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Ma ZY, Wu XJ, Li C, Gao J, Kou YJ, Wang M, Zhu XQ, Zheng XN. Functional Characterization of 11 Tentative Microneme Proteins in Type I RH Strain of Toxoplasma gondii Using the CRISPR-Cas9 System. Animals (Basel) 2024; 14:2543. [PMID: 39272328 PMCID: PMC11394663 DOI: 10.3390/ani14172543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2024] [Revised: 08/28/2024] [Accepted: 08/30/2024] [Indexed: 09/15/2024] Open
Abstract
Toxoplasma gondii, a pathogenic apicomplexan parasite, infects approximately one third of the world's population and poses a serious threat to global public health. Microneme proteins (MICs) secreted by the microneme, an apical secretory organelle of T. gondii, play important roles in the invasion, motility, and intracellular survival of T. gondii. In this study, we selected 11 genes of interest (GOIs) of T. gondii, tentative MICs predicted to be localized in micronemes, and we used the CRISPR-Cas9 system to construct epitope tagging strains and gene knockout strains to explore the localization and function of these 11 tentative MICs. Immunofluorescence assay showed that nine tentative MICs (TGME49_243930, TGME49_200270, TGME49_273320, TGME49_287040, TGME49_261710, TGME49_205680, TGME49_304490, TGME49_245485, and TGME49_224620) were localized or partially localized in the microneme, consistent with the prediction. However, TGME49_272380 and TGME49_243790 showed different localizations from the prediction, being localized in the endoplasmic reticulum and the dense granule, respectively. Further functional characterization of the 11 RHΔGOI strains revealed that deletion of these 11 GOIs had no significant effect on plaque formation, intracellular replication, egress, invasion ability, and virulence of T. gondii. Although these 11 GOIs are not essential genes for the growth and virulence of tachyzoites of type I RH strain, they may have potential roles in other developmental stages or other genotypes of T. gondii. Thus, further research should be performed to explore the possible role of the nine mics and the other two GOIs in other life cycle stages and other genotypes of T. gondii.
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Affiliation(s)
- Zhi-Ya Ma
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Xiao-Jing Wu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Chuan Li
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Jin Gao
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Yong-Jie Kou
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Meng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
| | - Xiao-Nan Zheng
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
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Eissa MM, Gaafar MR, Younis LK, Ismail CA, El Skhawy N. Prophylactic antineoplastic activity of Toxoplasma gondii RH derived antigen against ehrlich solid carcinoma with evidence of shared antigens by comparative immunoblotting. Infect Agent Cancer 2023; 18:21. [PMID: 37029378 PMCID: PMC10082516 DOI: 10.1186/s13027-023-00500-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/22/2023] [Indexed: 04/09/2023] Open
Abstract
BACKGROUND With cancer cases escalation, an urgent request to develop novel combating strategies arise. Pathogen-based cancer-immunotherapy is getting more consideration. Autoclaved parasitic antigens seem promising candidates, taking steadily their first steps. Our aim was to examine the prophylactic antineoplastic activity of autoclaved Toxoplasma vaccine (ATV) and to test for the shared antigen theory between Toxoplasma gondii and cancer cells. METHODS Mice were immunized with ATV followed by Ehrlich solid carcinoma (ESC) inoculation. Tumor weight, volume, histopathology, and immunohistochemistry for CD8+ T cells, Treg cells and VEGF were assessed. In addition, the proposed shared antigen theory between parasites and cancer was also verified using SDS-PAGE and immunoblotting. RESULTS Results revealed powerful prophylactic activity of ATV with 13.3% inhibition of ESC incidence, significant reduction in tumor weight and volume in ATV vaccinated mice. Immunologically, significantly higher CD8+T cells and lower FOXP3+ Treg cells surrounded and infiltrated ESC in ATV immunized mice with higher CD8+T/Treg cells ratio and significant antiangiogenic effect. Moreover, SDS-PAGE and immunoblotting showed four shared bands between Ehrlich carcinoma and ATV of approximate molecular weights 60, 26, 22 and 12.5 KDa. CONCLUSION Exclusively, we demonstrated a prophylactic antineoplastic activity of autoclaved Toxoplasma vaccine against ESC. Moreover, to the best of our knowledge this is the first report highlighting the existence of cross-reactive antigens between Toxoplasma gondi parasite and cancer cells of Ehrlich carcinoma.
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Affiliation(s)
- Maha M Eissa
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Maha R Gaafar
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Layla K Younis
- Department of Pathology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Cherine A Ismail
- Department of Clinical Pharmacology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Nahla El Skhawy
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
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Ismail CA, Eissa MM, Gaafar MR, Younis LK, El Skhawy N. Toxoplasma gondii-derived antigen modifies tumor microenvironment of Ehrlich solid carcinoma murine model and enhances immunotherapeutic activity of cyclophosphamide. Med Oncol 2023; 40:136. [PMID: 37014499 PMCID: PMC10073061 DOI: 10.1007/s12032-023-01994-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/08/2023] [Indexed: 04/05/2023]
Abstract
Pathogen-based cancer vaccine is a promising immunotherapeutic weapon to stimulate cancer immunosuppressive state. Toxoplasma gondii is a potent immunostimulant, and low-dose infection was linked to cancer resistance. Our goal was to evaluate the therapeutic antineoplastic activity of autoclaved Toxoplasma vaccine (ATV) against Ehrlich solid carcinoma (ESC) in mice in reference to and in combination with low-dose cyclophosphamide (CP), a cancer immunomodulator. Mice inoculation with ESC was followed by applying different treatment modalities including ATV, CP, and CP/ATV. We evaluated the impact of the different treatments on liver enzymes and pathology, tumor weight, volume, and histopathological changes. Using immunohistochemistry, we evaluated CD8+ T cell, FOXP3+ Treg, CD8+/Treg outside and inside ESC, and angiogenesis. Results showed significant tumor weights and volumes reduction with all treatments with 13.3% inhibition of tumor development upon combined CP/ATV use. Significant necrosis and fibrosis were noted in ESC by all treatments with improved hepatic functions versus non-treated control. Although ATV was almost equivalent to CP in tumor gross and histopathology, it promoted an immunostimulatory activity with significant Treg cells depletion outside ESC and CD8+ T cells infiltration inside ESC with higher CD8+ T/Treg ratio inside ESC superior to CP. Combined with CP, ATV exhibited significant synergistic immunotherapeutic and antiangiogenic action compared to either treatment alone with significant Kupffer cells hyperplasia and hypertrophy. Exclusively, therapeutic antineoplastic and antiangiogenic activity of ATV against ESC was verified that boosted CP immunomodulatory action which highlights a novel biological cancer immunotherapeutic vaccine candidate.
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Affiliation(s)
- Cherine A Ismail
- Department of Clinical Pharmacology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Maha M Eissa
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Maha R Gaafar
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Layla K Younis
- Department of Pathology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Nahla El Skhawy
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
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Allam AF, Hagras NAE, Farag HF, Osman MM, Shalaby TI, Kazem AH, Shehab AY, Mogahed NMFH. Remarkable histopathological improvement of experimental toxoplasmosis after receiving spiramycin-chitosan nanoparticles formulation. J Parasit Dis 2022; 46:166-177. [PMID: 35299902 PMCID: PMC8901813 DOI: 10.1007/s12639-021-01431-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 08/01/2021] [Indexed: 11/28/2022] Open
Abstract
The present study investigated the anti-Toxoplasma effect of chitosan nanoparticles [CS NPs], spiramycin, spiramycin co-administered with metronidazole and spiramycin-CS NPs formulation on the parasite burden and histopathological changes in the liver, spleen and brain in experimentally infected mice. Seventy male Swiss albino mice were classified into seven equal groups: healthy control (I), infected untreated control (II), infected group receiving CS NPs (III), spiramycin administered infected group (IV), infected group receiving spiramycin-metronidazole (V), infected receiving 400 mg/kg spiramycin-CS NPs (VI) and infected treated with spiramycin-loaded CS NPs 100 mg/kg (VII). All groups were inoculated intraperitoneally with 2500 T. gondii tachyzoites RH strain except the healthy control group. All groups were sacrificed on the 8th day after infection. Density of the parasite and histopathological examination of the liver, spleen and brain of all treated mice revealed reduction in the mean tachyzoites count as well as decreased inflammation, congestion and necrosis within tissue sections. Spiramycin-loaded NPs displayed the highest significant reduction in the pathological insult tailed by spiramycin-metronidazole and CS NPs. In conclusion, spiramycin-loaded CS NPs showed a promising synergistic combination in the treatment of the histopathology caused by toxoplasmosis.
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Affiliation(s)
- Amal Farahat Allam
- Department of Parasitology, Medical Research Institute, Alexandria University, 165 El Horreya Avenue, El Hadara, Alexandria, Egypt
| | - Nancy Abd-elkader Hagras
- Department of Medical Laboratory, Faculty of Applied Health Sciences Technology, Pharos University in Alexandria, Alexandria, Egypt
| | - Hoda Fahmy Farag
- Department of Parasitology, Medical Research Institute, Alexandria University, 165 El Horreya Avenue, El Hadara, Alexandria, Egypt
| | - Mervat Mostafa Osman
- Department of Parasitology, Medical Research Institute, Alexandria University, 165 El Horreya Avenue, El Hadara, Alexandria, Egypt
| | - Thanaa Ibrahim Shalaby
- Department of Medical Biophysics, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Amani Hussein Kazem
- Department of Pathology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Amel Youssef Shehab
- Department of Parasitology, Medical Research Institute, Alexandria University, 165 El Horreya Avenue, El Hadara, Alexandria, Egypt
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Gaafar MR, El-Mansoury ST, Eissa MM, Shalaby TI, Younis LK, Rashed HA. Effect of alginate nanoparticles on the immunogenicity of excretory-secretory antigens against acute toxoplasmosis in murine model. Acta Trop 2022; 225:106215. [PMID: 34687647 DOI: 10.1016/j.actatropica.2021.106215] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 08/08/2021] [Accepted: 10/19/2021] [Indexed: 11/18/2022]
Abstract
Efficacy of alginate nanoparticles (Alg-NPs) as vaccine delivery for the excretory-secretory antigens (ESAs) against the virulent strain of Toxoplasma gondii was evaluated. Swiss albino mice were intraperitoneally immunized with three doses of either in vivo and in vitro-prepared ESA vaccines, 20 µg each, at 2-week intervals, then were challenged with 2500 tachyzoites of the RH HXGPRT (-) Toxoplasma gondii strain, four weeks later. Mice mortality, tachyzoite number in both peritoneal fluid and impression smear, and viability, ultrastructural tachyzoite changes, measuring immunological markers, and histopathological changes of both liver and spleen were studied, in comparison to alum adjuvanted ESAs and infected control subgroups. The in vivo-prepared Alg-NPs loaded ESAs vaccinated subgroups induced significant reduction in mice mortality, tachyzoite count in both peritoneal fluid and impression smears and viability. Scanning electron microscopy revealed tachyzoites deformities with multiple irregularities, while transmission electron microscopy showed tachyzoites distortion, disrupted plasma membranes, loss of nuclear integrities, and absence of dense granules with extensive vacuolations. A statistically significant increase in the level of both IFN-γ and anti-Toxoplasma IgG was noted. Histopathological results recorded amelioration of the pathological changes induced by Toxoplasma infection in both liver and spleen, with scanty parasites. Therefore, Alg-NPs proved its effectiveness in enhancing the ESAs antigencity, and recommended to test its potentiality as drugs carrier for anti-Toxoplasma agents to enhance their therapeutic efficacy.
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Affiliation(s)
- Maha R Gaafar
- Medical Parasitology Department, Faculty of Medicine, Alexandria University, Egypt.
| | - Salwa T El-Mansoury
- Medical Parasitology Department, Faculty of Medicine, Alexandria University, Egypt
| | - Maha M Eissa
- Medical Parasitology Department, Faculty of Medicine, Alexandria University, Egypt
| | - Thanaa I Shalaby
- Medical Biophysics Department, Medical Research Institute, Alexandria University, Egypt
| | - Layla K Younis
- Pathology Department, Faculty of Medicine, Alexandria University, Egypt
| | - Hoda A Rashed
- Medical Parasitology Department, Faculty of Medicine, Alexandria University, Egypt
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Fan X, Zhang Y, Ouyang R, Luo B, Li L, He W, Liu M, Jiang N, Yang F, Wang L, Zhou B. Cysticercus cellulosae Regulates T-Cell Responses and Interacts With the Host Immune System by Excreting and Secreting Antigens. Front Cell Infect Microbiol 2021; 11:728222. [PMID: 34540719 PMCID: PMC8447960 DOI: 10.3389/fcimb.2021.728222] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/06/2021] [Indexed: 11/26/2022] Open
Abstract
Cysticercus cellulosae (C. cellulosae) excretes and secretes antigens during the parasitic process to regulate the host immune response; however, resulting immune response and cytokine production in the host during infection still remains unclear. We used C. cellulosae crude antigens (CAs) as controls to explore the effect of excretory secretory antigens (ESAs) on T-cell immune responses in piglets. C. cellulosae ESAs induced imbalanced CD4+/CD8+ T-cell proportions, increased the CD4+Foxp3+ and CD8+Foxp3+ T-cell frequencies, and induced lymphocytes to produce interleukin-10, which was mainly attributed to CD4+ and CD4-CD8- T cells. The ESAs also induced Th2-type immune responses. The results showed that the ability of C. cellulosae to escape the host immune attacks and establish a persistent infection may be related to host immune response regulation by the ESAs.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Biying Zhou
- Department of Parasitology, School of Basic Medical Sciences, Zunyi Medical University, Zunyi, China
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Ghaffari AD, Dalimi A, Ghaffarifar F, Pirestani M, Majidiani H. Immunoinformatic analysis of immunogenic B- and T-cell epitopes of MIC4 protein to designing a vaccine candidate against Toxoplasma gondii through an in-silico approach. Clin Exp Vaccine Res 2021; 10:59-77. [PMID: 33628756 PMCID: PMC7892946 DOI: 10.7774/cevr.2021.10.1.59] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/25/2021] [Indexed: 12/21/2022] Open
Abstract
Purpose Toxoplasmosis, transmitted by Toxoplasma gondii, is a worldwide parasitic disease that affects approximately one-third of the world's inhabitants. Today, there are no appropriate drugs to deter tissue cysts from developing in infected hosts. So, developing an effective vaccine would be valuable to avoid from toxoplasmosis. Considering the role of microneme antigens such as microneme protein 4 (MIC4) in T. gondii pathogenesis, it can be used as potential candidates for vaccine against T. gondii. Materials and Methods In this study several bioinformatics methods were used to assess the different aspects of MIC4 protein such as secondary and tertiary structure, physicochemical characteristics, the transmembrane domains, subcellular localization, B-cell, helper-T lymphocyte, cytotoxic-T lymphocyte epitopes, and other notable characteristic of this protein design a suitable vaccine against T. gondii. Results The studies revealed that MIC4 protein includes 59 potential post-translational modification sites without any transmembrane domains. Moreover, several probable epitopes of B- and T-cells were detected for MIC4. The secondary structure comprised 55.69% random coil, 5.86% beta-turn, 19.31% extended strand, and 19.14% alpha helix. According to the Ramachandran plot results, 87.42% of the amino acid residues were located in the favored, 9.44% in allowed, and 3.14% in outlier regions. The protein allergenicity and antigenicity revealed that it was non-allergenic and antigenic. Conclusion This study gives vital basic on MIC4 protein for further research and also established an effective vaccine with different techniques against acute and chronic toxoplasmosis.
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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
| | - Hamidreza Majidiani
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Yang WB, Wang JL, Gui Q, Zou Y, Chen K, Liu Q, Liang QL, Zhu XQ, Zhou DH. Immunization With a Live-Attenuated RH:Δ NPT1 Strain of Toxoplasma gondii Induces Strong Protective Immunity Against Toxoplasmosis in Mice. Front Microbiol 2019; 10:1875. [PMID: 31456786 PMCID: PMC6701201 DOI: 10.3389/fmicb.2019.01875] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/29/2019] [Indexed: 12/14/2022] Open
Abstract
Toxoplasmosis, one of the most important health-threatening diseases worldwide, is caused by Toxoplasma gondii, which infects a wide range of warm-blooded animals and humans, leading to enormous health and socioeconomic concerns. T. gondii can establish chronic infection to evade the immune response in hosts. Once a chronic infection has been established, the available treatments cannot efficiently control this stage of T. gondii efficiently. Moreover, the available treatments rely only on a few drugs, such as sulfapyridine and pyrimethamine, that tend to have severe side effects. Given these factors, vaccination has been considered to be the most efficient method to prevent and control this disease. However, there is currently lack of effective vaccine available for use to prevent toxoplasmosis apart form Toxovax®, the only available vaccine, which is used in sheep to prevent abortion. To address this problem, we knocked out the NPT1 gene of the type I T. gondii strain using the CRISPR-Cas9 system, constructed a live-attenuated vaccine and evaluated its protective efficacy in a mouse model. Immunization of mice with RH:ΔNPT1 induced a high level of Toxoplasma-specific IgG1, IgG2a and total IgG 42 days after immunization. There was a significant increase in the levels of cytokines in the splenocyte suspensions of RH:ΔNPT1-infected mice, and a mixed Th1/Th2 response was induced in the mice. Remarkably, after heterologous challenges with tachyzoites of the RH, PYS and Pru strains and cysts of the Pru strain by different infection routes, the immunized animals were protected from toxoplasmosis with a 100% survival rate, in both acute and chronic infection. In addition, compared with control mice, the Pru cyst load was clearly reduced in the brains of RH:ΔNPT1-infected immunization-mice. Our study demonstrated that the RH:ΔNPT1 strain was able to evoke strong anti-Toxoplasma immune responses and provide effective protection against parasite strains with different levels of virulence, suggesting that the RH:ΔNPT1 strain may represent a promising live-attenuated vaccine against toxoplasmosis, which is worthy of further evaluation in food-producing animals and in definitive feline host.
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Affiliation(s)
- Wen-Bin Yang
- Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- 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
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Jin-Lei 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
| | - Qian Gui
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yang Zou
- 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
| | - Kai Chen
- 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
| | - Qing Liu
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - Qin-Li Liang
- 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
| | - 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
| | - Dong-Hui Zhou
- Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
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The course of infection with Toxoplasma gondii RH strain in mice pre-vaccinated with gamma irradiated tachyzoites. Exp Parasitol 2019; 205:107733. [PMID: 31408623 DOI: 10.1016/j.exppara.2019.107733] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 08/01/2019] [Accepted: 08/02/2019] [Indexed: 11/23/2022]
Abstract
Toxoplasma gondii is a ubiquitous protozoan of major medical and veterinary importance. Its treatment is difficult since the available drugs have severe side effects and reactivation may occur anytime. Vaccination with irradiated parasites exhibits ideal characteristics for vaccine development. In our experimental mice model, the protection against challenge with the virulent RH strain was assessed, using 255Gy irradiated tachyzoites. Eighty mice were allocated into 3 groups: naive control group, challenged with virulent RH tachyzoites group and a third group which is challenged with 1 × 106 irradiated tachyzoites, administered as two biweekly doses intraperitoneally. Protection was tested by challenging vaccinated mice with the virulent type RH tachyzoites 30 days after the 2nd vaccination dose. The assessment was built on qualitative clinical, quantitative parasitological, histopathological parameters and measurement of serum Nitric Oxide (NO). The results showed prolonged survival rate, absence of tachyzoites in the peritoneal aspirate by counting, absence of tachyzoites in all examined organs by impression smears, amelioration of histopathological changes in the liver, spleen, brain and lung specimens and increase of the serum NO level in the vaccinated group. Therefore, we propose that irradiated Toxoplasma tachyzoites confer protection for challenged mice and could be an alternative immunization schedule for vaccine development especially for who are at risk of severe immunosuppression.
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10
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A systematic review on efficiency of microneme proteins to induce protective immunity against Toxoplasma gondii. Eur J Clin Microbiol Infect Dis 2019; 38:617-629. [DOI: 10.1007/s10096-018-03442-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/22/2018] [Indexed: 12/13/2022]
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11
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Xia N, Zhou T, Liang X, Ye S, Zhao P, Yang J, Zhou Y, Zhao J, Shen B. A Lactate Fermentation Mutant of Toxoplasma Stimulates Protective Immunity Against Acute and Chronic Toxoplasmosis. Front Immunol 2018; 9:1814. [PMID: 30147689 PMCID: PMC6096001 DOI: 10.3389/fimmu.2018.01814] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/23/2018] [Indexed: 12/20/2022] Open
Abstract
Toxoplasma gondii is an important zoonotic pathogen infecting one-third of the world’s population and numerous animals, causing significant healthcare burden and socioeconomic problems. Vaccination is an efficient way to reduce global sero-prevalence, however, ideal vaccines are not yet available. We recently discovered that the Toxoplasma mutant lacking both lactate dehydrogenases LDH1 and LDH2 (Δldh) grew well in vitro but was unable to propagate in mice, making it a good live vaccine candidate. Here, we tested the protection efficacy of ME49 Δldh using a mouse model. Vaccinated mice were efficiently protected from the lethal challenge of a variety of wild-type strains, including type 1 strain RH, type 2 strain ME49, type 3 strain VEG, and a field isolate of Chinese 1. The protection efficacies of a single vaccination were nearly 100% for most cases and it worked well against the challenges of both tachyzoites and tissue cysts. Re-challenging parasites were unable to propagate in vaccinated mice, nor did they make tissue cysts. High levels of Toxoplasma-specific IgG were produced 30 days after immunization and stayed high during the whole tests (at least 125 days). However, passive immunization of naïve mice with sera from vaccinated mice did reduce parasite propagation, but the overall protection against parasite infections was rather limited. On the other hand, Δldh immunization evoked elevated levels of Th1 cytokines like INF-γ and IL-12, at early time points. In addition, splenocytes extracted from immunized mice were able to induce quick and robust INF-γ and other pro-inflammatory cytokine production upon T. gondii antigen stimulation. Together these results suggest that cellular immune responses are the main contributors to the protective immunity elicited by Δldh vaccination, and humoral immunity also contributes partially. We also generated uracil auxotrophic mutants in ME49 and compared their immune protection efficiencies to the Δldh mutants. The results showed that these two types of mutants have similar properties as live vaccine candidates. Taken together, these results suggest that mutants lacking LDH were severely attenuated in virulence but were able to induce strong anti-toxoplasma immune responses, therefore are good candidates for live vaccines.
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Affiliation(s)
- Ningbo Xia
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Taifang Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Xiaohan Liang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Shu Ye
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Pengfei Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Jichao Yang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Yanqin Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Hubei Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China.,Key Laboratory of Preventive Medicine in Hubei Province, Wuhan, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Medicine in Hubei Province, Wuhan, China
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