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Li J, Kang Y, Wu ZX, Yang SF, Tian YY, Zhu XQ, Zheng XN. Live-attenuated PruΔgra72 strain of Toxoplasma gondii induces strong protective immunity against acute and chronic toxoplasmosis in mice. Parasit Vectors 2024; 17:377. [PMID: 39237959 PMCID: PMC11378421 DOI: 10.1186/s13071-024-06461-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Accepted: 08/20/2024] [Indexed: 09/07/2024] Open
Abstract
BACKGROUND Toxoplasma gondii is an intracellular opportunistic pathogenic protozoan that poses serious threats, particularly in immunocompromised individuals. In the absence of a robust prophylactic measure, the mitigation and management of toxoplasmosis present formidable challenges to public health. We recently found that GRA72 plays an important role in parasitophorous vacuole (PV) morphology, growth and virulence of T. gondii. However, whether gra72-deficient strain can be used as a vaccine remains unknown. METHODS We first examined the attenuated virulence of gra72 gene knockout strain (PruΔgra72) and the parasite load in organs of the infected mice. Subsequently, we evaluated the immune-protective effects of the PruΔgra72 vaccination against challenge with various types of T. gondii tachyzoites and Pru cysts. Furthermore, levels of antibodies and cytokines induced by PruΔgra72 vaccination were examined. Statistical analysis was conducted by Student's t-test or Mantel-Cox log-rank test based on data obtained from three independent experiments with GraphPad Prism 8.0. RESULTS We found that PruΔgra72 strain exhibited a significantly attenuated virulence even at the highest dose of 5 × 107 tachyzoites in Kunming mice model. The significant decrease of brain cyst burden and parasite load in the organs of the PruΔgra72-infected mice suggested its potentiality as a live-attenuated vaccine. Hence, we explored the protective immunity of PruΔgra72 vaccination against toxoplasmosis. Results showed that vaccination with 5 × 106 PruΔgra72 tachyzoites triggered a strong and sustained Th1-biased immune response, marked by significantly increased levels of anti-T. gondii IgG antibodies, and significantly higher levels of Th1 type cytokines (IL-2, IL-12 and IFN-γ) compared to that of Th2 type (IL-4 and IL-10). Vaccination with 5 × 106 PruΔgra72 tachyzoites in mice conferred long-term protection against T. gondii infection by less virulent tachyzoites (ToxoDB#9 PYS and Pru strains) and Pru cysts, provided partial protection against acute infection by high virulent Type I RH tachyzoites and significantly decreased brain cyst burden of chronically infected mice. CONCLUSIONS The avirulent PruΔgra72 induced strong protective immunity against acute and chronic T. gondii infection and is a promising candidate for developing a safe and effective live-attenuated vaccine against T. gondii infection.
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Affiliation(s)
- Jing Li
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Yu Kang
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Ze-Xuan Wu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Shu-Feng Yang
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Yu-Yang Tian
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China.
| | - Xiao-Nan Zheng
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China.
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Yang C, Liu S, Tao C, Yu J, Yang M, Guo L, Bao L, Li X, Yang J, Jiang K. Serological and molecular survey of Toxoplasma gondii infection and associated risk factors in urban cats in Kunming, Southwest China. Front Vet Sci 2024; 11:1393236. [PMID: 38957802 PMCID: PMC11218566 DOI: 10.3389/fvets.2024.1393236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/22/2024] [Indexed: 07/04/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is a worldwide zoonotic parasite that can infect almost warm-blood animals, including humans, which seriously affect the health of host. Cats are known to be the only definitive host of T. gondii and continuously excrete highly infectious oocysts. This parasite carried by the companion animals leads to a great public health risk. However, there is little information on epidemiology of T. gondii in urban cats in Kunming, Southwest China. In the present study, a total of 231 serum and fecal samples were collected in Kunming aera, and then seroprevalence of T. gondii IgG antibodies in serum and molecular investigation in feces were analyzed to elucidate T. gondii infection in urban cats. The results revealed that 168 of 231 cats (72.7%) were positive for T. gondii antibodies, and 1 of 74 cat feces (1.4%) also showed a positive PCR for T. gondii DNA. The positive fecal sample was sequenced and then phylogenetically analyzed, and the isolate of T. gondii in the present study was closely related to T. gondii strain CN. In addition, the food, water and age of cats were identified as the risk factor for seropositivity. Overall, our findings indicate the widespread occurrence of T. gondii infection in urban cats in Kunming, Southwest China and identify food, water and age are the risk factors associated with T. gondii infection, which can provide effective information for developing strategies to prevent and control this zoonosis.
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Affiliation(s)
- Chunli Yang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Songhao Liu
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Cong Tao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Jing Yu
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Mengping Yang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Lijuan Guo
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Liya Bao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Xiaobing Li
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Jing Yang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
- Fujian Provincial Key Laboratory for Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, Fujian, China
| | - Kangfeng Jiang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
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Zhang HS, Cao H, Li CX, Zhang ZW, Wang M, Zhu XQ, Zheng XN. Immunization with Live-Attenuated RHΔ had2a Strain Confers Partial Protective Immunity against Acute and Chronic Infection of Toxoplasma gondii in Mice. Pathogens 2024; 13:121. [PMID: 38392859 PMCID: PMC10892008 DOI: 10.3390/pathogens13020121] [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: 12/09/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Toxoplasmosis caused by Toxoplasma gondii is an important zoonosis of human and animal health significance. Current chemical therapeutics have side effects, and no commercially available vaccine is licensed for the prevention of toxoplasmosis in humans and most animals. Developing a safe and effective vaccine with long-term protection against T. gondii infection is necessary to control toxoplasmosis. HAD2a is a key member of the haloacid dehalogenase (HAD) phosphatase family, which is essential for T. gondii daughter budding. However, the role of HAD2a in T. gondii virulence remains unknown. In this study, we successfully constructed the had2a gene knockout strain in the T. gondii-type I RH strain (RHΔhad2a) and determined its role in virulence and vaccination. These results demonstrate that HAD2a played an important role in parasite daughter budding and in vitro replication. Knockout of the had2a gene attenuated the virulence of the T. gondii-type I RH strain. Vaccination with RHΔhad2a tachyzoites induced a Th1-biased immune response, provided partial protection against acute T. gondii infection in mice by highly virulent tachyzoites of RH and PYS (ToxoDB#9, Chinese I) strains, and conferred strong protection against challenge infection by cysts and oocysts of the less virulent type II Pru strain. These results demonstrate that T. gondii had2a is important for its in vitro proliferation and virulence in mice and that RHΔhad2a may be used as a candidate strain to generate a multiple gene knockout live-attenuated strain or be collaboratively applied with other live-attenuated strains to confer more effective protection against T. gondii infection.
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Affiliation(s)
- Hai-Sheng Zhang
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China; (H.-S.Z.); (H.C.); (C.-X.L.)
- 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; (Z.-W.Z.); (M.W.)
| | - Hui Cao
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China; (H.-S.Z.); (H.C.); (C.-X.L.)
| | - Chen-Xu Li
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China; (H.-S.Z.); (H.C.); (C.-X.L.)
| | - Zhi-Wei Zhang
- 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; (Z.-W.Z.); (M.W.)
| | - 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; (Z.-W.Z.); (M.W.)
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China; (H.-S.Z.); (H.C.); (C.-X.L.)
| | - Xiao-Nan Zheng
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China; (H.-S.Z.); (H.C.); (C.-X.L.)
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Yang J, Liu S, Zhao Q, Li X, Jiang K. Gut microbiota-related metabolite alpha-linolenic acid mitigates intestinal inflammation induced by oral infection with Toxoplasma gondii. MICROBIOME 2023; 11:273. [PMID: 38087373 PMCID: PMC10714487 DOI: 10.1186/s40168-023-01681-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 09/27/2023] [Indexed: 12/18/2023]
Abstract
BACKGROUND Oral infection with cysts is the main transmission route of Toxoplasma gondii (T. gondii), which leads to lethal intestinal inflammation. It has been widely recognized that T. gondii infection alters the composition and metabolism of the gut microbiota, thereby affecting the progression of toxoplasmosis. However, the potential mechanisms remain unclear. In our previous study, there was a decrease in the severity of toxoplasmosis after T. gondii α-amylase (α-AMY) was knocked out. Here, we established mouse models of ME49 and Δα-amy cyst infection and then took advantage of 16S rRNA gene sequencing and metabolomics analysis to identify specific gut microbiota-related metabolites that mitigate T. gondii-induced intestinal inflammation and analyzed the underlying mechanism. RESULTS There were significant differences in the intestinal inflammation between ME49 cyst- and Δα-amy cyst-infected mice, and transferring feces from mice infected with Δα-amy cysts into antibiotic-treated mice mitigated colitis caused by T. gondii infection. 16S rRNA gene sequencing showed that the relative abundances of gut bacteria, such as Lactobacillus and Bacteroides, Bifidobacterium, [Prevotella], Paraprevotella and Macellibacteroides, were enriched in mice challenged with Δα-amy cysts. Spearman correlation analysis between gut microbiota and metabolites indicated that some fatty acids, including azelaic acid, suberic acid, alpha-linolenic acid (ALA), and citramalic acid, were highly positively correlated with the identified bacterial genera. Both oral administration of ALA and fecal microbiota transplantation (FMT) decreased the expression of pro-inflammatory cytokines and restrained the MyD88/NF-κB pathway, which mitigated colitis and ultimately improved host survival. Furthermore, transferring feces from mice treated with ALA reshaped the colonization of beneficial bacteria, such as Enterobacteriaceae, Proteobacteria, Shigella, Lactobacillus, and Enterococcus. CONCLUSIONS The present findings demonstrate that the host gut microbiota is closely associated with the severity of T. gondii infection. We provide the first evidence that ALA can alleviate T. gondii-induced colitis by improving the dysregulation of the host gut microbiota and suppressing the production of pro-inflammatory cytokines via the MyD88/NF-κB pathway. Our study provides new insight into the medical application of ALA for the treatment of lethal intestinal inflammation caused by Toxoplasma infection. Video Abstract.
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Affiliation(s)
- Jing Yang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, Yunnan, China
| | - Songhao Liu
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, Yunnan, China
| | - Qian Zhao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, Yunnan, China
| | - Xiaobing Li
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, Yunnan, China.
| | - Kangfeng Jiang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, Yunnan, China.
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Guo Q, Guo X, Ji N, Shen B, Zhong X, Xiao L, Feng Y, Xia N. Role of 6-phosphogluconate dehydrogenase enzyme 1 in growth and virulence of Toxoplasma gondii and development of attenuated live vaccine. Microb Biotechnol 2023; 16:1957-1970. [PMID: 37556171 PMCID: PMC10527188 DOI: 10.1111/1751-7915.14324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 07/21/2023] [Accepted: 07/24/2023] [Indexed: 08/10/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous pathogen that infects all warm-blooded animals, including humans, causing substantial socioeconomic and healthcare burdens. However, there is no ideal vaccine for toxoplasmosis. As metabolism is important in the growth and virulence of Toxoplasma, some key pathways are promising antiparasitic targets. Here, we identified 6-phosphogluconate dehydrogenase 1 (Tg6PGDH1) in the oxidative pentose phosphate pathway as a cytoplasmic protein that is dispensable for tachyzoite growth of T. gondii in vitro but critical for virulence and cyst formation in vivo. The depletion of Tg6PGDH1 causes decreased gene transcription involved in signal transduction, transcriptional regulation and virulence. Furthermore, we analysed the protective effect of the ME49Δ6pgdh1 mutant as an attenuated vaccine and found that ME49Δ6pgdh1 immunization stimulated strong protective immunity against lethal challenges and blocked cyst formation caused by reinfection. Furthermore, we showed that ME49Δ6pgdh1 immunization stimulated increased levels of interferon-gamma, tumour necrosis factor-alpha and Toxoplasma-specific IgG antibodies. These data highlight the role of Tg6PGDH1 in the growth and virulence of T. gondii and its potential as a target for the development of a live-attenuated vaccine.
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Affiliation(s)
- Qinghong Guo
- State Key Laboratory for Animal Disease Control and PreventionSouth China Agricultural UniversityGuangzhouChina
| | - Xuefang Guo
- State Key Laboratory for Animal Disease Control and PreventionSouth China Agricultural UniversityGuangzhouChina
| | - Nuo Ji
- State Key Laboratory for Animal Disease Control and PreventionSouth China Agricultural UniversityGuangzhouChina
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanChina
| | - Xinhua Zhong
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Materials and EnergySouth China Agricultural UniversityGuangzhouChina
| | - Lihua Xiao
- State Key Laboratory for Animal Disease Control and PreventionSouth China Agricultural UniversityGuangzhouChina
| | - Yaoyu Feng
- State Key Laboratory for Animal Disease Control and PreventionSouth China Agricultural UniversityGuangzhouChina
| | - Ningbo Xia
- State Key Laboratory for Animal Disease Control and PreventionSouth China Agricultural UniversityGuangzhouChina
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Murphy RD, Troublefield CA, Miracle JS, Young LEA, Brizzee CO, Dhara A, Sun RC, Vander Kooi CW, Gentry MS, Sinai AP. TgLaforin, a glucan phosphatase, reveals the dynamic role of storage polysaccharides in Toxoplasma gondii tachyzoites and bradyzoites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.29.560185. [PMID: 37808860 PMCID: PMC10557770 DOI: 10.1101/2023.09.29.560185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The asexual stages of Toxoplasma gondii are defined by the rapidly growing tachyzoite during the acute infection and by the slow growing bradyzoite housed within tissue cysts during the chronic infection. These stages represent unique physiological states, each with distinct glucans reflecting differing metabolic needs. A defining feature of T. gondii bradyzoites is the presence of insoluble storage glucans known as amylopectin granules (AGs) that are believed to play a role in reactivation, but their functions during the chronic infection remain largely unexplored. More recently, the presence of storage glucans has been recognized in tachyzoites where their precise function and architecture have yet to be fully defined. Importantly, the T. gondii genome encodes activities needed for glucan turnover: a glucan phosphatase (TgLaforin; TGME49_205290) and a glucan kinase (TgGWD; TGME49_214260) that catalyze a cycle of reversible glucan phosphorylation required for glucan degradation by amylases. The expression of these enzymes in tachyzoites supports the existence of a storage glucan, evidence that is corroborated by specific labeling with the anti-glycogen antibody IV58B6. Disruption of reversible glucan phosphorylation via a CRISPR/Cas9 knockout (KO) of TgLaforin revealed no growth defects under nutrient-replete conditions in tachyzoites. However, the growth of TgLaforin-KO tachyzoites was severely stunted when starved of glutamine, even under glucose replete conditions. The loss of TgLaforin also resulted in the attenuation of acute virulence in mice accompanied by a lower cyst burden. Defective cyst formation due to profound changes in AG morphology was also observed in TgLaforin-KO parasites, both in vitro and in vivo. Together, these data demonstrate the importance of glucan turnover across the T. gondii asexual cycle. These findings, alongside our previously identified class of small molecules that inhibit TgLaforin, implicate reversible glucan phosphorylation as a legitimate target for the development of new drugs against chronic T. gondii infections.
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Affiliation(s)
- Robert D Murphy
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Cortni A Troublefield
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
| | - Joy S Miracle
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
| | - Lyndsay E A Young
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Corey O Brizzee
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Animesh Dhara
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
| | - Ramon C Sun
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Anthony P Sinai
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
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Ronizi RR, Namavari M, Moazamian E. Evaluation of the protective immune response of an attenuated strain of Toxoplasma gondii with long-term passages on the Gecko cell line. Vet Parasitol 2023; 320:109969. [PMID: 37301090 DOI: 10.1016/j.vetpar.2023.109969] [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: 01/27/2023] [Revised: 05/27/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Toxoplasma gondii is an obligate intracellular parasite that causes the zoonoses disease, named toxoplasmosis, with global prevalence. Until now, no cost-effective treatment method has been found to deal with toxoplasma, and vaccination is the best way to deal with the infection. In the case of pathogenic protozoa, mainly live vaccines have had successful results compared to other vaccine platforms. This study evaluated the efficacy of a live experimental vaccine through long-term passages on the Gecko cell line (Z1) in inducing a protective immune response in BALB/c mice. Thirty mice were divided into three equal groups; G1: the immunized/challenged group (injection of attenuated strain), G2: the immunized/unchallenged group (injection of attenuated strain), and G3: the control group (injection of culture medium).One month after immunization, the studied mice were challenged with 1ₓ103 live tachyzoites of Toxoplasma acute RH strain. We performed Serological investigations, including evaluating antibodies, interferon-gamma (IFN-γ), and interleukins 2, 4, 10, and 12 (IL-2,4,10,12). At the study's end, a molecular test was performed on brain and liver tissues in the immunized groups to check the presence of parasites. The results from the serological tests for the evaluation of antibodies, interferon-gamma (IFN-γ), and interleukins 10 and 12 (IL-10, 12) show a significant difference (p < 0.05) between the vaccinated group and the control group, which are essential indicators of protective immunity against toxoplasma infection. Thus, in the vaccinated group, the survival rate of mice against the challenge was 70%. Also, in group two (G2), the attenuated strain of Toxoplasma gondii had no pathogenicity, and all mice survived until the end of the study period. Molecular results also showed the absence of parasites in the brain and liver tissues in this immunized group and the parasite was found in only one case of liver tissue in G1. Therefore, the attenuated strain has caused significant and protective humoral and cellular immune responses in vaccinated groups. This study showed that with the long-term passage of the acute strain on the Gecko cell line, it is possible to quickly obtain a non-diseased attenuated strain with the ability to induce protective immunity. This successful finding can introduce further research to achieve a promising vaccine in the target animals.
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Affiliation(s)
- Roghayeh Ramezanpoor Ronizi
- Department of Microbiology, Faculty of Sciences, Agriculture and Modern Technology, Shiraz branch, Islamic Azad University, Shiraz, Iran
| | - Mehdi Namavari
- Razi Vaccine and Serum Research Institute; Agricultural Research, Agricultural and Extension Organization, Shiraz, Iran.
| | - Elham Moazamian
- Department of Microbiology, Faculty of Sciences, Agriculture and Modern Technology, Shiraz branch, Islamic Azad University, Shiraz, Iran
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Chen M, Yang P, Xin Z, Chen J, Zou W, Zhou L, Yang L, Peng J, Peng H. Toxoplasma gondii gra5 deletion mutant protects hosts against Toxoplasma gondii infection and breast tumors. Front Immunol 2023; 14:1173379. [PMID: 37426671 PMCID: PMC10327641 DOI: 10.3389/fimmu.2023.1173379] [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: 02/24/2023] [Accepted: 04/13/2023] [Indexed: 07/11/2023] Open
Abstract
Toxoplasma gondii is the causative agent of toxoplasmosis, a zoonotic disease that poses a threat to human health and a considerable loss to livestock farming. At present, clinical therapeutic drugs mainly target T. gondii tachyzoites and fail to eradicate bradyzoites. Developing a safe and effective vaccine against toxoplasmosis is urgent and important. Breast cancer has become a major public health problem and the therapeutic method needs to be further explored. Many similarities exist between the immune responses caused by T. gondii infection and the immunotherapy for cancers. T. gondii dense granule organelles secrete immunogenic dense granule proteins (GRAs). GRA5 is localized to the parasitophorous vacuole membrane in the tachyzoite stage and the cyst wall in the bradyzoite stage. We found that T. gondii ME49 gra5 knockout strain (ME49Δgra5) was avirulent and failed to form cysts but stimulated antibodies, inflammatory cytokines, and leukocytes infiltration in mice. We next investigated the protective efficacy of ME49Δgra5 vaccination against T. gondii infection and tumor development. All the immunized mice survived the challenge infection of either wild-type RH, ME49, VEG tachyzoites, or ME49 cysts. Moreover, ME49Δgra5 tachyzoite inoculation in situ attenuated the growth of murine breast tumor (4T1) in mice and prevented 4T1's lung metastasis. ME49Δgra5 inoculation upregulated the levels of Th1 cytokines and tumor-infiltrating T cells in the tumor microenvironment and triggered anti-tumor responses by increasing the number of natural killer, B, and T cells, macrophages, and dendritic cells in the spleen. Collectively, these results suggested that ME49Δgra5 was a potent live attenuated vaccine against T. gondii infection and breast cancer.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
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Zhao M, Yang Y, Shi Y, Chen X, Yang Y, Pan L, Du Z, Sun H, Yao C, Ma G, Du A. PP2Acα-B'/PR61 Holoenzyme of Toxoplasma gondii Is Required for the Amylopectin Metabolism and Proliferation of Tachyzoites. Microbiol Spectr 2023; 11:e0010423. [PMID: 37199633 PMCID: PMC10269777 DOI: 10.1128/spectrum.00104-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/26/2023] [Indexed: 05/19/2023] Open
Abstract
Here, we report that the inhibition of the PP2A subfamily by okadaic acid results in an accumulation of polysaccharides in the acute infection stage (tachyzoites) of Toxoplasma gondii, which is a protozoan of global zoonotic importance and a model for the apicomplexan parasites. The loss of the catalytic subunit α of PP2A (ΔPP2Acα) in RHΔku80 leads to the polysaccharide accumulation phenotype in the base of tachyzoites as well as residual bodies and significantly compromises the intracellular growth in vitro and the virulence in vivo. A metabolomic analysis revealed that the accumulated polysaccharides in ΔPP2Acα are derived from interrupted glucose metabolism, which affects the production of ATP and energy homeostasis in the T. gondii knockout. The assembly of the PP2Acα holoenzyme complex involved in the amylopectin metabolism in tachyzoites is possibly not regulated by LCMT1 or PME1, and this finding contributes to the identification of the regulatory B subunit (B'/PR61). The loss of B'/PR61 results in the accumulation of polysaccharide granules in the tachyzoites as well as reduced plaque formation ability, exactly the same as ΔPP2Acα. Taken together, we have identified a PP2Acα-B'/PR61 holoenzyme complex that plays a crucial role in the carbohydrate metabolism and viability in T. gondii, and its deficiency in function remarkably suppresses the growth and virulence of this important zoonotic parasite both in vitro and in vivo. Hence, rendering the PP2Acα-B'/PR61 holoenzyme functionless should be a promising strategy for the intervention of Toxoplasma acute infection and toxoplasmosis. IMPORTANCE Toxoplasma gondii switches back and forth between acute and chronic infections, mainly in response to host immunologic status, which is characterized by flexible but specific energy metabolism. Polysaccharide granules are accumulated in the acute infection stage of T. gondii that have been exposed to a chemical inhibitor of the PP2A subfamily. The genetic depletion of the catalytic subunit α of PP2A leads to this phenotype and significantly affects the cell metabolism, energy production, and viability. Further, a regulatory B subunit PR61 is necessary for the PP2A holoenzyme to function in glucose metabolism and in the intracellular growth of T. gondii tachyzoites. A deficiency of this PP2A holoenzyme complex (PP2Acα-B'/PR61) in T. gondii knockouts results in the abnormal accumulation of polysaccharides and the disruption of energy metabolism, suppressing their growth and virulence. These findings provide novel insights into cell metabolism and identify a potential target for an intervention against a T. gondii acute infection.
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Affiliation(s)
- Mingxiu Zhao
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yi Yang
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yue Shi
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China
| | - Xueqiu Chen
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yimin Yang
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Lingtao Pan
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Zhendong Du
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hongchao Sun
- Department of Animal Parasitology, Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Science, Hangzhou, Zhejiang Province, China
| | - Chaoqun Yao
- Department of Biomedical Sciences and One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, St. Kitts and Nevis
| | - Guangxu Ma
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Aifang Du
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
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10
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Finkensieper J, Mayerle F, Rentería-Solís Z, Fertey J, Makert GR, Lange F, Besecke J, Schopf S, Poremba A, König U, Standfest B, Thoma M, Daugschies A, Ulbert S. Apicomplexan parasites are attenuated by low-energy electron irradiation in an automated microfluidic system and protect against infection with Toxoplasma gondii. Parasitol Res 2023:10.1007/s00436-023-07880-w. [PMID: 37233817 DOI: 10.1007/s00436-023-07880-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/14/2023] [Indexed: 05/27/2023]
Abstract
Radiation-attenuated intracellular parasites are promising immunization strategies. The irradiated parasites are able to invade host cells but fail to fully replicate, which allows for the generation of an efficient immune response. Available radiation technologies such as gamma rays require complex shielding constructions and are difficult to be integrated into pharmaceutical production processes. In this study, we evaluated for the first time low-energy electron irradiation (LEEI) as a method to generate replication-deficient Toxoplasma gondii and Cryptosporidium parvum. Similar to other radiation technologies, LEEI mainly damages nucleic acids; however, it is applicable in standard laboratories. By using a novel, continuous, and microfluidic-based LEEI process, tachyzoites of T. gondii and oocysts of C. parvum were irradiated and subsequently analyzed in vitro. The LEEI-treated parasites invaded host cells but were arrested in intracellular replication. Antibody-based analysis of surface proteins revealed no significant structural damage due to LEEI. Similarly, excystation rates of sporozoites from irradiated C. parvum oocysts were similar to those from untreated controls. Upon immunization of mice, LEEI-attenuated T. gondii tachyzoites induced high levels of antibodies and protected the animals from acute infection. These results suggest that LEEI is a useful technology for the generation of attenuated Apicomplexan parasites and has potential for the development of anti-parasitic vaccines.
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Affiliation(s)
- Julia Finkensieper
- Fraunhofer Institute for Cell Therapy and Immunology IZI, Perlickstrasse 1, 04103, Leipzig, Germany
| | - Florian Mayerle
- Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Nobelstrasse 12, 70569, Stuttgart, Germany
| | - Zaida Rentería-Solís
- Institute of Parasitology, Centre for Infection Medicine, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 35, 04103, Leipzig, Germany
- Albrecht-Daniel-Thaer Institute, Rudolf-Breitscheid-Str. 35, 04463 Großpösna, Germany
| | - Jasmin Fertey
- Fraunhofer Institute for Cell Therapy and Immunology IZI, Perlickstrasse 1, 04103, Leipzig, Germany
| | - Gustavo R Makert
- Fraunhofer Institute for Cell Therapy and Immunology IZI, Perlickstrasse 1, 04103, Leipzig, Germany
| | - Franziska Lange
- Fraunhofer Institute for Cell Therapy and Immunology IZI, Perlickstrasse 1, 04103, Leipzig, Germany
| | - Joana Besecke
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Winterbergstrasse 28, 01277, Dresden, Germany
| | - Simone Schopf
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Winterbergstrasse 28, 01277, Dresden, Germany
| | - Andre Poremba
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Winterbergstrasse 28, 01277, Dresden, Germany
| | - Ulla König
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Winterbergstrasse 28, 01277, Dresden, Germany
| | - Bastian Standfest
- Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Nobelstrasse 12, 70569, Stuttgart, Germany
| | - Martin Thoma
- Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Nobelstrasse 12, 70569, Stuttgart, Germany
| | - Arwid Daugschies
- Institute of Parasitology, Centre for Infection Medicine, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 35, 04103, Leipzig, Germany
| | - Sebastian Ulbert
- Fraunhofer Institute for Cell Therapy and Immunology IZI, Perlickstrasse 1, 04103, Leipzig, Germany.
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11
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Li H, Liang X, Sun W, Zhuang B, Cao Y, Zhang J, Shen J, Wang Y, Yu L. Immunological evaluation of a recombinant vaccine delivered with an analogous hyaluronic acid chitosan nanoparticle-hydrogel against Toxoplasma gondii in mice. Microb Pathog 2023; 179:106092. [PMID: 37003502 DOI: 10.1016/j.micpath.2023.106092] [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: 02/04/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
BACKGROUND Toxoplasma gondii (T. gondii) is not only a threat to the public health but it also poses adverse impacts on the livestock industry. This study aimed to develop a recombinant vaccine composed of T. gondii microneme protein 6 (TgMIC6) and T. gondii rhoptry protein 18 (TgROP18).The vaccine was delivered with a novel vector, named analogous hyaluronic acid chitosan nanoparticle-hydrogel (AHACNP-HG) and its immune protection was evaluated. METHODS The recombinant MIC6 and ROP18 proteins were obtained by affinity chromatography and loaded onto AHACNP-HG by magnetic stirring. The characterizations of AHACNP-HG were investigated, including its structure, rheological property, nanoparticle size and zeta potential, its ability to release protein in vitro and toxicology in vivo. The immunological and anti-infection effects of AHACNP-HG/rMIC6/rROP18 were examined in the mice model. RESULTS AHACNP-HG presented a characteristic of composite system and possessed biosecurity with excellent protein control-release property. AHACNP-HG/rMIC6/rROP18 vaccine enhanced a mixed Th1/Th2 cellular immune response accompanied by an increased level of the cytokines, IFN-γ and IL-10. It also provoked a stronger humoral immune response. Additionally, after challenge with T. gondii tachyzoite, AHACNP-HG/rMIC6/rROP18 inoculation prolonged the survival time of mice. CONCLUSION Our data indicated that mixed rMIC6 and rROP18 induced strong immune response and played a certain protective role in controlling T. gondii infection, and the novel adjuvant AHACNP-HG improved modestly some immunogenicity properties in mouse model, which indicated that it can be used as a novel delivery system in vaccine development.
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Affiliation(s)
- Hu Li
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China; Department of Clinical Laboratory, Taihe People's Hospital, Fuyang, 236600, China.
| | - Xiao Liang
- School of Life Sciences, Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, 230032, China.
| | - Wenze Sun
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
| | - Baocan Zhuang
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
| | - Yuanyuan Cao
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
| | - Junling Zhang
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
| | - Jilong Shen
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
| | - Yongzhong Wang
- School of Life Sciences, Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, 230032, China.
| | - Li Yu
- Department of Microbiology and Parasitology, Anhui Province Key Laboratory of Microbiology and Parasitology, The Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
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12
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Recombinant Mouse Prolactin Confers Partial Protection Against Toxoplasma gondii Infection in a Pre-treated Experimental Murine Model. Acta Parasitol 2023; 68:182-193. [PMID: 36542295 DOI: 10.1007/s11686-022-00651-0] [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: 04/09/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Toxoplasmosis is one of the most important health-threatening diseases with worldwide distribution and global impact. It is caused by Toxoplasma gondii (T. gondii), an intracellular apicomplexan parasite that can evade the host immune responses and establish a chronic infection. The available treatments are not efficient against this stage and have many adverse effects. There are no available effective vaccines, apart from Toxovax®, which is used in sheep to prevent abortion. Studies documented that prolactin (PRL) had in vivo and in vitro anti-Toxoplasma effects. Detailed research was recommended about the mechanisms of such inhibitory effects. AIM This study was designed to assess the possible protective role of the recombinant prolactin (rPRL) against T. gondii. MATERIALS AND METHODS Sixty experimentally infected mice with T. gondii were used. The treated mice received rPRL for five days before infection. Serum prolactin levels were measured; survival rate was monitored; number, size, and DNA of T. gondii cysts in the brain were measured; and histopathological and immunological studies were done. RESULTS There was a significant increase in the survival rate of the rPRL-treated mice, a significant decrease in the number, size, and DNA amount of T. gondii cysts in the brain with a noticeable improvement of histopathological lesions in the brain and liver tissues when compared to the infected untreated group. These effects seem to be achieved through stimulating humoral and cell-mediated immune responses that were evident by the significant rise in serum levels of anti-Toxoplasma IgM, IFN-γ, and TNF-α. CONCLUSION The rPRL elicited robust immune responses, which provided efficient protection against murine T. gondii infection.
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13
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Murphy RD, Chen T, Lin J, He R, Wu L, Pearson CR, Sharma S, Vander Kooi CD, Sinai AP, Zhang ZY, Vander Kooi CW, Gentry MS. The Toxoplasma glucan phosphatase TgLaforin utilizes a distinct functional mechanism that can be exploited by therapeutic inhibitors. J Biol Chem 2022; 298:102089. [PMID: 35640720 PMCID: PMC9254107 DOI: 10.1016/j.jbc.2022.102089] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 01/19/2023] Open
Abstract
Toxoplasma gondii is an intracellular parasite that generates amylopectin granules (AGs), a polysaccharide associated with bradyzoites that define chronic T. gondii infection. AGs are postulated to act as an essential energy storage molecule that enable bradyzoite persistence, transmission, and reactivation. Importantly, reactivation can result in the life-threatening symptoms of toxoplasmosis. T. gondii encodes glucan dikinase and glucan phosphatase enzymes that are homologous to the plant and animal enzymes involved in reversible glucan phosphorylation and which are required for efficient polysaccharide degradation and utilization. However, the structural determinants that regulate reversible glucan phosphorylation in T. gondii are unclear. Herein, we define key functional aspects of the T. gondii glucan phosphatase TgLaforin (TGME49_205290). We demonstrate that TgLaforin possesses an atypical split carbohydrate-binding-module domain. AlphaFold2 modeling combined with hydrogen-deuterium exchange mass spectrometry and differential scanning fluorimetry also demonstrate the unique structural dynamics of TgLaforin with regard to glucan binding. Moreover, we show that TgLaforin forms a dual specificity phosphatase domain-mediated dimer. Finally, the distinct properties of the glucan phosphatase catalytic domain were exploited to identify a small molecule inhibitor of TgLaforin catalytic activity. Together, these studies define a distinct mechanism of TgLaforin activity, opening up a new avenue of T. gondii bradyzoite biology as a therapeutic target.
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Affiliation(s)
- Robert D Murphy
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA; Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Tiantian Chen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Jianping Lin
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Rongjun He
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Li Wu
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Caden R Pearson
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Savita Sharma
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Carl D Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Anthony P Sinai
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Zhong-Yin Zhang
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA.
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
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14
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Yang J, He Z, Chen C, Zhao J, Fang R. Starch Branching Enzyme 1 Is Important for Amylopectin Synthesis and Cyst Reactivation in Toxoplasma gondii. Microbiol Spectr 2022; 10:e0189121. [PMID: 35446124 PMCID: PMC9241709 DOI: 10.1128/spectrum.01891-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 03/28/2022] [Indexed: 11/21/2022] Open
Abstract
Toxoplasma gondii (T. gondii) bradyzoites facilitate chronic infections that evade host immune response. Furthermore, reactivation in immunocompromised individuals causes severe toxoplasmosis. The presence of abundant granules containing the branched starch amylopectin is major characteristic of bradyzoites that is nearly absent from tachyzoites that drive acute disease. T. gondii genome encodes to potential Starch branching enzyme 1 (SBE1) that creates branching during amylopectin biosynthesis. However, the physiological function of the amylopectin in T. gondii remains unclear. In this study, we generated a SBE1 knockout parasites and revealed that deletion of SBE1 caused amylopectin synthesis defects while having no significant impact on the growth of tachyzoites under normal culture conditions in vitro as well as virulence and brain cyst formation. Nevertheless, SBE1 knockout decreased the influx of exogenous glucose and reduced tachyzoites proliferation in nutrition-deficient conditions. Deletion of SBE1 together with the α-amylase (α-AMY), responsible for starch digestion, abolished amylopectin production and attenuated virulence while restoring brain cyst formation. In addition, cysts with defective amylopectin metabolism showed abnormal morphology and were avirulent to mice. In conclusion, SBE1 is essential for the synthesis of amylopectin, which serves as energy storage during the development and reactivation of bradyzoites. IMPORTANCE Toxoplasmosis has become a global, serious public health problem due to the extensiveness of the host. There are great differences in the energy metabolism in the different stages of infection. The most typical difference is the abundant accumulation of amylopectin granules in bradyzoites, which is almost absent in tachyzoites. Until now, the physiological functions of amylopectin have not been clearly elucidated. We focused on starch branching enzyme 1 (SBE1) in the synthesis pathway to reveal the exact physiological significance of amylopectin. Our study clarified the role of SBE1 in the synthesis pathway and amylopectin in tachyzoites and bradyzoites, and demonstrated that amylopectin, as an important carbon source, was critical to parasites growth under an unfavorable environment and the reactivation of bradyzoites to tachyzoites. The findings obtained from our study provides a new avenue for the development of Toxoplasma vaccines and anti-chronic toxoplasmosis drugs.
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Affiliation(s)
- Jing Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Zhengming He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chengjie Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Rui Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
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15
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Deletion of Toxoplasma Rhoptry Protein 38 (PruΔ rop38) as a Vaccine Candidate for Toxoplasmosis in a Murine Model. Biomedicines 2022; 10:biomedicines10061336. [PMID: 35740356 PMCID: PMC9220005 DOI: 10.3390/biomedicines10061336] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/03/2022] [Accepted: 06/04/2022] [Indexed: 11/16/2022] Open
Abstract
Toxoplasmosis is a serious zoonotic disease that threatens human and animal health. Here, we evaluated the vaccine potential of the deletion of Toxoplasma rhoptry protein 38 (PruΔrop38) through its pathogenicity and immunoprotective efficacy in mice. Mice inoculated intraperitoneally with 1 × 103, 2 × 103, or 4 × 103 PruΔrop38 showed no visible signs, whereas mice inoculated with 1 × 103 parental Pru strain showed obvious wasting and bow-back, suggesting a significantly lower pathogenicity of PruΔrop38 in mice. Vaccination with 1 × 102 PruΔrop38 triggered a mixed Th1/Th2 response (Th1 response predominant), with higher IgG, IgG2a, and IgG1 levels in serum from week 3 to week 12, and a significant increase in IFN-γ, IL-12, and IL-10 in suspensions of splenocytes at 30 or 60 days post-immunization. All vaccinated mice survived when infected intraperitoneally with tachyzoites (RH, Pru, VEG, or TgcatBJ1) or when infected orally with cysts (Pru or ME49). The brain parasite burden during Pru tachyzoite, Pru cyst and ME49 cyst challenges were significantly reduced in vaccinated mice. The duration of immunization showed that vaccination with PruΔrop38 could protect mice from challenge with different varied genotypes of Toxoplasma strains against different routes of infection. Collectively, these findings indicate that PruΔrop38 is an attenuated strain that provides long-term protective efficacy against acute or chronic toxoplasmosis in mice.
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16
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Borkens Y. [Toxoplasma gondii-Current drugs and future vaccines against an underestimated protozoan infection]. Internist (Berl) 2021; 62:1123-1132. [PMID: 34467425 DOI: 10.1007/s00108-021-01155-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2021] [Indexed: 12/01/2022]
Abstract
Toxoplasma gondii is a unicellular organism of the Apicomplexa that occurs worldwide and is therefore a close relative of the malaria pathogen Plasmodium. As T. gondii infests every warm-blooded vertebrate species as an intermediate host and has a very high prevalence worldwide, toxoplasmosis is one of the most important international foodborne diseases. Potential vaccines (human as well as veterinary) play a crucial role in controlling this disease.
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Affiliation(s)
- Yannick Borkens
- College of Public Health, Medical and Veterinary Science, James Cook University, 1 James Cook Drive, 4811, Townsville, Queensland, Australien.
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17
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Chu KB, Quan FS. Advances in Toxoplasma gondii Vaccines: Current Strategies and Challenges for Vaccine Development. Vaccines (Basel) 2021; 9:vaccines9050413. [PMID: 33919060 PMCID: PMC8143161 DOI: 10.3390/vaccines9050413] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 02/06/2023] Open
Abstract
Toxoplasmosis, caused by the apicomplexan parasite Toxoplasma gondii, is one of the most damaging parasite-borne zoonotic diseases of global importance. While approximately one-third of the entire world’s population is estimated to be infected with T. gondii, an effective vaccine for human use remains unavailable. Global efforts in pursuit of developing a T. gondii vaccine have been ongoing for decades, and novel innovative approaches have been introduced to aid this process. A wide array of vaccination strategies have been conducted to date including, but not limited to, nucleic acids, protein subunits, attenuated vaccines, and nanoparticles, which have been assessed in rodents with promising results. Yet, translation of these in vivo results into clinical studies remains a major obstacle that needs to be overcome. In this review, we will aim to summarize the current advances in T. gondii vaccine strategies and address the challenges hindering vaccine development.
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Affiliation(s)
- Ki-Back Chu
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Korea;
| | - Fu-Shi Quan
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea
- Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
- Correspondence:
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