scholarly journals De novo pyrimidine biosynthesis is required for virulence of Toxoplasma gondii

Nature ◽  
2002 ◽  
Vol 415 (6874) ◽  
pp. 926-929 ◽  
Author(s):  
Barbara A. Fox ◽  
David J. Bzik
Keyword(s):  
Toxoplasma Gondii ◽  
De Novo ◽  
Pyrimidine Biosynthesis

scholarly journals A Carbamoyl Phosphate Synthetase II (CPSII) Deletion Mutant of Toxoplasma gondii Induces Partial Protective Immunity in Mice

2021 ◽  
Vol 11 ◽  
Author(s):  
Xunhui Zhuo ◽  
Kaige Du ◽  
Haojie Ding ◽  
Di Lou ◽  
Bin Zheng ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
De Novo ◽  
Parasite Growth ◽  
Pyrimidine Biosynthesis ◽  
Mrna Levels ◽  
Biosynthesis Pathway ◽  
Carbamoyl Phosphate Synthetase ◽  
Carbamoyl Phosphate

Toxoplasma gondii is an obligate intracellular protozoan parasite. T. gondii primarily infection in pregnant women may result in fetal abortion, and infection in immunosuppressed population may result in toxoplasmosis. Carbamoyl phosphate synthetase II (CPSII) is a key enzyme in the de novo pyrimidine-biosynthesis pathway, and has a crucial role in parasite replication. We generated a mutant with complete deletion of CPSII via clustered regularly interspaced short palindromic repeats (CRISPR)/cas9 in type-1 RH strain of T. gondii. We tested the intracellular proliferation of this mutant and found that it showed significantly reduced replication in vitro, though CPSII deletion did not completely stop the parasite growth. The immune responses induced by the infection of RHΔCPSII tachyzoites in mice were evaluated. During infection in mice, the RHΔCPSII mutant displayed notable defects in replication and virulence, and significantly enhanced the survival of mice compared with survival of RH-infected mice. We tracked parasite propagation from ascitic fluid in mice infected with the RHΔCPSII mutant, and few tachyzoites were observed at early infection. We also observed that the RHΔCPSII mutant induced greater accumulation of neutrophils. The mutant induced a higher level of T-helper type-1 cytokines [interferon (IFN)-γ, interleukin (IL)-12]. The mRNA levels of signal transducer and activator of transcription cellular transcription factor 1 and IFN regulatory factor 8 were significantly higher in the RHΔCPSII mutant-infected group. Together, these data suggest that CPSII is crucial for parasite growth, and that strains lack the de novo pyrimidine biosynthesis pathway and salvage pathway may become a promising live attenuated vaccine to prevent infection with T. gondii.

scholarly journals Pyrimidine Pathway-Dependent and -Independent Functions of the Toxoplasma gondii Mitochondrial Dihydroorotate Dehydrogenase

2016 ◽  
Vol 84 (10) ◽  
pp. 2974-2981 ◽  
Author(s):  
Miryam Andrea Hortua Triana ◽  
Daniela Cajiao Herrera ◽  
Barbara H. Zimmermann ◽  
Barbara A. Fox ◽  
David J. Bzik
Keyword(s):  
Toxoplasma Gondii ◽  
Drug Target ◽  
De Novo ◽  
Mutant Gene ◽  
Pyrimidine Biosynthesis ◽  
Dihydroorotate Dehydrogenase ◽  
Content Type ◽  
Independent Functions ◽  
Fourth Step ◽  
Essential Function

Dihydroorotate dehydrogenase (DHODH) mediates the fourth step ofde novopyrimidine biosynthesis and is a proven drug target for inducing immunosuppression in therapy of human disease as well as a rapidly emerging drug target for treatment of malaria. InToxoplasma gondii, disruption of the first, fifth, or sixth step ofde novopyrimidine biosynthesis induced uracil auxotrophy. However, previous attempts to generate uracil auxotrophy by genetically deleting the mitochondrion-associated DHODH ofT. gondii(TgDHODH) failed. To further address the essentiality ofTgDHODH, mutant gene alleles deficient inTgDHODH activity were designed to ablate the enzyme activity. Replacement of the endogenousDHODHgene with catalytically deficientDHODHgene alleles induced uracil auxotrophy. Catalytically deficientTgDHODH localized to the mitochondria, and parasites retained mitochondrial membrane potential. These results show thatTgDHODH is essential for the synthesis of pyrimidines and suggest thatTgDHODH is required for a second essential function independent of its role in pyrimidine biosynthesis.

scholarly journals Original Chemical Series of Pyrimidine Biosynthesis Inhibitors That Boost the Antiviral Interferon Response

2017 ◽  
Vol 61 (10) ◽  
Author(s):  
Marianne Lucas-Hourani ◽  
Daniel Dauzonne ◽  
Hélène Munier-Lehmann ◽  
Samira Khiar ◽  
Sébastien Nisole ◽  
...  
Keyword(s):  
Metabolic Pathway ◽  
Defense Mechanisms ◽  
De Novo ◽  
Pyrimidine Biosynthesis ◽  
Interferon Response ◽  
Type I ◽  
Innate Defense ◽  
New Class ◽  
Biosynthesis Inhibitors ◽  
Tightly Coupled

ABSTRACT De novo pyrimidine biosynthesis is a key metabolic pathway involved in multiple biosynthetic processes. Here, we identified an original series of 3-(1H-indol-3-yl)-2,3-dihydro-4H-furo[3,2-c]chromen-4-one derivatives as a new class of pyrimidine biosynthesis inhibitors formed by two edge-fused polycyclic moieties. We show that identified compounds exhibit broad-spectrum antiviral activity and immunostimulatory properties, in line with recent reports linking de novo pyrimidine biosynthesis with innate defense mechanisms against viruses. Most importantly, we establish that pyrimidine deprivation can amplify the production of both type I and type III interferons by cells stimulated with retinoic acid-inducible gene 1 (RIG-I) ligands. Altogether, our results further expand the current panel of pyrimidine biosynthesis inhibitors and illustrate how the production of antiviral interferons is tightly coupled to this metabolic pathway. Functional and structural similarities between this new chemical series and dicoumarol, which was reported before to inhibit pyrimidine biosynthesis at the dihydroorotate dehydrogenase (DHODH) step, are discussed.

scholarly journals Toxoplasma gondii acetyl-CoA synthetase is involved in fatty acid elongation (of long fatty acid chains) during tachyzoite life stages

2018 ◽  
Vol 59 (6) ◽  
pp. 994-1004 ◽  
Author(s):  
David Dubois ◽  
Stella Fernandes ◽  
Souad Amiar ◽  
Sheena Dass ◽  
Nicholas J. Katris ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Toxoplasma Gondii ◽  
Isotope Labeling ◽  
De Novo ◽  
Lipid Synthesis ◽  
Minor Effect ◽  
Parasite Line ◽  
Acetyl Coa ◽  
Apicomplexan Parasites ◽  
A Minor

Apicomplexan parasites are pathogens responsible for major human diseases such as toxoplasmosis caused by Toxoplasma gondii and malaria caused by Plasmodium spp. Throughout their intracellular division cycle, the parasites require vast and specific amounts of lipids to divide and survive. This demand for lipids relies on a fine balance between de novo synthesized lipids and scavenged lipids from the host. Acetyl-CoA is a major and central precursor for many metabolic pathways, especially for lipid biosynthesis. T. gondii possesses a single cytosolic acetyl-CoA synthetase (TgACS). Its role in the parasite lipid synthesis is unclear. Here, we generated an inducible TgACS KO parasite line and confirmed the cytosolic localization of the protein. We conducted 13C-stable isotope labeling combined with mass spectrometry-based lipidomic analyses to unravel its putative role in the parasite lipid synthesis pathway. We show that its disruption has a minor effect on the global FA composition due to the metabolic changes induced to compensate for its loss. However, we could demonstrate that TgACS is involved in providing acetyl-CoA for the essential fatty elongation pathway to generate FAs used for membrane biogenesis. This work provides novel metabolic insight to decipher the complex lipid synthesis in T. gondii.

scholarly journals Novel AR-12 derivatives, P12-23 and P12-34, inhibit flavivirus replication by blocking host de novo pyrimidine biosynthesis

2018 ◽  
Vol 7 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Chao-Fu Yang ◽  
Balraj Gopula ◽  
Jian-Jong Liang ◽  
Jin-Kun Li ◽  
Si-Yu Chen ◽  
...  
Keyword(s):  
De Novo ◽  
Pyrimidine Biosynthesis

scholarly journals MCT4 regulates de novo pyrimidine biosynthesis in GBM in a lactate-independent manner

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Raffaella Spina ◽  
Dillon M Voss ◽  
Xiaohua Yang ◽  
Jason W Sohn ◽  
Robert Vinkler ◽  
...  
Keyword(s):  
De Novo ◽  
Apoptotic Cell ◽  
Pyrimidine Biosynthesis ◽  
Monocarboxylate Transporter ◽  
Independent Manner ◽  
Pyrimidine Nucleosides ◽  
Significant Prolongation ◽  
Orthotopic Xenografts

Abstract Background Necrotic foci with surrounding hypoxic cellular pseudopalisades and microvascular hyperplasia are histological features found in glioblastoma (GBM). We have previously shown that monocarboxylate transporter 4 (MCT4) is highly expressed in necrotic/hypoxic regions in GBM and that increased levels of MCT4 are associated with worse clinical outcomes. Methods A combined transcriptomics and metabolomics analysis was performed to study the effects of MCT4 depletion in hypoxic GBM neurospheres. Stable and inducible MCT4-depletion systems were used to evaluate the effects of and underlining mechanisms associated with MCT4 depletion in vitro and in vivo, alone and in combination with radiation. Results This study establishes that conditional depletion of MCT4 profoundly impairs self-renewal and reduces the frequency and tumorigenicity of aggressive, therapy-resistant, glioblastoma stem cells. Mechanistically, we observed that MCT4 depletion induces anaplerotic glutaminolysis and abrogates de novo pyrimidine biosynthesis. The latter results in a dramatic increase in DNA damage and apoptotic cell death, phenotypes that were readily rescued by pyrimidine nucleosides supplementation. Consequently, we found that MCT4 depletion promoted a significant prolongation of survival of animals bearing established orthotopic xenografts, an effect that was extended by adjuvant treatment with focused radiation. Conclusions Our findings establish a novel role for MCT4 as a critical regulator of cellular deoxyribonucleotide levels and provide a new therapeutic direction related to MCT4 depletion in GBM.

Sign in / Sign up

Export Citation Format

Share Document