020.104441] [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: 07/09/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 12/12/2022]
Abstract
Toxoplasma gondii is an intracellular obligate parasitic protozoon that can infect all warm-blooded animals, causing zoonotic toxoplasmosis. So far, there is no commercial toxoplasmosis vaccine for human use. In the present study, we constructed a DNA vaccine cocktail which includes the surface protein (SAG1) and the rhoptry protein ROP2 denoted as pEGFP-N1-SAG1-ROP2. In order to improve the efficacy, HBsAg was used as a genetic adjuvant to construct pEGFP-N1-HBsAg-SAG1-ROP2. Two eukaryotic plasmids were transiently transfected into HEK293T cells and the expression was examined using fluorescence microscopy and western blotting. We then immunized Kunming mice intramuscularly with the DNA vaccine. After three immunizations, the immune response was evaluated by measuring antibody levels, cytokine production, percentages of CD4+ and CD8+ T lymphocytes, and the survival times of the T. gondii RH strain challenged mice. The results showed that the two DNA vaccines stimulated Th1 responses, and had a higher antibody titer, IL-2, IL-12, and IFN-γ levels, and percentage of CD4+ and CD8+ T lymphocytes than the control group. In addition, mice immunized with the pEGFP-N1-HBsAg-SAG1-ROP2 vaccine showed increased survival times compared with pEGFP-N1-SAG1-ROP2.
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Ghaffari AD, Dalimi A, Ghaffarifar F, Pirestani M. Antigenic properties of dense granule antigen 12 protein using bioinformatics tools in order to improve vaccine design against Toxoplasma gondii. Clin Exp Vaccine Res 2020; 9:81-96. [PMID: 32864364 PMCID: PMC7445328 DOI: 10.7774/cevr.2020.9.2.81] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/23/2020] [Accepted: 07/28/2020] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Toxoplasma gondii is an opportunistic parasite infecting all warm-blooded animals including humans. The dense granule antigens (GRAs) play an important role in parasite survival and virulence and in forming the parasitophorous vacuole. Identification of protein characteristics increases our knowledge about them and leads to develop the vaccine and diagnostic studies. MATERIALS AND METHODS This paper gave a comprehensive definition of the important aspects of GRA12 protein, including physico-chemical features, a transmembrane domain, subcellular position, secondary and tertiary structure, potential epitopes of B-cells and T-cells, and other important features of this protein using different and reliable bioinformatics methods to determine potential epitopes for designing of a high-efficient vaccine. RESULTS The findings showed that GRA12 protein had 53 potential post-translational modification sites. Also, only one transmembrane domain was recognized for this protein. The secondary structure of GRA12 protein comprises 35.55% alpha-helix, 19.50% extended strand, and 44.95% random coil. Moreover, several potential B- and T-cell epitopes were identified for GRA12. Based on the results of the Ramachandran plot, 79.26% of amino acid residues were located in favored, 11.85% in allowed and 8.89% in outlier regions. Furthermore, the results of the antigenicity and allergenicity assessment noted that GRA12 is immunogenic and non-allergenic. CONCLUSION This research provided important basic and conceptual data on GRA12 to develop an effective vaccine against acute and chronic toxoplasmosis for further in vivo investigations. More studies are required on vaccine development using the GRA12 alone or combined with other antigens in the future.
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Affiliation(s)
- Ali Dalir Ghaffari
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abdolhossein Dalimi
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Fatemeh Ghaffarifar
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Majid Pirestani
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Naghi Vishteh M, Javadi Mamaghani A, Rashidi S, Seyyed Tabaei SJ, Jeddi-Tehrani M. Peptide-Based Monoclonal Antibody Production Against SAG1 (P30) Protein of Toxoplasma gondii. Monoclon Antib Immunodiagn Immunother 2020; 39:51-56. [DOI: 10.1089/mab.2019.0041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Mohadeseh Naghi Vishteh
- Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amirreza Javadi Mamaghani
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Parasitology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sama Rashidi
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyyed Javad Seyyed Tabaei
- Department of Parasitology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahmood Jeddi-Tehrani
- Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
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Ghaffari AD, Dalimi A, Ghaffarifar F, Pirestani M. Structural predication and antigenic analysis of ROP16 protein utilizing immunoinformatics methods in order to identification of a vaccine against Toxoplasma gondii: An in silico approach. Microb Pathog 2020; 142:104079. [PMID: 32084578 DOI: 10.1016/j.micpath.2020.104079] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/25/2020] [Accepted: 02/18/2020] [Indexed: 01/20/2023]
Abstract
Toxoplasmosis, caused by Toxoplasma gondii, is a common parasitic disease, affecting almost one-third of the world's population. Currently, there are no effective treatments for inhibiting the formation of chronic tissue cysts in infected hosts. Thus, the production of appropriate vaccines against this pathogen is an important goal to avoid toxoplasmosis. considering the role of rhoptry antigens like ROP16 in virulence and satisfactory immunogenicity, they can be used as promising vaccine candidates against T. gondii. In the present study, an in silico approach was used to analyze various aspects of the ROP16 protein, including physicochemical characteristics, the potential epitopes of B and T-cells, the secondary and tertiary structure, the subcellular localization, the transmembrane domain, and other important features of this protein using several bioinformatics tools to design a proper vaccine against T. gondii. The results showed that ROP16 protein includes 93 potential post-translational modification sites. The secondary structure of the ROP16 protein comprises 34.23% alpha-helix, 54.46% random coil, and 11.32% extended strand. Moreover, several potential B- and T-cell epitopes were identified for ROP16. Based on the results of Ramachandran plot, 84.64% of the amino acid residues were located in the favored, 10.34% in allowed, and 5.02% in outlier regions. Furthermore, the results of the antigenicity and allergenicity assessment noted that this protein was immunogenic and non-allergenic. Our findings suggested that structural and functional predictions applied to ROP16 protein using in silico tools can reduce the failure risk of the laboratory studies. This research provided an important basis for further studies and also developed an effective vaccine against acute and chronic toxoplasmosis by various strategies. Further studies are needed on the development of vaccines in vivo using ROP16 alone or in combination with other antigens in the future.
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Affiliation(s)
- Ali Dalir Ghaffari
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Abdolhossein Dalimi
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Fatemeh Ghaffarifar
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Majid Pirestani
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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Pagheh AS, Sarvi S, Sharif M, Rezaei F, Ahmadpour E, Dodangeh S, Omidian Z, Hassannia H, Mehrzadi S, Daryani A. Toxoplasma gondii surface antigen 1 (SAG1) as a potential candidate to develop vaccine against toxoplasmosis: A systematic review. Comp Immunol Microbiol Infect Dis 2020; 69:101414. [PMID: 31958746 DOI: 10.1016/j.cimid.2020.101414] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/30/2019] [Accepted: 12/31/2019] [Indexed: 12/13/2022]
Abstract
Toxoplasma gondii is an intracellular parasite that infects a broad range of animal species and humans. As the main surface antigen of the tachyzoite, SAG1 is involved in the process of recognition, adhesion and invasion of host cells. The aim of the current systematic review study is to clarify the latest status of studies in the literature regarding SAG1-associated recombinant proteins or SAG1-associated recombinant DNAs as potential vaccines against toxoplasmosis. Data were systematically collected from six databases including PubMed, Science Direct, Web of Science, Google Scholar, EBSCO and Scopus, up to 1st of January 2019. A total of 87 articles were eligible for inclusion criteria in the current systematic review. The most common antigens used for experimental cocktail vaccines together with SAG1 were ROP2 and SAG2. In addition, the most parasite strains used were RH and ME49. Freund's adjuvant and cholera toxin have been predominantly utilized. Furthermore, regarding the animal models, route and dose of vaccination, challenge methods, measurement of immune responses and cyst burden have been discussed in the text. Most of these experimental vaccines induce immune responses and have a high degree of protection against parasite infections, increase survival rates and duration and reduce cyst burdens. The data demonstrated that SAG1 antigen has a high potential for use as a vaccine and provided a promising approach for protecting humans and animals against toxoplasmosis.
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Affiliation(s)
- Abdol Sattar Pagheh
- Infectious Disease Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mehdi Sharif
- Department of Parasitology, School of Medicine, Sari Branch, Islamic AZAD University, Sari, Iran
| | - Fatemeh Rezaei
- Toxoplasmosis Research Center, Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ehsan Ahmadpour
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Samira Dodangeh
- Toxoplasmosis Research Center, Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Zahra Omidian
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - Hadi Hassannia
- Immunonogenetics Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Saeed Mehrzadi
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Daryani
- Toxoplasmosis Research Center, Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran..
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Sobati H, Dalimi A, Kazemi B, Ghaffarifar F. Evaluation of Anti-Toxoplasma gondii Immune Responses in BALB/c Mice Induced by DNA Vaccines Encoding Surface Antigen 1 (SAG1) and 3 (SAG3). MOLECULAR GENETICS MICROBIOLOGY AND VIROLOGY 2019. [DOI: 10.3103/s0891416819010099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Watson GF, Davis PH. Systematic review and meta-analysis of variation in Toxoplasma gondii cyst burden in the murine model. Exp Parasitol 2019; 196:55-62. [PMID: 30562481 PMCID: PMC6447088 DOI: 10.1016/j.exppara.2018.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/14/2018] [Accepted: 12/14/2018] [Indexed: 11/20/2022]
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite that infects approximately 30% of the population of the United States, with worldwide distribution. The chronic (latent) infection, mediated by the bradyzoite parasite life stage, has attracted attention due to possible links to host behavioral alteration and psychomotor effects. Mice are a common model organism for studying the chronic stage, as they are natural hosts of infection. Notably, published studies demonstrate vast ranges of measured cyst burden within the murine brain tissue. The inconsistency of measured cyst burden within and between experiments makes interpretation of statistical significance difficult, potentially confounding studies of experimental anti-parasitic approaches. This review analyzes variation in measured cyst burden in a wide array of experimental mouse infections across published literature. Factors such as parasite infection strain, mouse strain, mode of infection, and infectious dose were all examined. The lowest variation in measured cyst burden occurred with the commonly available Balb/c and CBA mice undergoing infection by the ME49 strain of T. gondii. A summary of cyst variation and average cyst counts in T. gondii mouse models is presented, which may be useful for designing future experiments.
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Affiliation(s)
| | - Paul H Davis
- Department of Biology, University of Nebraska at Omaha, Omaha, NE, USA.
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Zhang NZ, Gao Q, Wang M, Hou JL, Zhang FK, Hu LY, Zhu XQ. Protective Efficacy Against Acute and Chronic Toxoplasma gondii Infection Induced by Immunization With the DNA Vaccine TgDOC2C. Front Microbiol 2018; 9:2965. [PMID: 30564214 PMCID: PMC6288300 DOI: 10.3389/fmicb.2018.02965] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 11/18/2018] [Indexed: 01/27/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous intracellular apicomplexan parasite that can cause zoonotic toxoplasmosis. Effective vaccines against T. gondii infection are necessary to prevent and control the spread of toxoplasmosis. The present study analyzed the B-linear epitopes of T. gondii DOC2 (TgDOC2) protein and then cloned the C-terminus of the TgDOC2 gene (TgDOC2C) to construct the pVAX-TgDOC2C eukaryotic vector. After intramuscular injection of pVAX-TgDOC2C, immune responses were monitored. Two weeks after the last immunization, the protective effects of pVAX-TgDOC2C against acute and chronic toxoplasmosis were evaluated by challenges with T. gondii RH tachyzoites (genotype I) and PRU cysts (genotype II). The DNA vaccine elicited strong humoral and cellular immune responses with high levels of IgG antibody, IL-2 and IFN-γ production compared to those of the controls. The percentage of CD4+ and CD8+ T cells in mice immunized with pVAX-TgDOC2C was significantly increased compared to that of mice injected with empty pVAX I or PBS. After acute infection with 103 lethal tachyzoites, mice immunized with pVAX-TgDOC2C survived longer (12.5 days) than mice treated with pVAX I (8 days) and PBS (7.5 days). Mice immunized with pVAX-TgDOC2C had significantly less brain cysts (1600.83 ± 284.61) compared to mice immunized with pVAX I (3016.67 ± 153.84) or PBS (3100 ± 246.98). Together, these results demonstrated that TgDOC2C confers protective immunity against T. gondii infection and may be a promising candidate antigen for further development of an effective multicomponent vaccine for veterinary use against toxoplasmosis in livestock animals.
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Affiliation(s)
- Nian-Zhang Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qi Gao
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Hunan Entry-Exit Inspection and Quarantine Bureau, Changsha, China
| | - Meng Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Jun-Ling Hou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Fu-Kai Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ling-Ying Hu
- Fujian Yongcheng Agricultural and Animal Husbandry Sci-Tech Group, Fuzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
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14
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Bioinformatics analysis of single and multi-hybrid epitopes of GRA-1, GRA-4, GRA-6 and GRA-7 proteins to improve DNA vaccine design against Toxoplasma gondii. J Parasit Dis 2018; 42:269-276. [PMID: 29844632 DOI: 10.1007/s12639-018-0996-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 04/10/2018] [Indexed: 02/05/2023] Open
Abstract
Toxoplasma gondii, is a causative agent of morbidity and mortality in immunocompromised and congenitally-infected individuals. Attempts to construct DNA vaccines against T. gondii using surface proteins are increasing. The dense granule antigens are highly expressed in the acute and chronic phases of T. gondii infection and considered as suitable DNA vaccine candidates to control toxoplasmosis. In the present study, bioinformatics tools and online software were used to predict, analyze and compare the structural, physical and chemical characters and immunogenicity of the GRA-1, GRA-4, GRA-6 and GRA-7 proteins. Sequence alignment results indicated that the GRA-1, GRA-4, GRA-6 and GRA-7 proteins had low similarity. The secondary structure prediction demonstrated that among the four proteins, GRA-1 and GRA-6 had similar secondary structure except for a little discrepancy. Hydrophilicity/hydrophobicity analysis showed multiple hydrophilic regions and some classical high hydrophilic domains for each protein sequence. Immunogenic epitope prediction results demonstrated that the GRA-1 and GRA-4 epitopes were stable and GRA-4 showed the highest degree of antigenicity. Although the GRA-7 epitope had the highest score of immunogenicity, this epitope was instable and had the lowest degree of antigenicity and half-time in eukaryotic cell. Also, the results indicated that GRA4-GRA7 epitope and GRA6-GRA7 had the highest degree of antigenicity and immunogenicity among multi-hybrid epitopes, respectively. Totally, in the present study, single epitopes showed the highest degree of antigenicity compared with multi-hybrid epitopes. Given the results, it can be concluded that GRA-4 and GRA-7 can be powerful DNA vaccine candidates against T. gondii.
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Vargas-Villavicencio JA, Besné-Mérida A, Correa D. Vertical transmission and fetal damage in animal models of congenital toxoplasmosis: A systematic review. Vet Parasitol 2016; 223:195-204. [PMID: 27198800 DOI: 10.1016/j.vetpar.2016.04.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/04/2016] [Accepted: 04/18/2016] [Indexed: 11/17/2022]
Abstract
In humans, the probability of congenital infection and fetal damage due to Toxoplasma gondii is dependent on the gestation period at which primary infection occurs. Many animal models have been used for vaccine, drug testing, or studies on host or parasite factors that affect transmission or fetal pathology, but few works have directly tested fetal infection and damage rates along gestation. So, the purpose of this work was to perform a systematic review of the literature to determine if there is a model which reflects these changes as they occur in humans. We looked for papers appearing between 1970 and 2014 in major databases like Medline and Scopus, as well as gray literature. From almost 11,000 citations obtained, only 49 papers fulfilled the criteria of having data of all independent variables and at least one dependent datum for control (untreated) groups. Some interesting findings could be extracted. For example, pigs seem resistant and sheep susceptible to congenital infection. Also, oocysts cause more congenitally infected offspring than tissue cysts, bradyzoites or tachyzoites. In spite of these interesting findings, very few results on vertical transmission or fetal damage rates were similar to those described for humans and only for one of the gestation thirds, not all. Moreover, in most designs tissue cysts - with unknown number of bradyzoites - were used, so actual dose could not be established. The meta-analysis could not be performed, mainly because of great heterogeneity in experimental conditions. Nevertheless, results gathered suggest that a model could be designed to represent the increase in vertical transmission and decrease in fetal damage found in humans under natural conditions.
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Affiliation(s)
- José Antonio Vargas-Villavicencio
- Lab. de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Ciudad de México 04530, Mexico
| | - Alejandro Besné-Mérida
- Lab. de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Ciudad de México 04530, Mexico
| | - Dolores Correa
- Lab. de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Ciudad de México 04530, Mexico.
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Vargas-Villavicencio JA, Cedillo-Peláez C, Rico-Torres CP, Besné-Mérida A, García-Vázquez F, Saldaña JI, Correa D. Mouse model of congenital infection with a non-virulent Toxoplasma gondii strain: Vertical transmission, "sterile" fetal damage, or both? Exp Parasitol 2016; 166:116-23. [PMID: 27068784 DOI: 10.1016/j.exppara.2016.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 03/23/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022]
Abstract
Congenital transmission of Toxoplasma gondii may occur if the mother gets infected for the first time while pregnant. The risk of mother-to-child transmission depends on the gestation trimester at infection, being lowest in the first and highest in the last. Conversely, fetal damage is frequent and more severe at the beginning of pregnancy. The objective of this study was to evaluate congenital transmission and pathological aspects in the placenta and the fetus using a mouse model of congenital infection of the second gestation third. Forty-five female BALB/c mice were infected intravenously with 2.5-10.0 × 10(6) tachyzoites of the ME49 strain at middle gestation. Samples of maternal spleen and fetal/placental units were taken 72 h later. We determined parasite load and vertical transmission by qPCR, as well as damage macroscopically and by histopathology. With the lowest dose, 18% of the fetuses were infected. Also, 40% of fetuses/litter were altered, while this value was 10% in the control group (P < 0.05). These results are similar to those described in humans in terms of vertical transmission and fetal damage during the second third of gestation. The maternal spleen had 10-1000 times more tachyzoites than the placenta, and the later retained 90-99% of the parasites that could reach the fetus. Nevertheless, we found resorptions, abortions or fetal tissue damage in the presence but also in the absence of parasites. Our data indicate a strong protective effect of maternal organs and the placenta against fetal infection, but extensive damage of the later may led to resorption or abortion without vertical transmission.
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Affiliation(s)
- J A Vargas-Villavicencio
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - C Cedillo-Peláez
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - C P Rico-Torres
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - A Besné-Mérida
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico; Doctorado en Ciencias de la Salud y Reproducción Animal, FMVZ, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - F García-Vázquez
- Departamento de Anatomía Patológica, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - J I Saldaña
- Investigador Cátedra CONACyT en el Instituto Nacional de pediatría, Laboratorio de Inmunología Experimental, Mexico City, Mexico
| | - D Correa
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico.
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Albarracín RM, Becher ML, Farran I, Sander VA, Corigliano MG, Yácono ML, Pariani S, López ES, Veramendi J, Clemente M. The fusion of Toxoplasma gondii SAG1 vaccine candidate to Leishmania infantum heat shock protein 83-kDa improves expression levels in tobacco chloroplasts. Biotechnol J 2015; 10:748-59. [PMID: 25823559 DOI: 10.1002/biot.201400742] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/12/2015] [Accepted: 03/25/2015] [Indexed: 11/12/2022]
Abstract
Chloroplast transformation technology has emerged as an alternative platform offering many advantages over nuclear transformation. SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and a promising candidate to produce an anti-T. gondii vaccine. The aim of this study was to investigate the expression of SAG1 using chloroplast transformation technology in tobacco plants. In order to improve expression in transplastomic plants, we also expressed the 90-kDa heat shock protein of Leishmania infantum (LiHsp83) as a carrier for the SAG1 antigen. SAG1 protein accumulation in transplastomic plants was approximately 0.1-0.2 μg per gram of fresh weight (FW). Fusion of SAG1 to LiHsp83 significantly increased the level of SAG1 accumulation in tobacco chloroplasts (by up to 500-fold). We also evaluated the functionality of the chLiHsp83-SAG1. Three human seropositive samples reacted with SAG1 expressed in transplastomic chLiHsp83-SAG1 plants. Oral immunization with chLiHsp83-SAG1 elicited a significant reduction of the cyst burden that correlated with an increase of SAG1-specific antibodies. We propose the fusion of foreign proteins to LiHsp83 as a novel strategy to increase the expression level of the recombinant proteins using chloroplast transformation technology, thus addressing one of the current challenges for this approach in antigen protein production.
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Affiliation(s)
- Romina M Albarracín
- Laboratorio de Biotecnología Vegetal, IIB-INTECH, CONICET-UNSAM, Chascomús, Provincia de Buenos Aires, Argentina
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18
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Hassan IA, Wang S, Xu L, Yan R, Song X, Li X. Immunoglobulin and cytokine changes induced following immunization with a DNA vaccine encoding Toxoplasma gondii selenium-dependent glutathione reductase protein. Exp Parasitol 2014; 146:1-10. [DOI: 10.1016/j.exppara.2014.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 08/07/2014] [Accepted: 08/11/2014] [Indexed: 01/30/2023]
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Cong H, Yuan Q, Zhao Q, Zhao L, Yin H, Zhou H, He S, Wang Z. Comparative efficacy of a multi-epitope DNA vaccine via intranasal, peroral, and intramuscular delivery against lethal Toxoplasma gondii infection in mice. Parasit Vectors 2014; 7:145. [PMID: 24685150 PMCID: PMC4229990 DOI: 10.1186/1756-3305-7-145] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 03/21/2014] [Indexed: 12/03/2022] Open
Abstract
Background Toxoplasmosis is an important zoonosis, being a cause of congenital disease and abortion in animals and humans. DNA vaccination as a promising vaccine remains a challenge for an improved delivery system. Methods In this study, attenuated Salmonella typhimurium BRD509 was used to deliver a DNA vaccine encoding several epitopes, derived from the tachyzoite proteins SAG1, GRA1, ROP2, GRA4 and bradyzoite proteins SAG2C, SAG2X of Toxoplasma gondii and A2/B subunit of cholera toxin. The recombinant plasmids were electroporated into attenuated Salmonella typhimurium. Humoral and cellular immune responses were evaluated for BALB/c mice administered with this attenuated recombinant Salmonella vaccine via the oral and nasal route or by intramuscular injection with DNA plasmid directly. Results High IgG levels were present in the mice immunized intramuscularly, while IgA levels were higher in the oral and nasal immunization groups. Furthermore, cellular immunity was activated in oral immunization groups with 60% survival rate following challenge with high virulent RH strain. Conclusions The results from this study indicate that a DNA vaccine encoding multi-epitopes of T. gondii delivered by attenuated Salmonella is promising.
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Affiliation(s)
- Hua Cong
- Department of human parasitology, Medical school, Shandong University, No,44 Wenhuaxi Road, Jinan, Shandong 250012, P, R, China.
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Ocular toxoplasmosis past, present and new aspects of an old disease. Prog Retin Eye Res 2014; 39:77-106. [DOI: 10.1016/j.preteyeres.2013.12.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 12/19/2013] [Accepted: 12/27/2013] [Indexed: 12/22/2022]
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21
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Kur J, Holec-Gąsior L, Hiszczyńska-Sawicka E. Current status of toxoplasmosis vaccine development. Expert Rev Vaccines 2014; 8:791-808. [DOI: 10.1586/erv.09.27] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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22
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Zhao G, Zhou A, Lu G, Meng M, Sun M, Bai Y, Han Y, Wang L, Zhou H, Cong H, Zhao Q, Zhu XQ, He S. Identification and characterization of Toxoplasma gondii aspartic protease 1 as a novel vaccine candidate against toxoplasmosis. Parasit Vectors 2013; 6:175. [PMID: 23768047 PMCID: PMC3691725 DOI: 10.1186/1756-3305-6-175] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 06/09/2013] [Indexed: 11/26/2022] Open
Abstract
Background Toxoplasma gondii is an obligate intracellular parasite that can pose a serious threat to human health by causing toxoplasmosis. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance. Aspartic proteases play essential roles in the T. gondii lifecycle. The parasite has four aspartic protease encoding genes, which are called toxomepsin 1, 2, 3 and 5 (TgASP1, 2, 3 and 5, respectively). Methods Bioinformatics approaches have enabled us to identify several promising linear-B cell epitopes and potential Th-cell epitopes on TgASP1, thus supporting its potential as a DNA vaccine against toxoplasmosis. We expressed TgASP1 in Escherichia coli and used the purified protein to immunize BALB/c mice. The antibodies obtained were used to determine where TgASP1 was localized in the parasite. We also made a TgASP1 DNA vaccine construct and evaluated it for the level of protection conferred to mice against infection with the virulent RH strain of T. gondii. Results TgASP1 appears to be a membrane protein located primarily at the tip of the T. gondii tachyzoite. Investigation of its potential as a DNA vaccine showed that it elicited strong humoral and cellular immune responses in mice, and that these responses were mediated by Th-1 cells. Mice immunized with the vaccine had greater levels of protection against mortality following challenge with T. gondii RH tachyzoites than did those immunized with PBS or the empty vector control. Conclusions TgASP1 is a novel candidate DNA vaccine that merits further investigation.
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Affiliation(s)
- Guanghui Zhao
- Department of Parasitology, Shandong University School of Medicine, Jinan, Shandong Province, People's Republic of China
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Cong H, Zhang M, Xin Q, Wang Z, Li Y, Zhao Q, Zhou H, He S. Compound DNA vaccine encoding SAG1/ SAG3 with A2/B subunit of cholera toxin as a genetic adjuvant protects BALB/c mice against Toxoplasma gondii. Parasit Vectors 2013; 6:63. [PMID: 23497561 PMCID: PMC3622580 DOI: 10.1186/1756-3305-6-63] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 03/11/2013] [Indexed: 01/23/2023] Open
Abstract
Background Intracellular parasites, such as T. gondii, present a plurality of antigens because of the complexity of its life cycle. Compound DNA vaccines bring a new approach and hope for the treatment of toxoplasmosis. In this study, a DNA vaccine encoding two major surface antigens SAG1, SAG3 from T. gondii, with A2/B subunit of cholera toxin as a genetic adjuvant was constructed. Methods BALB/c mice were immunized intramuscularly with PBS, pcDNA3.1, pSAG1, pSAG1/SAG3 and pSAG1/SAG3-CTXA2/B three times separately. Immunized mice were tested for IgG antibody and IFN-γ and IL-4 production by ELISA. The proliferation of T cells was measured by DNA synthesis assay and the lymphocyte subsets of spleen cells by flow cytometry. All the immunized mice were challenged with 103 highly virulent RH tachyzoites of Toxoplasma gondii intraperitoneally and the survival times were recorded. Results An enhanced production of IgG antibodies, antigen-specific lymphocyte proliferation and IFN-γ production from splenic cells were induced in mice immunized with pSAG1/SAG3 compared to mice immunized with pSAG1 (P<0.05). Introduction of CTXA2/B further enhanced the Th1 cell-mediated immunity with higher levels of IFN-γ, lymphocyte proliferation activity and percentage of CD8+ T-cells. When challenged with lethal doses of T. gondii (1×103), all control mice (PBS and empty plasmid group) died within 6 days. Mice immunized with pSAG1 died within 8 days. While 20% and 40% survival rate were achieved from mice immunized with pSAG1/SAG3 and pSAG1/SAG3-CTXA2/B. Conclusions This study indicates the compound DNA vaccine encoding T. gondii antigens SAG1, SAG3 with CTXA2/B gene was a promising DNA vaccine candidate against toxoplasmosis, which could effectively enhance the humoral and cellular immune response and prolong survival time in vaccinated mice.
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Affiliation(s)
- Hua Cong
- Department of human parasitology, Shandong University School of Medicine, No44 wenhuaxi Road, Jinan, Shandong, 250012, PR China.
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Gong P, Huang X, Yu Q, Li Y, Huang J, Li J, Yang J, Li H, Zhang G, Ren W, Zhang X. The protective effect of a DNA vaccine encoding theToxoplasma gondiicyclophilin gene in BALB/c mice. Parasite Immunol 2013; 35:140-146. [DOI: 10.1111/pim.12024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 11/30/2012] [Indexed: 11/29/2022]
Affiliation(s)
- P. Gong
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - X. Huang
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - Q. Yu
- Jilin Provincial Animal Disease Control Centre; Changchun China
| | - Y. Li
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - J. Huang
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - J. Li
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - J. Yang
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - H. Li
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - G. Zhang
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - W. Ren
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
| | - X. Zhang
- College of Animal Science and Veterinary Medicine; Jilin University; Changchun China
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Multicomponent DNA vaccine-encoding Toxoplasma gondii GRA1 and SAG1 primes: anti-Toxoplasma immune response in mice. Parasitol Res 2012; 111:2001-9. [PMID: 22837100 PMCID: PMC3480591 DOI: 10.1007/s00436-012-3047-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 07/10/2012] [Indexed: 12/20/2022]
Abstract
A multicomponent DNA vaccine, encoding Toxoplasma gondii GRA1 and SAG1, was constructed and tested for its ability to confer protection. BALB/c mice were challenged with tachyzoites of the virulent T. gondii RH strain at 4 weeks following the last immunization, and immune responses and survival times were observed. The results show that vaccination by the multicomponent vaccine prolonged survival of mice challenged with the T. gondii RH strain (from average 4.50 ± 0.22 to 7.60 ± 0.74 days); induced high levels of IgG antibody (from 0.252 ± 0.080 to 0.790 ± 0.083), IFN-gamma (from 598.74 ± 67.50 to 853.77 ± 66.74 pg/ml), and IL-2 (from 89.44 ± 10.66 to 192.24 ± 19.90 pg/ml); changed the CD4(+)/CD8(+) lymphocyte ratio (from 1.81 ± 0.14 to 1.09 ± 0.19); and stimulated NK cell-killing activity (from 46.81 ± 3.96 to 64.15 ± 7.71 %). These findings demonstrate that a multicomponent DNA vaccine, encoding GRA1 and SAG1, primes a strong humoral and cellular immune response and enhances protection against T. gondii challenge. The new, combined DNA vaccine provides another means to combat T. gondii infection.
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Li J, Han Q, Gong P, Yang T, Ren B, Li S, Zhang X. Toxoplasma gondii rhomboid protein 1 (TgROM1) is a potential vaccine candidate against toxoplasmosis. Vet Parasitol 2012; 184:154-60. [DOI: 10.1016/j.vetpar.2011.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/04/2011] [Accepted: 08/09/2011] [Indexed: 11/28/2022]
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Khosroshahi KH, Ghaffarifar F, Sharifi Z, D'Souza S, Dalimi A, Hassan ZM, Khoshzaban F. Comparing the effect of IL-12 genetic adjuvant and alum non-genetic adjuvant on the efficiency of the cocktail DNA vaccine containing plasmids encoding SAG-1 and ROP-2 of Toxoplasma gondii. Parasitol Res 2012; 111:403-11. [PMID: 22350714 DOI: 10.1007/s00436-012-2852-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2010] [Accepted: 02/02/2012] [Indexed: 11/28/2022]
Abstract
Various methods are available for enhancing the potency of DNA vaccines, including employment of different forms of adjuvant. The current study was carried out to evaluate and compare the effects of genetic and non-genetic adjuvants on the immune response stimulated by DNA vaccine. Thus, two adjuvants, IL-12 (genetic adjuvant) and aluminum hydroxide (alum, non-genetic adjuvant), were used with cocktail DNA vaccine containing plasmids encoding complete rhoptry antigen 2 (ROP-2) and surface major antigen 1 (SAG-1) of Toxoplasma gondii. The efficacy of pcROP2+pcSAG1 in stimulation of the immune response against toxoplasmosis with and without adjuvant was evaluated in female BALB/c mice by measuring the level of total IgG antibody and cytokines. The results obtained indicated that after challenging the mice with the fatal RH strain of T. gondii, the survival rates of mice immunized with pcROP2+pcSAG1 (DNA cocktail), pcSAG1+pcROP2+alum, and pcSAG1+pcROP2+IL-12 were significantly greater than that of the control groups (p<0.05). Moreover, measurement of total IgG antibody indicated the significant difference between the control and experimental groups (p<0.05). Finally, the results obtained by measurement of cytokines (IFN-γ and IL-4) showed high levels of IFN-γ and low levels of IL-4 in groups vaccinated with pcROP2+pcSAG1 (DNA cocktail), pcSAG1+pcROP2+alum, and pcSAG1+pcROP2+IL-12 as the experiment groups, in comparison with the controls groups (PBS, pc-DNA3, alum+PBS, and pCAGGS-IL-12+pcDNA3). The results of the study showed that use of adjuvants (IL-12 and alum) coincident with DNA cocktail leads to significant change in the survival rates of the experiment groups in comparison with control groups. Also, there is no significant difference between adjuvants to induce immune responses.
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Immune response and protective efficacy against homologous challenge in BALB/c mice vaccinated with DNA vaccine encoding Toxoplasma gondii actin depolymerizing factor gene. Vet Parasitol 2011; 179:1-6. [DOI: 10.1016/j.vetpar.2011.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 01/04/2011] [Accepted: 03/03/2011] [Indexed: 11/21/2022]
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The protective effect of a Toxoplasma gondii SAG1 plasmid DNA vaccine in mice is enhanced with IL-18. Res Vet Sci 2010; 89:93-7. [DOI: 10.1016/j.rvsc.2010.01.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 12/20/2009] [Accepted: 01/12/2010] [Indexed: 11/24/2022]
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Laguía-Becher M, Martín V, Kraemer M, Corigliano M, Yacono ML, Goldman A, Clemente M. Effect of codon optimization and subcellular targeting on Toxoplasma gondii antigen SAG1 expression in tobacco leaves to use in subcutaneous and oral immunization in mice. BMC Biotechnol 2010; 10:52. [PMID: 20633272 PMCID: PMC2920232 DOI: 10.1186/1472-6750-10-52] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 07/15/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Codon optimization and subcellular targeting were studied with the aim to increase the expression levels of the SAG178-322 antigen of Toxoplasma gondii in tobacco leaves. The expression of the tobacco-optimized and native versions of the SAG1 gene was explored by transient expression from the Agrobacterium tumefaciens binary expression vector, which allows targeting the recombinant protein to the endoplasmic reticulum (ER) and the apoplast. Finally, mice were subcutaneously and orally immunized with leaf extracts-SAG1 and the strategy of prime boost with rSAG1 expressed in Escherichia coli was used to optimize the oral immunization with leaf extracts-SAG1. RESULTS Leaves agroinfiltrated with an unmodified SAG1 gene accumulated 5- to 10-fold more than leaves agroinfiltrated with a codon-optimized SAG1 gene. ER localization allowed the accumulation of higher levels of native SAG1. However, no significant differences were observed between the mRNA accumulations of the different versions of SAG1. Subcutaneous immunization with leaf extracts-SAG1 (SAG1) protected mice against an oral challenge with a non-lethal cyst dose, and this effect could be associated with the secretion of significant levels of IFN-gamma. The protection was increased when mice were ID boosted with rSAG1 (SAG1+boost). This group elicited a significant Th1 humoral and cellular immune response characterized by high levels of IFN-gamma. In an oral immunization assay, the SAG1+boost group showed a significantly lower brain cyst burden compared to the rest of the groups. CONCLUSION Transient agroinfiltration was useful for the expression of all of the recombinant proteins tested. Our results support the usefulness of endoplasmic reticulum signal peptides in enhancing the production of recombinant proteins meant for use as vaccines. The results showed that this plant-produced protein has potential for use as vaccine and provides a potential means for protecting humans and animals against toxoplasmosis.
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Affiliation(s)
| | - Valentina Martín
- Escuela de Ciencia y Tecnología, UNSAM, Av. Gral. Paz 5445, San Martin, Argentina
| | - Mauricio Kraemer
- IIB-INTECH, Camino de Circunvalación km 6, Provincia de Buenos Aires, Argentina
| | - Mariana Corigliano
- IIB-INTECH, Camino de Circunvalación km 6, Provincia de Buenos Aires, Argentina
| | - María L Yacono
- IIB-INTECH, Camino de Circunvalación km 6, Provincia de Buenos Aires, Argentina
| | - Alejandra Goldman
- Escuela de Ciencia y Tecnología, UNSAM, Av. Gral. Paz 5445, San Martin, Argentina
| | - Marina Clemente
- IIB-INTECH, Camino de Circunvalación km 6, Provincia de Buenos Aires, Argentina
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Carvalho JA, Rodgers J, Atouguia J, Prazeres DMF, Monteiro GA. DNA vaccines: a rational design against parasitic diseases. Expert Rev Vaccines 2010; 9:175-91. [PMID: 20109028 DOI: 10.1586/erv.09.158] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Parasitic diseases are one of the most devastating causes of morbidity and mortality worldwide. Although immunization against these infections would be an ideal solution, the development of effective vaccines has been hampered by specific challenges posed by parasitic pathogens. Plasmid-based DNA vaccines may prove to be promising immunization tools in this area because vectors can be designed to integrate several antigens from different stages of the parasite life cycle or different subspecies; vaccines, formulations and immunization protocols can be tuned to match the immune response that offers protective immunity; and DNA vaccination is an affordable platform for developing countries. Partial and full protective immunity have been reported following DNA vaccination against the most significant parasitic diseases in the world.
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Affiliation(s)
- Joana A Carvalho
- Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
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Jongert E, Roberts CW, Gargano N, Förster-Waldl E, Förster-Wald E, Petersen E. Vaccines against Toxoplasma gondii: challenges and opportunities. Mem Inst Oswaldo Cruz 2010; 104:252-66. [PMID: 19430651 DOI: 10.1590/s0074-02762009000200019] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 12/04/2008] [Indexed: 12/21/2022] Open
Abstract
Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge.
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Affiliation(s)
- Erik Jongert
- Laboratory for Toxoplasmosis, Pasteur Institute of Brussels, Scientific Institute for Public Health, Brussels, Belgium
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Chen R, Lu SH, Tong QB, Lou D, Shi DY, Jia BB, Huang GP, Wang JF. Protective effect of DNA-mediated immunization with liposome-encapsulated GRA4 against infection of Toxoplasma gondii. J Zhejiang Univ Sci B 2009; 10:512-21. [PMID: 19585669 DOI: 10.1631/jzus.b0820300] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The dense granule protein 4 (GRA4) is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3.1-GRA4 (pGRA4), encoding for the GRA4 antigen, was incorporated by the dehydration-rehydration method into liposomes composed of 16 mmol/L egg phosphatidylcholine (PC), 8 mmol/L dioleoyl phosphatidylethanolamine (DOPE), and 4 mmol/L 1,2-diodeoyl-3-(trimethylammonium) propane (DOTAP). C57BL/6 mice and BALB/c mice were immunized intramuscularly three times with liposome-encapsulated pGRA4 to determine whether DNA immunization could elicit a protective immune response to T. gondii. Enzyme-linked immunosorbent assay (ELISA) of sera from immunized mice showed that liposome-encapsulated pGRA4 generated high levels of IgG antibodies to GRA4. Production of primary interferon (IFN)-gamma and interleukin (IL)-2 in GRA4-stimulated splenocytes from vaccinated mice suggested a modulated Th1-type response. 72.7% of C57BL/6 mice immunized with liposome-encapsulated pGRA4 survived the challenge with 80 tissue cysts of ME49 strain, whereas C57BL/6 mice immunized with pGRA4 had only a survival rate of 54.5%. When immunized BALB/c mice were intraperitoneally challenged with 10(3) tachyzoites of the highly virulent RH strain, the survival time of mice immunized with liposome-encapsulated pGRA4 was markedly longer than that of other groups. Our observations show that liposome-encapsulated pGRA4 enhanced the protective effect against infection of T. gondii.
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Affiliation(s)
- Rui Chen
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China; Institute of Parasitology, Zhejiang Academy of Medical Science, Hangzhou 310013, China
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Wang H, He S, Yao Y, Cong H, Zhao H, Li T, Zhu XQ. Toxoplasma gondii: Protective effect of an intranasal SAG1 and MIC4 DNA vaccine in mice. Exp Parasitol 2009; 122:226-32. [DOI: 10.1016/j.exppara.2009.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 02/19/2009] [Accepted: 04/04/2009] [Indexed: 10/20/2022]
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35
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Shang L, Liu Q, Liu W, Men J, Gao S, Jiang L, Wang Z, Zhai Y, Jin H, Lian H, Chen C, Xia Z, Yuan Z, Zhu XQ. Protection in mice immunized with a heterologous prime-boost regime using DNA and recombinant pseudorabies expressing TgSAG1 against Toxoplasma gondii challenge. Vaccine 2009; 27:2741-5. [DOI: 10.1016/j.vaccine.2009.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 03/03/2009] [Accepted: 03/05/2009] [Indexed: 11/26/2022]
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Toxoplasma rhoptries: unique secretory organelles and source of promising vaccine proteins for immunoprevention of toxoplasmosis. J Biomed Biotechnol 2008; 2008:632424. [PMID: 18670609 PMCID: PMC2486357 DOI: 10.1155/2008/632424] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 03/07/2008] [Accepted: 06/15/2008] [Indexed: 11/18/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite classified in the phylum Apicomplexa, which includes numerous notable human and animal pathogens (Plasmodium species, Cryptosporidium species, Neospora caninum, etc.). The invasive stages of apicomplexans are characterized by the presence of an apical complex composed of specialized cytoskeletal and secretory organelles, including rhoptries. Rhoptries, unique apical secretory organelles shared exclusively by all apicomplexan parasites, are known to be involved in an active parasite's penetration into the host cell associated with the biogenesis of specific intracellular compartment, parasitophorous vacuole in which the parasite multiplies intensively, avoiding intracellular killing. Due to the key biological role of rhoptries, rhoptry proteins have recently become vaccine candidates for the prevention of several parasitoses, toxoplasmosis among them. The article presents current data on T. gondii rhoptries biology and new approaches to the development of effective vaccines against toxoplasmosis using rhoptry antigens.
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Protective effect of a DNA vaccine delivered in attenuated Salmonella typhimurium against Toxoplasma gondii infection in mice. Vaccine 2008; 26:4541-8. [DOI: 10.1016/j.vaccine.2008.06.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Revised: 06/04/2008] [Accepted: 06/10/2008] [Indexed: 11/23/2022]
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Cellular and molecular physiopathology of congenital toxoplasmosis: the dual role of IFN-gamma. Parasitology 2008; 134:1895-902. [PMID: 17958925 DOI: 10.1017/s0031182007000200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Toxoplasma gondii is one of the few pathogens that can cross the placenta. Frequency and severity of transmission vary with gestational age. While the control of acquired toxoplasmosis is already well explored, the control of materno-foetal transmission of the parasite remains almost unknown. This is partly due to the lack of an animal model to study this process. This review summarises the studies which have been undertaken and shows that the mouse is a valuable model despite obvious differences to the human case. The paramount role of the cellular immune response has been shown by several experiments. However, IFN-gamma has a dual role in this process. While its beneficial effects in the control of toxoplasmosis are well known, it also seems to have transmission-enhancing effects and can also directly harm the developing foetus. The ultimate goal of these studies is to develop a vaccine which protects both mother and foetus. Therefore, it is useful to study the mechanisms of natural resistance against transmission during a secondary infection. In this setting, the process is more complicated, involving both cellular and also humoral components of the immune system. In summary, even if the whole process is far from being elucidated, important insights have been gained so far which will help us to undertake rational vaccine research.
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Cui YL, He SY, Xue MF, Zhang J, Wang HX, Yao Y. Protective effect of a multiantigenic DNA vaccine against Toxoplasma gondii with co-delivery of IL-12 in mice. Parasite Immunol 2008; 30:309-13. [PMID: 18331395 DOI: 10.1111/j.1365-3024.2008.01025.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we constructed a multiantigenic DNA vaccine, pSAG1-ROP2-SAG2 and examined its effect with co-delivery of a plasmid encoding IL-12 (pIL-12) as an adjuvant in BALB/c mice against Toxoplasma gondii. After a lethal challenge of T. gondii RH strain, survival of the mice immunized with this pSAG1-ROP2-SAG2 vaccine was significantly prolonged in comparison to the control groups. Furthermore, the protection was significantly augmented by pIL-12 co-delivery. As demonstrated by lymphocyte proliferation assay, cytokine and antibody level determinations, the humoral and Th1-type cellular responses elicited by this multiantigenic DNA vaccine were significantly stronger than those elicited by double-antigenic, or single-antigenic DNA vaccines. Our data suggest that multiantigenic DNA vaccine with pIL-12 co-delivery is a very effective approach in the protection against T. gondii.
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Affiliation(s)
- Y-L Cui
- Department of Parasitology, School of Medicine, Shandong University, Shandong, China
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40
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Gatkowska J, Gasior A, Kur J, Dlugonska H. Toxoplasma gondii: Chimeric Dr fimbriae as a recombinant vaccine against toxoplasmosis. Exp Parasitol 2008; 118:266-70. [PMID: 17825290 DOI: 10.1016/j.exppara.2007.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 07/10/2007] [Accepted: 07/16/2007] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii is responsible for fetopathy in farm animals and humans and severe disease in immunocompromised individuals (i.e. AIDS patients). Effective vaccines, inducing protective and long-lasting immunity to this global parasite, are still desired. In the work, we evaluated the immunogenic and immunoprotective activity of Escherichia coli chimeric Dr fimbriae bearing selected antigenic epitopes of three T. gondii antigens (SAG1, GRA1 and MAG1), in comparison with conventional recombinant antigens obtained in E. coli expression system. Our data demonstrate a very high protective efficacy of recombinant antigens supplemented with Freund's adjuvants, whereas chimeric Dr fimbriae as a vaccine proved non-protective. The recombinant antigen vaccine induced a strong specific antibody response and prevented the brain cysts formation by 89%. The results are promising and should be confirmed in further study on farm animals by use of less aggressive than Freund's adjuvant preparations.
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Affiliation(s)
- Justyna Gatkowska
- Department of Immunoparasitology, University of Lodz, Banacha Str. 12/16, 90-237 Lodz, Poland.
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41
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Immunological control of congenital toxoplasmosis in the murine model. Immunol Lett 2008; 115:83-9. [DOI: 10.1016/j.imlet.2007.10.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2007] [Revised: 10/09/2007] [Accepted: 10/12/2007] [Indexed: 11/23/2022]
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Jongert E, de Craeye S, Dewit J, Huygen K. GRA7 provides protective immunity in cocktail DNA vaccines against Toxoplasma gondii. Parasite Immunol 2007; 29:445-53. [PMID: 17727568 DOI: 10.1111/j.1365-3024.2007.00961.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In a previous study, single-gene vaccination with GRA1, GRA7 or ROP2 was shown to elicit partial protection against Toxoplasma gondii. In this study, the contribution of each antigen in the evoked humoral and cellular immune responses was evaluated after vaccination with plasmid mixtures containing GRA1, GRA7 and ROP2. Cocktail DNA vaccinated mice developed high antibody titers against the antigens from two-gene DNA vaccine cocktails, but lower titres when immunized with the three-gene cocktail. High numbers of IFN-gamma secreting splenocytes were generated predominantly against GRA7. Brain cyst burden was reduced by 81% in mice vaccinated with the three-gene mixture and they were completely protected against acute toxoplasmosis. Similar high levels of brain cyst reductions were obtained after vaccination with cocktails composed of GRA1 and GRA7 (89% reduction), or GRA7 and ROP2 (79% reduction), but not with the cocktail composed of GRA1 and ROP2. In low dose single-gene vaccinations, IFN-gamma and strong protection could only be elicited by GRA7. Hence, the presence of GRA7 in the DNA vaccine formulation was important for optimal protection and this was correlated with GRA7-specific IFN-gamma production. We propose GRA7 as a main component in cocktail DNA vaccines for vaccination against T. gondii.
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Affiliation(s)
- E Jongert
- Toxoplasma Research Unit, WIV-Pasteur Institute of Brussels (Federal Service of Public Health), Brussels, Belgium.
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Lee YH, Shin DW, Lee JH, Nam HW, Ahn MH. Vaccination against murine toxoplasmosis using recombinant Toxoplasma gondii SAG3 antigen alone or in combination with Quil A. Yonsei Med J 2007; 48:396-404. [PMID: 17594146 PMCID: PMC2628080 DOI: 10.3349/ymj.2007.48.3.396] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Surface antigen 3 (SAG3) of Toxoplasma gondii is very similar in structure to the major surface antigen 1 (SAG1). Although numerous studies have supported the importance of SAG1 in protection against T. gondii infection, few reports exist on SAG3. MATERIALS AND METHODS Glutathione-S-transferase (GST)-fused SAG3 of T. gondii (rSAG3) were immunized into BALB/c mice alone or in combination with Quil A (rSAG3/Quil A), and then evaluated the protective immunity in vivo and in vitro against murine toxoplasmosis. RESULTS Immunization with rSAG3 or rSAG3/Quil A resulted in significantly more survival days and fewer brain cysts after challenge with T. gondii compared to an infected control group. Mice immunized with rSAG3 alone or in combination with Quil A produced significantly more specific IgG2a antibody, whereas specific IgG1 antibody titers did not increase. The percentage of CD8+ T cells, IFN-gamma mRNA expression, and nitric oxide production significantly increased in rSAG3- and rSAG3/Quil A-immunized mice. CONCLUSION These results indicate that vaccination with Toxoplasma rSAG3 results in partial protective immunity against T. gondii infection through induction of a Th1-type immune response, and that protective immunity is accelerated by the modulating effects of Quil A.
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Affiliation(s)
- Young-Ha Lee
- Department of Infection Biology, College of Medicine, Chungnam National University, 6 Munwha-dong, Jung-gu, Daejeon 301-131, Korea.
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Golkar M, Shokrgozar MA, Rafati S, Musset K, Assmar M, Sadaie R, Cesbron-Delauw MF, Mercier C. Evaluation of protective effect of recombinant dense granule antigens GRA2 and GRA6 formulated in monophosphoryl lipid A (MPL) adjuvant against Toxoplasma chronic infection in mice. Vaccine 2007; 25:4301-11. [PMID: 17418457 DOI: 10.1016/j.vaccine.2007.02.057] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2006] [Revised: 02/16/2007] [Accepted: 02/20/2007] [Indexed: 10/23/2022]
Abstract
To investigate the vaccine potential of both the Toxoplasma GRA2 and GRA6 antigens, the full length recombinant proteins were produced in Escherichia coli, formulated in MPL adjuvant, and used alone and in combination ("mix"), to immunize CBA/J mice. Although high ratios of specific IgG2a/IgG1 were measured against both proteins, only spleen cells from GRA2-immunized mice and mix-immunized mice produced high amounts of both IFN-gamma and IL-2 upon induction with Toxoplasma gondii Excretory-Secretory Antigens. Intra peritoneal challenge with Toxoplasma cysts resulted in significant reduction of brain cysts in GRA2- and in mix-vaccinated mice only. This study shows the protective efficacy of recombinant GRA2 against chronic infection by T. gondii and confirms the utility of MPL adjuvant in enabling a vaccine candidate to induce a protective Th1 immune response.
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MESH Headings
- Adjuvants, Immunologic
- Animals
- Antibodies, Protozoan/blood
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/isolation & purification
- Brain/parasitology
- Cytokines/immunology
- Disease Models, Animal
- Escherichia coli/genetics
- Humans
- Lipid A/analogs & derivatives
- Lipid A/immunology
- Mice
- Mice, Inbred CBA
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/isolation & purification
- Protozoan Vaccines/immunology
- Th1 Cells/immunology
- Toxoplasma/immunology
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/prevention & control
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
- Vaccines, Subunit/isolation & purification
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Vaccines, Synthetic/isolation & purification
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Affiliation(s)
- Majid Golkar
- CNRS UMR 5163 - Université Joseph Fourier, UFR de Biologie, Institut Jean Roget, Campus Santé, Domaine de la Merci. BP 170, 38042 Grenoble cedex 09, France
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45
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Innes EA, Vermeulen AN. Vaccination as a control strategy against the coccidial parasitesEimeria,ToxoplasmaandNeospora. Parasitology 2007; 133 Suppl:S145-68. [PMID: 17274844 DOI: 10.1017/s0031182006001855] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The protozoan parasitesEimeriaspp.Toxoplasma gondiiandNeospora caninumare significant causes of disease in livestock worldwide andT. gondiiis also an important human pathogen. Drugs have been used with varying success to help control aspects of these diseases and commercial vaccines are available for all three groups of parasites. However, there are issues with increasing development of resistance to many of the anti-coccidial drugs used to help control avian eimeriosis and public concerns about the use of drugs in food animals. In addition there are no drugs available that can act against the tissue cyst stage of eitherT. gondiiorN. caninumand thus cure animals or people of infection. All three groups of parasites multiply within the cells of their host species and therefore cell mediated immune mechanisms are thought to be an important component of host protective immunity. Successful vaccination strategies for bothEimeriaandToxoplasmahave relied on using a live vaccination approach using attenuated parasites which allows correct processing and presentation of antigen to the host immune system to stimulate appropriate cell mediated immune responses. However, live vaccines can have problems with safety, short shelf-life and large-scale production; therefore there is continued interest in devising new vaccines using defined recombinant antigens. The major challenges in devising novel vaccines are to select relevant antigens and then present them to the immune system in an appropriate manner to enable the induction of protective immune responses. With all three groups of parasites, vaccine preparations comprising antigens from the different life cycle stages may also be advantageous. In the case ofEimeriaparasites there are also problems with strain-specific immunity therefore a cocktail of antigens from different parasite strains may be required. Improving our knowledge of the different parasite transmission routes, host-parasite relationships, disease pathogenesis and determining the various roles of the host immune response being at times host-protective, parasite protective and in causing immunopathology will help to tailor a vaccination strategy against a particular disease target. This paper discusses current vaccination strategies to help combat infections withEimeria,ToxoplasmaandNeosporaand recent research looking towards developing new vaccine targets and approaches.
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Affiliation(s)
- E A Innes
- Moredun Research Institute, Pentlands Science Park, Edinburgh EH26 OPZ, UK.
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46
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Döşkaya M, Kalantari-Dehaghi M, Walsh CM, Hiszczyńska-Sawicka E, Davies DH, Felgner PL, Larsen LSZ, Lathrop RH, Hatfield GW, Schulz JR, Gürüz Y, Jurnak F. GRA1 protein vaccine confers better immune response compared to codon-optimized GRA1 DNA vaccine. Vaccine 2007; 25:1824-37. [PMID: 17234306 DOI: 10.1016/j.vaccine.2006.10.060] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 10/26/2006] [Accepted: 10/30/2006] [Indexed: 01/15/2023]
Abstract
The present study evaluates immunogenicity and protection potency of a codon-optimized GRA1 DNA vaccine, wild type GRA1 DNA vaccine and an adjuvanted recombinant GRA1 protein vaccine candidate in BALB/c mice against lethal toxoplasmosis. Of the three GRA1 vaccines tested, the recombinant GRA1 protein vaccine results reveal significant increase in immune response and prolonged survival against acute toxoplasmosis compared to DNA vaccinations. Immune response and protection conferred by codon-optimized GRA1 DNA vaccine was slightly better than wild type GRA1 DNA vaccine.
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Affiliation(s)
- Mert Döşkaya
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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Zhang J, Gu Q, Hou X, Zhou H, Cong H, Li Y, Zhao Q, Li S. Identification of a necessary element for Toxoplasma gondii SAG1 gene expression. Exp Parasitol 2007; 116:175-81. [PMID: 17258203 DOI: 10.1016/j.exppara.2006.11.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2006] [Revised: 11/26/2006] [Accepted: 11/29/2006] [Indexed: 10/23/2022]
Abstract
SAG1 codes for the stage-specific major surface antigen P30 of Toxoplasma gondii (T. gondii) tachyzoites. Six tandemly repeated, conserved 27 bp cassettes in the region from -231 to -70 bp were previously confirmed to be essential for high-level expression of SAG1 and serve as a positioning element directing the initiation of transcription. We demonstrate here that an element located between +19 and +28 bp is necessary for SAG1 gene expression by using deletion mutagenesis analysis and electrophoresis mobility shift assay (EMSA). This will provide an insight into the regulatory mechanisms of SAG1 gene expression.
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Affiliation(s)
- Jiaqin Zhang
- Department of Parasitology, School of Medicine, Shandong University, and Nephrology Department, The Second Hospital of Shandong University, PR China
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Freyre A, Falcón J, Mendez J, González M. Toxoplasma gondii: Differential protection rates by two strains against cyst formation in a rat model. Exp Parasitol 2006; 114:265-70. [PMID: 16709408 DOI: 10.1016/j.exppara.2006.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 04/04/2006] [Accepted: 04/04/2006] [Indexed: 10/24/2022]
Abstract
A previous infection with the ME-49 strain of Toxoplasma gondii (of low pathogenicity for mice), protected 17 of 20 rats against formation of brain cysts, following challenge with 10(3) oocysts of the high pathogenicity M3 strain, as determined by bioassay of rat brains in mice. The low pathogenic KSU strain did not afford comparable protection. Protection was further tested in rats that were orally or subcutaneously immunized with cysts or oocysts of the ME-49 strain, and later challenged with 2 x 10(2) cysts or 10(2) oocysts of the highly pathogenic strains M3, M-7741 and C. Protection ranged from 43 to 100%, compared to non immunized control rats and was independent of the stage of ME-49 strain and of the routes used to immunize the rats. The results obtained encourage further investigation into prevention of toxoplasmosis in humans and food animals.
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Affiliation(s)
- A Freyre
- Laboratorio de Toxoplasmosis, Departamento de Parasitología, Facultad de Veterinaria, Alberto Lasplaces 1550, Montevideo, Uruguay.
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Caetano BC, Bruña-Romero O, Fux B, Mendes EA, Penido MLO, Gazzinelli RT. Vaccination with replication-deficient recombinant adenoviruses encoding the main surface antigens of toxoplasma gondii induces immune response and protection against infection in mice. Hum Gene Ther 2006; 17:415-26. [PMID: 16610929 DOI: 10.1089/hum.2006.17.415] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have generated recombinant adenoviruses encoding three genetically modified surface antigens (SAGs) of the parasite Toxoplasma gondii, that is, AdSAG1, AdSAG2, and AdSAG3. Modifications included the removal of their glycosylphosphatidylinositol (GPI) anchoring motifs and, in some cases, the exchange of the native signal peptide for influenza virus hemagglutinin signal sequence. Adenovirus immunization of BALB/c mice elicited potent antibody responses against each protein, displaying a significant bias toward a helper T cell type 1 (Th1) profile in animals vaccinated with AdSAG1. Furthermore, the presence of parasite-specific IFN-gamma-producing T cells was analyzed by proliferation assays and enzyme-linked immunospot assays in the same animals. Splenocytes from immunized mice secreted IFN-gamma after in vitro stimulation with tachyzoite lysate antigen or with a fraction enriched for membrane-purified GPI-anchored proteins (F3) from the T. gondii tachyzoite surface. Epitopes recognized by CD8+ T cells were identified in SAG1 and SAG3, but not SAG2, sequences, although this protein also induced a specific response. We also tested the capacity of the immune responses detected to protect mice against a challenge with live T. gondii parasites. Although no protection was observed against tachyzoites of the highly virulent RH strain, a significant reduction in cyst loads in the brain was observed in animals challenged with the P-Br strain. Thus, up to 80% of the cysts were eliminated from animals vaccinated with a mixture of the three recombinant viruses. Because adenoviruses seemed capable of inducing Th1-biased protective immune responses against T. gondii antigens, other parasite antigens should be tested alone or in combination with those described here to further develop a protective vaccine against toxoplasmosis.
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MESH Headings
- Adenoviridae
- Animals
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Female
- Gene Deletion
- Immunity, Active
- Immunity, Cellular
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/immunology
- Mice
- Mice, Inbred BALB C
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Vaccines/genetics
- Protozoan Vaccines/immunology
- Recombination, Genetic
- Toxoplasma/immunology
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/prevention & control
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Virus Replication/genetics
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Affiliation(s)
- Bráulia C Caetano
- Laboratório de Imunoparasitologia, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
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Caetano BC, Bruna-Romero O, Fux B, Mendes EA, Penido MLO, Gazzinelli RT. Vaccination with Replication-Deficient Recombinant Adenoviruses Encoding the Main Surface Antigens of Toxoplasma gondii Induces Immune Response and Protection Against Infection in Mice. Hum Gene Ther 2006. [DOI: 10.1089/hum.2006.17.ft-199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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