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Angel SO, Vanagas L, Alonso AM. Mechanisms of adaptation and evolution in Toxoplasma gondii. Mol Biochem Parasitol 2024; 258:111615. [PMID: 38354788 DOI: 10.1016/j.molbiopara.2024.111615] [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: 09/15/2023] [Revised: 12/28/2023] [Accepted: 02/06/2024] [Indexed: 02/16/2024]
Abstract
Toxoplasma has high host flexibility, infecting all nucleated cells of mammals and birds. This implies that during its infective process the parasite must constantly adapt to different environmental situations, which in turn leads to modifications in its metabolism, regulation of gene transcription, translation of mRNAs and stage specific factors. There are conserved pathways that support these adaptations, which we aim to elucidate in this review. We begin by exploring the widespread epigenetic mechanisms and transcription regulators, continue with the supportive role of Heat Shock Proteins (Hsp), the translation regulation, stress granules, and finish with the emergence of contingency genes in highly variable genomic domains, such as subtelomeres. Within epigenetics, the discovery of a new histone variant of the H2B family (H2B.Z), contributing to T. gondii virulence and differentiation, but also gene expression regulation and its association with the metabolic state of the parasite, is highlighted. Associated with the regulation of gene expression are transcription factors (TFs). An overview of the main findings on TF and development is presented. We also emphasize the role of Hsp90 and Tgj1 in T. gondii metabolic fitness and the regulation of protein translation. Translation regulation is also highlighted as a mechanism for adaptation to conditions encountered by the parasite as well as stress granules containing mRNA and proteins generated in the extracellular tachyzoite. Another important aspect in evolution and adaptability are the subtelomeres because of their high variability and gene duplication rate. Toxoplasma possess multigene families of membrane proteins and contingency genes that are associated with different metabolic stresses. Among them parasite differentiation and environmental stresses stand out, including those that lead tachyzoite to bradyzoite conversion. Finally, we are interested in positioning protozoa as valuable evolution models, focusing on research related to the Extended Evolutionary Synthesis, based on models recently generated, such as extracellular adaptation and ex vivo cyst recrudescence.
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Affiliation(s)
- 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.
| | - Laura Vanagas
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov, Buenos Aires, Argentina.
| | - Andres M Alonso
- 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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Nayeri T, Sarvi S, Daryani A. Effective factors in the pathogenesis of Toxoplasmagondii. Heliyon 2024; 10:e31558. [PMID: 38818168 PMCID: PMC11137575 DOI: 10.1016/j.heliyon.2024.e31558] [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: 01/03/2023] [Revised: 05/11/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.
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Affiliation(s)
- Tooran Nayeri
- Infectious and Tropical Diseases Research Center, Dezful University of Medical Sciences, Dezful, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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Memariani H, Memariani M, Ghasemian A. Quercetin as a Promising Antiprotozoan Phytochemical: Current Knowledge and Future Research Avenues. BIOMED RESEARCH INTERNATIONAL 2024; 2024:7632408. [PMID: 38456097 PMCID: PMC10919984 DOI: 10.1155/2024/7632408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/20/2024] [Accepted: 02/12/2024] [Indexed: 03/09/2024]
Abstract
Despite tremendous advances in the prevention and treatment of infectious diseases, only few antiparasitic drugs have been developed to date. Protozoan infections such as malaria, leishmaniasis, and trypanosomiasis continue to exact an enormous toll on public health worldwide, underscoring the need to discover novel antiprotozoan drugs. Recently, there has been an explosion of research into the antiprotozoan properties of quercetin, one of the most abundant flavonoids in the human diet. In this review, we tried to consolidate the current knowledge on the antiprotozoal effects of quercetin and to provide the most fruitful avenues for future research. Quercetin exerts potent antiprotozoan activity against a broad spectrum of pathogens such as Leishmania spp., Trypanosoma spp., Plasmodium spp., Cryptosporidium spp., Trichomonas spp., and Toxoplasma gondii. In addition to its immunomodulatory roles, quercetin disrupts mitochondrial function, induces apoptotic/necrotic cell death, impairs iron uptake, inhibits multiple enzymes involved in fatty acid synthesis and the glycolytic pathways, suppresses the activity of DNA topoisomerases, and downregulates the expression of various heat shock proteins in these pathogens. In vivo studies also show that quercetin is effective in reducing parasitic loads, histopathological damage, and mortality in animals. Future research should focus on designing effective drug delivery systems to increase the oral bioavailability of quercetin. Incorporating quercetin into various nanocarrier systems would be a promising approach to manage localized cutaneous infections. Nevertheless, clinical trials are needed to validate the efficacy of quercetin in treating various protozoan infections.
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Affiliation(s)
- Hamed Memariani
- Department of Medical Microbiology, Tehran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Memariani
- Department of Medical Microbiology, Tehran University of Medical Sciences, Tehran, Iran
| | - Abdolmajid Ghasemian
- Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran
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Zhai B, Xie S, Peng J, Qiu Y, Liu Y, Zhu X, He J, Zhang J. Glycosylation Analysis of Feline Small Intestine Following Toxoplasma gondii Infection. Animals (Basel) 2022; 12:ani12202858. [PMID: 36290246 PMCID: PMC9597833 DOI: 10.3390/ani12202858] [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: 09/03/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 12/01/2022] Open
Abstract
Simple Summary Toxoplasma gondii has a serious impact on public health and the economic development of animal husbandry. Glycosylation, especially N-glycosylation, the pattern modification of proteins, is closely related to the biological functions of proteins, and our study used it to analyze glycosylation alterations in the small intestine of cats infected with T. gondii. The results of the present study showed that 56 glycosylated peptides were upregulated and 37 glycosylated peptides were downregulated. Additionally, we also identified eight N-glycosylated proteins of T. gondii including eight N-glycopeptides and eight N-glycosylation sites. Moreover, the protein eEF2 and its corresponding peptide sequence were identified, with GO terms (i.e., cellular process and metabolic process, cell and cell part, and catalytic activity) that were significantly enriched in the T. gondii MAPK pathway. In addition, the Clusters of Orthologous Groups of proteins (COG) function prediction results showed that posttranslational modification, protein turnover, and chaperones (11%) had the highest enrichment for T. gondii. The host proteins ICAM-1 and PPT1 and the endoplasmic reticulum stress pathway may play an important role in the glycosylation of T. gondii-infected hosts. Our study may provide a new target for T. gondii detection to prevent the spread of T. gondii oocysts in the future. Abstract Toxoplasma gondii (T. gondii) is responsible for severe human and livestock diseases, huge economic losses, and adversely affects the health of the public and the development of animal husbandry. Glycosylation is a common posttranslational modification of proteins in eukaryotes, and N-glycosylation is closely related to the biological functions of proteins. However, glycosylation alterations in the feline small intestine following T. gondii infection have not been reported. In this study, the experimental group was intragastrically challenged with 600 brain cysts of the Prugniuad (Pru) strain that were collected from infected mice. The cats’ intestinal epithelial tissues were harvested at 10 days post-infection and then sent for protein glycosylation analysis. High-performance liquid chromatography coupled to tandem mass spectrometry was used to analyze the glycosylation alterations in the small intestine of cats infected with T. gondii. The results of the present study showed that 56 glycosylated peptides were upregulated and 37 glycosylated peptides were downregulated in the feline small intestine infected by T. gondii. Additionally, we also identified eight N-glycosylated proteins of T. gondii including eight N-glycopeptides and eight N-glycosylation sites. The protein A0A086JND6_TOXGO (eEF2) and its corresponding peptide sequence were identified in T. gondii infection. Some special GO terms (i.e., cellular process and metabolic process, cell and cell part, and catalytic activity) were significantly enriched, and the Clusters of Orthologous Groups of proteins (COG) function prediction results showed that posttranslational modification, protein turnover, and chaperones (11%) had the highest enrichment for T. gondii. Interestingly, eEF2, a protein of T. gondii, is also involved in the significantly enriched T. gondii MAPK pathway. The host proteins ICAM-1 and PPT1 and the endoplasmic reticulum stress pathway may play an important role in the glycosylation of Toxoplasma-infected hosts. This is the first report showing that T. gondii oocysts can undergo N-glycosylation in the definitive host and that eEF2 is involved, which may provide a new target for T. gondii detection to prevent the spread of T. gondii oocysts in the future.
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Affiliation(s)
- Bintao Zhai
- Key Laboratory of Veterinary Pharmaceutical Development, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Lanzhou 730050, China
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Shichen Xie
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- Research Center for Parasites & Vectors, College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
| | - Junjie Peng
- 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 730046, China
| | - Yanhua Qiu
- Key Laboratory of Veterinary Pharmaceutical Development, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Lanzhou 730050, China
- College of Veterinary Medicine, Northwest A&F University, Xianyang 712100, China
| | - Yang Liu
- College of Life Science, Ningxia University, Yinchuan 750021, China
| | - Xingquan Zhu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China
- Research Center for Parasites & Vectors, College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Veterinary Public Health of Yunnan Province, College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Junjun He
- Key Laboratory of Veterinary Public Health of Yunnan Province, College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
- Correspondence: (J.H.); (J.Z.)
| | - Jiyu Zhang
- Key Laboratory of Veterinary Pharmaceutical Development, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Lanzhou 730050, China
- Correspondence: (J.H.); (J.Z.)
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Tan S, Tong WH, Vyas A. Impact of Plant-Based Foods and Nutraceuticals on Toxoplasma gondii Cysts: Nutritional Therapy as a Viable Approach for Managing Chronic Brain Toxoplasmosis. Front Nutr 2022; 9:827286. [PMID: 35284438 PMCID: PMC8914227 DOI: 10.3389/fnut.2022.827286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/31/2022] [Indexed: 12/13/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite that mainly infects warm-blooded animals including humans. T. gondii can encyst and persist chronically in the brain, leading to a broad spectrum of neurological sequelae. Despite the associated health threats, no clinical drug is currently available to eliminate T. gondii cysts. In a continuous effort to uncover novel therapeutic agents for these cysts, the potential of nutritional products has been explored. Herein, we describe findings from in vitro and in vivo studies that support the efficacy of plant-based foods and nutraceuticals against brain cyst burden and cerebral pathologies associated with chronic toxoplasmosis. Finally, we discuss strategies to increase the translatability of preclinical studies and nutritional products to address whether nutritional therapy can be beneficial for coping with chronic T. gondii infections in humans.
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Tucker MS, O’Brien CN, Jenkins MC, Rosenthal BM. Dynamically expressed genes provide candidate viability biomarkers in a model coccidian. PLoS One 2021; 16:e0258157. [PMID: 34597342 PMCID: PMC8486141 DOI: 10.1371/journal.pone.0258157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/18/2021] [Indexed: 11/29/2022] Open
Abstract
Eimeria parasites cause enteric disease in livestock and the closely related Cyclosporacayetanensis causes human disease. Oocysts of these coccidian parasites undergo maturation (sporulation) before becoming infectious. Here, we assessed transcription in maturing oocysts of Eimeria acervulina, a widespread chicken parasite, predicted gene functions, and determined which of these genes also occur in C. cayetanensis. RNA-Sequencing yielded ~2 billion paired-end reads, 92% of which mapped to the E. acervulina genome. The ~6,900 annotated genes underwent temporally-coordinated patterns of gene expression. Fifty-three genes each contributed >1,000 transcripts per million (TPM) throughout the study interval, including cation-transporting ATPases, an oocyst wall protein, a palmitoyltransferase, membrane proteins, and hypothetical proteins. These genes were enriched for 285 gene ontology (GO) terms and 13 genes were ascribed to 17 KEGG pathways, defining housekeeping processes and functions important throughout sporulation. Expression differed in mature and immature oocysts for 40% (2,928) of all genes; of these, nearly two-thirds (1,843) increased their expression over time. Eight genes expressed most in immature oocysts, encoding proteins promoting oocyst maturation and development, were assigned to 37 GO terms and 5 KEGG pathways. Fifty-six genes underwent significant upregulation in mature oocysts, each contributing at least 1,000 TPM. Of these, 40 were annotated by 215 GO assignments and 9 were associated with 18 KEGG pathways, encoding products involved in respiration, carbon fixation, energy utilization, invasion, motility, and stress and detoxification responses. Sporulation orchestrates coordinated changes in the expression of many genes, most especially those governing metabolic activity. Establishing the long-term fate of these transcripts in sporulated oocysts and in senescent and deceased oocysts will further elucidate the biology of coccidian development, and may provide tools to assay infectiousness of parasite cohorts. Moreover, because many of these genes have homologues in C. cayetanensis, they may prove useful as biomarkers for risk.
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Affiliation(s)
- Matthew S. Tucker
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, United States of America
| | - Celia N. O’Brien
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, United States of America
| | - Mark C. Jenkins
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, United States of America
| | - Benjamin M. Rosenthal
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, United States of America
- * E-mail:
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Çelik T, Önderci M, Pehlivan M, Yumrutaş Ö, Üçkardeş F. In vitro scolicidal effects of Sideritis perfoliata extract against Echinococcus granulosus. Int J Clin Pract 2021; 75:e14498. [PMID: 34160106 DOI: 10.1111/ijcp.14498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/10/2021] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Cystic echinococcosis, caused by helminths within the genus Echinococcus, is mainly localised in the liver and lungs of affected hosts. Surgery has been the best choice for the treatment of hydatidosis and using effective scolicidal agents during hydatid surgery is required to prevent secondary infection. Several plant extracts have been shown to exert scolicidal efficacy. This study was designed to investigate the in vitro scolicidal activity of methanol extract of Sideritis perfoliata against the protoscolices of hydatid cysts. METHODS The protoscolices were collected from a liver of a sheep slaughtered in Adiyaman city slaughter, Turkey. Three concentrations of the aerial part extract of S perfoliata (0.1, 0.2 and 0.4 mg/mL) were assessed at three different exposure periods. All tests were carried in duplicate. The viability of protoscolices was assessed by the eosin exclusion test (0.1% eosin staining). RESULTS Scolicidal effect of S perfoliata extract at exposure periods of 10, 20 and 30 minutes was 29.6%, 32.5% and 43.6% at the concentration of 0.1%, 37.8%, 50% and 58.1% at concentration of 0.2 mg/mL, and 57.9%, 71.8% and 79.1% at the concentration of 0.4 mg/mL, respectively; indicating a longer time is required to display protoscolicidal effects. LC-MS/MS analysis showed that some phenolic acids, such as fumaric acid (260.13 mg/L), syringic acid (27.92 mg/L) and caffeic acid (26.84 mg/L), and a flavonoid, luteolin (11.23 mg/L) were detected in high concentrations in the extract. CONCLUSIONS This study has demonstrated that the methanol extract of S perfoliata has high scolicidal activity in vitro. However, research on the in vivo efficacy of S perfoliata extract and its potential side effects is required.
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Affiliation(s)
- Tuncay Çelik
- Department of Microbiology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey
| | - Muhittin Önderci
- Department of Biochemistry, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey
| | - Mustafa Pehlivan
- Department of Medicinal and Aromatic Plants, Nurdağı Vocational High School, University of Gaziantep, Gaziantep, Turkey
| | - Önder Yumrutaş
- Department of Medical Biology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey
| | - Fatih Üçkardeş
- Department of Biostatistics, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey
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Bioflavonoid-Induced Apoptosis and DNA Damage in Amastigotes and Promastigotes of Leishmania donovani: Deciphering the Mode of Action. Molecules 2021; 26:molecules26195843. [PMID: 34641387 PMCID: PMC8512304 DOI: 10.3390/molecules26195843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/13/2021] [Accepted: 08/23/2021] [Indexed: 12/04/2022] Open
Abstract
Natural products from plants contain many interesting biomolecules. Among them, quercetin (Q), gallic acid (GA), and rutin (R) all have well-reported antileishmanial activity; however, their exact mechanisms of action are still not known. The current study is a step forward towards unveil the possible modes of action of these compounds against Leishmania donovani (the causative agent of visceral leishmaniasis). The selected compounds were checked for their mechanisms of action against L. donovani using different biological assays including apoptosis and necrosis evaluation, effects on genetic material (DNA), quantitative testing of nitric oxide production, ultrastructural modification via transmission electron microscopy, and real-time PCR analysis. The results confirmed that these compounds are active against L. donovani, with IC50 values of 84.65 µg/mL, 86 µg/mL, and 98 µg/mL for Q, GA, and R, respectively. These compounds increased nitric oxide production and caused apoptosis and DNA damage, which led to changes in the treated cells’ ultrastructural behavior and finally to the death of L. donovani. These compounds also suppressed essential enzymes like trypanothione reductase and trypanothione synthetase, which are critical for leishmanial survival. The selected compounds have high antileishmanial potentials, and thus in-vivo testing and further screening are highly recommended.
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The role of upstream open reading frames in translation regulation in the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii. Parasitology 2021; 148:1277-1287. [PMID: 34099078 PMCID: PMC8383288 DOI: 10.1017/s0031182021000937] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During their complex life cycles, the Apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii employ several layers of regulation of their gene expression. One such layer is mediated at the level of translation through upstream open reading frames (uORFs). As uORFs are found in the upstream regions of a majority of transcripts in both the parasites, it is essential that their roles in translational regulation be appreciated to a greater extent. This review provides a comprehensive summary of studies that show uORF-mediated gene regulation in these parasites and highlights examples of clinically and physiologically relevant genes, including var2csa in P. falciparum, and ApiAT1 in T. gondii, that exhibit uORF-mediated regulation. In addition to these examples, several studies that use bioinformatics, transcriptomics, proteomics and ribosome profiling also indicate the possibility of widespread translational regulation by uORFs. Further analysis of these genome-wide datasets, taking into account uORFs associated with each gene, will reveal novel genes involved in key biological pathways such as cell-cycle progression, stress-response and pathogenicity. The cumulative evidence from studies presented in this review suggests that uORFs will play crucial roles in regulating gene expression during clinical disease caused by these important human pathogens.
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Khalifa MM, Martorelli Di Genova B, McAlpine SG, Gallego-Lopez GM, Stevenson DM, Rozema SD, Monaghan NP, Morris JC, Knoll LJ, Golden JE. Dual-Stage Picolinic Acid-Derived Inhibitors of Toxoplasma gondii. ACS Med Chem Lett 2020; 11:2382-2388. [PMID: 33335660 DOI: 10.1021/acsmedchemlett.0c00267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/07/2020] [Indexed: 12/20/2022] Open
Abstract
Toxoplasma gondii causes a prevalent human infection for which only the acute stage has an FDA-approved therapy. To find inhibitors of both the acute stage parasites and the persistent cyst stage that causes a chronic infection, we repurposed a compound library containing known inhibitors of parasitic hexokinase, the first step in the glycolysis pathway, along with a larger collection of new structural derivatives. The focused screen of 22 compounds showed a 77% hit rate (>50% multistage inhibition) and revealed a series of aminobenzamide-linked picolinic acids with submicromolar potency against both T. gondii parasite forms. Picolinic acid 23, designed from an antiparasitic benzamidobenzoic acid class with challenging ADME properties, showed 60-fold-enhanced solubility, a moderate LogD7.4, and a 30% improvement in microsomal stability. Furthermore, isotopically labeled glucose tracing revealed that picolinic acid 23 does not function by hexokinase inhibition. Thus, we report a new probe scaffold to interrogate dual-stage inhibition of T. gondii.
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Affiliation(s)
- Muhammad M. Khalifa
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53703, United States
| | - Bruno Martorelli Di Genova
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Sarah G. McAlpine
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, 190 Collins Street, Clemson, South Carolina 29634, United States
| | - Gina M. Gallego-Lopez
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
- Morgridge Institute for Research, Madison, Wisconsin 53715, United States
| | - David M. Stevenson
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States of America
| | - Soren D. Rozema
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53703, United States
| | - Neil P. Monaghan
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, 190 Collins Street, Clemson, South Carolina 29634, United States
| | - James C. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, 190 Collins Street, Clemson, South Carolina 29634, United States
| | - Laura J. Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Jennifer E. Golden
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53703, United States
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Sokol-Borrelli SL, Coombs RS, Boyle JP. A Comparison of Stage Conversion in the Coccidian Apicomplexans Toxoplasma gondii, Hammondia hammondi, and Neospora caninum. Front Cell Infect Microbiol 2020; 10:608283. [PMID: 33344268 PMCID: PMC7744739 DOI: 10.3389/fcimb.2020.608283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/06/2020] [Indexed: 01/31/2023] Open
Abstract
Stage conversion is a critical life cycle feature for several Apicomplexan parasites as the ability to switch between life forms is critical for replication, dissemination, pathogenesis and ultimately, transmission to a new host. In order for these developmental transitions to occur, the parasite must first sense changes in their environment, such as the presence of stressors or other environmental signals, and then respond to these signals by initiating global alterations in gene expression. As our understanding of the genetic components required for stage conversion continues to broaden, we can better understand the conserved mechanisms for this process and unique components and their contribution to pathogenesis by comparing stage conversion in multiple closely related species. In this review, we will discuss what is currently known about the mechanisms driving stage conversion in Toxoplasma gondii and its closest relatives Hammondia hammondi and Neospora caninum. Work by us and others has shown that these species have some important differences in the way that they (1) progress through their life cycle and (2) respond to stage conversion initiating stressors. To provide a specific example of species-specific complexities associated with stage conversion, we will discuss our recent published and unpublished work comparing stress responses in T. gondii and H. hammondi.
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Affiliation(s)
| | | | - Jon P. Boyle
- University of Pittsburgh, Department of Biological Sciences, Kenneth P. Dietrich School of Arts and Sciences, Pittsburgh, PA, United States
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12
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He Q, Luo J, Xu JZ, Meng XZ, Pan GQ, Li T, Zhou ZY. Characterization of Hsp70 gene family provides insight into its functions related to microsporidian proliferation. J Invertebr Pathol 2020; 174:107394. [PMID: 32428446 DOI: 10.1016/j.jip.2020.107394] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 12/20/2022]
Abstract
Heat shock protein 70 (Hsp70), a highly conserved protein family, is widely distributed in organisms and plays fundamental roles in biotic and abiotic stress responses. However, reports on Hsp70 genes are scarce in microsporidia, a very large group of obligate intracellular parasites that can infect nearly all animals, including humans. In this study, we identified 37 Hsp70 proteins from eight microsporidian genomes and classified them into four subfamilies (A-D). The number of Hsp70 genes in these microsporidia was significantly fewer than in Rozella allomycis and yeast. All microsporidian species contained genes from each subfamily and similar subcellular locations (mitochondria, endoplasmic reticulum, cytosol, and cytosol and/or nucleus), indicating that each Hsp70 member may fulfil distinct functions. The conserved structures and motifs of the Hsp70 proteins in the same subfamily were highly similar. Expression analysis indicated that the subfamily C cytosol (cyto)-associated Hsp70s is functional during microsporidia development. Immunofluorescence assays revealed that Cyto-NbHsp70 was cytoplasmically located in the proliferation-stage of Nosema bombycis. Cyto-NbHsp70 antiserum also labeled Encephalitozoon hellem within infected cells, suggesting that this antiserum is a potential molecular marker for labeling the proliferative phases of different microsporidian species. The propagation of N. bombycis was significantly inhibited following RNAi of Cyto-NbHsp70, indicating that Cyto-NbHsp70 is important for pathogen proliferation. Our phylogenetic data suggest that Hsp70 proteins evolved during microsporidia adaption to intracellular parasitism, and they play important roles in pathogen development.
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Affiliation(s)
- Qiang He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Jian Luo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Jin-Zhi Xu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Xian-Zhi Meng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Guo-Qing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Tian Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China.
| | - Ze-Yang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China; College of Life Science, Chongqing Normal University, Chongqing 400047, China.
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13
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The Pharmacological Activity, Biochemical Properties, and Pharmacokinetics of the Major Natural Polyphenolic Flavonoid: Quercetin. Foods 2020; 9:foods9030374. [PMID: 32210182 PMCID: PMC7143931 DOI: 10.3390/foods9030374] [Citation(s) in RCA: 255] [Impact Index Per Article: 63.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 12/31/2022] Open
Abstract
Flavonoids are a class of natural substances present in plants, fruits, vegetables, wine, bulbs, bark, stems, roots, and tea. Several attempts are being made to isolate such natural products, which are popular for their health benefits. Flavonoids are now seen as an essential component in a number of cosmetic, pharmaceutical, and medicinal formulations. Quercetin is the major polyphenolic flavonoid found in food products, including berries, apples, cauliflower, tea, cabbage, nuts, and onions that have traditionally been treated as anticancer and antiviral, and used for the treatment of allergic, metabolic, and inflammatory disorders, eye and cardiovascular diseases, and arthritis. Pharmacologically, quercetin has been examined against various microorganisms and parasites, including pathogenic bacteria, viruses, and Plasmodium, Babesia, and Theileria parasites. Additionally, it has shown beneficial effects against Alzheimer’s disease (AD), and this activity is due to its inhibitory effect against acetylcholinesterase. It has also been documented to possess antioxidant, antifungal, anti-carcinogenic, hepatoprotective, and cytotoxic activity. Quercetin has been documented to accumulate in the lungs, liver, kidneys, and small intestines, with lower levels seen in the brain, heart, and spleen, and it is extracted through the renal, fecal, and respiratory systems. The current review examines the pharmacokinetics, as well as the toxic and biological activities of quercetin.
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14
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Xue Y, Theisen TC, Rastogi S, Ferrel A, Quake SR, Boothroyd JC. A single-parasite transcriptional atlas of Toxoplasma Gondii reveals novel control of antigen expression. eLife 2020; 9:e54129. [PMID: 32065584 PMCID: PMC7180058 DOI: 10.7554/elife.54129] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/16/2020] [Indexed: 12/21/2022] Open
Abstract
Toxoplasma gondii, a protozoan parasite, undergoes a complex and poorly understood developmental process that is critical for establishing a chronic infection in its intermediate hosts. Here, we applied single-cell RNA-sequencing (scRNA-seq) on >5,400 Toxoplasma in both tachyzoite and bradyzoite stages using three widely studied strains to construct a comprehensive atlas of cell-cycle and asexual development, revealing hidden states and transcriptional factors associated with each developmental stage. Analysis of SAG1-related sequence (SRS) antigenic repertoire reveals a highly heterogeneous, sporadic expression pattern unexplained by measurement noise, cell cycle, or asexual development. Furthermore, we identified AP2IX-1 as a transcription factor that controls the switching from the ubiquitous SAG1 to rare surface antigens not previously observed in tachyzoites. In addition, comparative analysis between Toxoplasma and Plasmodium scRNA-seq results reveals concerted expression of gene sets, despite fundamental differences in cell division. Lastly, we built an interactive data-browser for visualization of our atlas resource.
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Affiliation(s)
- Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, United States
| | - Terence C Theisen
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Suchita Rastogi
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Abel Ferrel
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, United States
- Department of Applied Physics, Stanford University, Stanford, United States
- Chan Zuckerberg Biohub, San Francisco, United States
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
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15
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CD40 in Endothelial Cells Restricts Neural Tissue Invasion by Toxoplasma gondii. Infect Immun 2019; 87:IAI.00868-18. [PMID: 31109947 DOI: 10.1128/iai.00868-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/10/2019] [Indexed: 02/08/2023] Open
Abstract
Little is known about whether pathogen invasion of neural tissue is affected by immune-based mechanisms in endothelial cells. We examined the effects of endothelial cell CD40 on Toxoplasma gondii invasion of the retina and brain, organs seeded hematogenously. T. gondii circulates in the bloodstream within infected leukocytes (including monocytes and dendritic cells) and as extracellular tachyzoites. After T. gondii infection, mice that expressed CD40 restricted to endothelial cells exhibited diminished parasite loads and histopathology in the retina and brain. These mice also had lower parasite loads in the retina and brain after intravenous (i.v.) injection of infected monocytes or dendritic cells. The protective effect of endothelial cell CD40 was not explained by changes in cellular or humoral immunity, reduced transmigration of leukocytes into neural tissue, or reduced invasion by extracellular parasites. Circulating T. gondii-infected leukocytes (dendritic cells used as a model) led to infection of neural endothelial cells. The number of foci of infection in these cells were reduced if endothelial cells expressed CD40. Infected dendritic cells and macrophages expressed membrane-associated inducible Hsp70. Infected leukocytes triggered Hsp70-dependent autophagy in CD40+ endothelial cells and anti-T. gondii activity dependent on ULK1 and beclin 1. Reduced parasite load in the retina and brain not only required CD40 expression in endothelial cells but was also dependent on beclin 1 and the expression of inducible Hsp70 in dendritic cells. These studies suggest that during endothelial cell-leukocyte interaction, CD40 restricts T. gondii invasion of neural tissue through a mechanism that appears mediated by endothelial cell anti-parasitic activity stimulated by Hsp70.
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Adeyemi OS, Murata Y, Sugi T, Han Y, Kato K. Nanoparticles show potential to retard bradyzoites in vitro formation of Toxoplasma gondii. Folia Parasitol (Praha) 2019; 66. [DOI: 10.14411/fp.2019.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 01/09/2019] [Indexed: 11/19/2022]
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17
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Bertschi NL, Voorberg-van der Wel A, Zeeman AM, Schuierer S, Nigsch F, Carbone W, Knehr J, Gupta DK, Hofman SO, van der Werff N, Nieuwenhuis I, Klooster E, Faber BW, Flannery EL, Mikolajczak SA, Chuenchob V, Shrestha B, Beibel M, Bouwmeester T, Kangwanrangsan N, Sattabongkot J, Diagana TT, Kocken CH, Roma G. Transcriptomic analysis reveals reduced transcriptional activity in the malaria parasite Plasmodium cynomolgi during progression into dormancy. eLife 2018; 7:41081. [PMID: 30589413 PMCID: PMC6344078 DOI: 10.7554/elife.41081] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/23/2018] [Indexed: 02/06/2023] Open
Abstract
Relapses of Plasmodium dormant liver hypnozoites compromise malaria eradication efforts. New radical cure drugs are urgently needed, yet the vast gap in knowledge of hypnozoite biology impedes drug discovery. We previously unraveled the transcriptome of 6 to 7 day-old P. cynomolgi liver stages, highlighting pathways associated with hypnozoite dormancy (Voorberg-van der Wel et al., 2017). We now extend these findings by transcriptome profiling of 9 to 10 day-old liver stage parasites, thus revealing for the first time the maturation of the dormant stage over time. Although progression of dormancy leads to a 10-fold decrease in transcription and expression of only 840 genes, including genes associated with housekeeping functions, we show that pathways involved in quiescence, energy metabolism and maintenance of genome integrity remain the prevalent pathways active in mature hypnozoites.
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Affiliation(s)
- Nicole L Bertschi
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | | | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Sven Schuierer
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Florian Nigsch
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Walter Carbone
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Judith Knehr
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Devendra K Gupta
- Novartis Institute for Tropical Diseases, Novartis Pharma AG, Emeryville, United States
| | - Sam O Hofman
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Nicole van der Werff
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Ivonne Nieuwenhuis
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Els Klooster
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Bart W Faber
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Erika L Flannery
- Novartis Institute for Tropical Diseases, Novartis Pharma AG, Emeryville, United States
| | | | - Vorada Chuenchob
- Novartis Institute for Tropical Diseases, Novartis Pharma AG, Emeryville, United States
| | - Binesh Shrestha
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Martin Beibel
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Tewis Bouwmeester
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
| | - Niwat Kangwanrangsan
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thierry T Diagana
- Novartis Institute for Tropical Diseases, Novartis Pharma AG, Emeryville, United States
| | - Clemens Hm Kocken
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Guglielmo Roma
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Europe
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18
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Jeffers V, Tampaki Z, Kim K, Sullivan WJ. A latent ability to persist: differentiation in Toxoplasma gondii. Cell Mol Life Sci 2018; 75:2355-2373. [PMID: 29602951 PMCID: PMC5988958 DOI: 10.1007/s00018-018-2808-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/01/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023]
Abstract
A critical factor in the transmission and pathogenesis of Toxoplasma gondii is the ability to convert from an acute disease-causing, proliferative stage (tachyzoite), to a chronic, dormant stage (bradyzoite). The conversion of the tachyzoite-containing parasitophorous vacuole membrane into the less permeable bradyzoite cyst wall allows the parasite to persist for years within the host to maximize transmissibility to both primary (felids) and secondary (virtually all other warm-blooded vertebrates) hosts. This review presents our current understanding of the latent stage, including the factors that are important in bradyzoite induction and maintenance. Also discussed are the recent studies that have begun to unravel the mechanisms behind stage switching.
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Affiliation(s)
- Victoria Jeffers
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| | - Zoi Tampaki
- Departments of Medicine, Microbiology and Immunology, and Pathology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Kami Kim
- Departments of Medicine, Microbiology and Immunology, and Pathology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- 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 University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
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19
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Pales Espinosa E, Allam B. Reverse genetics demonstrate the role of mucosal C-type lectins in food particle selection in the oyster Crassostrea virginica. J Exp Biol 2018; 221:jeb.174094. [DOI: 10.1242/jeb.174094] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/01/2018] [Indexed: 12/13/2022]
Abstract
Prey selection governs species interactions and regulates physiological energetics of individuals and populations. Suspension-feeding bivalves represent key species in coastal and estuarine systems for their ecological and economic value. These animals are able to sort and selectively ingest nutritious microalgae from dilute and composite mixtures of particulate matter. This aptitude was suggested to be mediated by interactions between carbohydrates associated with the surface of microalgae and C-type lectins present in mucus covering the feeding organs although a direct, unequivocal, role of lectins in food sorting in bivalves remains elusive. This study was designed to identify and characterize mucosal C-type lectins from oysters and manipulate the expression of these proteins in order to obtain decisive information regarding their involvement in food choice. Thus, 2 mucosal C-type lectins (CvML3912 and CvML3914) were identified based on transcriptomic and proteomic information. Transcripts of these lectins were detected in the feeding organs and their expression was upregulated following starvation. Recombinant lectin (rCvML3912) competitively inhibited the binding of commercial mannose/glucose-specific lectins to microalgae. Short DsiRNA targeting these two lectins were designed and used to evaluate the effect of gene silencing on food particle sorting. As a result, the abundance of the two cognate transcripts significantly decreased and food sorting ability was significantly reduced among silenced oysters as compared to control animals. Overall, these findings propose a novel concept establishing the role of carbohydrate-protein interactions to provide an efficient food particle sorting, and establish a new dimension for the role of evolutionarily-conserved mannose/glucose-binding proteins in the metazoan.
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Affiliation(s)
| | - Bassem Allam
- School of Marine and Atmospheric Sciences, State University of New York, Stony Brook, NY 11794, USA
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20
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Tu V, Yakubu R, Weiss LM. Observations on bradyzoite biology. Microbes Infect 2017; 20:466-476. [PMID: 29287987 DOI: 10.1016/j.micinf.2017.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 02/06/2023]
Abstract
Tachyzoites of the Apicomplexan Toxoplasma gondii cause acute infection, disseminate widely in their host, and eventually differentiate into a latent encysted form called bradyzoites that are found within tissue cysts. During latent infection, whenever transformation to tachyzoites occurs, any tachyzoites that develop are removed by the immune system. In contrast, cysts containing bradyzoites are sequestered from the immune system. In the absence of an effective immune response released organisms that differentiate into tachyzoites cause acute infection. Tissue cysts, therefore, serve as a reservoir for the reactivation of toxoplasmosis when the host becomes immunocompromised by conditions such as HIV infection, organ transplantation, or due to the impaired immune response that occurs when pathogens are acquired in utero. While tachyzoites and bradyzoites are well defined morphologically, there is no clear consensus on how interconversion occurs or what exact signal(s) mediate this transformation. Advances in research methods have facilitated studies on T. gondii bradyzoites providing important new insights into the biology of latent infection.
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Affiliation(s)
- Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rama Yakubu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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21
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Integrative transcriptome and proteome analyses define marked differences between Neospora caninum isolates throughout the tachyzoite lytic cycle. J Proteomics 2017; 180:108-119. [PMID: 29154927 DOI: 10.1016/j.jprot.2017.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/25/2017] [Accepted: 11/09/2017] [Indexed: 11/22/2022]
Abstract
Neospora caninum is one of the main causes of transmissible abortion in cattle. Intraspecific variations in virulence have been widely shown among N. caninum isolates. However, the molecular basis governing such variability have not been elucidated to date. In this study label free LC-MS/MS was used to investigate proteome differences between the high virulence isolate Nc-Spain7 and the low virulence isolate Nc-Spain1H throughout the tachyzoite lytic cycle. The results showed greater differences in the abundance of proteins at invasion and egress with 77 and 62 proteins, respectively. During parasite replication, only 19 proteins were differentially abundant between isolates. The microneme protein repertoire involved in parasite invasion and egress was more abundant in the Nc-Spain1H isolate, which displays a lower invasion rate. Rhoptry and dense granule proteins, proteins related to metabolism and stress responses also showed differential abundances between isolates. Comparative RNA-Seq analyses during tachyzoite egress were also performed, revealing an expression profile of genes associated with the bradyzoite stage in the low virulence Nc-Spain1H isolate. The differences in proteome and RNA expression profiles between these two isolates reveal interesting insights into likely mechanisms involved in specific phenotypic traits and virulence in N. caninum. SIGNIFICANCE The molecular basis that governs biological variability in N. caninum and the pathogenesis of neosporosis has not been well-established yet. This is the first study in which high throughput technology of LC-MS/MS and RNA-Seq is used to investigate differences in the proteome and transcriptome between two well-characterized isolates. Both isolates displayed different proteomes throughout the lytic cycle and the transcriptomes also showed marked variations but were inconsistent with the proteome results. However, both datasets identified a pre-bradyzoite status of the low virulence isolate Nc-Spain1H. This study reveals interesting insights into likely mechanisms involved in virulence in N. caninum and shed light on a subset of proteins that are potentially involved in the pathogenesis of this parasite.
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22
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Abugri DA, Witola WH, Russell AE, Troy RM. In vitro activity of the interaction between taxifolin (dihydroquercetin) and pyrimethamine against Toxoplasma gondii. Chem Biol Drug Des 2017; 91:194-201. [PMID: 28696589 DOI: 10.1111/cbdd.13070] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 06/19/2017] [Accepted: 07/02/2017] [Indexed: 11/26/2022]
Abstract
Toxoplasmosis is one of the most neglected zoonotic foodborne parasitic diseases that cause public health and socioeconomic concern worldwide. The current drugs used for the treatment of toxoplasmosis have been identified to have clinical limitations. Hence, new drugs are urgently needed to eradicate T.gondii infections globally. Here, an in vitro anti-Toxoplasma gondii activity of taxifolin (dihydroquercetin) and dihydrofolate inhibitor (pyrimethamine) alone and in combination with a fixed concentration of pyrimethamine were investigated against the rapidly proliferating T.gondii RH strain at 48 hr using colorimetric assay. Pyrimethamine showed the highest anti-T. gondii activity with IC50P of 0.84 μg/ml (p > .05), respectively. The combination of pyrimethamine with dihydroquercetin gave a significant inhibitory activity against tachyzoites in in vitro with IC50p of 1.39 μg/ml (p < .05). The IC50p ranges obtained for the individual and the combination of taxifolin with pyrimethamine inhibition of parasite growth were not cytotoxic to the infected HFF and Hek-293 cell lines used. These compounds combination should be investigated further using in vivo model of toxoplasmosis.
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Affiliation(s)
- Daniel A Abugri
- Department of Chemistry, Tuskegee University, Tuskegee, AL, USA.,Department of Biology, Tuskegee University, Tuskegee, AL, USA.,Laboratory of Ethnomedicine, Parasitology and Drug Discovery, Tuskegee University, Tuskegee, AL, USA
| | - William H Witola
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana Champaign, IL, USA
| | | | - Roberta M Troy
- Department of Biology, Tuskegee University, Tuskegee, AL, USA
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Abstract
The unicellular parasite Toxoplasma gondii infects warm-blooded animals and humans, and it is highly prevalent throughout the world. Infection of immunocompetent hosts is usually asymptomatic or benign but leads to long-term parasite persistence mainly within neural and muscular tissues. The transition from acute primary infection towards chronic toxoplasmosis is accompanied by a developmental switch from fast replicating and metabolically highly active tachyzoites to slow replicating and largely dormant bradyzoites within tissue cysts. Such developmental differentiation is critical for T. gondii in order to complete its life cycle and for pathogenesis. Herein, we summarize accumulating evidence indicating a major impact of the host cell physiology on stage conversion between the tachyzoite and the bradyzoite stage of the parasite. Withdrawal from cell cycle progression, proinflammatory responses, reduced availability of nutrients and extracellular adenosine can indeed induce tachyzoite-to-bradyzoite differentiation and tissue cyst formation. In contrast, high glycolytic activity as indicated by increased lactate secretion can inhibit bradyzoite formation. These examples argue for the intriguing possibility that after dissemination within its host, T. gondii can sense its cellular microenvironment to initiate the developmental program towards the bradyzoite stage in distinct cells. This may also explain the predominant localization of T. gondii in neural and muscular tissues during chronic toxoplasmosis.
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Affiliation(s)
- Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center Goettingen, Goettingen, Germany
| | - Taibur Rahman
- Institute for Medical Microbiology, University Medical Center Goettingen, Goettingen, Germany
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24
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Czarnewski P, Araújo ECB, Oliveira MC, Mineo TWP, Silva NM. Recombinant TgHSP70 Immunization Protects against Toxoplasma gondii Brain Cyst Formation by Enhancing Inducible Nitric Oxide Expression. Front Cell Infect Microbiol 2017; 7:142. [PMID: 28487847 PMCID: PMC5403831 DOI: 10.3389/fcimb.2017.00142] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/06/2017] [Indexed: 11/17/2022] Open
Abstract
Toxoplasma gondii is known to cause congenital infection in humans and animals and severe disease in immunocompromised individuals; consequently development of vaccines against the parasite is highly necessary. Under stress conditions, T. gondii expresses the highly immunogenic heat shock protein 70 (TgHSP70). Here, we assessed the protective efficacy of rTgHSP70 immunization combined with Alum in oral ME-49 T. gondii infection and the mechanisms involved on it. It was observed that immunized mice with rTgHSP70 or rTgHSP70 adsorbed in Alum presented a significantly reduced number of cysts in the brain that was associated with increased iNOS+ cell numbers in the organ, irrespective the use of the adjuvant. Indeed, ex vivo experiments showed that peritoneal macrophages pre-stimulated with rTgHSP70 presented increased NO production and enhanced parasite killing, and the protein was able to directly stimulate B cells toward antibody producing profile. In addition, rTgHSP70 immunization leads to high specific antibody titters systemically and a mixed IgG1/IgG2a response, with predominance of IgG1 production. Nonetheless, it was observed that the pretreatment of the parasite with rTgHSP70 immune sera was not able to control T. gondii internalization and replication by NIH fibroblast neither peritoneal murine macrophages, nor anti-rTgHSP70 antibodies were able to kill T. gondii by complement-mediated lysis, suggesting that these mechanisms are not crucial to resistance. Interestingly, when in combination with Alum, rTgHSP70 immunization was able to reduce inflammation in the brain of infected mice and in parallel anti-rTgHSP70 immune complexes in the serum. In conclusion, immunization with rTgHSP70 induces massive amounts of iNOS expression and reduced brain parasitism, suggesting that iNOS expression and consequently NO production in the brain is a protective mechanism induced by TgHSP70 immunization, therefore rTgHSP70 can be a good candidate for vaccine development against toxoplasmosis.
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Affiliation(s)
- Paulo Czarnewski
- Laboratory of Immunopathology, Institute of Biomedical Sciences, Federal University of UberlândiaUberlândia, Brazil
| | - Ester C B Araújo
- Laboratory of Immunopathology, Institute of Biomedical Sciences, Federal University of UberlândiaUberlândia, Brazil
| | - Mário C Oliveira
- Laboratory of Immunopathology, Institute of Biomedical Sciences, Federal University of UberlândiaUberlândia, Brazil
| | - Tiago W P Mineo
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of UberlândiaUberlândia, Brazil
| | - Neide M Silva
- Laboratory of Immunopathology, Institute of Biomedical Sciences, Federal University of UberlândiaUberlândia, Brazil
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Leesombun A, Boonmasawai S, Nishikawa Y. Effects of Thai piperaceae plant extracts on Neospora caninum infection. Parasitol Int 2017; 66:219-226. [PMID: 28137670 DOI: 10.1016/j.parint.2017.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 01/19/2017] [Accepted: 01/27/2017] [Indexed: 11/29/2022]
Abstract
Neosporosis has a worldwide distribution and causes economic losses in farming, particularly by increasing the risk of abortion in cattle. This study investigated the effects of Thai piperaceae (Piper betle, P. nigrum, and P. sarmentosum) extracts on Neospora caninum infections in vitro and in vivo. In an in vitro parasite growth assay based on the green fluorescent protein (GFP) signal, P. betle was the most effective extract at inhibiting parasite growth in human foreskin fibroblast cells (IC50 of GFP-expressing N. caninum parasites, 22.1μg/ml). The P. betle extract, at 25μg per ml, inhibited parasite invasion into host cells. Furthermore, in two independent experiments, treating N. caninum-infected mice with the P. betle extract for 7days post-infection increased their survival. In trial one, the anti-N. caninum effects of the P. betle extract reduced the mouse clinical scores for 30days post-infection (dpi). The survival rate of the mice treated with 400mg/kg was 100% compared with 66.6% for those treated with 100mg/kg and the non-treated controls. In trial two, treating the infected mice with the P. betle extract increased their survival at 50dpi. All mice in the non-treatment group died; however, the survival rates of the 400mg/kg-treated and 100mg/kg-treated mice were 83.3% and 33.3%, respectively. Also, a trend towards a reduced parasite burden was noted in the brains of the P. betle extract-treated mice, compared with the control mice. Therefore P. betle extract has potential as a medicinal plant for treating neosporosis.
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Affiliation(s)
- Arpron Leesombun
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Sookruetai Boonmasawai
- Department of Preclinical and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, 999 Phutthamonthon Sai 4 Road Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand.
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
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Abugri DA, Witola WH, Jaynes JM, Toufic N. In vitro activity of Sorghum bicolor extracts, 3-deoxyanthocyanidins, against Toxoplasma gondii. Exp Parasitol 2016; 164:12-9. [PMID: 26855040 DOI: 10.1016/j.exppara.2016.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 01/29/2016] [Accepted: 02/03/2016] [Indexed: 10/22/2022]
Abstract
We investigated dried red leaf extracts of Sorghum bicolor for activity against Toxoplasma gondii tachyzoites. S. bicolor red leaf extracts were obtained by bioassay-guided fractionation using ethanol and ethyl acetate as solvents. Analysis of the crude and fractionated extracts from S. bicolor using electrospray ionization mass spectrometry (ESI-MS) showed that they contained significant amounts of apigeninidin, luteolinidin, 7-methoxyapigeninidin, 5-methoxyapigeninidin, 5-methoxyluteolinidin, 7-methoxyluteolinidin 5,7-dimethoxyapigeninidin or 5,7-dimethoxyluteolinidin, based on mass per charge (m/z). When tested in vitro, the IC50s for inhibitory activity against T. gondii tachyzoites' growth of the ethanol and ethyl acetate extracts were 2.3- and 4-fold, respectively, lower than their cytotoxic IC50s in mammalian cells. Ethyl acetate extracts fractionated in chloroform-methanol and chloroform had IC50s against T. gondii that were 56.1- and 3-fold lower than their respective cytotoxic IC50s in mammalian cells. These antiparasitic activities were found to be consistent with those of the respective pure 3-deoxyanthocyanidin compounds identified to be contained in the fractions in significant amounts. Further, we observed that, the position and number of methoxy groups possessed by the 3-deoyanthocyanidins influenced their antiparasitic activity. Together, our findings indicate that S. bicolor red-leaf 3-deoxyanthocyanidins-rich extracts have potent in vitro inhibitory activity against the proliferative stage of T. gondii parasites.
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Affiliation(s)
- Daniel A Abugri
- Department of Chemistry, College of Arts and Sciences, Tuskegee University, Tuskegee, AL, USA; Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Sciences, Tuskegee University, Tuskegee, AL, USA
| | - William H Witola
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, USA.
| | - Jesse M Jaynes
- Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Sciences, Tuskegee University, Tuskegee, AL, USA
| | - Nashar Toufic
- Department of Pathobiology, College of Veterinary Medicine, Nursing & Allied Health, Tuskegee University, Tuskegee, AL, USA
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Activity of Euterpe edulis Martius, Mikania glomerata Spreng, and Mikania laevigata Schultz Bip. Extracts on Gastrointestinal Nematodes Toxocara canis and Ancylostoma caninum. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2015. [DOI: 10.5812/archcid.27495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Toxoplasma gondii seropositivity and cognitive functions in school-aged children. Parasitology 2015; 142:1221-7. [PMID: 25990628 DOI: 10.1017/s0031182015000505] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Toxoplasma gondii (T. gondii) infects one-third of the world population, but its association with cognitive functions in school-aged children is unclear. We examined the relationship between Toxoplasma seropositivity and neuropsychological tests scores (including math, reading, visuospatial reasoning and verbal memory) in 1755 school-aged children 12-16 years old who participated to the Third National Health and Nutrition Examination Survey, using multiple linear regressions adjusted for covariates. Toxoplasma seroprevalence was 7·7% and seropositivity to the parasite was associated with lower reading skills (regression coefficient [β] = -5·86, 95% confidence interval [CI]: -11·11, -0·61, P = 0·029) and memory capacities (β = -0·86, 95% CI: -1·58, -0·15, P = 0·017). The interaction between T. gondii seropositivity and vitamin E significantly correlated with memory scores. In subgroup analysis, Toxoplasma-associated memory impairment was worse in children with lower serum vitamin E concentrations (β = -1·61, 95% CI: -2·44, -0·77, P < 0·001) than in those with higher values (β = -0·12, 95% CI: -1·23, 0·99, P = 0·83). In conclusion, Toxoplasma seropositivity may be associated with reading and memory impairments in school-aged children. Serum vitamin E seems to modify the relationship between the parasitic infection and memory deficiency.
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Eastman AJ, He X, Qiu Y, Davis MJ, Vedula P, Lyons DM, Park YD, Hardison SE, Malachowski AN, Osterholzer JJ, Wormley FL, Williamson PR, Olszewski MA. Cryptococcal heat shock protein 70 homolog Ssa1 contributes to pulmonary expansion of Cryptococcus neoformans during the afferent phase of the immune response by promoting macrophage M2 polarization. THE JOURNAL OF IMMUNOLOGY 2015; 194:5999-6010. [PMID: 25972480 DOI: 10.4049/jimmunol.1402719] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/19/2015] [Indexed: 12/13/2022]
Abstract
Numerous virulence factors expressed by Cryptococcus neoformans modulate host defenses by promoting nonprotective Th2-biased adaptive immune responses. Prior studies demonstrate that the heat shock protein 70 homolog, Ssa1, significantly contributes to serotype D C. neoformans virulence through the induction of laccase, a Th2-skewing and CNS tropic factor. In the present study, we sought to determine whether Ssa1 modulates host defenses in mice infected with a highly virulent serotype A strain of C. neoformans (H99). To investigate this, we assessed pulmonary fungal growth, CNS dissemination, and survival in mice infected with either H99, an SSA1-deleted H99 strain (Δssa1), and a complement strain with restored SSA1 expression (Δssa1::SSA1). Mice infected with the Δssa1 strain displayed substantial reductions in lung fungal burden during the innate phase (days 3 and 7) of the host response, whereas less pronounced reductions were observed during the adaptive phase (day 14) and mouse survival increased only by 5 d. Surprisingly, laccase activity assays revealed that Δssa1 was not laccase deficient, demonstrating that H99 does not require Ssa1 for laccase expression, which explains the CNS tropism we still observed in the Ssa1-deficient strain. Lastly, our immunophenotyping studies showed that Ssa1 directly promotes early M2 skewing of lung mononuclear phagocytes during the innate phase, but not the adaptive phase, of the immune response. We conclude that Ssa1's virulence mechanism in H99 is distinct and laccase-independent. Ssa1 directly interferes with early macrophage polarization, limiting innate control of C. neoformans, but ultimately has no effect on cryptococcal control by adaptive immunity.
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Affiliation(s)
- Alison J Eastman
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109; Veterans Affairs Hospital, Ann Arbor, MI 48105
| | - Xiumiao He
- Veterans Affairs Hospital, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Yafeng Qiu
- Veterans Affairs Hospital, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Michael J Davis
- Veterans Affairs Hospital, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109
| | | | | | - Yoon-Dong Park
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Sarah E Hardison
- Department of Biology, University of Texas at San Antonio, San Antonio, TX 78458; South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249; and
| | - Antoni N Malachowski
- Veterans Affairs Hospital, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109
| | - John J Osterholzer
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109; Veterans Affairs Hospital, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Floyd L Wormley
- Department of Biology, University of Texas at San Antonio, San Antonio, TX 78458; South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249; and
| | - Peter R Williamson
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; Section of Infectious Diseases, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, IL 60612
| | - Michal A Olszewski
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109; Veterans Affairs Hospital, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109;
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Optimization of a Fluorescence-Based Assay for Large-Scale Drug Screening against Babesia and Theileria Parasites. PLoS One 2015; 10:e0125276. [PMID: 25915529 PMCID: PMC4411034 DOI: 10.1371/journal.pone.0125276] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 03/23/2015] [Indexed: 11/19/2022] Open
Abstract
A rapid and accurate assay for evaluating antibabesial drugs on a large scale is required for the discovery of novel chemotherapeutic agents against Babesia parasites. In the current study, we evaluated the usefulness of a fluorescence-based assay for determining the efficacies of antibabesial compounds against bovine and equine hemoparasites in in vitro cultures. Three different hematocrits (HCTs; 2.5%, 5%, and 10%) were used without daily replacement of the medium. The results of a high-throughput screening assay revealed that the best HCT was 2.5% for bovine Babesia parasites and 5% for equine Babesia and Theileria parasites. The IC50 values of diminazene aceturate obtained by fluorescence and microscopy did not differ significantly. Likewise, the IC50 values of luteolin, pyronaridine tetraphosphate, nimbolide, gedunin, and enoxacin did not differ between the two methods. In conclusion, our fluorescence-based assay uses low HCT and does not require daily replacement of culture medium, making it highly suitable for in vitro large-scale drug screening against Babesia and Theileria parasites that infect cattle and horses.
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Genomic insights into processes driving the infection of Alexandrium tamarense by the Parasitoid Amoebophrya sp. EUKARYOTIC CELL 2014; 13:1439-49. [PMID: 25239978 DOI: 10.1128/ec.00139-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The regulatory circuits during infection of dinoflagellates by their parasites are largely unknown on the molecular level. Here we provide molecular insights into these infection dynamics. Alexandrium tamarense is one of the most prominent harmful algal bloom dinoflagellates. Its pathogen, the dinoflagellate parasitoid Amoebophrya sp., has been observed to infect and control the blooms of this species. We generated a data set of transcripts from three time points (0, 6, and 96 h) during the infection of this parasite-host system. Assembly of all transcript data from the parasitoid (>900,000 reads/313 Mbp with 454/Roche next-generation sequencing [NGS]) yielded 14,455 contigs, to which we mapped the raw transcript reads of each time point of the infection cycle. We show that particular surface lectins are expressed at the beginning of the infection cycle which likely mediate the attachment to the host cell. In a later phase, signal transduction-related genes together with transmembrane transport and cytoskeleton proteins point to a high integration of processes involved in host recognition, adhesion, and invasion. At the final maturation stage, cell division- and proliferation-related genes were highly expressed, reflecting the fast cell growth and nuclear division of the parasitoid. Our molecular insights into dinoflagellate parasitoid interactions point to general mechanisms also known from other eukaryotic parasites, especially from the Alveolata. These similarities indicate the presence of fundamental processes of parasitoid infection that have remained stable throughout evolution within different phyla.
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García-Lunar P, Regidor-Cerrillo J, Ortega-Mora LM, Gutiérrez-Expósito D, Alvarez-García G. Proteomics reveals differences in protein abundance and highly similar antigenic profiles between Besnoitia besnoiti and Besnoitia tarandi. Vet Parasitol 2014; 205:434-43. [PMID: 25260331 DOI: 10.1016/j.vetpar.2014.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 09/03/2014] [Accepted: 09/08/2014] [Indexed: 10/24/2022]
Abstract
Besnoitia besnoiti and Besnoitia tarandi are two cyst-forming apicomplexan parasites of the genus Besnoitia. B. besnoiti uses cattle as an intermediate host, in which it causes a disease that progresses in two sequential phases: the acute anasarca stage and the chronic scleroderma stage. Reindeer and caribou act as intermediate hosts for B. tarandi, which causes clinical signs similar to those caused by B. besnoiti. Previous studies demonstrated high molecular similarity, as determined by 18S and ITS-1 RNA sequences, between these Besnoitia spp., and strong serological cross-reactivity between these species has recently been demonstrated. Thus, a difference gel electrophoresis approach and mass spectrometry analysis were used to describe the proteomes and explore differences in protein abundance between B. besnoiti and B. tarandi in tachyzoite extracts. Immunoproteomes were also compared using 2-DE immunoblotting with polyclonal sera from experimentally infected rabbits. From approximately 1400 spots detected in DIGE-gels, 28 and 29 spots were differentially abundant in B. besnoiti and B. tarandi tachyzoites, respectively (± 1.5-fold, p<0.05). Four and 13 spots were exclusively detected in B. besnoiti and B. tarandi, respectively. Of the 32 differentially abundant spots analyzed by MALDI-TOF/MS, 6 up-regulated B. besnoiti proteins (LDH; HSP90; purine nucleoside phosphorylase and 3 hypothetical proteins) and 6 up-regulated B. tarandi proteins (G3PDH; LDH; PDI; mRNA decapping protein and 2 hypothetical proteins) were identified. Interestingly, no specific antigen spots were recognized by sera on any of the Besnoitia species studied and a similar antigen profile has been observed for B. tarandi and B. besnoiti sera when cross reactions were studied. This fact corroborates the difficulty in discerning Besnoitia infections using current serological assays. The present study underscores the importance of sequencing the B. besnoiti genome for species diversity studies of the genus Besnoitia.
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Affiliation(s)
- P García-Lunar
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - J Regidor-Cerrillo
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - L M Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - D Gutiérrez-Expósito
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - G Alvarez-García
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
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Schlüter D, Däubener W, Schares G, Groß U, Pleyer U, Lüder C. Animals are key to human toxoplasmosis. Int J Med Microbiol 2014; 304:917-29. [PMID: 25240467 DOI: 10.1016/j.ijmm.2014.09.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Toxoplasma gondii is an extremely sucessfull protozoal parasite which infects almost all mamalian species including humans. Approximately 30% of the human population worldwide is chronically infected with T. gondii. In general, human infection is asymptomatic but the parasite may induce severe disease in fetuses and immunocompromised patients. In addition, T. gondii may cause sight-threatening posterior uveitis in immunocompetent patients. Apart from few exceptions, humans acquire T. gondii from animals. Both, the oral uptake of T. gondii oocysts released by specific hosts, i.e. felidae, and of cysts persisting in muscle cells of animals result in human toxoplasmosis. In the present review, we discuss recent new data on the cell biology of T. gondii and parasite diversity in animals. In addition, we focus on the impact of these various parasite strains and their different virulence on the clinical outcome of human congenital toxoplasmosis and T. gondii uveitis.
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Affiliation(s)
- Dirk Schlüter
- Institute of Medical Microbiology, Infection Control and Prevention, Otto-von-Guericke-University, Magdeburg, Germany; Helmholtz Centre for Infection Research, Braunschweig, Germany.
| | - Walter Däubener
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University, Düsseldorf, Germany
| | - Gereon Schares
- Institute of Epidemiology, Friedrich-Loeffler-Institute, Greifswald-Insel Riems, Germany
| | - Uwe Groß
- Institute for Medical Microbiology, University Medical Center, Göttingen, Germany
| | - Uwe Pleyer
- Eye Clinic, Charité Universitätsmedizin, Berlin, Germany
| | - Carsten Lüder
- Institute for Medical Microbiology, University Medical Center, Göttingen, Germany
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Toxoplasma gondii 70 kDa heat shock protein: systemic detection is associated with the death of the parasites by the immune response and its increased expression in the brain is associated with parasite replication. PLoS One 2014; 9:e96527. [PMID: 24801069 PMCID: PMC4011789 DOI: 10.1371/journal.pone.0096527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/07/2014] [Indexed: 11/19/2022] Open
Abstract
The heat shock protein of Toxoplasma gondii (TgHSP70) is a parasite virulence factor that is expressed during T. gondii stage conversion. To verify the effect of dexamethasone (DXM)-induced infection reactivation in the TgHSP70-specific humoral immune response and the presence of the protein in the mouse brain, we produced recombinant TgHSP70 and anti-TgHSP70 IgY antibodies to detect the protein, the specific antibody and levels of immune complexes (ICs) systemically, as well as the protein in the brain of resistant (BALB/c) and susceptible (C57BL/6) mice. It was observed higher TgHSP70-specific antibody titers in serum samples of BALB/c compared with C57BL/6 mice. However, the susceptible mice presented the highest levels of TgHSP70 systemically and no detection of specific ICs. The DXM treatment induced increased parasitism and lower inflammatory changes in the brain of C57BL/6, but did not interfere with the cerebral parasitism in BALB/c mice. Additionally, DXM treatment decreased the serological TgHSP70 concentration in both mouse lineages. C57BL/6 mice presented high expression of TgHSP70 in the brain with the progression of infection and under DXM treatment. Taken together, these data indicate that the TgHSP70 release into the bloodstream depends on the death of the parasites mediated by the host immune response, whereas the increased TgHSP70 expression in the brain depends on the multiplication rate of the parasite.
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The protein kinase double-stranded RNA-dependent (PKR) enhances protection against disease cause by a non-viral pathogen. PLoS Pathog 2013; 9:e1003557. [PMID: 23990781 PMCID: PMC3749959 DOI: 10.1371/journal.ppat.1003557] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 07/01/2013] [Indexed: 01/08/2023] Open
Abstract
PKR is well characterized for its function in antiviral immunity. Using Toxoplasma gondii, we examined if PKR promotes resistance to disease caused by a non-viral pathogen. PKR(-/-) mice infected with T. gondii exhibited higher parasite load and worsened histopathology in the eye and brain compared to wild-type controls. Susceptibility to toxoplasmosis was not due to defective expression of IFN-γ, TNF-α, NOS2 or IL-6 in the retina and brain, differences in IL-10 expression in these organs or to impaired induction of T. gondii-reactive T cells. While macrophages/microglia with defective PKR signaling exhibited unimpaired anti-T. gondii activity in response to IFN-γ/TNF-α, these cells were unable to kill the parasite in response to CD40 stimulation. The TRAF6 binding site of CD40, but not the TRAF2,3 binding sites, was required for PKR phosphorylation in response to CD40 ligation in macrophages. TRAF6 co-immunoprecipitated with PKR upon CD40 ligation. TRAF6-PKR interaction appeared to be indirect, since TRAF6 co-immunoprecipitated with TRAF2 and TRAF2 co-immunoprecipitated with PKR, and deficiency of TRAF2 inhibited TRAF6-PKR co-immunoprecipitation as well as PKR phosphorylation induced by CD40 ligation. PKR was required for stimulation of autophagy, accumulation the autophagy molecule LC3 around the parasite, vacuole-lysosomal fusion and killing of T. gondii in CD40-activated macrophages and microglia. Thus, our findings identified PKR as a mediator of anti-microbial activity and promoter of protection against disease caused by a non-viral pathogen, revealed that PKR is activated by CD40 via TRAF6 and TRAF2, and positioned PKR as a link between CD40-TRAF signaling and stimulation of the autophagy pathway.
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36
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García-Lunar P, Regidor-Cerrillo J, Gutiérrez-Expósito D, Ortega-Mora L, Alvarez-García G. First 2-DE approach towards characterising the proteome and immunome of Besnoitia besnoiti in the tachyzoite stage. Vet Parasitol 2013; 195:24-34. [DOI: 10.1016/j.vetpar.2012.12.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 11/07/2012] [Accepted: 12/15/2012] [Indexed: 10/27/2022]
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Identifying factors inducing trophozoite differentiation into hypnospores in Perkinsus species. Eur J Protistol 2013; 49:201-9. [DOI: 10.1016/j.ejop.2012.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 06/29/2012] [Accepted: 07/23/2012] [Indexed: 11/15/2022]
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Identification of Besnoitia besnoiti proteins that showed differences in abundance between tachyzoite and bradyzoite stages by difference gel electrophoresis. Parasitology 2013; 140:999-1008. [PMID: 23594379 DOI: 10.1017/s003118201300036x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Bovine besnoitiosis is a chronic and debilitating disease, caused by the apicomplexan parasite Besnoitia besnoiti. Infection of cattle by B. besnoiti is governed by the tachyzoite stage, which is related to acute infection, and the bradyzoite stage gathered into macroscopic cysts located in subcutaneous tissue in the skin, mucosal membranes and sclera conjunctiva and related to persistence and chronic infection. However, the entire life cycle of this parasite and the molecular mechanisms underlying tachyzoite-to-bradyzoite conversion remain unknown. In this context, a different antigenic pattern has been observed between tachyzoite and bradyzoite extracts. Thus, to identify stage-specific proteins, a difference gel electrophoresis (DIGE) approach was used on tachyzoite and bradyzoite extracts followed by mass spectrometry (MS) analysis. A total of 130 and 132 spots were differentially expressed in bradyzoites and tachyzoites, respectively (average ratio ± 1.5, P<0.05 in t-test). Furthermore, 25 differentially expressed spots were selected and analysed by MALDI-TOF/MS. As a result, 5 up-regulated bradyzoite proteins (GAPDH, ENO1, LDH, SOD and RNA polymerase) and 5 up-regulated tachyzoite proteins (ENO2; LDH; ATP synthase; HSP70 and PDI) were identified. The present results set the basis for the identification of new proteins as drug targets. Moreover, the role of these proteins in tachyzoite-to-bradyzoite conversion and the role of the host cell environment should be a subject of further research.
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Shields JM, Joo J, Kim R, Murphy HR. Assessment of three commercial DNA extraction kits and a laboratory-developed method for detecting Cryptosporidium and Cyclospora in raspberry wash, basil wash and pesto. J Microbiol Methods 2013; 92:51-8. [DOI: 10.1016/j.mimet.2012.11.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/02/2012] [Accepted: 11/02/2012] [Indexed: 10/27/2022]
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40
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Paredes-Santos TC, Martins-Duarte ES, Vitor RWA, de Souza W, Attias M, Vommaro RC. Spontaneous cystogenesis in vitro of a Brazilian strain of Toxoplasma gondii. Parasitol Int 2012; 62:181-8. [PMID: 23269201 DOI: 10.1016/j.parint.2012.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 12/12/2012] [Accepted: 12/14/2012] [Indexed: 11/30/2022]
Abstract
Conversion of Toxoplasma gondii tachyzoites to the bradyzoite stage and tissue cyst formation in the life cycle of the parasite have crucial roles in the establishment of chronic toxoplasmosis. In this work we investigated the in vitro cystogenesis and behavior of the EGS strain, isolated from human amniotic fluid. We observed that tachyzoites of the EGS strain converted to intracellular cysts spontaneously in LLC-MK2 epithelial cells, HSFS fibroblasts and C6 glial cell lineage. The peak of conversion occurred in the LLC-MK2 cells after 4days of infection, when 72.3±15.9 of the infected cells contained DBA positive cysts. Using specific markers against bradyzoite, tachyzoite and cyst wall components, we confirmed stage conversion and distinguished immature from mature cysts. It was also observed that the deposition of cyst wall components occurred before the total conversion of parasites. Transmission electron microscopy confirmed the fully conversion of parasites presenting the typical characteristics of bradyzoites as the posterior position of the nucleus and the presence of amylopectin granules. A thick cyst wall was also detected. Besides, the scanning microscopy revealed that the intracyst matrix tubules were shorter than those from the parasitophorous vacuole intravacuolar network and were immersed in a granular electron dense material. The EGS strain spontaneously forms high burden of cysts in cell culture without artificial stress conditions, and constitutes a useful tool to study this stage of the T. gondii life cycle.
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Affiliation(s)
- T C Paredes-Santos
- Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Brazil
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Schares G, Langenmayer MC, Scharr JC, Minke L, Maksimov P, Maksimov A, Schares S, Bärwald A, Basso W, Dubey JP, Conraths FJ, Gollnick NS. Novel tools for the diagnosis and differentiation of acute and chronic bovine besnoitiosis. Int J Parasitol 2012; 43:143-54. [PMID: 23160022 DOI: 10.1016/j.ijpara.2012.10.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 10/18/2012] [Accepted: 10/19/2012] [Indexed: 10/27/2022]
Abstract
Diagnosis of acute bovine besnoitiosis is a major diagnostic problem. We developed diagnostic tests to serologically diagnose and differentiate acute and chronic cases of bovine besnoitiosis using affinity purified antigens of Besnoitia besnoiti tachyzoites in immunoblots and in both, a conventional ELISA and an avidity ELISA. Sera of acutely and chronically infected cattle were investigated using these tests. Acutely infected cattle initially recognised an antigen of 74 kDa relative molecular mass, followed by reactions with increasing intensity against 81 and 28 kDa antigens. In addition, faint reactions against antigens with 36, 37, 39 and 42 kDa molecular mass started soon after seroconversion and increased over time. An antigen of 45 kDa molecular mass was transiently recognised early after infection but not or only weakly in the chronic stage. At least two antigens, the 39 and the 42 kDa antigens, seem to be located on the surface of B. besnoiti tachyzoites as determined by biotinylation. Affinity purified antigen was used to establish an APure-BbELISA which showed excellent sensitivity (100%) relative to a serological reference system in naturally, most likely chronically, infected cattle. Specificity was also high (99.8%) as determined in cattle from herds with Neospora caninum-associated abortions. The antibody levels in APure-BbELISA were correlated with the parasite load in the skin or the mucous membrane of the vestibulum vaginae as determined by real-time PCR. In acute cases of bovine besnoitiosis (confirmed by the detection of low avidity IgG in the APure-BbELISA) first specific antibodies were detected by ELISA in all animals except one, at the same time or earlier than in the serological reference system. The detection of parasite DNA in skin by real-time PCR was clearly superior to serological analysis in detecting infected cattle during acute besnoitiosis.
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Affiliation(s)
- G Schares
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Wusterhausen, Germany.
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Sullivan WJ, Jeffers V. Mechanisms of Toxoplasma gondii persistence and latency. FEMS Microbiol Rev 2012; 36:717-33. [PMID: 22091606 PMCID: PMC3319474 DOI: 10.1111/j.1574-6976.2011.00305.x] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 08/22/2011] [Accepted: 08/25/2011] [Indexed: 11/28/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite that causes opportunistic disease, particularly in immunocompromised individuals. Central to its transmission and pathogenesis is the ability of the proliferative stage (tachyzoite) to convert into latent tissue cysts (bradyzoites). Encystment allows Toxoplasma to persist in the host and affords the parasite a unique opportunity to spread to new hosts without proceeding through its sexual stage, which is restricted to felids. Bradyzoite tissue cysts can cause reactivated toxoplasmosis if host immunity becomes impaired. A greater understanding of the molecular mechanisms orchestrating bradyzoite development is needed to better manage the disease. Here, we will review key studies that have contributed to our knowledge about this persistent form of the parasite and how to study it, with a focus on how cellular stress can signal for the reprogramming of gene expression needed during bradyzoite development.
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Affiliation(s)
- William J Sullivan
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Toxoplasma on the brain: understanding host-pathogen interactions in chronic CNS infection. J Parasitol Res 2012; 2012:589295. [PMID: 22545203 PMCID: PMC3321570 DOI: 10.1155/2012/589295] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 01/04/2012] [Indexed: 11/18/2022] Open
Abstract
Toxoplasma gondii is a prevalent obligate intracellular parasite which chronically infects more than a third of the world's population. Key to parasite prevalence is its ability to form chronic and nonimmunogenic bradyzoite cysts, which typically form in the brain and muscle cells of infected mammals, including humans. While acute clinical infection typically involves neurological and/or ocular damage, chronic infection has been more recently linked to behavioral changes. Establishment and maintenance of chronic infection involves a balance between the host immunity and parasite evasion of the immune response. Here, we outline the known cellular interplay between Toxoplasma gondii and cells of the central nervous system and review the reported effects of Toxoplasma gondii on behavior and neurological disease. Finally, we review new technologies which will allow us to more fully understand host-pathogen interactions.
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Figueras MJ, Martin OA, Echeverria PC, de Miguel N, Naguleswaran A, Sullivan WJ, Corvi MM, Angel SO. Toxoplasma gondii Sis1-like J-domain protein is a cytosolic chaperone associated to HSP90/HSP70 complex. Int J Biol Macromol 2011; 50:725-33. [PMID: 22209934 DOI: 10.1016/j.ijbiomac.2011.12.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 11/24/2011] [Accepted: 12/14/2011] [Indexed: 10/14/2022]
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite in which 36 predicted Hsp40 family members were identified by searching the T. gondii genome. The predicted protein sequence from the gene ID TGME49_065310 showed an amino acid sequence and domain structure similar to Saccharomyces cerevisiae Sis1. TgSis1 did not show differences in its expression profile during alkaline stress by microarray analysis. Furthermore, TgSis1 showed to be a cytosolic Hsp40 which co-immunoprecipitated with T. gondii Hsp70 and Hsp90. Structural modeling of the TgSis1 peptide binding fragment revealed structural and electrostatic properties different from the experimental model of human Sis1-like protein (Hdj1). Based on these differences; we propose that TgSis1 may be a potentially attractive drug target for developing a novel anti-T. gondii therapy.
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Affiliation(s)
- Maria J Figueras
- Laboratorio de Parasitología Molecular, IIB-INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
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Involvement of a Toxoplasma gondii chromatin remodeling complex ortholog in developmental regulation. PLoS One 2011; 6:e19570. [PMID: 21655329 PMCID: PMC3104990 DOI: 10.1371/journal.pone.0019570] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 04/12/2011] [Indexed: 01/18/2023] Open
Abstract
The asexual cycle of the parasite Toxoplasma gondii has two developmental stages: a rapidly replicating form called a tachyzoite and a slow growing cyst form called a bradyzoite. While the importance of ATP-independent histone modifications for gene regulation in T. gondii have been demonstrated, ATP-dependent chromatin remodeling pathways have not been examined. In this study we characterized C9, an insertional mutant showing reduced expression of bradyzoite differentiation marker BAG1, in cultured human fibroblasts. This mutant contains an insertion in the gene encoding TgRSC8, which is homologous to the Saccharomyces cerevisiae proteins Rsc8p (remodel the structure of chromatin complex subunit 8) and Swi3p (switch/sucrose non-fermentable [SWI/SNF]) of ATP-dependent chromatin-remodeling complexes. In the C9 mutant, TgRSC8 is the downstream open reading frame on a dicistronic transcript. Though protein was expressed from the downstream gene of the dicistron, TgRSC8 levels were decreased in C9 from those of wild-type parasites, as determined by western immunoblot and flow cytometry. As TgRSC8 localized to the parasite nucleus, we postulated a role in gene regulation. Transcript levels of several markers were assessed by quantitative PCR to test this hypothesis. The C9 mutant displayed reduced steady state transcript levels of bradyzoite-induced genes BAG1, LDH2, SUSA1, and ENO1, all of which were significantly increased with addition of TgRSC8 to the mutant. Transcript levels of some bradyzoite markers were unaltered in C9, or unable to be increased by complementation with TgRSC8, indicating multiple pathways control bradyzoite-upregulated genes. Together, these data suggest a role for TgRSC8 in control of bradyzoite-upregulated gene expression. Thus chromatin remodeling, by both ATP-independent and dependent mechanisms, is an important mode of gene regulation during stage differentiation in parasites.
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Ueno A, Dautu G, Haga K, Munyaka B, Carmen G, Kobayashi Y, Igarashi M. Toxoplasma gondii: a bradyzoite-specific DnaK-tetratricopeptide repeat (DnaK-TPR) protein interacts with p23 co-chaperone protein. Exp Parasitol 2011; 127:795-803. [PMID: 21281637 DOI: 10.1016/j.exppara.2011.01.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 12/22/2010] [Accepted: 01/21/2011] [Indexed: 10/18/2022]
Abstract
The DnaK-tetratricopeptide repeat (DnaK-TPR) gene (ToxoDB ID, TGME49_002020) is expressed predominantly at the bradyzoite stage. DnaK-TPR protein has a heat shock protein (DnaK) and tetratricopeptide repeat (TPR) domains with amino acid sequence similarity to the counterparts of other organisms (40.2-43.7% to DnaK domain and 41.1-66.0% to TPR domain). These findings allowed us to infer that DnaK-TPR protein is important in the tachyzoite-to-bradyzoite development or maintenance of cyst structure although the function of this gene is still unknown. An immunofluorescence assay (IFA) revealed that DnaK-TPR protein was expressed in Toxoplasma gondii-encysted and in vitro-induced bradyzoites and distributed in the whole part of parasite cells. We conducted yeast two-hybrid screening to identify proteins interacting with DnaK-TPR protein, and demonstrated that DnaK-TPR protein interacts with p23 co-chaperone protein (Tgp23). It was expected that DnaK-TPR protein would have a function as a molecular chaperon in bradyzoite cells associated with Tgp23. Possible mechanisms for this gene are discussed.
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Affiliation(s)
- Akio Ueno
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan
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Marugán-Hernández V, Alvarez-García G, Risco-Castillo V, Regidor-Cerrillo J, Ortega-Mora LM. Identification of Neospora caninum proteins regulated during the differentiation process from tachyzoite to bradyzoite stage by DIGE. Proteomics 2010; 10:1740-50. [PMID: 20162558 DOI: 10.1002/pmic.200900664] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Identification of differentially expressed proteins during Neospora caninum tachyzoite-bradyzoite conversion processes may lead to a better knowledge of the pathogenic mechanisms developed by this important parasite of cattle. In the present work, a differential expression proteomic study of tachyzoite and bradyzoite stages was accomplished for the first time by applying DIGE technology coupled with MS analysis. Up to 72 differentially expressed spots were visualized (1.5-fold in relative abundance, p<0.05, t-test). A total of 53 spots were more abundant in bradyzoites and 19 spots in tachyzoites. MS analysis identified 26 proteins; 20 of them overexpressed in the bradyzoite stage and 6 in the tachyzoite stage. Among the novel proteins, enolase and glyceraldehyde-3-phosphate dehydrogenase (involved in glycolysis), HSP70 and HSP90 (related to stress response) as well as the dense granule protein GRA9, which showed higher abundance in the bradyzoite stage, might be highlighted. On the other hand, isocitrate dehydrogenase 2, involved in the Krebs cycle, was found to be more abundant in tachyzoites extract. Biological functions from most novel proteins were correlated with previously reported processes during the differentiation process in Toxoplasma gondii. Thus, DIGE technology arises as a suitable tool to study mechanisms involved in the N. caninum tachyzoite to bradyzoite conversion.
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Affiliation(s)
- Virginia Marugán-Hernández
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, Madrid, Spain
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Toxoplasma gondii: determinants of tachyzoite to bradyzoite conversion. Parasitol Res 2010; 107:253-60. [PMID: 20514494 DOI: 10.1007/s00436-010-1899-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 04/27/2010] [Indexed: 12/11/2022]
Abstract
Apicomplexa are primarily obligate intracellular protozoa that have evolved complex developmental stages important for pathogenesis and transmission. Toxoplasma gondii, responsible for the disease toxoplasmosis, has the broadest host range of the Apicomplexa as it infects virtually any warm-blooded vertebrate host. Key to T. gondii's pathogenesis is its ability to differentiate from a rapidly replicating tachyzoite stage during acute infection to a relatively non-immunogenic, dormant bradyzoite stage contained in tissue cysts. These bradyzoite cysts can reconvert back to tachyzoites years later causing serious pathology and death if a person becomes immune-compromised. Like the sexual stage sporozoites, bradyzoites are also orally infectious and a major contributor to transmission. Because of the critical role of stage conversion to pathogenesis and transmission, a major research focus is aimed at identifying molecular mediators and pathways that regulate differentiation. Tachyzoite to bradyzoite development can occur spontaneously in vitro and be induced in response to exogenous stress including but not limited to host immunity. The purpose of this review is to explore the potential contributors to stage differentiation in infection and how a determination is made by the parasite to differentiate from tachyzoites to bradyzoites.
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Molecular characterization of Neospora caninum MAG1, a dense granule protein secreted into the parasitophorous vacuole, and associated with the cyst wall and the cyst matrix. Parasitology 2010; 137:1605-19. [PMID: 20444303 DOI: 10.1017/s0031182010000442] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARY In Neospora caninum and Toxoplasma gondii, the parasitophorous vacuole (PV) is synthesized at the time of infection. During tachyzoite-to-bradyzoite stage conversion, the PV is later transformed into a tissue cyst that allows parasites to survive in their host for extended periods of time. We report on the characterization of NcMAG1, the N. caninum orthologue of T. gondii MAG1 (matrix antigen 1; TgMAG1). The 456 amino acid predicted NcMAG1 protein is 54% identical to TgMAG1. By immunoblotting, a rabbit antiserum raised against recombinant NcMAG1 detected a major product of approximately 67 kDa in extracts of N. caninum tachyzoite-infected Vero cells, which was stained more prominently in extracts of infected Vero cells treated to induce in vitro bradyzoite conversion. Immunofluorescence and TEM localized the protein mainly within the cyst wall and the cyst matrix. In both tachyzoites and bradyzoites, NcMAG1 was associated with the parasite dense granules. Comparison between NcMAG1 and TgMAG1 amino acid sequences revealed that the C-terminal conserved regions exhibit 66% identity, while the N-terminal variable regions exhibit only 32% identity. Antibodies against NcMAG1-conserved region cross-reacted with the orthologuous protein in T. gondii but those against the variable region did not. This indicates that the variable region possesses unique antigenic characteristics.
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Joseph SJ, Fernández-Robledo JA, Gardner MJ, El-Sayed NM, Kuo CH, Schott EJ, Wang H, Kissinger JC, Vasta GR. The Alveolate Perkinsus marinus: biological insights from EST gene discovery. BMC Genomics 2010; 11:228. [PMID: 20374649 PMCID: PMC2868825 DOI: 10.1186/1471-2164-11-228] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 04/07/2010] [Indexed: 12/05/2022] Open
Abstract
Background Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica, has devastated natural and farmed oyster populations along the Atlantic and Gulf coasts of the United States. It is classified as a member of the Perkinsozoa, a recently established phylum considered close to the ancestor of ciliates, dinoflagellates, and apicomplexans, and a key taxon for understanding unique adaptations (e.g. parasitism) within the Alveolata. Despite intense parasite pressure, no disease-resistant oysters have been identified and no effective therapies have been developed to date. Results To gain insight into the biological basis of the parasite's virulence and pathogenesis mechanisms, and to identify genes encoding potential targets for intervention, we generated >31,000 5' expressed sequence tags (ESTs) derived from four trophozoite libraries generated from two P. marinus strains. Trimming and clustering of the sequence tags yielded 7,863 unique sequences, some of which carry a spliced leader. Similarity searches revealed that 55% of these had hits in protein sequence databases, of which 1,729 had their best hit with proteins from the chromalveolates (E-value ≤ 1e-5). Some sequences are similar to those proven to be targets for effective intervention in other protozoan parasites, and include not only proteases, antioxidant enzymes, and heat shock proteins, but also those associated with relict plastids, such as acetyl-CoA carboxylase and methyl erythrithol phosphate pathway components, and those involved in glycan assembly, protein folding/secretion, and parasite-host interactions. Conclusions Our transcriptome analysis of P. marinus, the first for any member of the Perkinsozoa, contributes new insight into its biology and taxonomic position. It provides a very informative, albeit preliminary, glimpse into the expression of genes encoding functionally relevant proteins as potential targets for chemotherapy, and evidence for the presence of a relict plastid. Further, although P. marinus sequences display significant similarity to those from both apicomplexans and dinoflagellates, the presence of trans-spliced transcripts confirms the previously established affinities with the latter. The EST analysis reported herein, together with the recently completed sequence of the P. marinus genome and the development of transfection methodology, should result in improved intervention strategies against dermo disease.
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Affiliation(s)
- Sandeep J Joseph
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
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