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Ju K, Zhang Y, Xu Z, Li L, Zhao X, Zhou H. Protective Efficacy of a Novel DNA Vaccine with a CL264 Molecular Adjuvant against Toxoplasma gondii in a Murine Model. Vaccines (Basel) 2024; 12:577. [PMID: 38932306 PMCID: PMC11209281 DOI: 10.3390/vaccines12060577] [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: 04/22/2024] [Revised: 05/15/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
Toxoplasmosis is a significant global zoonosis with devastating impacts, and an effective vaccine against toxoplasmosis for humans has not yet been developed. In this study, we designed and formulated a novel DNA vaccine encoding the inhibitor of STAT1 transcriptional activity (IST) of T. gondii utilizing the eukaryotic expression vector pEGFP-N1 for the first time, with CL264 being a molecular adjuvant. Following intramuscular injection of the vaccine into mice, the levels of antibodies and cytokines were assessed to evaluate the immune response. Additionally, mice were challenged with highly virulent RH-strain tachyzoites of T. gondii, and their survival time was observed. The results show that the levels of IgG in serum, the ratio of IgG2a/IgG1 and the levels of IFN-γ in splenocytes of mice were significantly higher in the pEGFP-TgIST group and the pEGFP-TgIST + CL264 group than in the control group. In addition, the proportion of CD4+/CD8+ T cells was higher in mice immunized with either the pEGFP-TgIST group (p < 0.001) or the pEGFP-TgIST + CL264 group (p < 0.05) compared to the three control groups. Notably, TgIST-immunized mice exhibited prolonged survival times after T. gondii RH strain infection (p < 0.05). Our findings collectively demonstrate that the TgIST DNA vaccine elicits a significant humoral and cellular immune response and offers partial protection against acute T. gondii infection in the immunized mice, which suggests that TgIST holds potential as a candidate for further development as a DNA vaccine.
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Affiliation(s)
| | | | | | | | | | - Huaiyu Zhou
- Department of Pathogen Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China; (K.J.); (Y.Z.); (Z.X.); (L.L.); (X.Z.)
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Zhang Y, Li S, Chu H, Li J, Lu S, Zheng B. A novel mRNA vaccine, TGGT1_278620 mRNA-LNP, prolongs the survival time in BALB/c mice with acute toxoplasmosis. Microbiol Spectr 2024; 12:e0286623. [PMID: 38038457 PMCID: PMC10783036 DOI: 10.1128/spectrum.02866-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Toxoplasma gondii, an obligate intracellular eukaryotic parasite, can infect about one-third of the world's population. One vaccine, Toxovax, has been developed and licensed commercially; however, it is only used in the sheep industry to reduce the losses caused by congenital toxoplasmosis. Various other vaccine approaches have been explored, including excretory secretion antigen vaccines, subunit vaccines, epitope vaccines, and DNA vaccines. However, current research has not yet developed a safe and effective vaccine for T. gondii. Here, we generated an mRNA vaccine candidate against T. gondii. We investigated the efficacy of vaccination with a novel identified candidate, TGGT1_278620, in a mouse infection model. We screened T. gondii-derived protective antigens at the genome-wide level, combined them with mRNA-lipid nanoparticle vaccine technology against T. gondii, and investigated immune-related factors and mechanisms. Our findings might contribute to developing vaccines for immunizing humans and animals against T. gondii.
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Affiliation(s)
- Yizhuo Zhang
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Shiyu Li
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Hongkun Chu
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Jing Li
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Shaohong Lu
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Bio-Tech Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Bin Zheng
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Bio-Tech Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
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Shi TY, Zhou SH, Kong YR, Fu Y, Liu Y, Yan WC, Zhou YX, Zhang L, Hao LL, Sun HC. A rhoptry protein, localizing in the bulb region of rhoptries, could induce protective immunity against Eimeria tenella infection. Front Immunol 2023; 14:1277955. [PMID: 38111572 PMCID: PMC10725939 DOI: 10.3389/fimmu.2023.1277955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 11/17/2023] [Indexed: 12/20/2023] Open
Abstract
Background Rhoptry organelle proteins (ROPs) secreted by apicomplexan parasites play important roles during parasites invasion and survival in host cells, and are potential vaccine candidates against apicomplexan diseases. Eimeria tenella (E. tenella) is one of the most noteworthy apicomplexan species, which causes hemorrhagic pathologies. Although dozens of putative E. tenella ROP sequences are annotated, most ROP proteins are not well studied. Methods In this study, an E. tenella ROP21 gene was identified and the recombinant EtROP21 protein (rEtROP21) was expressed in Escherichia coli. The developmental expression levels, localization, and protective efficacy against E. tenella infection in chickens were studied. Results An EtROP21 gene fragment with an open reading frame (ORF) of 981 bp was obtained from the Beijing strain of E. tenella. The rEtROP21 has a molecular weight of approximately 50 kDa and was recognized by rEtROP21-immunized mouse serum. Two specific protein bands, about 43 KDa and 95 KDa in size, were detected in the whole sporozoite proteins using the rEtROP21-immunized chicken serum. RT-qPCR analysis of the E. tenella ROP21 gene (EtROP21) revealed that its mRNA levels were higher in merozoites and sporozoites than in sporulated and unsporulated oocysts. Immunofluorescence and immunoelectron analyses showed that the EtROP21 protein predominantly localizes in the bulb region of rhoptries distributed at anterior, posterior, and perinuclear regions of E. tenella sporozoites. Immunization and challenge experiments revealed that immunizing chickens with rEtROP21 significantly increased their average body weight gain while decreasing mean lesion score and oocyst output (P <0.05). When compared with the challenged control group, the rEtROP21-immunized group was associated with a significantly higher relative weight gain (90.2%) and a greater reduction in oocyst output (67%) (P <0.05). The anticoccidial index of the rEtROP21-immunized group was 163.2. Chicken serum ELISA revealed that the levels of the specific anti- rEtROP21 antibody, IFN-γ, and IL-4 were significantly higher in the rEtROP21-immunized group than in the challenged control group (P <0.05). Conclusion These results indicate that rEtROP21 can induce a high level of specific immune response and it is a potential candidate for the development of vaccines against E. tenella infection in chickens.
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Affiliation(s)
- Tuan-yuan Shi
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Si-han Zhou
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China
| | - Ya-ru Kong
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
- Department of Epidemic Surveillance, Lingcheng Center for Disease Control and Prevention, Dezhou, Shandong, China
| | - Yuan Fu
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Yan Liu
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Wen-chao Yan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China
| | - Yong-xue Zhou
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Liang Zhang
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Li-li Hao
- Department of Animal Parasitology, College of Animal and Veterinaty Sciences, Southwest Minzu University, Chengdu, Sichuan, China
| | - Hong-chao Sun
- Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
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Chu KB, Quan FS. Recent progress in vaccine development targeting pre-clinical human toxoplasmosis. PARASITES, HOSTS AND DISEASES 2023; 61:231-239. [PMID: 37648228 PMCID: PMC10471472 DOI: 10.3347/phd.22097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 05/30/2023] [Indexed: 09/01/2023]
Abstract
Toxoplasma gondii is an intracellular parasitic organism affecting all warm-blooded vertebrates. Due to the unavailability of commercialized human T. gondii vaccine, many studies have been reported investigating the protective efficacy of pre-clinical T. gondii vaccines expressing diverse antigens. Careful antigen selection and implementing multifarious immunization strategies could enhance protection against toxoplasmosis in animal models. Although none of the available vaccines could remove the tissue-dwelling parasites from the host organism, findings from these pre-clinical toxoplasmosis vaccine studies highlighted their developmental potential and provided insights into rational vaccine design. We herein explored the progress of T. gondii vaccine development using DNA, protein subunit, and virus-like particle vaccine platforms. Specifically, we summarized the findings from the pre-clinical toxoplasmosis vaccine studies involving T. gondii challenge infection in mice published in the past 5 years.
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Affiliation(s)
- Ki-Back Chu
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
| | - Fu-Shi Quan
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
- Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
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Brito C, Lourenço C, Magalhães J, Reis S, Borges M. Nanoparticles as a Delivery System of Antigens for the Development of an Effective Vaccine against Toxoplasma gondii. Vaccines (Basel) 2023; 11:vaccines11040733. [PMID: 37112645 PMCID: PMC10142924 DOI: 10.3390/vaccines11040733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/10/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
Nanoparticles include particles ranging in size from nanometers to micrometers, whose physicochemical characteristics are optimized to make them appropriate delivery vehicles for drugs or immunogens important in the fight and/or prevention of infectious diseases. There has been a rise in the use of nanoparticles in preventive vaccine formulations as immunostimulatory adjuvants, and as vehicles for immunogen delivery to target immune cells. Toxoplasma is important worldwide, and may cause human toxoplasmosis. In immunocompetent hosts, infection is usually asymptomatic, but in immunocompromised patients it can cause serious neurological and ocular consequences, such as encephalitis and retinochoroiditis. Primary infection during pregnancy may cause abortion or congenital toxoplasmosis. Currently, there is no effective human vaccine against this disease. Evidence has emerged from several experimental studies testing nanovaccines showing them to be promising tools in the prevention of experimental toxoplasmosis. For the present study, a literature review was carried out on articles published over the last 10 years through the PubMed database, pertaining to in vivo experimental models of T. gondii infection where nanovaccines were tested and protection and immune responses evaluated. This review aims to highlight the way forward in the search for an effective vaccine for toxoplasmosis.
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Zhang Y, Li D, Shen Y, Li S, Lu S, Zheng B. Immunization with a novel mRNA vaccine, TGGT1_216200 mRNA-LNP, prolongs survival time in BALB/c mice against acute toxoplasmosis. Front Immunol 2023; 14:1161507. [PMID: 37122740 PMCID: PMC10140528 DOI: 10.3389/fimmu.2023.1161507] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/31/2023] [Indexed: 05/02/2023] Open
Abstract
Toxoplasma gondii, a specialized intracellular parasite, causes a widespread zoonotic disease and is a severe threat to social and economic development. There is a lack of effective drugs and vaccines against T. gondii infection. Recently, mRNA vaccines have been rapidly developed, and their packaging materials and technologies are well established. In this study, TGGT1_216200 (TG_200), a novel molecule from T. gondii, was identified using bioinformatic screening analysis. TG_200 was purified and encapsulated with a lipid nanoparticle (LNP) to produce the TG_200 mRNA-LNP vaccine. The immune protection provided by the new vaccine and its mechanisms after immunizing BABL/C mice via intramuscular injection were investigated. There was a strong immune response when mice were vaccinated with TG_200 mRNA-LNP. Elevated levels of anti-T. gondii-specific immunoglobulin G (IgG), and a higher IgG2a-to-IgG1 ratio was observed. The levels of interleukin-12 (IL-12), interferon-γ (IFN-γ), IL-4, and IL-10 were also elevated. The result showed that the vaccine induced a mixture of Th1 and Th2 cells, and Th1-dominated humoral immune response. Significantly increased antigen-specific splenocyte proliferation was induced by TG_200 mRNA-LNP immunization. The vaccine could also induce T. gondii-specific cytotoxic T lymphocytes (CTLs). The expression levels of interferon regulatory factor 8 (IRF8), T-Box 21 (T-bet), and nuclear factor kappa B (NF-κB) were significantly elevated after TG_200 mRNA-LNP immunization. The levels of CD83, CD86, MHC-I, MHC-II, CD8, and CD4 molecules were also higher. The results indicated that TG_200 mRNA-LNP produced specific cellular and humoral immune responses. Most importantly, TG_200 mRNA-LNP immunized mice survived significantly longer (19.27 ± 3.438 days) than the control mice, which died within eight days after T. gondii challenge (P< 0.001). The protective effect of adoptive transfer was also assessed, and mice receiving serum and splenocytes from mice immunized with TG_200 mRNA-LNP showed improved survival rates of 9.70 ± 1.64 days and, 13.40 ± 2.32 days, respectively (P< 0.001). The results suggested that TG_200 mRNA-LNP is a safe and promising vaccine against T. gondii infection.
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Affiliation(s)
- Yizhuo Zhang
- Institute of Parasitic Diseases, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Dan Li
- Institute of Parasitic Diseases, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Yu Shen
- Institute of Parasitic Diseases, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Shiyu Li
- Institute of Parasitic Diseases, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Shaohong Lu
- Institute of Parasitic Diseases, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Bio-tech Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- *Correspondence: Shaohong Lu, ; Bin Zheng,
| | - Bin Zheng
- Institute of Parasitic Diseases, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Bio-tech Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- *Correspondence: Shaohong Lu, ; Bin Zheng,
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