scholarly journals Vitamin and cofactor acquisition in apicomplexans: Synthesis versus salvage

2019 ◽  
Vol 295 (3) ◽  
pp. 701-714 ◽  
Author(s):  
Aarti Krishnan ◽  
Joachim Kloehn ◽  
Matteo Lunghi ◽  
Dominique Soldati-Favre
Keyword(s):  
Toxoplasma Gondii ◽  
Nutrient Availability ◽  
Metabolic Reconstruction ◽  
Mammalian Host ◽  
Free Living ◽  
Apicomplexan Parasites ◽  
Obligate Intracellular ◽  
Functional Studies ◽  
Intracellular Parasites ◽  
Large Repertoire

The Apicomplexa phylum comprises diverse parasitic organisms that have evolved from a free-living ancestor. These obligate intracellular parasites exhibit versatile metabolic capabilities reflecting their capacity to survive and grow in different hosts and varying niches. Determined by nutrient availability, they either use their biosynthesis machineries or largely depend on their host for metabolite acquisition. Because vitamins cannot be synthesized by the mammalian host, the enzymes required for their synthesis in apicomplexan parasites represent a large repertoire of potential therapeutic targets. Here, we review recent advances in metabolic reconstruction and functional studies coupled to metabolomics that unravel the interplay between biosynthesis and salvage of vitamins and cofactors in apicomplexans. A particular emphasis is placed on Toxoplasma gondii, during both its acute and latent stages of infection.

scholarly journals Untargeted Metabolomics Uncovers the Essential Lysine Transporter in Toxoplasma gondii

Metabolites ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 476
Author(s):  
Joachim Kloehn ◽  
Matteo Lunghi ◽  
Emmanuel Varesio ◽  
David Dubois ◽  
Dominique Soldati-Favre
Keyword(s):  
Amino Acids ◽  
Toxoplasma Gondii ◽  
Rna Degradation ◽  
Major Facilitator Superfamily ◽  
Untargeted Metabolomics ◽  
Apicomplexan Parasites ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
Major Facilitator ◽  
Plasma Membrane Transporter

Apicomplexan parasites are responsible for devastating diseases, including malaria, toxoplasmosis, and cryptosporidiosis. Current treatments are limited by emerging resistance to, as well as the high cost and toxicity of existing drugs. As obligate intracellular parasites, apicomplexans rely on the uptake of many essential metabolites from their host. Toxoplasma gondii, the causative agent of toxoplasmosis, is auxotrophic for several metabolites, including sugars (e.g., myo-inositol), amino acids (e.g., tyrosine), lipidic compounds and lipid precursors (cholesterol, choline), vitamins, cofactors (thiamine) and others. To date, only few apicomplexan metabolite transporters have been characterized and assigned a substrate. Here, we set out to investigate whether untargeted metabolomics can be used to identify the substrate of an uncharacterized transporter. Based on existing genome- and proteome-wide datasets, we have identified an essential plasma membrane transporter of the major facilitator superfamily in T. gondii—previously termed TgApiAT6-1. Using an inducible system based on RNA degradation, TgApiAT6-1 was depleted, and the mutant parasite’s metabolome was compared to that of non-depleted parasites. The most significantly reduced metabolite in parasites depleted in TgApiAT6-1 was identified as the amino acid lysine, for which T. gondii is predicted to be auxotrophic. Using stable isotope-labeled amino acids, we confirmed that TgApiAT6-1 is required for efficient lysine uptake. Our findings highlight untargeted metabolomics as a powerful tool to identify the substrate of orphan transporters.

scholarly journals Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal

2014 ◽  
Vol 23 (4) ◽  
pp. 547-553 ◽  
Author(s):  
Selma Samiko Miyazaki Onuma ◽  
Andréia Lima Tomé Melo ◽  
Daniel Luis Zanella Kantek ◽  
Peter Gransden Crawshaw-Junior ◽  
Ronaldo Gonçalves Morato ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Antibody Test ◽  
Free Living ◽  
Sarcocystis Neurona ◽  
Mato Grosso ◽  
Apicomplexan Parasites ◽  
Wide Range ◽  
Coccidian Parasites ◽  
Brazilian Pantanal

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT) was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca) in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9%) showed seropositivity for T. gondii, eight (72.7%) for S. neurona, and seven (63.6%) for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars.

scholarly journals Survey of Toxoplasma gondii, Neospora caninum and Sarcocystis neurona antibodies in wild red-tailed Amazon parrots (Amazona brasiliensis)

2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Ana Paula Sato ◽  
Frederico Fontanelli Vaz ◽  
Aline Luiza Konell ◽  
Marilia de Oliveira Koch ◽  
Rafaela Furioso Ferreira ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Plasma Samples ◽  
Sarcocystis Neurona ◽  
Blood Samples ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
Antibody Tests ◽  
Immunofluorescence Antibody ◽  
Near Threatened

Abstract Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are obligate intracellular parasites within the phylum Apicomplexa. The red-tailed Amazon parrot (Amazona brasiliensis) is a near-threatened species of psittacine that is endemic to the Atlantic Forest of Brazil and has been designated as a bioindicator because of its sensitivity to environmental qualitative status and changes. The aim of this study was to evaluate the presence of antibodies against T. gondii, N. caninum and S. neurona in wild red-tailed Amazon parrot nestlings on Rasa Island, Brazil. Blood samples were collected from 51 parrots and plasma samples were stored at – 20 °C until immunofluorescence antibody tests (IFAT) were performed. Antigen slides were prepared using tachyzoites of T. gondii (RH strain) and, N. caninum (NC-1 strain) and using merozoites of S. neurona (SNR37 strain). Plasma samples were tested at initial dilutions of 1:16 for T. gondii, 1:50 for N. caninum and 1:5 for S. neurona. An anti-chicken antibody conjugated with FITC was used as a secondary antibody at 1:50 dilution. No antibodies for any of these three protozoa were found, thus suggesting that these wild red-tailed Amazon parrot nestlings had not been exposed to these parasites.

scholarly journals Cytoskeleton of Apicomplexan Parasites

2002 ◽  
Vol 66 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Naomi S. Morrissette ◽  
L. David Sibley
Keyword(s):  
Cytoskeletal Proteins ◽  
Opportunistic Pathogens ◽  
Protozoan Parasites ◽  
Apicomplexan Parasites ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
Eimeria Spp ◽  
Cytoskeletal Elements ◽  
Theileria Spp

SUMMARY The Apicomplexa are a phylum of diverse obligate intracellular parasites including Plasmodium spp., the cause of malaria; Toxoplasma gondii and Cryptosporidium parvum, opportunistic pathogens of immunocompromised individuals; and Eimeria spp. and Theileria spp., parasites of considerable agricultural importance. These protozoan parasites share distinctive morphological features, cytoskeletal organization, and modes of replication, motility, and invasion. This review summarizes our current understanding of the cytoskeletal elements, the properties of cytoskeletal proteins, and the role of the cytoskeleton in polarity, motility, invasion, and replication. We discuss the unusual properties of actin and myosin in the Apicomplexa, the highly stereotyped microtubule populations in apicomplexans, and a network of recently discovered novel intermediate filament-like elements in these parasites.

scholarly journals Protection against Lethal Neospora caninum Infection in Mice Induced by Heterologous Vaccination with a mic1 mic3 Knockout Toxoplasma gondii Strain

2009 ◽  
Vol 78 (2) ◽  
pp. 651-660 ◽  
Author(s):  
Diana Marcela Penarete-Vargas ◽  
Marie Noelle Mévélec ◽  
Sarah Dion ◽  
Edouard Sèche ◽  
Isabelle Dimier-Poisson ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Survival Rates ◽  
Congenital Toxoplasmosis ◽  
Neonatal Morbidity ◽  
Caninum Infection ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
Wide Range ◽  
Vertebrate Hosts

ABSTRACT Neospora caninum and Toxoplasma gondii are closely related, obligate intracellular parasites infecting a wide range of vertebrate hosts and causing abortion and neonatal morbidity and mortality. Several lines of evidence suggest that cross immunity between these two pathogens could be exploited in the design of strategies for heterologous vaccination. We assessed the ability of an attenuated strain of T. gondii (“mic1-3KO strain”) conferring strong protection against chronic and congenital toxoplasmosis to protect mice against lethal N. caninum infection. Mice immunized with mic1-3KO tachyzoites by the oral and intraperitoneal routes developed a strong cellular Th1 response and displayed significant protection against lethal heterologous N. caninum infection, with survival rates of 70% and 80%, respectively, whereas only 30% of the nonimmunized mice survived. We report here the acquisition of heterologous protective immunity against N. caninum following immunization with a live attenuated mic1-3KO strain of T. gondii.

scholarly journals High throughput screening of Toxoplasma gondii clones by PCR after limitation cloning

2013 ◽  
Author(s):  
Ting-Kai Liu
Keyword(s):  
Toxoplasma Gondii ◽  
High Throughput ◽  
High Throughput Screening ◽  
Early Stage ◽  
Gene Knockout ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
Serological Studies ◽  
Gene Defects ◽  
Global Population

Toxoplasma gondii is a kind of obligate intracellular parasites that are capable of infecting virtually all warm-blooded animals. It is one of the most common parasites in human. Serological studies estimated that up to a third of the global population has been chronically infected with the parsites. Toxoplasma gondii is also used as a model orgnisim of Apicomplexans that includes Plasmodium – the parasites that cause malaria. Gene knockout is a very important way to study gene function in all organisms. When it comes to Toxoplasma, it’s very difficult as this haploid parasite has strong adaptability to circumvent the condition of gene defects by gene duplication. High throughput screening at very early stage of transfection is very important for generating a true knockout of this parasite. For some genes that are required forToxoplasma gondii, the high throughput screening is necessary. Different labs use different protocols. After reading and practicing protocols from different papers or different labs, here I established an efficient pipeline for this purpose.

scholarly journals High throughput screening of Toxoplasma gondii clones by PCR after limitation cloning

2013 ◽  
Author(s):  
Ting-Kai Liu
Keyword(s):  
Toxoplasma Gondii ◽  
High Throughput ◽  
High Throughput Screening ◽  
Early Stage ◽  
Gene Knockout ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
Serological Studies ◽  
Gene Defects ◽  
Global Population

Toxoplasma gondii is a kind of obligate intracellular parasites that are capable of infecting virtually all warm-blooded animals. It is one of the most common parasites in human. Serological studies estimated that up to a third of the global population has been chronically infected with the parsites. Toxoplasma gondii is also used as a model orgnisim of Apicomplexans that includes Plasmodium – the parasites that cause malaria. Gene knockout is a very important way to study gene function in all organisms. When it comes to Toxoplasma, it’s very difficult as this haploid parasite has strong adaptability to circumvent the condition of gene defects by gene duplication. High throughput screening at very early stage of transfection is very important for generating a true knockout of this parasite. For some genes that are required forToxoplasma gondii, the high throughput screening is necessary. Different labs use different protocols. After reading and practicing protocols from different papers or different labs, here I established an efficient pipeline for this purpose.

scholarly journals Receptor for Retrograde Transport in the Apicomplexan Parasite Toxoplasma gondii

2005 ◽  
Vol 4 (2) ◽  
pp. 432-442 ◽  
Author(s):  
Stacy L. Pfluger ◽  
Holly V. Goodson ◽  
Jennifer M. Moran ◽  
Christine J. Ruggiero ◽  
Xin Ye ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Membrane Trafficking ◽  
Cell Biology ◽  
Retrograde Transport ◽  
Stable Expression ◽  
Host Cells ◽  
Functional Assay ◽  
Obligate Intracellular ◽  
Intracellular Parasites ◽  
A Subunit

ABSTRACT Toxoplasma gondii and its apicomplexan relatives (such as Plasmodium falciparum, which causes malaria) are obligate intracellular parasites that rely on sequential protein release from specialized secretory organelles for invasion and multiplication within host cells. Because of the importance of these unusual membrane trafficking pathways for drug development and comparative cell biology, characterizing them is essential. In particular, it is unclear what role retrieval mechanisms play in parasite membrane trafficking or where they operate. Previously, we showed that T. gondii’s beta-COP (TgΒCOP; a subunit of coatomer protein complex I, COPI) and retrieval reporters localize exclusively to the zone between the parasite endoplasmic reticulum (ER) and Golgi apparatus. This suggested the existence of an HDEL receptor in T. gondii. We have now identified, cloned, and sequenced this receptor, TgERD2. TgERD2 localizes in a Golgi or ER pattern suggestive of the HDEL retrieval reporter (K. M. Hager, B. Striepen, L. G. Tilney, and D. S. Roos, J. Cell Sci. 112 :2631-2638, 1999). A functional assay reveals that TgERD2 is able to complement the Saccharomyces cerevisiae ERD2 null mutant. Retrieval studies reveal that stable expression of a fluorescent exogenous retrieval ligand results in a dispersal of βCOP signal throughout the cytoplasm and, surprisingly, results in βCOP staining of the vacuolar space of the parasite. In contrast, stable expression of TgERD2GFP does not appear to disturb βCOP staining. In addition to TgERD2, Toxoplasma contains two more divergent ERD2 relatives. Phylogenetic analysis reveals that these proteins belong to a previously unrecognized ERD2 subfamily common to plants and alveolate organisms and as such could represent mediators of parasite-specific retrieval functions. No evidence of class 2 ERD2 proteins was found in metazoan organisms or fungi.

scholarly journals Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Yong H Woo ◽  
Hifzur Ansari ◽  
Thomas D Otto ◽  
Christen M Klinger ◽  
Martin Kolisko ◽  
...  
Keyword(s):  
Rna Binding ◽  
Flagellar Apparatus ◽  
Extracellular Proteins ◽  
Free Living ◽  
Obligate Intracellular ◽  
Dna And Rna ◽  
Intracellular Parasites ◽  
Genes Encoding ◽  
Endomembrane Trafficking ◽  
Dna And Rna Binding

The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga.

scholarly journals POFUT2-mediated O-glycosylation of MIC2 is dispensable for Toxoplasma gondii tachyzoites

2018 ◽  
Author(s):  
Sachin Khurana ◽  
Michael J. Coffey ◽  
Alan John ◽  
Alessandro D. Uboldi ◽  
My-Hang Huynh ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Birth Defects ◽  
Plaque Formation ◽  
Protein Glycosylation ◽  
Apicomplexan Parasites ◽  
Obligate Intracellular ◽  
Congenital Birth Defects ◽  
Glycosylation Sites ◽  
Great Relevance ◽  
Host Infection

AbstractToxoplasma gondii is a ubiquitous obligate intracellular eukaryotic parasite that causes congenital birth defects, disease of the immunocompromised and blindness. Protein glycosylation plays an important role in the infectivity and evasion of immune response of many eukaryotic parasites and is also of great relevance to vaccine design. Here, we demonstrate that MIC2, the motility-associated adhesin of T. gondii, has highly glycosylated thrombospondin repeat domains (TSR). At least seven C-linked and three O-linked glycosylation sites exist within MIC2, with >95% occupancy at O-glycosylation sites. We demonstrate that the addition of O-glycans to MIC2 is mediated by a protein O-fucosyltransferase 2 homologue (TgPOFUT2) encoded by TGGT1_273550. While POFUT2 homologues are important for stabilizing motility associated adhesins and host infection in other apicomplexan parasites, in T. gondii loss of TgPOFUT2 has only a modest impact on MIC2 levels and the wider proteome. Consistent with this, both plaque formation and tachyzoite infectivity are broadly similar in the presence or absence of TgPOFUT2. These findings demonstrate that TgPOFUT2 O-glycosylates MIC2 and that this glycan is dispensable in T. gondii tachyzoites.

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