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Jiang Y, Shi Y, Xue Y, Hu D, Song X. AP2XII-1 and AP2XI-2 Suppress Schizogony Gene Expression in Toxoplasma gondii. Int J Mol Sci 2024; 25:5527. [PMID: 38791568 PMCID: PMC11122372 DOI: 10.3390/ijms25105527] [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: 03/24/2024] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Toxoplasma gondii is an intracellular parasite that is important in medicine and veterinary science and undergoes distinct developmental transitions in its intermediate and definitive hosts. The switch between stages of T. gondii is meticulously regulated by a variety of factors. Previous studies have explored the role of the microrchidia (MORC) protein complex as a transcriptional suppressor of sexual commitment. By utilizing immunoprecipitation and mass spectrometry, constituents of this protein complex have been identified, including MORC, Histone Deacetylase 3 (HDAC3), and several ApiAP2 transcription factors. Conditional knockout of MORC or inhibition of HDAC3 results in upregulation of a set of genes associated with schizogony and sexual stages in T. gondii tachyzoites. Here, our focus extends to two primary ApiAP2s (AP2XII-1 and AP2XI-2), demonstrating their significant impact on the fitness of asexual tachyzoites and their target genes. Notably, the targeted disruption of AP2XII-1 and AP2XI-2 resulted in a profound alteration in merozoite-specific genes targeted by the MORC-HDAC3 complex. Additionally, considerable overlap was observed in downstream gene profiles between AP2XII-1 and AP2XI-2, with AP2XII-1 specifically binding to a subset of ApiAP2 transcription factors, including AP2XI-2. These findings reveal an intricate cascade of ApiAP2 regulatory networks involved in T. gondii schizogony development, orchestrated by AP2XII-1 and AP2XI-2. This study provides valuable insights into the transcriptional regulation of T. gondii growth and development, shedding light on the intricate life cycle of this parasitic pathogen.
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Affiliation(s)
- Yucong Jiang
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China; (Y.J.); (Y.X.); (D.H.)
| | - Yuehong Shi
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China;
| | - Yingying Xue
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China; (Y.J.); (Y.X.); (D.H.)
| | - Dandan Hu
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China; (Y.J.); (Y.X.); (D.H.)
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China;
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning 530004, China
| | - Xingju Song
- College of Animal Science and Technology, Guangxi University, Nanning 530004, China; (Y.J.); (Y.X.); (D.H.)
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning 530004, China;
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning 530004, China
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2
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Sun M, Tang T, He K, Long S. TBC9, an essential TBC-domain protein, regulates early vesicular transport and IMC formation in Toxoplasma gondii. Commun Biol 2024; 7:596. [PMID: 38762629 PMCID: PMC11102469 DOI: 10.1038/s42003-024-06310-6] [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: 10/25/2023] [Accepted: 05/08/2024] [Indexed: 05/20/2024] Open
Abstract
Apicomplexan parasites harbor a complex endomembrane system as well as unique secretory organelles. These complex cellular structures require an elaborate vesicle trafficking system, which includes Rab GTPases and their regulators, to assure the biogenesis and secretory of the organelles. Here we exploit the model apicomplexan organism Toxoplasma gondii that encodes a family of Rab GTPase Activating Proteins, TBC (Tre-2/Bub2/Cdc16) domain-containing proteins. Functional profiling of these proteins in tachyzoites reveals that TBC9 is the only essential regulator, which is localized to the endoplasmic reticulum (ER) in T. gondii strains. Detailed analyses demonstrate that TBC9 is required for normal distribution of proteins targeting to the ER, and the Golgi apparatus in the parasite, as well as for the normal formation of daughter inner membrane complexes (IMCs). Pull-down assays show a strong protein interaction between TBC9 and specific Rab GTPases (Rab11A, Rab11B, and Rab2), supporting the role of TBC9 in daughter IMC formation and early vesicular transport. Thus, this study identifies the only essential TBC domain-containing protein TBC9 that regulates early vesicular transport and IMC formation in T. gondii and potentially in closely related protists.
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Affiliation(s)
- Ming Sun
- National Key Laboratory of Veterinary Public Health Safety and College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Tao Tang
- National Key Laboratory of Veterinary Public Health Safety and College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Kai He
- National Key Laboratory of Veterinary Public Health Safety and College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Shaojun Long
- National Key Laboratory of Veterinary Public Health Safety and College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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3
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Holmes MJ, Bastos MS, Dey V, Severo V, Wek RC, Sullivan WJ. mRNA cap-binding protein eIF4E1 is a novel regulator of Toxoplasma gondii latency. mBio 2024:e0295423. [PMID: 38747593 DOI: 10.1128/mbio.02954-23] [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: 11/03/2023] [Accepted: 04/15/2024] [Indexed: 05/28/2024] Open
Abstract
The protozoan parasite Toxoplasma gondii causes serious opportunistic disease due to its ability to persist in patients as latent tissue cysts. The molecular mechanisms coordinating conversion between proliferative parasites (tachyzoites) and latent cysts (bradyzoites) are not fully understood. We previously showed that phosphorylation of eIF2α accompanies bradyzoite formation, suggesting that this clinically relevant process involves regulation of mRNA translation. In this study, we investigated the composition and role of eIF4F multi-subunit complexes in translational control. Using CLIPseq, we find that the cap-binding subunit, eIF4E1, localizes to the 5'-end of all tachyzoite mRNAs, many of which show evidence of stemming from heterogeneous transcriptional start sites. We further show that eIF4E1 operates as the predominant cap-binding protein in two distinct eIF4F complexes. Using genetic and pharmacological approaches, we found that eIF4E1 deficiency triggers efficient spontaneous formation of bradyzoites without stress induction. Consistent with this result, we also show that stress-induced bradyzoites exhibit reduced eIF4E1 expression. Overall, our findings establish a novel role for eIF4F in translational control required for parasite latency and microbial persistence. IMPORTANCE Toxoplasma gondii is an opportunistic pathogen important to global human and animal health. There are currently no chemotherapies targeting the encysted form of the parasite. Consequently, a better understanding of the mechanisms controlling encystation is required. Here we show that the mRNA cap-binding protein, eIF4E1, regulates the encystation process. Encysted parasites reduce eIF4E1 levels, and depletion of eIF4E1 decreases the translation of ribosome-associated machinery and drives Toxoplasma encystation. Together, these data reveal a new layer of mRNA translational control that regulates parasite encystation and latency.
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Affiliation(s)
- Michael J Holmes
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Matheus S Bastos
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Vishakha Dey
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Vanessa Severo
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Ronald C Wek
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - William J Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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4
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Hryckowian ND, Knoll LJ. Sex in a dish: high-efficiency Toxoplasma pre-sexual development. Trends Parasitol 2024; 40:209-210. [PMID: 38311493 PMCID: PMC10939770 DOI: 10.1016/j.pt.2024.01.009] [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: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/06/2024]
Abstract
Antunes et al. successfully grew cat-restricted stages of Toxoplasma gondii in cell culture by targeting parasite epigenetics and transcription factors. The highlight of this report is how efficiently parasites convert to these pre-sexual stages. Their work is an important step toward achieving feline-free recapitulation of the T. gondii sexual cycle.
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Affiliation(s)
- Nicole D Hryckowian
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Laura J Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA.
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5
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Xia J, Fu Y, Huang W, Sibley LD. Constitutive upregulation of transcription factors underlies permissive bradyzoite differentiation in a natural isolate of Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582596. [PMID: 38464000 PMCID: PMC10925318 DOI: 10.1101/2024.02.28.582596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Toxoplasma gondii bradyzoites play a critical role in pathology due to their long-term persistence in intermediate hosts and their potential to reactivate, resulting in severe diseases in immunocompromised individuals. Currently there is no effective treatment for eliminating bradyzoites. Hence, better in vitro models of T. gondii cyst development would facilitate identification of therapeutic targets for bradyzoites. Herein we characterized a natural isolate of T. gondii, called Tg68, which showed slower in vitro replication of tachyzoites, and permissive bradyzoite development under stress conditions in vitro. Transcriptional analysis revealed constitutive expression in Tg68 tachyzoites of the key regulators of bradyzoite development including BFD1, BFD2, and several AP2 factors. Consistent with this finding, Tg68 tachyzoites expressed high levels of bradyzoite-specific genes including BAG1, ENO1, and LDH2. Moreover, after stress induced differentiation, Tg68 bradyzoites exhibited gene expression profiles of mature bradyzoites, even at early time points. These data suggest that Tg68 tachyzoites exist in a pre-bradyzoite stage primed to readily develop into mature bradyzoites under stress conditions in vitro. Tg68 presents a novel model for differentiation in vitro that will serve as a useful tool for investigation of bradyzoite biology and development of therapeutics.
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Affiliation(s)
- Jing Xia
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Yong Fu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Wanyi Huang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
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Zheng XN, Sun LX, Elsheikha HM, Li TT, Gao J, Wu XJ, Zhang ZW, Wang M, Fu BQ, Zhu XQ, Wang JL. A newly characterized dense granule protein (GRA76) is important for the growth and virulence of Toxoplasma gondii. Int J Parasitol 2024; 54:109-121. [PMID: 37832712 DOI: 10.1016/j.ijpara.2023.09.001] [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: 07/26/2023] [Revised: 08/30/2023] [Accepted: 09/03/2023] [Indexed: 10/15/2023]
Abstract
Pathogenicity of the zoonotic pathogen Toxoplasma gondii largely depends on the secretion of effector proteins into the extracellular milieu and host cell cytosol, including the dense granule proteins (GRAs). The protein-encoding gene TGME49_299780 was previously identified as a contributor to parasite fitness. However, its involvement in parasite growth, virulence and infectivity in vitro and in vivo remains unknown. Here, we comprehensively examined the role of this new protein, termed GRA76, in parasite pathogenicity. Subcellular localization revealed high expression of GRA76 in tachyzoites inside the parasitophorous vacuole (PV). However, its expression was significantly decreased in bradyzoites. A CRISPR-Cas9 approach was used to knock out the gra76 gene in the T. gondii type I RH strain and type II Pru strain. The in vitro plaque assays and intracellular replication showed the involvement of GRA76 in replication of RH and Pru strains. Deletion of the gra76 gene significantly decreased parasite virulence, and reduced the brain cyst burden in mice. Using RNA sequencing, we detected a significant increase in the expression of bradyzoite-associated genes such as BAG1 and LDH2 in the PruΔgra76 strain compared with the wild-type Pru strain. Using an in vitro bradyzoite differentiation assay, we showed that loss of GRA76 significantly increased the propensity for parasites to form bradyzoites. Immunization with PruΔgra76 conferred partial protection against acute and chronic infection in mice. These findings show the important role of GRA76 in the pathogenesis of T. gondii and highlight the potential of PruΔgra76 as a candidate for a live-attenuated vaccine.
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Affiliation(s)
- Xiao-Nan Zheng
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province 030801, People's Republic of China
| | - Li-Xiu Sun
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Research Center for Parasites & Vectors, College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province 410128, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
| | - Ting-Ting Li
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, Sichuan Province 610213, People's Republic of China
| | - Jin Gao
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province 030801, People's Republic of China
| | - Xiao-Jing Wu
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province 030801, People's Republic of China
| | - Zhi-Wei Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China
| | - Meng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, Sichuan Province 610213, People's Republic of China
| | - Bao-Quan Fu
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, Sichuan Province 610213, People's Republic of China
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province 030801, People's Republic of China.
| | - Jin-Lei Wang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, Sichuan Province 610213, People's Republic of China.
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7
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Xing Y, Yang J, Yao P, Xie L, Liu M, Cai Y. Comparison of the immune response and protection against the experimental Toxoplasma gondii infection elicited by immunization with the recombinant proteins BAG1, ROP8, and BAG1-ROP8. Parasite Immunol 2024; 46:e13023. [PMID: 38372452 DOI: 10.1111/pim.13023] [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: 08/03/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 02/20/2024]
Abstract
Toxoplasmosis is one of the most dangerous zoonotic diseases, causing serious economic losses worldwide due to abortion and reproductive problems. Vaccination is the best way to prevent disease; thus, it is imperative to develop a candidate vaccine for toxoplasmosis. BAG1 and ROP8 have the potential to become vaccine candidates. In this study, rTgBAG1, rTgROP8, and rTgBAG1-rTgROP8 were used to evaluate the immune effect of vaccines in each group by detecting the humoral and cellular immune response levels of BABL/c mice after immunization and the ability to resist acute and chronic infection with Toxoplasma gondii (T. gondii). We divided the mice into vaccine groups with different proteins, and the mice were immunized on days 0, 14, and 28. The protective effects of different proteins against T. gondii were analysed by measuring the cytokines, serum antibodies, splenocyte proliferation assay results, survival time, and number and diameter of brain cysts of mice after infection. The vaccine groups exhibited substantially higher IgG, IgG1, and IgG2a levels and effectively stimulated lymphocyte proliferation. The levels of IFN-γ and IL-2 in the vaccine group were significantly increased. The survival time of the mice in each vaccine group was prolonged and the diameter of the cysts in the vaccine group was smaller; rTgBAG1-rTgROP8 had a better protection. Our study showed that the rTgBAG1, rTgROP8, and rTgBAG1-rTgROP8 recombinant protein vaccines are partial but effective approaches against acute or chronic T. gondii infection. They are potential candidates for a toxoplasmosis vaccine.
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Affiliation(s)
- Yien Xing
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Jun Yang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Pengjing Yao
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Linding Xie
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Min Liu
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Yihong Cai
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
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8
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Wang JL, Li TT, Zhang NZ, Wang M, Sun LX, Zhang ZW, Fu BQ, Elsheikha HM, Zhu XQ. The transcription factor AP2XI-2 is a key negative regulator of Toxoplasma gondii merogony. Nat Commun 2024; 15:793. [PMID: 38278808 PMCID: PMC10817966 DOI: 10.1038/s41467-024-44967-z] [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: 07/08/2023] [Accepted: 01/10/2024] [Indexed: 01/28/2024] Open
Abstract
Sexual development in Toxoplasma gondii is a multistep process that culminates in the production of oocysts, constituting approximately 50% of human infections. However, the molecular mechanisms governing sexual commitment in this parasite remain poorly understood. Here, we demonstrate that the transcription factors AP2XI-2 and AP2XII-1 act as negative regulators, suppressing merozoite-primed pre-sexual commitment during asexual development. Depletion of AP2XI-2 in type II Pru strain induces merogony and production of mature merozoites in an alkaline medium but not in a neutral medium. In contrast, AP2XII-1-depleted Pru strain undergoes several rounds of merogony and produces merozoites in a neutral medium, with more pronounced effects observed under alkaline conditions. Additionally, we identified two additional AP2XI-2-interacting proteins involved in repressing merozoite programming. These findings underscore the intricate regulation of pre-sexual commitment by a network of factors and suggest that AP2XI-2 or AP2XII-1-depleted Pru parasites can serve as a model for studying merogony in vitro.
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Affiliation(s)
- Jin-Lei 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, Gansu Province, 730046, People's Republic of China.
| | - Ting-Ting Li
- 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, Gansu Province, 730046, People's Republic of China
| | - Nian-Zhang 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, Gansu Province, 730046, People's Republic of 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, Gansu Province, 730046, People's Republic of China
| | - Li-Xiu Sun
- 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, Gansu Province, 730046, People's Republic of China
| | - 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, Gansu Province, 730046, People's Republic of China
| | - Bao-Quan Fu
- 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, Gansu Province, 730046, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province, 030801, People's Republic of China.
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9
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Pan M, Ge CC, Niu SZ, Duan YY, Fan YM, Jin QW, Chen X, Tao JP, Huang SY. Functional analyses of Toxoplasma gondii dihydroorotase reveal a promising anti-parasitic target. FASEB J 2024; 38:e23397. [PMID: 38149908 DOI: 10.1096/fj.202301493r] [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: 07/21/2023] [Revised: 11/20/2023] [Accepted: 12/15/2023] [Indexed: 12/28/2023]
Abstract
Toxoplasma gondii relies heavily on the de novo pyrimidine biosynthesis pathway for fueling the high uridine-5'-monophosphate (UMP) demand during parasite growth. The third step of de novo pyrimidine biosynthesis is catalyzed by dihydroorotase (DHO), a metalloenzyme that catalyzes the reversible condensation of carbamoyl aspartate to dihydroorotate. Here, functional analyses of TgDHO reveal that tachyzoites lacking DHO are impaired in overall growth due to decreased levels of UMP, and the noticeably growth restriction could be partially rescued after supplementation with uracil or high concentrations of L-dihydroorotate in vitro. When pyrimidine salvage pathway is disrupted, both DHOH35A and DHOD284E mutant strains proliferated much slower than DHO-expressing parasites, suggesting an essential role of both TgDHO His35 and Asp284 residues in parasite growth. Additionally, DHO deletion causes the limitation of bradyzoite growth under the condition of uracil supplementation or uracil deprivation. During the infection in mice, the DHO-deficient parasites are avirulent, despite the generation of smaller tissue cysts. The results reveal that TgDHO contributes to parasite growth both in vitro and in vivo. The significantly differences between TgDHO and mammalian DHO reflect that DHO can be exploited to produce specific inhibitors targeting apicomplexan parasites. Moreover, potential DHO inhibitors exert beneficial effects on enzymatic activity of TgDHO and T. gondii growth in vitro. In conclusion, these data highlight the important role of TgDHO in parasite growth and reveal that it is a promising anti-parasitic target for future control of toxoplasmosis.
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Affiliation(s)
- Ming Pan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, PR China
| | - Ceng-Ceng Ge
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Shui-Zhu Niu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Yin-Yan Duan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Yi-Min Fan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Qi-Wang Jin
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, PR China
| | - Xiang Chen
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Jian-Ping Tao
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Si-Yang Huang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, PR China
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10
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Rodriguez JB, Szajnman SH. An updated review of chemical compounds with anti-Toxoplasma gondii activity. Eur J Med Chem 2023; 262:115885. [PMID: 37871407 DOI: 10.1016/j.ejmech.2023.115885] [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: 08/24/2023] [Revised: 09/30/2023] [Accepted: 10/15/2023] [Indexed: 10/25/2023]
Abstract
The opportunistic apicomplexan parasite Toxoplasma gondii is the etiologic agent for toxoplasmosis, which can infect a widespread range of hosts, particularly humans and warm-blooded animals. The present chemotherapy to treat or prevent toxoplasmosis is deficient and is based on diverse drugs such as atovaquone, trimethoprim, spiramycine, which are effective in acute toxoplasmosis. Therefore, a safe chemotherapy is required for toxoplasmosis considering that its responsible agent, T. gondii, provokes severe illness and death in pregnant women and immunodeficient patients. A certain disadvantage of the available treatments is the lack of effectiveness against the tissue cyst of the parasite. A safe chemotherapy to combat toxoplasmosis should be based on the metabolic differences between the parasite and the mammalian host. This article covers different relevant molecular targets to combat this disease including the isoprenoid pathway (farnesyl diphosphate synthase, squalene synthase), dihydrofolate reductase, calcium-dependent protein kinases, histone deacetylase, mitochondrial electron transport chain, etc.
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Affiliation(s)
- Juan B Rodriguez
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Unidad de Microanálisis y Métodos Físicos en Química Orgánica (UMYMFOR), C1428EHA, Buenos Aires, Argentina.
| | - Sergio H Szajnman
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Unidad de Microanálisis y Métodos Físicos en Química Orgánica (UMYMFOR), C1428EHA, Buenos Aires, Argentina
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11
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Domann N, Rezende SR, Fleury ACC, Barbosa IMFN, Ribeiro IDC, Dornelas JB, de Oliveira TFC, de Moura VOL, Storchilo HR, de Castro AM, Garcia JL, Cardoso LPV, Rezende HHA. Molecular characterization and epidemiology of Toxoplasma gondii isolates from free-range chickens in the southwest region of Goiás: new genotypes. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA = BRAZILIAN JOURNAL OF VETERINARY PARASITOLOGY : ORGAO OFICIAL DO COLEGIO BRASILEIRO DE PARASITOLOGIA VETERINARIA 2023; 32:e009823. [PMID: 38055433 PMCID: PMC10704866 DOI: 10.1590/s1984-29612023069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/16/2023] [Indexed: 12/08/2023]
Abstract
The purpose of this study was to isolate Toxoplasma gondii from tissues of free-range chickens in the southwestern region of Goiás, to detect and molecularly characterize the genetic material of the parasite, and to determine the seroprevalence of the protozoan parasite in these animals. A seroprevalence of T. gondii antibodies of 76% (19/25) was found among the chickens, while genetic material from their tissues was detected in 56% (14/25). A total of 14 isolates was obtained in the bioassay, ten of which were considered acute, eight were considered isolates of high virulence lethal to mice, and four of low virulence, considered non-lethal but with the ability to chronify the infection. Seven of the ten isolates showed significant morphometric differences from the RH strain, in terms of nucleus-complex-apical distance, length and width. Genotyping of the acute isolates was performed by RFLP-PCR, using 11 genetic markers: SAG1, SAG2 (3'SAG2 and 5'SAG2), alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and APICO. The results were compared and classified according to the genotypes listed on the ToxoDB Platform, where different profiles were observed indicating the presence of two known genotypes (#7 and #63) and five new genotypes (NEW 3, NEW4, NEW5, NEW6, NEW 7). The results showed high seroprevalence, isolation rate, molecular detection and genotypic variations of T. gondii in free-range chickens in the southwestern region of Goiás.
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Affiliation(s)
- Natália Domann
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | - Stéfanne Rodrigues Rezende
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | - Amanda Cristina Corrêa Fleury
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | | | - Isabella da Costa Ribeiro
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | - Júlia Batista Dornelas
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | | | - Vanessa Oliveira Lopes de Moura
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | - Heloísa Ribeiro Storchilo
- Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás – UFG, Goiânia, GO, Brasil
| | - Ana Maria de Castro
- Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás – UFG, Goiânia, GO, Brasil
| | - João Luís Garcia
- Laboratório de Protozoologia Veterinária, Universidade Estadual de Londrina – UEL, Londrina, PR, Brasil
| | - Ludimila Paula Vaz Cardoso
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
| | - Hanstter Hallison Alves Rezende
- Instituto de Ciências da Saúde, Laboratório de Bacteriologia e Micologia, Universidade Federal de Jataí – UFJ, Jataí, GO, Brasil
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12
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Zarringhalam K, Ye S, Lou J, Rezvani Y, Gubbels MJ. Cell cycle-regulated ApiAP2s and parasite development: the Toxoplasma paradigm. Curr Opin Microbiol 2023; 76:102383. [PMID: 37898053 PMCID: PMC10840917 DOI: 10.1016/j.mib.2023.102383] [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: 04/29/2023] [Revised: 08/11/2023] [Accepted: 08/27/2023] [Indexed: 10/30/2023]
Abstract
The cell division cycle of T. gondii is driven by cyclically expressed ApiAP2 transcription factors (AP2s) that promote gene sets (regulons) associated with specific biological functions. AP2s drive other AP2s, thereby propelling the progressive gene expression waves defining the lytic cycle. AP2s can act as dimers by themselves, in combination with other AP2s (constitutive or cyclical) or in complexes with epigenetic factors. Exit from the cell cycle into either the extracellular state or differentiation into bradyzoites results in major changes in gene expression. Surprisingly, both transitions lead to expression of a shared set of unique AP2s that suggest a shared stress response that, governed by the specific conditions, leads to different outcomes.
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Affiliation(s)
- Kourosh Zarringhalam
- Department of Mathematics, University of Massachusetts Boston, Boston, MA, USA; Center for Personalized Cancer Therapy, University of Massachusetts Boston, Boston, MA, USA.
| | - Sida Ye
- Department of Mathematics, University of Massachusetts Boston, Boston, MA, USA; Center for Personalized Cancer Therapy, University of Massachusetts Boston, Boston, MA, USA
| | - Jingjing Lou
- Department of Biology, Boston College, Chestnut Hill, MA, USA
| | - Yasaman Rezvani
- Department of Mathematics, University of Massachusetts Boston, Boston, MA, USA; Center for Personalized Cancer Therapy, University of Massachusetts Boston, Boston, MA, USA
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13
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Holmes MJ, Bastos MS, Dey V, Severo V, Wek RC, Sullivan WJ. mRNA cap-binding protein eIF4E1 is a novel regulator of Toxoplasma gondii latency. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.09.561274. [PMID: 37873335 PMCID: PMC10592687 DOI: 10.1101/2023.10.09.561274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The protozoan parasite Toxoplasma gondii causes serious opportunistic disease due to its ability to persist in patients as latent tissue cysts. The molecular mechanisms coordinating conversion between proliferative parasites (tachyzoites) and dormant cysts (bradyzoites) are not fully understood. We previously showed that phosphorylation of eIF2α accompanies bradyzoite formation, suggesting that this clinically relevant process involves regulation of mRNA translation. In this study, we investigated the composition and role of eIF4F multi-subunit complexes in translational control. Using CLIPseq, we find that the cap-binding subunit, eIF4E1, localizes to the 5'-end of all tachyzoite mRNAs, many of which show evidence of stemming from heterogenous transcriptional start sites. We further show that eIF4E1 operates as the predominant cap-binding protein in two distinct eIF4F complexes. Using genetic and pharmacological approaches, we found that eIF4E1 deficiency triggers efficient spontaneous formation of bradyzoites without stress induction. Consistent with this result, we also show that stress-induced bradyzoites exhibit reduced eIF4E1 expression. Overall, our findings establish a novel role for eIF4F in translational control required for parasite latency and microbial persistence.
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Affiliation(s)
- Michael J. Holmes
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis IN
| | - Matheus S. Bastos
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis IN
| | - Vishakha Dey
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis IN
| | - Vanessa Severo
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis IN
| | - Ronald C. Wek
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis IN
| | - William J. Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis IN
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis IN
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14
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de Giacometi M, Mayer JCP, de Mello AB, Islabão YW, Strothmann AL, da Fonseca RN, Sena-Lopes Â, Dornelles L, Borsuk S, Hübner SDO, Oliveira CB. Activity of compounds derived from benzofuroxan in Trichomonasvaginalis. Exp Parasitol 2023; 253:108601. [PMID: 37625643 DOI: 10.1016/j.exppara.2023.108601] [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: 05/19/2023] [Revised: 08/08/2023] [Accepted: 08/19/2023] [Indexed: 08/27/2023]
Abstract
Trichomoniasis is a sexually transmitted infection caused by the protozoan Trichomonas vaginalis. Currently, trichomoniasis is treated with the class of nitroimidazoles, namely, metronidazole; however, resistant isolates and strains have been reported. The compounds derived from benzofuroxan are biologically active heterocycles. This study evaluated the in vitro antiparasitic activity of these compounds in trophozoites of T. vaginalis and determined the mean inhibitory concentration (IC50), minimum inhibitory concentration (MIC), mortality curve, and cytotoxicity. The compounds were named EH1, EH2, EH3, and EA2 and tested in various concentrations: 100 to 15 μM (EH1 and EH2); 100 to 5 μM (EH3); and 100 to 25 μM (EA2), respectively. The greatest efficacy was observed in the highest concentrations in 24 h, with inhibition of approximately 100% of trophozoites. Compounds EH2 and EH3 had the lowest MIC: EH2 (35 μM) and EH3 (45 μM), with IC50 of 11.33 μM and 6.83 μM, respectively. Compound EA2 was effective at the highest concentrations. The activity of the compounds in T. vaginalis started in the first hour of incubation with 90% inhibition; after 12 h, inhibition >95% was observed. Compound EH1 showed the lowest activity, with the highest activity between 12 and 24 h after incubation. These results demonstrate that benzofuroxan derivatives are promising compounds for the in vitro treatment of T. vaginalis.
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Affiliation(s)
- Marjorie de Giacometi
- Department of Microbiology and Parasitology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - João Cândido Pilar Mayer
- Department of Chemistry, LabSelen-NanoBio, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Alexia Brauner de Mello
- Department of Microbiology and Parasitology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Yan Wahast Islabão
- Department of Microbiology and Parasitology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Adriane Leites Strothmann
- Center for Technological Development, Biotechnology, Federal University of Pelotas, Pelotas, RS, Brazil
| | | | - Ângela Sena-Lopes
- Center for Technological Development, Biotechnology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Luciano Dornelles
- Department of Chemistry, LabSelen-NanoBio, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Sibele Borsuk
- Center for Technological Development, Biotechnology, Federal University of Pelotas, Pelotas, RS, Brazil
| | | | - Camila Belmonte Oliveira
- Department of Microbiology and Parasitology, Federal University of Pelotas, Pelotas, RS, Brazil.
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15
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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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16
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Sokol-Borrelli SL, Reilly SM, Holmes MJ, Orchanian SB, Massmann MD, Sharp KG, Cabo LF, Alrubaye HS, Martorelli Di Genova B, Lodoen MB, Sullivan WJ, Boyle JP. A transcriptional network required for bradyzoite development in Toxoplasma gondii is dispensable for recrudescent disease. Nat Commun 2023; 14:6078. [PMID: 37770433 PMCID: PMC10539341 DOI: 10.1038/s41467-023-40948-w] [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: 02/23/2023] [Accepted: 08/16/2023] [Indexed: 09/30/2023] Open
Abstract
Identification of regulators of Toxoplasma gondii bradyzoite development and cyst formation is the most direct way to address the importance of parasite development in long-term persistence and reactivation of this parasite. Here we show that a T. gondii gene (named Regulator of Cystogenesis 1; ROCY1) is sufficient for T. gondii bradyzoite formation in vitro and in vivo. ROCY1 encodes an RNA binding protein that has a preference for 3' regulatory regions of hundreds of T. gondii transcripts, and its RNA-binding domains are required to mediate bradyzoite development. Female mice infected with ΔROCY1 parasites have reduced (>90%) cyst burden. While viable parasites can be cultivated from brain tissue for up to 6 months post-infection, chronic brain-resident ΔROCY1 parasites have reduced oral infectivity compared to wild type. Despite clear defects in bradyzoite formation and oral infectivity, ΔROCY1 parasites were able to reactivate with similar timing and magnitude as wild type parasites for up to 5 months post-infection. Therefore while ROCY1 is a critical regulator of the bradyzoite developmental pathway, it is not required for parasite reactivation, raising new questions about the persisting life stage responsible for causing recrudescent disease.
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Affiliation(s)
- Sarah L Sokol-Borrelli
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sarah M Reilly
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael J Holmes
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 462022, USA
| | - Stephanie B Orchanian
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, USA
| | - Mackenzie D Massmann
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Katherine G Sharp
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leah F Cabo
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hisham S Alrubaye
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bruno Martorelli Di Genova
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Melissa B Lodoen
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, USA
| | - William J Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 462022, USA
| | - Jon P Boyle
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
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17
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Tarannum A, Rodríguez-Almonacid CC, Salazar-Bravo J, Karamysheva ZN. Molecular Mechanisms of Persistence in Protozoan Parasites. Microorganisms 2023; 11:2248. [PMID: 37764092 PMCID: PMC10534552 DOI: 10.3390/microorganisms11092248] [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: 07/28/2023] [Revised: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Protozoan parasites are known for their remarkable capacity to persist within the bodies of vertebrate hosts, which frequently results in prolonged infections and the recurrence of diseases. Understanding the molecular mechanisms that underlie the event of persistence is of paramount significance to develop innovative therapeutic approaches, given that these pathways still need to be thoroughly elucidated. The present article provides a comprehensive overview of the latest developments in the investigation of protozoan persistence in vertebrate hosts. The focus is primarily on the function of persisters, their formation within the host, and the specific molecular interactions between host and parasite while they persist. Additionally, we examine the metabolomic, transcriptional, and translational changes that protozoan parasites undergo during persistence within vertebrate hosts, focusing on major parasites such as Plasmodium spp., Trypanosoma spp., Leishmania spp., and Toxoplasma spp. Key findings of our study suggest that protozoan parasites deploy several molecular and physiological strategies to evade the host immune surveillance and sustain their persistence. Furthermore, some parasites undergo stage differentiation, enabling them to acclimate to varying host environments and immune challenges. More often, stressors such as drug exposure were demonstrated to impact the formation of protozoan persisters significantly. Understanding the molecular mechanisms regulating the persistence of protozoan parasites in vertebrate hosts can reinvigorate our current insights into host-parasite interactions and facilitate the development of more efficacious disease therapeutics.
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Affiliation(s)
| | | | | | - Zemfira N. Karamysheva
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA; (A.T.); (C.C.R.-A.); (J.S.-B.)
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18
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Vanagas L, Muñoz D, Cristaldi C, Ganuza A, Nájera R, Bonardi MC, Turowski VR, Guzman F, Deng B, Kim K, Sullivan WJ, Angel SO. Histone variant H2B.Z acetylation is necessary for maintenance of Toxoplasma gondii biological fitness. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194943. [PMID: 37217032 PMCID: PMC10524646 DOI: 10.1016/j.bbagrm.2023.194943] [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: 03/01/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023]
Abstract
Through regulation of DNA packaging, histone proteins are fundamental to a wide array of biological processes. A variety of post-translational modifications (PTMs), including acetylation, constitute a proposed histone code that is interpreted by "reader" proteins to modulate chromatin structure. Canonical histones can be replaced with variant versions that add an additional layer of regulatory complexity. The protozoan parasite Toxoplasma gondii is unique among eukaryotes in possessing a novel variant of H2B designated H2B.Z. The combination of PTMs and the use of histone variants are important for gene regulation in T. gondii, offering new targets for drug development. In this work, T. gondii parasites were generated in which the 5 N-terminal acetylatable lysines in H2B.Z were mutated to either alanine (c-Myc-A) or arginine (c-Myc-R). The c-Myc-A mutant displayed no phenotype over than a mild defect in its ability to kill mice. The c-Myc-R mutant presented an impaired ability to grow and an increase in differentiation to latent bradyzoites. The c-Myc-R mutant was also more sensitive to DNA damage, displayed no virulence in mice, and provided protective immunity against future infection. While nucleosome composition was unaltered, key genes were abnormally expressed during in vitro bradyzoite differentiation. Our results show that regulation of the N-terminal positive charge patch of H2B.Z is important for these processes. We also show that acetylated N-terminal H2B.Z interacts with some unique proteins compared to its unacetylated counterpart; the acetylated peptide pulled down proteins associated with chromosome maintenance/segregation and cell cycle, suggesting a link between H2B.Z acetylation status and mitosis.
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Affiliation(s)
- Laura Vanagas
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina.
| | - Daniela Muñoz
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Constanza Cristaldi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Agustina Ganuza
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Rosario Nájera
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Mabel C Bonardi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Valeria R Turowski
- Laboratorio de Bioquímica y Biología Celular de Parásitos, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA Chascomús, Prov. Buenos Aires, Argentina
| | - Fanny Guzman
- Núcleo de Biotecnología Curauma, Pontificia Universidad Católica de Valparaiso, Av. Universidad 330 Curauma, Valparaiso, Chile
| | - Bin Deng
- Department of Biology and VBRN, University of Vermont, VT, USA
| | - Kami Kim
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - William J Sullivan
- Department of Pharmacology and Toxicology, Indiana School of Medicine, Indianapolis, IN 46202, USA
| | - Sergio O Angel
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina.
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Colos-Arango A, Largo-de la Torre A, Calero-Bernal R, Miguel Ortega-Mora L, Regidor-Cerrillo J. Short-term culture adaptation of Toxoplasma gondii archetypal II and III field isolates affects cystogenic capabilities and modifies virulence in mice. Int J Parasitol 2023:S0020-7519(23)00074-7. [PMID: 37059167 DOI: 10.1016/j.ijpara.2023.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/28/2023] [Accepted: 03/20/2023] [Indexed: 04/16/2023]
Abstract
Most Toxoplasma gondii research has been carried out using strains maintained in the laboratory for long periods of time. Long-term passage in mice or cell culture influences T. gondii phenotypic traits such as the capability to produce oocysts in cats and virulence in mice. In this work, we investigated the effect of cell culture adaptation in the short term for recently obtained type II (TgShSp1 (Genotype ToxoDB#3), TgShSp2 (#1), TgShSp3 (#3) and TgShSp16 (#3)) and type III (#2) isolates (TgShSp24 and TgPigSp1). With this purpose, spontaneous and alkaline stress-induced cyst formation in Vero cells during 40 passages, from passage 10 (p10) to 50 (p50), and isolate virulence at p10 versus p50 were studied using a harmonized bioassay method in Swiss/CD1 mice. Toxoplasma gondii cell culture maintenance showed a drastic loss of spontaneous and induced production of mature cysts after ≈ 25-30 passages. The TgShSp1, TgShSp16 and TgShSp24 isolates failed to generate spontaneously formed mature cysts at p50. Limited cyst formation was associated with an increase in parasite growth and a shorter lytic cycle. In vitro maintenance also modified T. gondii virulence in mice at p50 with events of exacerbation, increasing cumulative morbidity for TgShSp2 and TgShSp3 isolates and mortality for TgShSp24 and TgPigSp1 isolates, or attenuation, with absence of mortality and severe clinical signs for TgShSp16, and better control of the infection with the lowest parasite and cyst burdens in lungs and brain for the TgShSp1 isolate. The present findings show deep changes in relevant phenotypic traits in laboratory-adapted T. gondii isolates and open new discussion about their use for inferring keys to parasite biology and virulence.
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Affiliation(s)
- Alicia Colos-Arango
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Andrea Largo-de la Torre
- SALUVET-Innova S.L., Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Rafael Calero-Bernal
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Javier Regidor-Cerrillo
- SALUVET-Innova S.L., Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
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20
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Mutka T, Seyfang A, Yoo JY, Dutra SVO, Ji M, Louis-Jacques A, Bruder K, Prescott S, Kim K, Groer M. Adverse pregnancy outcomes in Toxoplasma gondii seropositive Hispanic women. J Obstet Gynaecol Res 2023; 49:893-903. [PMID: 36495217 PMCID: PMC9991953 DOI: 10.1111/jog.15511] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/24/2022] [Accepted: 11/13/2022] [Indexed: 12/14/2022]
Abstract
AIMS Chronic Toxoplasma gondii infection is not thought to affect pregnancy or birth outcomes, but there are few prospective studies. The study aims were T. gondii immunoglobulin G measurement and relationship of chronic T. gondii infection with gestational age at birth and adverse pregnancy outcomes in 690 Hispanic women in Tampa, Florida. METHODS Hispanic women, born either in the United States or in Latin America or the Caribbean had a venous blood sample drawn to measure T. gondii IgG and T. gondii serotype at the first prenatal visit, along with collection of demographic and health-related measures. Seropositive and seronegative women were followed throughout their pregnancy. Gestational age, infant weights, and adverse pregnancy outcomes (miscarriages, preterm births) were compared in the two groups. RESULTS There were 740 women of self-reported Hispanic ethnicity screened and enrolled in Tampa, Florida, with 690 having birth data extracted from the electronic health record (538 T. gondii negative and 152 T. gondii seropositive). T. gondii seropositivity was 22.4% and the majority (83%) had high avidity titers, indicating chronic infection. Compared to T. gondii seronegative Hispanic women, seroseropositive women had more smaller for gestational age infants and higher prevalences of miscarriages and preterm birth. CONCLUSION This is one of the largest longitudinal cohort studies of women with chronic T. gondii infection followed through pregnancy. There was a higher percentages of adverse pregnancy outcomes in this group compared to T. gondii seronegative controls. The mechanism for this is unknown and warrants reexamination of the dogma that chronic T. gondii infection in pregnant women has no significant clinical consequences.
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Affiliation(s)
- Tina Mutka
- University of South Florida College of Nursing, Tampa, FL
| | | | - Ji Youn Yoo
- University of Tennessee College of Nursing, Knoxville, TN
| | | | - Ming Ji
- University of South Florida College of Nursing, Tampa, FL
| | | | | | | | - Kami Kim
- Morsani College of Medicine, Tampa, FL
| | - Maureen Groer
- University of South Florida College of Nursing, Tampa, FL
- Morsani College of Medicine, Tampa, FL
- University of Tennessee College of Nursing, Knoxville, TN
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Vanagas L, Muñoz D, Cristaldi C, Ganuza A, Nájera R, Bonardi MC, Turowski VR, Guzman F, Deng B, Kim K, Sullivan WJ, Angel SO. Histone variant H2B.Z acetylation is necessary for maintenance of Toxoplasma gondii biological fitness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528480. [PMID: 36824796 PMCID: PMC9949044 DOI: 10.1101/2023.02.14.528480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Through regulation of DNA packaging, histone proteins are fundamental to a wide array of biological processes. A variety of post-translational modifications (PTMs), including acetylation, constitute a proposed histone code that is interpreted by "reader" proteins to modulate chromatin structure. Canonical histones can be replaced with variant versions that add an additional layer of regulatory complexity. The protozoan parasite Toxoplasma gondii is unique among eukaryotes in possessing a novel variant of H2B designated H2B.Z. The combination of PTMs and the use of histone variants is important for gene regulation in T. gondii, offering new targets for drug development. In this work, T. gondii parasites were generated in which the 5 N-terminal acetylatable lysines in H2B.Z were mutated to either alanine (c-Myc-A) or arginine (c-Myc-R). c-Myc-A mutant only displayed a mild effect in its ability to kill mice. c-Myc-R mutant presented an impaired ability to grow and an increase in differentiation to latent bradyzoites. This mutant line was also more sensitive to DNA damage, displayed no virulence in mice, and provided protective immunity against future infection. While nucleosome composition was unaltered, key genes were abnormally expressed during in vitro bradyzoite differentiation. Our results show that the N-terminal positive charge patch of H2B.Z is important for these procceses. Pull down assays with acetylated N-terminal H2B.Z peptide and unacetylated one retrieved common and differential interactors. Acetylated peptide pulled down proteins associated with chromosome maintenance/segregation and cell cycle, opening the question of a possible link between H2B.Z acetylation status and mitosis.
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Affiliation(s)
- Laura Vanagas
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Daniela Muñoz
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Constanza Cristaldi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Agustina Ganuza
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Rosario Nájera
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Mabel C. Bonardi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Valeria R. Turowski
- Laboratorio de Bioquímica y Biología Celular de Parásitos, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Fanny Guzman
- Núcleo de Biotecnología Curauma, Pontificia Universidad Católica de Valparaiso. Av. Universidad 330 Curauma, Valparaiso
| | - Bin Deng
- Department of Biology and VBRN, University of Vermont, Vermont, USA
| | - Kami Kim
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612
| | - William J. Sullivan
- Department of Pharmacology and Toxicology, Indiana School of Medicine, Indianapolis, Indiana 46202, USA
| | - Sergio O. Angel
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
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Abstract
Toxoplasma gondii is a widespread protozoan parasite that has a significant impact on human and veterinary health. The parasite undergoes a complex life cycle involving multiple hosts and developmental stages. How Toxoplasma transitions between life cycle stages is poorly understood yet central to controlling transmission. Of particular neglect are the factors that contribute to its sexual development, which takes place exclusively in feline intestines. While epigenetic repressors have been shown to play an important role in silencing the spurious gene expression of sexually committed parasites, the specific factors that recruit this generalized machinery to the appropriate genes remain largely unexplored. Here, we establish that a member of the AP2 transcription factor family, AP2XII-2, is targeted to genomic loci associated with sexually committed parasites along with epigenetic regulators of transcriptional silencing, HDAC3 and MORC. Despite its widespread association with gene promoters, AP2XII-2 is required for the silencing of relatively few genes. Using the CUT&Tag (cleavage under targets and tagmentation) methodology, we identify two major genes associated with sexual development downstream of AP2XII-2 control, AP2X-10 and the amino acid hydroxylase AAH1. Our findings show that AP2XII-2 is a key contributor to the gene regulatory pathways modulating Toxoplasma sexual development. IMPORTANCE Toxoplasma gondii is a parasite that undergoes its sexual stage exclusively in feline intestines, making cats a major source of transmission. A better understanding of the proteins controlling the parasite's life cycle stage transitions is needed for the development of new therapies aimed at treating toxoplasmosis and the transmission of the infection. Genes that regulate the sexual stages need to be turned on and off at the appropriate times, activities that are mediated by specific transcription factors that recruit general machinery to silence or activate gene expression. In this study, we identify a transcription factor called AP2XII-2 as being important for the repression of a subset of sexual stage genes, including a sexual stage-specific AP2 factor (AP2X-10) and a protein (AAH1) required to construct the infectious oocysts expelled from infected cats.
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Wang JL, Li TT, Elsheikha HM, Liang QL, Zhang ZW, Wang M, Sibley LD, Zhu XQ. The protein phosphatase 2A holoenzyme is a key regulator of starch metabolism and bradyzoite differentiation in Toxoplasma gondii. Nat Commun 2022; 13:7560. [PMID: 36476594 PMCID: PMC9729606 DOI: 10.1038/s41467-022-35267-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 11/22/2022] [Indexed: 12/12/2022] Open
Abstract
Phenotypic switching between tachyzoite and bradyzoite is the fundamental mechanism underpinning the pathogenicity and adaptability of the protozoan parasite Toxoplasma gondii. Although accumulation of cytoplasmic starch granules is a hallmark of the quiescent bradyzoite stage, the regulatory factors and mechanisms contributing to amylopectin storage in bradyzoites are incompletely known. Here, we show that T. gondii protein phosphatase 2A (PP2A) holoenzyme is composed of a catalytic subunit PP2A-C, a scaffold subunit PP2A-A and a regulatory subunit PP2A-B. Disruption of any of these subunits increased starch accumulation and blocked the tachyzoite-to-bradyzoite differentiation. PP2A contributes to the regulation of amylopectin metabolism via dephosphorylation of calcium-dependent protein kinase 2 at S679. Phosphoproteomics identified several putative PP2A holoenzyme substrates that are involved in bradyzoite differentiation. Our findings provide novel insight into the role of PP2A as a key regulator of starch metabolism and bradyzoite differentiation in T. gondii.
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Affiliation(s)
- 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, Gansu Province, 730046, People's Republic of China.
| | - Ting-Ting Li
- 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, Gansu Province, 730046, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - 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, Gansu Province, 730046, People's Republic of China
| | - Zhi-Wei Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Meng Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province, 030801, People's Republic of China.
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24
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Shao H, Wu W, Wang P, Han T, Zhuang C. Role of Necroptosis in Central Nervous System Diseases. ACS Chem Neurosci 2022; 13:3213-3229. [PMID: 36373337 DOI: 10.1021/acschemneuro.2c00405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Necroptosis is a type of precisely regulated necrotic cell death activated in caspase-deficient conditions. Multiple factors initiate the necroptotic signaling pathway, including toll-like receptor 3/4, tumor necrosis factor (TNF), dsRNA viruses, and T cell receptors. Presently, TNF-induced necroptosis via the phosphorylation of three key proteins, receptor-interacting protein kinase 1, receptor-interacting protein kinase 3, and mixed lineage kinase domain-like protein, is the best-characterized process. Necroptosis induced by Z-DNA-binding protein 1 (ZBP-1) and toll/interleukin-1 receptor (TIR)-domain-containing adapter-inducing interferon (TRIF) plays a significant role in infectious diseases, such as influenza A virus, Zika virus, and herpesvirus infection. An increasing number of studies have demonstrated the close association of necroptosis with multiple diseases, and disrupting necroptosis has been confirmed to be effective for treating (or managing) these diseases. The central nervous system (CNS) exhibits unique physiological structures and immune characteristics. Necroptosis may occur without the sequential activation of signal proteins, and the necroptosis of supporting cells has more important implications in disease development. Additionally, necroptotic signals can be activated in the absence of necroptosis. Here, we summarize the role of necroptosis and its signal proteins in CNS diseases and characterize typical necroptosis regulators to provide a basis for the further development of therapeutic strategies for treating such diseases. In the present review, relevant information has been consolidated from recent studies (from 2010 until the present), excluding the patents in this field.
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Affiliation(s)
- Hongming Shao
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | - Wenbin Wu
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | - Pei Wang
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | - Ting Han
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | - Chunlin Zhuang
- School of Pharmacy, Second Military Medical University, Shanghai 200433, China.,School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China
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25
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Keroack CD, Duraisingh MT. Molecular mechanisms of cellular quiescence in apicomplexan parasites. Curr Opin Microbiol 2022; 70:102223. [PMID: 36274498 DOI: 10.1016/j.mib.2022.102223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 01/25/2023]
Abstract
Quiescence is a reversible nonproliferative cellular state that allows organisms to persist through unfavorable conditions. Quiescence can be stimulated by a wide range of external or intrinsic factors. Cells undergo a coordinated molecular program to enter and exit from the quiescent state, which is governed by signaling, transcriptional and translational changes, epigenetic mechanisms, metabolic switches, and changes in cellular architecture. These mechanisms have been extensively studied in model organisms, and a growing number of studies have identified conserved mechanisms in apicomplexan parasites. Quiescence in the context of a parasitic infection has significant clinical impact: quiescent forms may underlie treatment failures, relapsing infections, and stress tolerance. Here, we review the latest understanding of quiescence in apicomplexa, synthesizing these studies to highlight conserved mechanisms, and identifying technologies to assist in further characterization of quiescence. Understanding conserved mechanisms of quiescence in apicomplexans will provide avenues for transmission prevention and radical cure of infections.
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26
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T cell surveillance of Toxoplasma gondii: Basic insights into how T cells operate in the central nervous system. Curr Opin Neurobiol 2022; 77:102640. [PMID: 36240583 DOI: 10.1016/j.conb.2022.102640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 01/10/2023]
Abstract
The ability of T cells to operate in the central nervous system (CNS) is required for resistance to multiple pathogens that affect this tissue. The intracellular parasite Toxoplasma gondii has evolved to persist in the CNS and poses unique challenges to the immune system with the need to control parasite replication while balancing the adverse pathology associated with local inflammation. This article reviews the models used to study the response to T. gondii during toxoplasmic encephalitis and highlights some of the broader lessons that are relevant to understanding how T cells function in the CNS.
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27
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Pan M, Ge CC, Fan YM, Jin QW, Shen B, Huang SY. The determinants regulating Toxoplasma gondii bradyzoite development. Front Microbiol 2022; 13:1027073. [PMID: 36439853 PMCID: PMC9691885 DOI: 10.3389/fmicb.2022.1027073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/24/2022] [Indexed: 11/04/2023] Open
Abstract
Toxoplasma gondii is an obligate intracellular zoonotic pathogen capable of infecting almost all cells of warm-blooded vertebrates. In intermediate hosts, this parasite reproduces asexually in two forms, the tachyzoite form during acute infection that proliferates rapidly and the bradyzoite form during chronic infection that grows slowly. Depending on the growth condition, the two forms can interconvert. The conversion of tachyzoites to bradyzoites is critical for T. gondii transmission, and the reactivation of persistent bradyzoites in intermediate hosts may lead to symptomatic toxoplasmosis. However, the mechanisms that control bradyzoite differentiation have not been well studied. Here, we review recent advances in the study of bradyzoite biology and stage conversion, aiming to highlight the determinants associated with bradyzoite development and provide insights to design better strategies for controlling toxoplasmosis.
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Affiliation(s)
- Ming Pan
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Ceng-Ceng Ge
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yi-Min Fan
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Qi-Wang Jin
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Si-Yang Huang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
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Oliveira-Scussel ACDM, Ferreira PTM, Resende RDS, Ratkevicius-Andrade CM, Gomes ADO, Paschoini MC, De Vito FB, Farnesi-de-Assunção TS, da Silva MV, Mineo JR, Rodrigues DBR, Rodrigues V. Association of gestational diabetes mellitus and negative modulation of the specific humoral and cellular immune response against Toxoplasma gondii. Front Immunol 2022; 13:925762. [PMID: 36203592 PMCID: PMC9531261 DOI: 10.3389/fimmu.2022.925762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/17/2022] [Indexed: 11/24/2022] Open
Abstract
In order to evaluate and compare the specific immune response of pregnant women (PW) chronically infected with Toxoplasma gondii, with and without gestational diabetes mellitus (GDM), and the humoral response of their respective newborns (NB), the study was carried out on 81 PW (34 GDM and 47 controls) from whose medical records the results of the oral glucose tolerance test (OGTT) were obtained, and blood samples were collected at the third trimester of pregnancy; also, on 45 NBs (20 GDM and 25 controls) from whom umbilical cord blood samples were obtained. Humoral immunity was analyzed by measuring anti-T. gondii total IgG, IgG subclasses and IgG avidity. To evaluate cellular immunity, peripheral blood mononuclear cells (PBMC) from 32 PW (16 GDM and 16 controls) were cultured, supernatant cytokines were determined, and flow cytometry was performed to analyze the expression at lymphocytes of surface molecules, cytokines and transcription factors. All PW and NBs were positive for total IgG, and the prevalent subclass was IgG1. There was a negative correlation between the OGTT glycemia of PW and the levels of total IgG, IgG1 and IgG avidity. The IgG avidity of the GDM group was significantly lower than the control group. Patients from the GDM group had a higher number of T lymphocytes expressing markers of cell activation and exhaustion (CD28 and PD-1). In the presence of T. gondii soluble antigen (STAg) the amount of CD4+ T cells producing IFN-γ, IL-10 and IL-17 was significantly lower in the GDM group, while there was no difference between groups in the number of CD4+ CD25HighFOXP3+LAP+ functional Treg cells. Additionally, under STAg stimulus, the secretion of IL-17, IL-4, TNF and IL-2 cytokines at PBMCs culture supernatant was lower in the GDM group. In conclusion, there was a correlation between the increase in blood glucose and the decrease in levels of anti-T. gondii antibodies, associated with the decreased IgG avidity in patients who develop GDM. Also, the GDM group had decreased immune responses in Th1, Th2 and Th17 profiles, suggesting an association between GDM and the negative modulation of the humoral and cellular immune responses against T. gondii.
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Affiliation(s)
- Ana Carolina de Morais Oliveira-Scussel
- Laboratory of Immunology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Paula Tatiana Mutão Ferreira
- Laboratory of Immunology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Renata de Souza Resende
- Laboratory of Immunology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Cristhianne Molinero Ratkevicius-Andrade
- Laboratory of Immunology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Angelica de Oliveira Gomes
- Laboratory of Cellular Interactions, Institute of Biological and Natural Sciences, Department of Structural Biology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Marina Carvalho Paschoini
- Institute of Health Sciences, Department of Obstetricy, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Fernanda Bernadelli De Vito
- Laboratory of Hematology and Hemotherapy, Institute of Health Sciences, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Thaís Soares Farnesi-de-Assunção
- Laboratory of Immunology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - Marcos Vinícius da Silva
- Laboratory of Parasitology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
| | - José Roberto Mineo
- Laboratory of Immunology “Dr. Mário Endsfeldz Camargo”, Institute of Biomedical Sciences, Universidade Federal de Uberlândia (UFU), Uberlândia, Minas Gerais, Brazil
| | | | - Virmondes Rodrigues
- Laboratory of Immunology, Institute of Biological and Natural Sciences, Department of Microbiology, Immunology and Parasitology, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Minas Gerais, Brazil
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Tian X, Yang Z, Wan G, Xie T, Wang M, Sun H, Mei X, Zhang Z, Li X, Wang S. Vaccination with recombinant Toxoplasma gondii bradyzoite-formation deficient 1 (rTgBFD1) antigen provides partial protective immunity against chronic T. gondii infection. Front Vet Sci 2022; 9:957479. [PMID: 36172608 PMCID: PMC9510678 DOI: 10.3389/fvets.2022.957479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
As an apicomplexan pathogen, Toxoplasma gondii still remains a major threat to public health and requires special attention. In fact, positive attempts to identify more effective antigens to provide protection are important to control toxoplasmosis. Latest scientific advances in T. gondii study hint at the probability of the T. gondii bradyzoite-formation deficient 1 (TgBFD1) as an ideal vaccine candidate, since this molecule plays a critical role in regulating the chronic infection of T. gondii. Thus, BALB/c mouse models of acute and chronic T. gondii infections were used to evaluate the TgBFD1 protection efficacy in this study. Before conducting animal trials, antigen analysis of TgBFD1 was performed using DNAstar software and Western blots. The preliminary results suggested that TgBFD1 should be a potent immunogen. Then, this conclusion is confirmed by ELISA assays. After immunization with rTgBFD1, high levels of specific IgG, IgG1, IgG2a, and cytokines (Interferon γ and interleukin 10) were observed, indicating that TgBFD1 could induce strong protective antibody responses. While TgBFD1-specific IgG antibodies were measurable in vaccinated mice, no protection was observed in the acute T. gondii infection (RH strain) assay. However, a noticeable decrease in brain cysts counts of immunized mice compared with negative controls in the latent T. gondii infection (PRU strain) assay was observed. Taken together, these results indicated that rTgBFD1 had the remarkable ability to elicit both humoral and cellular immune responses and could provide partial protective immunity against chronic T. gondii infection.
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Affiliation(s)
- Xiaowei Tian
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Zhenke Yang
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Guangmin Wan
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Tong Xie
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Meng Wang
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Hanqi Sun
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Xuefang Mei
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Zhenchao Zhang
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Xiangrui Li
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- *Correspondence: Xiangrui Li
| | - Shuai Wang
- Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
- Shuai Wang
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30
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Abstract
The intracellular parasite Toxoplasma gondii adapts to diverse host cell environments within a replicative compartment that is heavily decorated by secreted proteins. In an attempt to identify novel parasite secreted proteins that influence host cell activity, we identified and characterized a transmembrane dense granule protein dubbed GRA64 (TGME49_202620). We found that GRA64 is on the parasitophorous vacuolar membrane (PVM) and is partially exposed to the host cell cytoplasm in both tachyzoite and bradyzoite parasitophorous vacuoles. Using co-immunoprecipitation and proximity-based biotinylation approaches, we demonstrated that GRA64 appears to interact with components of the host endosomal sorting complexes required for transport (ESCRT). Genetic disruption of GRA64 does not affect acute Toxoplasma virulence or encystation in mice, as observed via tissue cyst burdens in mice during chronic infection. However, ultrastructural analysis of Δgra64 tissue cysts using electron tomography revealed enlarged vesicular structures underneath the cyst membrane, suggesting a role for GRA64 in organizing the recruitment of ESCRT proteins and subsequent intracystic vesicle formation. This study uncovers a novel host-parasite interaction that contributes to an emerging paradigm in which specific host ESCRT proteins are recruited to the limiting membranes (PVMs) of tachyzoite and bradyzoite vacuoles formed during acute and chronic Toxoplasma infection. IMPORTANCE Toxoplasma gondii is a widespread foodborne parasite that causes congenital disease and life-threatening complications in immunocompromised individuals. Part of this parasite's success lies in its ability to infect diverse organisms and host cells and to persist as a latent infection within parasite-constructed structures called tissue cysts. In this study, we characterized a protein that is secreted by T. gondii into its parasitophorous vacuole during intracellular infection, which we dub GRA64. On the vacuolar membrane, this protein is exposed to the host cell cytosol and interacts with specific host ESCRT proteins. Parasites lacking the GRA64 protein exhibit ultrastructural changes in tissue cysts during chronic infection. This study lays the foundation for future studies on the mechanics and consequences of host ESCRT-parasite protein interactions.
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31
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Activity of (1-benzyl-4-triazolyl)-indole-2-carboxamides against Toxoplasma gondii and Cryptosporidium parvum. Int J Parasitol Drugs Drug Resist 2022; 19:6-20. [PMID: 35462232 PMCID: PMC9046076 DOI: 10.1016/j.ijpddr.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/30/2022] [Accepted: 04/05/2022] [Indexed: 11/21/2022]
Abstract
Parasitic diseases such as toxoplasmosis and cryptosporidiosis remain serious global health challenges, not only to humans but also to domestic animals and wildlife. With only limited treatment options available, Toxoplasma gondii and Cryptosporidium parvum (the causative agents of toxoplasmosis and cryptosporidiosis, respectively) constitute a substantial health threat especially to young children and immunocompromised individuals. Herein, we report the synthesis and biological evaluation of a series of novel (1-benzyl-4-triazolyl)-indole-2-carboxamides and related compounds that show efficacy against T. gondii and C. parvum. Closely related analogs 7c (JS-2-30) and 7e (JS-2-44) showed low micromolar activity with IC50 indices ranging between 2.95 μM and 7.63 μM against both T. gondii and C. parvum, whereas the compound representing (1-adamantyl)-4-phenyl-triazole, 11b (JS-2-41), showed very good activity with an IC50 of 1.94 μM, and good selectivity against T. gondii in vitro. Importantly, compounds JS-2-41 and JS-2-44 showed appreciable in vivo efficacy in decreasing the number of T. gondii cysts in the brains of Brown Norway rats. Together, these results indicate that (1-benzyl-4-triazolyl)-indole-2-carboxamides and (1-adamantyl)-4-phenyl-triazoles are potential hits for medicinal chemistry explorations in search for novel antiparasitic agents for effective treatment of cryptosporidiosis and toxoplasmosis. (1-Benzyl-4-triazolyl)-indole-2-carboxamide show interesting antiparasitic activity. Compounds' concentrations of 1.94–7.63 μM inhibited growth of T. gondii & C. parvum. The best hits displayed in vivo efficacy comparable to the standard drug atovaquone. Those compounds show good potential for further development as antiparasitic agents.
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32
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Cromar GL, Epp JR, Popovic A, Gu Y, Ha V, Walters BJ, St. Pierre J, Xiong X, Howland JG, Josselyn SA, Frankland PW, Parkinson J. Toxoplasma infection in male mice alters dopamine-sensitive behaviors and host gene expression patterns associated with neuropsychiatric disease. PLoS Negl Trop Dis 2022; 16:e0010600. [PMID: 35857765 PMCID: PMC9342775 DOI: 10.1371/journal.pntd.0010600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 08/01/2022] [Accepted: 06/21/2022] [Indexed: 11/18/2022] Open
Abstract
During chronic infection, the single celled parasite, Toxoplasma gondii, can migrate to the brain where it has been associated with altered dopamine function and the capacity to modulate host behavior, increasing risk of neurocognitive disorders. Here we explore alterations in dopamine-related behavior in a new mouse model based on stimulant (cocaine)-induced hyperactivity. In combination with cocaine, infection resulted in heightened sensorimotor deficits and impairment in prepulse inhibition response, which are commonly disrupted in neuropsychiatric conditions. To identify molecular pathways in the brain affected by chronic T. gondii infection, we investigated patterns of gene expression. As expected, infection was associated with an enrichment of genes associated with general immune response pathways, that otherwise limits statistical power to identify more informative pathways. To overcome this limitation and focus on pathways of neurological relevance, we developed a novel context enrichment approach that relies on a customized ontology. Applying this approach, we identified genes that exhibited unexpected patterns of expression arising from the combination of cocaine exposure and infection. These include sets of genes which exhibited dampened response to cocaine in infected mice, suggesting a possible mechanism for some observed behaviors and a neuroprotective effect that may be advantageous to parasite persistence. This model offers a powerful new approach to dissect the molecular pathways by which T. gondii infection contributes to neurocognitive disorders.
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Affiliation(s)
- Graham L. Cromar
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Canada
| | - Jonathan R. Epp
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Ana Popovic
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Canada
- Dept. of Biochemistry, University of Toronto, Toronto, Canada
| | - Yusing Gu
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Violet Ha
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Brandon J. Walters
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
| | - James St. Pierre
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Canada
| | - Xuejian Xiong
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Canada
| | - John G. Howland
- Dept. of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | - Sheena A. Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
- Dept. of Physiology, University of Toronto, Toronto, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Canada
- Dept. of Psychology, University of Toronto, Toronto, Canada
| | - Paul W. Frankland
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
- Dept. of Physiology, University of Toronto, Toronto, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Canada
- Dept. of Psychology, University of Toronto, Toronto, Canada
- * E-mail: (PF); (JP)
| | - John Parkinson
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Canada
- Dept. of Biochemistry, University of Toronto, Toronto, Canada
- Dept. of Molecular Genetics, University of Toronto, Toronto, Canada
- * E-mail: (PF); (JP)
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33
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Naumov AV, Wang C, Chaput D, Ting LM, Alvarez CA, Keller T, Ramadan A, White MW, Kim K, Suvorova ES. Restriction Checkpoint Controls Bradyzoite Development in Toxoplasma gondii. Microbiol Spectr 2022; 10:e0070222. [PMID: 35652638 PMCID: PMC9241953 DOI: 10.1128/spectrum.00702-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/04/2022] [Indexed: 11/21/2022] Open
Abstract
Human toxoplasmosis is a life-threatening disease caused by the apicomplexan parasite Toxoplasma gondii. Rapid replication of the tachyzoite is associated with symptomatic disease, while suppressed division of the bradyzoite is responsible for chronic disease. Here, we identified the T. gondii cell cycle mechanism, the G1 restriction checkpoint (R-point), that operates the switch between parasite growth and differentiation. Apicomplexans lack conventional R-point regulators, suggesting adaptation of alternative factors. We showed that Cdk-related G1 kinase TgCrk2 forms alternative complexes with atypical cyclins (TgCycP1, TgCycP2, and TgCyc5) in the rapidly dividing developmentally incompetent RH and slower dividing developmentally competent ME49 tachyzoites and bradyzoites. Examination of cyclins verified the correlation of cyclin expression with growth dependence and development capacity of RH and ME49 strains. We demonstrated that rapidly dividing RH tachyzoites were dependent on TgCycP1 expression, which interfered with bradyzoite differentiation. Using the conditional knockdown model, we established that TgCycP2 regulated G1 duration in the developmentally competent ME49 tachyzoites but not in the developmentally incompetent RH tachyzoites. We tested the functions of TgCycP2 and TgCyc5 in alkaline induced and spontaneous bradyzoite differentiation (rat embryonic brain cells) models. Based on functional and global gene expression analyses, we determined that TgCycP2 also regulated bradyzoite replication, while signal-induced TgCyc5 was critical for efficient tissue cyst maturation. In conclusion, we identified the central machinery of the T. gondii restriction checkpoint comprised of TgCrk2 kinase and three atypical T. gondii cyclins and demonstrated the independent roles of TgCycP1, TgCycP2, and TgCyc5 in parasite growth and development. IMPORTANCE Toxoplasma gondii is a virulent and abundant human pathogen that puts millions of silently infected people at risk of reactivation of the chronic disease. Encysted bradyzoites formed during the chronic stage are resistant to current therapies. Therefore, insights into the mechanism of tissue cyst formation and reactivation are major areas of investigation. The fact that rapidly dividing parasites differentiate poorly strongly suggests that there is a threshold of replication rate that must be crossed to be considered for differentiation. We discovered a cell cycle mechanism that controls the T. gondii growth-rest switch involved in the conversion of dividing tachyzoites into largely quiescent bradyzoites. This switch operates the T. gondii restriction checkpoint using a set of atypical and parasite-specific regulators. Importantly, the novel T. gondii R-point network was not present in the parasite's human and animal hosts, offering a wealth of new and parasite-specific drug targets to explore in the future.
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Affiliation(s)
- Anatoli V. Naumov
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Chengqi Wang
- Center for Global Health and Infectious Diseases Research and USF Genomics Program, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Dale Chaput
- Proteomics Core, College of Arts and Sciences, University of South Florida, Tampa, Florida, USA
| | - Li-Min Ting
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Carmelo A. Alvarez
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Thomas Keller
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Ahmed Ramadan
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Michael W. White
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Kami Kim
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Elena S. Suvorova
- Department of Internal Medicine, Division of Infectious Diseases and International Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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34
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Taggart PL, Liddicoat C, Tong WH, Breed MF, Weinstein P, Wheeler D, Vyas A. Gut microbiota composition does not associate with Toxoplasma infection in rats. Mol Ecol 2022; 31:3963-3970. [PMID: 35621391 PMCID: PMC9546062 DOI: 10.1111/mec.16552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 04/01/2022] [Accepted: 05/25/2022] [Indexed: 11/30/2022]
Abstract
Toxoplasma infection in intermediate host species closely associates with inflammation. This association has led to suggestions that the behavioural changes associated with infection may be indirectly driven by the resulting sustained inflammation rather than a direct behavioural manipulation by the parasite. If this is correct, sustained inflammation in chronically infected rodents should present as widespread differences in the gastrointestinal microbiota due to the dependency between the composition of these microbiota and sustained inflammation. We conducted a randomized controlled experiment in rats that were assigned to a Toxoplasma‐treatment, placebo‐treatment or negative control group. We euthanised rats during the chronic phase of infection, collected their caecal stool samples and sequenced the V3‐V4 region of the 16S rRNA gene to characterize the bacterial community in these samples. Toxoplasma infection did not induce widespread differences in the bacterial community composition of the gastrointestinal tract of rats. Rather, we found sex differences in the bacterial community composition of rats. We conclude that it is unlikely that sustained inflammation is the mechanism driving the highly specific behavioural changes observed in Toxoplasma‐positive rats.
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Affiliation(s)
- Patrick L Taggart
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, 5371, Australia.,Vertebrate Pest Research Unit, Department of Primary Industries NSW, Queanbeyan, NSW, Australia, 2620.,School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia, 2033
| | - Craig Liddicoat
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia.,School of Public Health, The University of Adelaide, SA, 5005, Australia
| | - Wen Han Tong
- Chief Scientist Unit, Department of Primary Industries NSW, Orange, NSW, 2800, Australia
| | - Martin F Breed
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
| | - Philip Weinstein
- School of Public Health, The University of Adelaide, SA, 5005, Australia
| | - David Wheeler
- Chief Scientist Unit, Department of Primary Industries NSW, Orange, NSW, 2800, Australia
| | - Ajai Vyas
- School of Biological Sciences, Nanyang Technological University (SBS-NTU), 60 Nanyang Drive, Singapore, 637551, Singapore
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35
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Quach EV, Cao B, Babacarkhial E, Ho D, Sharma J, Guiton PS. Phosphoglucomutase 1 contributes to optimal cyst development in Toxoplasma gondii. BMC Res Notes 2022; 15:188. [PMID: 35597992 PMCID: PMC9123713 DOI: 10.1186/s13104-022-06073-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/11/2022] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Toxoplasma gondii is a ubiquitous parasite of medical and veterinary importance; however, there exists no cure for chronic toxoplasmosis. Metabolic enzymes required for the production and maintenance of tissue cysts represent promising targets for novel therapies. Here, we use reverse genetics to investigate the role of Toxoplasma phosphoglucomutase 1, PGM1, in Toxoplasma growth and cystogenesis. RESULTS We found that disruption of pgm1 did not significantly affect Toxoplasma intracellular growth and the lytic cycle. pgm1-defective parasites could differentiate into bradyzoites and produced cysts containing amylopectin in vitro. However, cysts produced in the absence of pgm1 were significantly smaller than wildtype. Together, our findings suggest that PGM1 is dispensable for in vitro growth but contributes to optimal Toxoplasma cyst development in vitro, thereby necessitating further investigation into the function of this enzyme in Toxoplasma persistence in its host.
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Affiliation(s)
- Emily V Quach
- Department of Biology, Laney College, Oakland, CA, USA
| | - Binh Cao
- School of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Edres Babacarkhial
- Department of Biological Sciences, California State University East Bay, Hayward, CA, USA
| | - Daniel Ho
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Janak Sharma
- Department of Biological Sciences, California State University East Bay, Hayward, CA, USA
| | - Pascale S Guiton
- Department of Biological Sciences, California State University East Bay, Hayward, CA, USA.
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36
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Christiansen C, Maus D, Hoppenz E, Murillo-León M, Hoffmann T, Scholz J, Melerowicz F, Steinfeldt T, Seeber F, Blume M. In vitro maturation of Toxoplasma gondii bradyzoites in human myotubes and their metabolomic characterization. Nat Commun 2022; 13:1168. [PMID: 35246532 PMCID: PMC8897399 DOI: 10.1038/s41467-022-28730-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 02/02/2022] [Indexed: 12/15/2022] Open
Abstract
The apicomplexan parasite Toxoplasma gondii forms bradyzoite-containing tissue cysts that cause chronic and drug-tolerant infections. However, current in vitro models do not allow long-term culture of these cysts to maturity. Here, we developed a human myotube-based in vitro culture model of functionally mature tissue cysts that are orally infectious to mice and tolerate exposure to a range of antibiotics and temperature stresses. Metabolomic characterization of purified cysts reveals global changes that comprise increased levels of amino acids and decreased abundance of nucleobase- and tricarboxylic acid cycle-associated metabolites. In contrast to fast replicating tachyzoite forms of T. gondii these tissue cysts tolerate exposure to the aconitase inhibitor sodium fluoroacetate. Direct access to persistent stages of T. gondii under defined cell culture conditions will be essential for the dissection of functionally important host-parasite interactions and drug evasion mechanisms. It will also facilitate the identification of new strategies for therapeutic intervention. Bradyzoites are a quiescent form of Toxoplasma gondii enclosed in cysts during chronic infections. Here, Christiansen et al. develop a human myotube-based in vitro culture model of cysts that are infectious to mice and characterize their metabolism in comparison to fast replicating tachyzoites.
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Affiliation(s)
- Céline Christiansen
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Deborah Maus
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Ellen Hoppenz
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Mateo Murillo-León
- Institute of Virology, Medical Center University of Freiburg, 79104, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.,Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Tobias Hoffmann
- ZBS 4: Advanced Light and Electron Microscopy, Centre for Biological Threats and Special Pathogens 4, Robert Koch-Institute, 13353, Berlin, Germany
| | - Jana Scholz
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Florian Melerowicz
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Tobias Steinfeldt
- Institute of Virology, Medical Center University of Freiburg, 79104, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany
| | - Frank Seeber
- FG 16: Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, 13353, Berlin, Germany
| | - Martin Blume
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany.
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37
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Loh FK, Nathan S, Chow SC, Fang CM. Cytolysin A-mediated protein exportation efficiency and its role in enhancing the fitness of live recombinant Salmonella Typhi vaccine strain. Lett Appl Microbiol 2022; 74:820-830. [PMID: 35138654 DOI: 10.1111/lam.13669] [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: 07/26/2021] [Revised: 01/13/2022] [Accepted: 02/04/2022] [Indexed: 11/30/2022]
Abstract
The genetic fusion of cytolysin A (ClyA) to heterologous antigen expressed in live Salmonella vector demonstrated efficient translocation into periplasmic space and extracellular medium. Accumulating evidence has shown that clyA-mediated antigen delivery improved growth fitness and enhanced immunogenicity of live vector vaccine, but the factors influencing this protein exportation has not been investigated. In this study, Toxoplasma gondii antigen fused at C-terminal of clyA protein was expressed in live S. Typhi vector via both plasmid and chromosomal-based expressions. The bivalent strains showed comparable growth rates as monovalent strains, but in varies antigen exportation efficiency. ClyA-fusion antigen with positive charges were translocated to the extracellular spaces, whereas those with negative charges were retained in the cytoplasm. Furthermore, excessive cellular resources expenditure on antigen expression, especially antigen with larger size, could limit the clyA-fusion antigen exportation, resulting in undesirable metabolic burden that eventually affects the growth fitness. Altogether, the present work indicates potential linkage of factors mainly on antigen properties and expression platforms that may affect clyA-mediated antigen delivery to enhance the growth fitness of live vector strain.
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Affiliation(s)
- Fei-Kean Loh
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, 43500, Semenyih Selangor, Malaysia
| | - Sheila Nathan
- Faculty of Science & Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Sek-Chuen Chow
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway Selangor, Malaysia
| | - Chee-Mun Fang
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, 43500, Semenyih Selangor, Malaysia
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38
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Chen M, Yao L, Zhou L, Yang P, Zou W, Xu L, Li S, Peng H. Toxoplasma gondii
ROP18
I
inhibits host innate immunity through cGAS‐STING signaling. FASEB J 2022; 36:e22171. [DOI: 10.1096/fj.202101347r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/19/2021] [Accepted: 01/10/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Min Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Lijie Yao
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Lijuan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Pei Yang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Weihao Zou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Liqing Xu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Shengmin Li
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
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39
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Bicyclic azetidines target acute and chronic stages of Toxoplasma gondii by inhibiting parasite phenylalanyl t-RNA synthetase. Nat Commun 2022; 13:459. [PMID: 35075105 PMCID: PMC8786932 DOI: 10.1038/s41467-022-28108-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/10/2022] [Indexed: 11/24/2022] Open
Abstract
Toxoplasma gondii commonly infects humans and while most infections are controlled by the immune response, currently approved drugs are not capable of clearing chronic infection in humans. Hence, approximately one third of the world’s human population is at risk of reactivation, potentially leading to severe sequelae. To identify new candidates for treating chronic infection, we investigated a series of compounds derived from diversity-oriented synthesis. Bicyclic azetidines are potent low nanomolar inhibitors of phenylalanine tRNA synthetase (PheRS) in T. gondii, with excellent selectivity. Biochemical and genetic studies validate PheRS as the primary target of bicyclic azetidines in T. gondii, providing a structural basis for rational design of improved analogs. Favorable pharmacokinetic properties of a lead compound provide excellent protection from acute infection and partial protection from chronic infection in an immunocompromised mouse model of toxoplasmosis. Collectively, PheRS inhibitors of the bicyclic azetidine series offer promise for treatment of chronic toxoplasmosis. Current treatments for toxoplasmosis are limited by adverse reactions and inability to cure chronic infections dominated by semi-dormant cyst forms. Here the authors demonstrate the potential of small molecule inhibitors of PheRS for controlling acute and chronic toxoplasmosis.
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Toxoplasma gondii in humans and animals in Japan: An epidemiological overview. Parasitol Int 2021; 87:102533. [PMID: 34968753 DOI: 10.1016/j.parint.2021.102533] [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: 08/09/2021] [Revised: 11/29/2021] [Accepted: 12/22/2021] [Indexed: 11/23/2022]
Abstract
Toxoplasmosis is a cosmopolitan protozoan zoonosis caused by Toxoplasma gondii infamous for inducing severe clinical manifestations in humans. Although the disease affects at least one billion people worldwide, it is neglected in many countries including developed ones. In literature, the epidemiological data documenting the actual incidence of the disease in humans and domestic animals from Japan are limited and importantly many earlier papers on T. gondii infections were published in Japanese and a considerable part is not available online. Herein, we review the current summary about the epidemiological situation of T. gondii infection in Japan and the potential associated risk factors in humans and animals as well as the different T. gondii genotypes isolated in Japan. Several T. gondii isolates have been identified among cats (TgCatJpTy1/k-3, TgCatJpGi1/TaJ, TgCatJpObi1 and TgCatJpOk1-4) and goats (TgGoatJpOk1-13). This literature review underscores the need for a nationwide investigation of T. gondii infection in Japanese people and assessment of the socioeconomic impact of the disease burden. Furthermore, epidemiological studies in domestic and wild animals and estimation of degree of contamination of soil or water with T. gondii oocysts are needed, for a better understanding of the scope of this public health concern.
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The Extracellular Milieu of Toxoplasma's Lytic Cycle Drives Lab Adaptation, Primarily by Transcriptional Reprogramming. mSystems 2021; 6:e0119621. [PMID: 34874774 PMCID: PMC8651083 DOI: 10.1128/msystems.01196-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Evolve and resequencing (E&R) was applied to lab adaptation of Toxoplasma gondii for over 1,500 generations with the goal of mapping host-independent in vitro virulence traits. Phenotypic assessments of steps across the lytic cycle revealed that only traits needed in the extracellular milieu evolved. Nonsynonymous single-nucleotide polymorphisms (SNPs) in only one gene, a P4 flippase, fixated across two different evolving populations, whereas dramatic changes in the transcriptional signature of extracellular parasites were identified. Newly developed computational tools correlated phenotypes evolving at different rates with specific transcriptomic changes. A set of 300 phenotype-associated genes was mapped, of which nearly 50% is annotated as hypothetical. Validation of a select number of genes by knockouts confirmed their role in lab adaptation and highlights novel mechanisms underlying in vitro virulence traits. Further analyses of differentially expressed genes revealed the development of a “pro-tachyzoite” profile as well as the upregulation of the fatty acid biosynthesis (FASII) pathway. The latter aligned with the P4 flippase SNP and aligned with a low abundance of medium-chain fatty acids at low passage, indicating this is a limiting factor in extracellular parasites. In addition, partial overlap with the bradyzoite differentiation transcriptome in extracellular parasites indicated that stress pathways are involved in both situations. This was reflected in the partial overlap between the assembled ApiAP2 and Myb transcription factor network underlying the adapting extracellular state with the bradyzoite differentiation program. Overall, E&R is a new genomic tool successfully applied to map the development of polygenic traits underlying in vitro virulence of T. gondii. IMPORTANCE It has been well established that prolonged in vitro cultivation of Toxoplasma gondii augments progression of the lytic cycle. This lab adaptation results in increased capacities to divide, migrate, and survive outside a host cell, all of which are considered host-independent virulence factors. However, the mechanistic basis underlying these enhanced virulence features is unknown. Here, E&R was utilized to empirically characterize the phenotypic, genomic, and transcriptomic changes in the non-lab-adapted strain, GT1, during 2.5 years of lab adaptation. This identified the shutdown of stage differentiation and upregulation of lipid biosynthetic pathways as the key processes being modulated. Furthermore, lab adaptation was primarily driven by transcriptional reprogramming, which rejected the starting hypothesis that genetic mutations would drive lab adaptation. Overall, the work empirically shows that lab adaptation augments T. gondii’s in vitro virulence by transcriptional reprogramming and that E&R is a powerful new tool to map multigenic traits.
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Rahman MT, Swierzy IJ, Downie B, Salinas G, Blume M, McConville MJ, Lüder CGK. The Redox Homeostasis of Skeletal Muscle Cells Regulates Stage Differentiation of Toxoplasma gondii. Front Cell Infect Microbiol 2021; 11:798549. [PMID: 34881198 PMCID: PMC8646093 DOI: 10.3389/fcimb.2021.798549] [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: 10/20/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii is an obligatory intracellular parasite that causes persistent infections in birds and mammals including ~30% of the world’s human population. Differentiation from proliferative and metabolically active tachyzoites to largely dormant bradyzoites initiates the chronic phase of infection and occurs predominantly in brain and muscle tissues. Here we used murine skeletal muscle cells (SkMCs) to decipher host cellular factors that favor T. gondii bradyzoite formation in terminally differentiated and syncytial myotubes, but not in proliferating myoblast precursors. Genome-wide transcriptome analyses of T. gondii-infected SkMCs and non-infected controls identified ~6,500 genes which were differentially expressed (DEGs) in myotubes compared to myoblasts, largely irrespective of infection. On the other hand, genes related to central carbohydrate metabolism, to redox homeostasis, and to the Nrf2-dependent stress response pathway were enriched in both infected myoblast precursors and myotubes. Stable isotope-resolved metabolite profiling indicated increased fluxes into the oxidative branch of the pentose phosphate pathway (OxPPP) in infected myoblasts and into the TCA cycle in infected myotubes. High OxPPP activity in infected myoblasts was associated with increased NADPH/NADP+ ratio while myotubes exhibited higher ROS levels and lower expression of anti-oxidants and detoxification enzymes. Pharmacological reduction of ROS levels in SkMCs inhibited bradyzoite differentiation, while increased ROS induced bradyzoite formation. Thus, we identified a novel host cell-dependent mechanism that triggers stage conversion of T. gondii into persistent tissue cysts in its natural host cell type.
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Affiliation(s)
- Md Taibur Rahman
- Institute for Medical Microbiology and Virology, University Medical Center Goettingen, Georg-August-University, Goettingen, Germany.,Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh
| | - Izabela J Swierzy
- Institute for Medical Microbiology and Virology, University Medical Center Goettingen, Georg-August-University, Goettingen, Germany
| | - Bryan Downie
- Transcriptome and Genome Analysis Laboratory, University Medical Center Goettingen, Georg-August-University, Goettingen, Germany
| | - Gabriela Salinas
- Transcriptome and Genome Analysis Laboratory, University Medical Center Goettingen, Georg-August-University, Goettingen, Germany
| | - Martin Blume
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, VIC, Australia.,Junior Research Group 'Metabolism of Microbial Pathogens', Robert-Koch-Institute, Berlin, Germany
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, VIC, Australia
| | - Carsten G K Lüder
- Institute for Medical Microbiology and Virology, University Medical Center Goettingen, Georg-August-University, Goettingen, Germany
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Fu Y, Brown KM, Jones NG, Moreno SNJ, Sibley LD. Toxoplasma bradyzoites exhibit physiological plasticity of calcium and energy stores controlling motility and egress. eLife 2021; 10:e73011. [PMID: 34860156 PMCID: PMC8683080 DOI: 10.7554/elife.73011] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/03/2021] [Indexed: 01/01/2023] Open
Abstract
Toxoplasma gondii has evolved different developmental stages for disseminating during acute infection (i.e., tachyzoites) and establishing chronic infection (i.e., bradyzoites). Calcium ion (Ca2+) signaling tightly regulates the lytic cycle of tachyzoites by controlling microneme secretion and motility to drive egress and cell invasion. However, the roles of Ca2+ signaling pathways in bradyzoites remain largely unexplored. Here, we show that Ca2+ responses are highly restricted in bradyzoites and that they fail to egress in response to agonists. Development of dual-reporter parasites revealed dampened Ca2+ responses and minimal microneme secretion by bradyzoites induced in vitro or harvested from infected mice and tested ex vivo. Ratiometric Ca2+ imaging demonstrated lower Ca2+ basal levels, reduced magnitude, and slower Ca2+ kinetics in bradyzoites compared with tachyzoites stimulated with agonists. Diminished responses in bradyzoites were associated with downregulation of Ca2+-ATPases involved in intracellular Ca2+ storage in the endoplasmic reticulum (ER) and acidocalcisomes. Once liberated from cysts by trypsin digestion, bradyzoites incubated in glucose plus Ca2+ rapidly restored their intracellular Ca2+ and ATP stores, leading to enhanced gliding. Collectively, our findings indicate that intracellular bradyzoites exhibit dampened Ca2+ signaling and lower energy levels that restrict egress, and yet upon release they rapidly respond to changes in the environment to regain motility.
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Affiliation(s)
- Yong Fu
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Kevin M Brown
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Silvia NJ Moreno
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of GeorgiaAthensUnited States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
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Lactate dehydrogenase and malate dehydrogenase: Potential antiparasitic targets for drug development studies. Bioorg Med Chem 2021; 50:116458. [PMID: 34687983 DOI: 10.1016/j.bmc.2021.116458] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 09/27/2021] [Accepted: 10/05/2021] [Indexed: 12/24/2022]
Abstract
Parasitic diseases remain a major public health concern for humans, claiming millions of lives annually. Although different treatments are required for these diseases, drug usage is limited due to the development of resistance and toxicity, which necessitate alternative therapies. It has been shown in the literature that parasitic lactate dehydrogenases (LDH) and malate dehydrogenases (MDH) have unique pharmacological selective and specificity properties compared to other isoforms, thus highlighting them as viable therapeutic targets involved in aerobic and anaerobic glycolytic pathways. LDH and MDH are important therapeutic targets for invasive parasites because they play a critical role in the progression and development of parasitic diseases. Any strategy to impede these enzymes would be fatal to the parasites, paving the way to develop and discover novel antiparasitic agents. This review aims to highlight the importance of parasitic LDH and MDH as therapeutic drug targets in selected obligate apicoplast parasites. To the best of our knowledge, this review presents the first comprehensive review of LDH and MDH as potential antiparasitic targets for drug development studies.
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Mouveaux T, Roger E, Gueye A, Eysert F, Huot L, Grenier-Boley B, Lambert JC, Gissot M. Primary brain cell infection by Toxoplasma gondii reveals the extent and dynamics of parasite differentiation and its impact on neuron biology. Open Biol 2021; 11:210053. [PMID: 34610266 PMCID: PMC8492179 DOI: 10.1098/rsob.210053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Toxoplasma gondii is a eukaryotic parasite that forms latent cysts in the brain of immunocompetent individuals. The latent parasite infection of the immune-privileged central nervous system is linked to most complications. With no drug currently available to eliminate the latent cysts in the brain of infected hosts, the consequences of neurons' long-term infection are unknown. It has long been known that T. gondii specifically differentiates into a latent form (bradyzoite) in neurons, but how the infected neuron responds to the infection remains to be elucidated. We have established a new in vitro model resulting in the production of mature bradyzoite cysts in brain cells. Using dual, host and parasite RNA-seq, we characterized the dynamics of differentiation of the parasite, revealing the involvement of key pathways in this process. Moreover, we identified how the infected brain cells responded to the parasite infection revealing the drastic changes that take place. We showed that neuronal-specific pathways are strongly affected, with synapse signalling being particularly affected, especially glutamatergic synapse signalling. The establishment of this new in vitro model allows investigating both the dynamics of parasite differentiation and the specific response of neurons to long-term infection by this parasite.
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Affiliation(s)
- Thomas Mouveaux
- U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000 Lille, France
| | - Emmanuel Roger
- U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000 Lille, France
| | - Alioune Gueye
- U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000 Lille, France
| | - Fanny Eysert
- U1167, University of Lille, Inserm, Institut Pasteur de Lille, F-59000 Lille, France
| | - Ludovic Huot
- U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000 Lille, France
| | | | - Jean-Charles Lambert
- U1167, University of Lille, Inserm, Institut Pasteur de Lille, F-59000 Lille, France
| | - Mathieu Gissot
- U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000 Lille, France
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Saraav I, Cervantes-Barragan L, Olias P, Fu Y, Wang Q, Wang L, Wang Y, Mack M, Baldridge MT, Stappenbeck T, Colonna M, Sibley LD. Chronic Toxoplasma gondii infection enhances susceptibility to colitis. Proc Natl Acad Sci U S A 2021; 118:e2106730118. [PMID: 34462359 PMCID: PMC8433586 DOI: 10.1073/pnas.2106730118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Oral infection with Toxoplasma gondii results in dysbiosis and enteritis, both of which revert to normal during chronic infection. However, whether infection leaves a lasting impact on mucosal responses remains uncertain. Here we examined the effect of the chemical irritant dextran sodium sulfate (DSS) on intestinal damage and wound healing in chronically infected mice. Our findings indicate that prior infection with T. gondii exacerbates damage to the colon caused by DSS and impairs wound healing by suppressing stem cell regeneration of the epithelium. Enhanced tissue damage was attributable to inflammatory monocytes that emerge preactivated from bone marrow, migrate to the intestine, and release inflammatory mediators, including nitric oxide. Tissue damage was reversed by neutralization of inflammatory monocytes or nitric oxide, revealing a causal mechanism for tissue damage. Our findings suggest that chronic infection with T. gondii enhances monocyte activation to increase inflammation associated with a secondary environmental insult.
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Affiliation(s)
- Iti Saraav
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Luisa Cervantes-Barragan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Philipp Olias
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Yong Fu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Leran Wang
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110
| | - Yi Wang
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Matthias Mack
- Department of Nephrology, University of Regensburg, 93042 Regensburg, Germany
| | - Megan T Baldridge
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110
| | - Thaddeus Stappenbeck
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110;
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Zhu L, Lei Z, Xia X, Zhang Y, Chen Y, Wang B, Li J, Li G, Yang G, Cao G, Yin Z. Yeast Shells Encapsulating Adjuvant AS04 as an Antigen Delivery System for a Novel Vaccine against Toxoplasma Gondii. ACS APPLIED MATERIALS & INTERFACES 2021; 13:40415-40428. [PMID: 34470103 DOI: 10.1021/acsami.1c12366] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Toxoplasma gondii (T. gondii) infection causes severe zoonotic toxoplasmosis, which threatens the safety of almost one-third of the human population globally. However, there is no effective protective vaccine against human toxoplasmosis. This necessitates anti-T. gondii vaccine development, which is a main priority of public health. In this study, we optimized the adjuvant system 04 (AS04), a vaccine adjuvant constituted by 3-O-desacyl-4'-monophosphoryl lipid A (a TLR4 agonist) and aluminum salts, by packing it within natural extracts of β-glucan particles (GPs) from Saccharomyces cerevisiae to form a GP-AS04 hybrid adjuvant system. Through a simple mixing procedure, we loaded GP-AS04 particles with the total extract (TE) of T. gondii lysate, forming a novel anti-T. gondii vaccine GP-AS04-TE. Results indicated that the hybrid adjuvant can efficiently and stably load antigens, mediate antigen delivery, facilitate the dendritic uptake of antigens, boost dendritic cell maturation and stimulation, and increase the secretion of pro-inflammatory cytokines. In the mouse inoculation model, GP-AS04-TE significantly stimulated the function of dendritic cells, induced a very strong TE-specific humoral and cellular immune response, and finally showed a strong and effective protection against toxoplasma chronic and acute infections. This work proves the potential of GP-AS04 for exploitation as a vaccine against a range of pathogens.
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Affiliation(s)
- Leqing Zhu
- The First Affiliated Hospital, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Zhiwei Lei
- Guangdong Provincial Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou 510632, China
- The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan 511518, China
| | - Xichun Xia
- Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Hospital Affiliated with Jinan University), Jinan University, Zhuhai 51900, China
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Yingying Zhang
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Yuyuan Chen
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Baocheng Wang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Jiawei Li
- Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Hospital Affiliated with Jinan University), Jinan University, Zhuhai 51900, China
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Guangqiang Li
- The First Affiliated Hospital, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Guang Yang
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Guangchao Cao
- Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Hospital Affiliated with Jinan University), Jinan University, Zhuhai 51900, China
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
| | - Zhinan Yin
- Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital (Zhuhai Hospital Affiliated with Jinan University), Jinan University, Zhuhai 51900, China
- The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou 510632, China
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Abstract
Infectious diseases pose two main compelling issues. First, the identification of the molecular factors that allow chronic infections, that is, the often completely asymptomatic coexistence of infectious agents with the human host. Second, the definition of the mechanisms that allow the switch from pathogen dormancy to pathologic (re)activation. Furthering previous studies, the present study (1) analyzed the frequency of occurrence of synonymous codons in coding DNA, that is, codon usage, as a genetic tool that rules protein expression; (2) described how human codon usage can inhibit protein expression of infectious agents during latency, so that pathogen genes the codon usage of which does not conform to the human codon usage cannot be translated; and (3) framed human codon usage among the front-line instruments of the innate immunity against infections. In parallel, it was shown that, while genetics can account for the molecular basis of pathogen latency, the changes of the quantitative relationship between codon frequencies and isoaccepting tRNAs during cell proliferation offer a biochemical mechanism that explains the pathogen switching to (re)activation. Immunologically, this study warns that using codon optimization methodologies can (re)activate, potentiate, and immortalize otherwise quiescent, asymptomatic pathogens, thus leading to uncontrollable pandemics.
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Affiliation(s)
- Darja Kanduc
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
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Farhat DC, Hakimi MA. The developmental trajectories of Toxoplasma stem from an elaborate epigenetic rewiring. Trends Parasitol 2021; 38:37-53. [PMID: 34456144 DOI: 10.1016/j.pt.2021.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/25/2021] [Accepted: 07/28/2021] [Indexed: 12/15/2022]
Abstract
Toxoplasma gondii is considered to be one of the most successful parasitic pathogens. It owes this success to its flexibility in responding to signals emanating from the different environments it encounters during its multihost life cycle. The adaptability of this unicellular organism relies on highly coordinated and evolutionarily optimized developmental abilities that allow it to adopt the forms best suited to the requirements of each environment. Here we discuss recent outstanding studies that have uncovered how master regulators epigenetically regulate the cryptic process of sexual development and the transition to chronicity. We also highlight the molecular and technical advances that allow the field to embark on a new journey of epigenetic reprogramming of T. gondii development.
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Affiliation(s)
- Dayana C Farhat
- IAB, Team Host-Pathogen Interactions & Immunity to Infection, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France.
| | - Mohamed-Ali Hakimi
- IAB, Team Host-Pathogen Interactions & Immunity to Infection, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France.
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Insights into the biochemical features and immunogenic epitopes of common bradyzoite markers of the ubiquitous Toxoplasma gondii. INFECTION GENETICS AND EVOLUTION 2021; 95:105037. [PMID: 34390868 DOI: 10.1016/j.meegid.2021.105037] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/16/2021] [Accepted: 08/09/2021] [Indexed: 12/17/2022]
Abstract
The widespread distribution of Toxoplasma gondii (T. gondii) infection and its harsh outcomes in pregnant women and immunocompromised patients lead researchers towards vaccination strategies. The present in silico investigation was done to reveal biophysical properties and immunogenic epitopes of six bradyzoite markers for rational vaccine design in future. For this purpose, different web servers were used to predict antigenicity, allergenicity, solubility, physicochemical properties, post-translational modification sites (PTMs), the presence of signal peptide and transmembrane domains. Moreover, the secondary and tertiary structures of the proteins were revealed followed by refinement and validation. Finally, NetCTL server was used to predict cytotoxic T-lymphocyte (CTL) epitopes, with subsequent immunogenicity analysis. Also, IEDB server was utilized to predict helper T-lymphocyte (HTL) epitopes, followed by IFN-γ and IL-4 induction, antigenicity and population coverage analysis. As well, several linear antigenic B-cell epitopes were found, with good water solubility and without allergenicity. Totally, these proteins showed appropriate antigenicity, abundant PTMs as well as many CTL, HTL and B-cell epitopes, which could be directed for future vaccination studies in the context of multi-epitope vaccine design.
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