1
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Henry B, Phillips AJ, Sibley LD, Rosenberg A. A combination of four Toxoplasma gondii nuclear-targeted effectors protects against interferon gamma-driven human host cell death. mBio 2024; 15:e0212424. [PMID: 39292011 PMCID: PMC11481881 DOI: 10.1128/mbio.02124-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Accepted: 08/20/2024] [Indexed: 09/19/2024] Open
Abstract
In both mice and humans, Type II interferon gamma (IFNγ) is crucial for the regulation of Toxoplasma gondii (T. gondii) infection, during acute or chronic phases. To thwart this defense, T. gondii secretes protein effectors hindering the host's immune response. For example, T. gondii relies on the MYR translocon complex to deploy soluble dense granule effectors (GRAs) into the host cell cytosol or nucleus. Recent genome-wide loss-of-function screens in IFNγ-primed primary human fibroblasts identified MYR translocon components as crucial for parasite resistance against IFNγ-driven vacuole clearance. However, these screens did not pinpoint specific MYR-dependent GRA proteins responsible for IFNγ signaling blockade, suggesting potential functional redundancy. Our study reveals that T. gondii depends on the MYR translocon complex to prevent parasite premature egress and host cell death in human cells stimulated with IFNγ post-infection, a unique phenotype observed in various human cell lines but not in murine cells. Intriguingly, inhibiting parasite egress did not prevent host cell death, indicating this mechanism is distinct from those described previously. Genome-wide loss-of-function screens uncovered TgIST, GRA16, GRA24, and GRA28 as effectors necessary for a complete block of IFNγ response. GRA24 and GRA28 directly influenced IFNγ-driven transcription, GRA24's action depended on its interaction with p38 MAPK, while GRA28 disrupted histone acetyltransferase activity of CBP/p300. Given the intricate nature of the immune response to T. gondii, it appears that the parasite has evolved equally elaborate mechanisms to subvert IFNγ signaling, extending beyond direct interference with the JAK/STAT1 pathway, to encompass other signaling pathways as well.IMPORTANCEToxoplasma gondii, an intracellular parasite, affects nearly one-third of the global human population, posing significant risks for immunocompromised patients and infants infected in utero. In murine models, the core mechanisms of IFNγ-mediated immunity against T. gondii are consistently preserved, showcasing a remarkable conservation of immune defense mechanisms. In humans, the recognized restriction mechanisms vary among cell types, lacking a universally applicable mechanism. This difference underscores a significant variation in the genes employed by T. gondii to shield itself against the IFNγ response in human vs murine cells. Here, we identified a specific combination of four parasite-secreted effectors deployed into the host cell nucleus, disrupting IFNγ signaling. This disruption is crucial in preventing premature egress of the parasite and host cell death. Notably, this phenotype is exclusive to human cells, highlighting the intricate and unique mechanisms T. gondii employs to modulate host responses in the human cellular environment.
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Affiliation(s)
- Brittany Henry
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Aubrey J. Phillips
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alex Rosenberg
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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2
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Dort EN, Hamelin RC. Heterogeneity in establishment of polyethylene glycol-mediated plasmid transformations for five forest pathogenic Phytophthora species. PLoS One 2024; 19:e0306158. [PMID: 39255283 PMCID: PMC11386421 DOI: 10.1371/journal.pone.0306158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 08/26/2024] [Indexed: 09/12/2024] Open
Abstract
Plasmid-mediated DNA transformation is a foundational molecular technique and the basis for most CRISPR-Cas9 gene editing systems. While plasmid transformations are well established for many agricultural Phytophthora pathogens, development of this technique in forest Phytophthoras is lacking. Given our long-term research objective to develop CRISPR-Cas9 gene editing in a forest pathogenic Phytophthora species, we sought to establish the functionality of polyethylene glycol (PEG)-mediated plasmid transformation in five species: P. cactorum, P. cinnamomi, P. cryptogea, P. ramorum, and P. syringae. We used the agricultural pathogen P. sojae, a species for which PEG-mediated transformations are well-established, as a transformation control. Using a protocol previously optimized for P. sojae, we tested transformations in the five forest Phytophthoras with three different plasmids: two developed for CRISPR-Cas9 gene editing and one developed for fluorescent protein tagging. Out of the five species tested, successful transformation, as indicated by stable growth of transformants on a high concentration of antibiotic selective growth medium and diagnostic PCR, was achieved only with P. cactorum and P. ramorum. However, while transformations in P. cactorum were consistent and stable, transformations in P. ramorum were highly variable and yielded transformants with very weak mycelial growth and abnormal morphology. Our results indicate that P. cactorum is the best candidate to move forward with CRISPR-Cas9 protocol development and provide insight for future optimization of plasmid transformations in forest Phytophthoras.
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Affiliation(s)
- Erika N Dort
- Department of Forest & Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Richard C Hamelin
- Department of Forest & Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, Québec, Canada
- Département des Sciences du bois et de la Forêt, Faculté de Foresterie et Géographie, Université Laval, Québec City, Québec, Canada
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3
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Giuliano CJ, Wei KJ, Harling FM, Waldman BS, Farringer MA, Boydston EA, Lan TCT, Thomas RW, Herneisen AL, Sanderlin AG, Coppens I, Dvorin JD, Lourido S. CRISPR-based functional profiling of the Toxoplasma gondii genome during acute murine infection. Nat Microbiol 2024; 9:2323-2343. [PMID: 38977907 DOI: 10.1038/s41564-024-01754-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/07/2024] [Indexed: 07/10/2024]
Abstract
Examining host-pathogen interactions in animals can capture aspects of infection that are obscured in cell culture. Using CRISPR-based screens, we functionally profile the entire genome of the apicomplexan parasite Toxoplasma gondii during murine infection. Barcoded gRNAs enabled bottleneck detection and mapping of population structures within parasite lineages. Over 300 genes with previously unknown roles in infection were found to modulate parasite fitness in mice. Candidates span multiple axes of host-parasite interaction. Rhoptry Apical Surface Protein 1 was characterized as a mediator of host-cell tropism that facilitates repeated invasion attempts. GTP cyclohydrolase I was also required for fitness in mice and druggable through a repurposed compound, 2,4-diamino-6-hydroxypyrimidine. This compound synergized with pyrimethamine against T. gondii and malaria-causing Plasmodium falciparum parasites. This work represents a complete survey of an apicomplexan genome during infection of an animal host and points to novel interfaces of host-parasite interaction.
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Affiliation(s)
| | - Kenneth J Wei
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | | | - Benjamin S Waldman
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | - Madeline A Farringer
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
- Biological Sciences in Public Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | | | - Raina W Thomas
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | - Alice L Herneisen
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | | | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Sebastian Lourido
- Whitehead Institute, Cambridge, MA, USA.
- Biology Department, MIT, Cambridge, MA, USA.
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4
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Zwahlen SM, Hayward JA, Maguire CS, Qin AR, van Dooren GG. A myzozoan-specific protein is an essential membrane-anchoring component of the succinate dehydrogenase complex in Toxoplasma parasites. Open Biol 2024; 14:230463. [PMID: 38835243 DOI: 10.1098/rsob.230463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 01/15/2024] [Indexed: 06/06/2024] Open
Abstract
Succinate dehydrogenase (SDH) is a protein complex that functions in the tricarboxylic acid cycle and the electron transport chain of mitochondria. In most eukaryotes, SDH is highly conserved and comprises the following four subunits: SdhA and SdhB form the catalytic core of the complex, while SdhC and SdhD anchor the complex in the membrane. Toxoplasma gondii is an apicomplexan parasite that infects one-third of humans worldwide. The genome of T. gondii encodes homologues of the catalytic subunits SdhA and SdhB, although the physiological role of the SDH complex in the parasite and the identity of the membrane-anchoring subunits are poorly understood. Here, we show that the SDH complex contributes to optimal proliferation and O2 consumption in the disease-causing tachyzoite stage of the T. gondii life cycle. We characterize a small membrane-bound subunit of the SDH complex called mitochondrial protein ookinete developmental defect (MPODD), which is conserved among myzozoans, a phylogenetic grouping that incorporates apicomplexan parasites and their closest free-living relatives. We demonstrate that TgMPODD is essential for SDH activity and plays a key role in attaching the TgSdhA and TgSdhB proteins to the membrane anchor of the complex. Our findings highlight a unique and important feature of mitochondrial energy metabolism in apicomplexan parasites and their relatives.
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Affiliation(s)
- Soraya M Zwahlen
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Jenni A Hayward
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Capella S Maguire
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Alex R Qin
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Giel G van Dooren
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
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5
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Henry B, Sibley LD, Rosenberg A. A Combination of Four Nuclear Targeted Effectors Protects Toxoplasma Against Interferon Gamma Driven Human Host Cell Death During Acute Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.24.573224. [PMID: 38234811 PMCID: PMC10793417 DOI: 10.1101/2023.12.24.573224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
In both mice and humans, Type II interferon-gamma (IFNγ) is crucial for regulation of Toxoplasma gondii (T. gondii) infection, during acute or chronic phases. To thwart this defense, T. gondii secretes protein effectors hindering the hosťs immune response. For example, T. gondii relies on the MYR translocon complex to deploy soluble dense granule effectors (GRAs) into the host cell cytosol or nucleus. Recent genome-wide loss-of-function screens in IFNγ-primed primary human fibroblasts identified MYR translocon components as crucial for parasite resistance against IFNγ driven vacuole clearance. However, these screens did not pinpoint specific MYR-dependent GRA proteins responsible for IFNγ signaling blockade, suggesting potential functional redundancy. Our study reveals that T. gondii depends on the MYR translocon complex to prevent host cell death and parasite premature egress in human cells stimulated with IFNγ postinfection, a unique phenotype observed in various human cell lines but not in murine cells. Intriguingly, inhibiting parasite egress did not prevent host cell death, indicating this mechanism is distinct from those described previously. Genome-wide loss-of-function screens uncovered TgIST, GRA16, GRA24, and GRA28 as effectors necessary for a complete block of IFNγ response. GRA24 and GRA28 directly influenced IFNγ driven transcription, GRA24's action depended on its interaction with p38 MAPK, while GRA28 disrupted histone acetyltransferase activity of CBP/p300. Given the intricate nature of the immune response to T. gondii, it appears that the parasite has evolved equally elaborate mechanisms to subvert IFNγ signaling, extending beyond direct interference with the JAK/STAT1 pathway, to encompass other signaling pathways as well.
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Affiliation(s)
- Brittany Henry
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA
| | - Alex Rosenberg
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA
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6
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Chan AW, Broncel M, Yifrach E, Haseley NR, Chakladar S, Andree E, Herneisen AL, Shortt E, Treeck M, Lourido S. Analysis of CDPK1 targets identifies a trafficking adaptor complex that regulates microneme exocytosis in Toxoplasma. eLife 2023; 12:RP85654. [PMID: 37933960 PMCID: PMC10629828 DOI: 10.7554/elife.85654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023] Open
Abstract
Apicomplexan parasites use Ca2+-regulated exocytosis to secrete essential virulence factors from specialized organelles called micronemes. Ca2+-dependent protein kinases (CDPKs) are required for microneme exocytosis; however, the molecular events that regulate trafficking and fusion of micronemes with the plasma membrane remain unresolved. Here, we combine sub-minute resolution phosphoproteomics and bio-orthogonal labeling of kinase substrates in Toxoplasma gondii to identify 163 proteins phosphorylated in a CDPK1-dependent manner. In addition to known regulators of secretion, we identify uncharacterized targets with predicted functions across signaling, gene expression, trafficking, metabolism, and ion homeostasis. One of the CDPK1 targets is a putative HOOK activating adaptor. In other eukaryotes, HOOK homologs form the FHF complex with FTS and FHIP to activate dynein-mediated trafficking of endosomes along microtubules. We show the FHF complex is partially conserved in T. gondii, consisting of HOOK, an FTS homolog, and two parasite-specific proteins (TGGT1_306920 and TGGT1_316650). CDPK1 kinase activity and HOOK are required for the rapid apical trafficking of micronemes as parasites initiate motility. Moreover, parasites lacking HOOK or FTS display impaired microneme protein secretion, leading to a block in the invasion of host cells. Taken together, our work provides a comprehensive catalog of CDPK1 targets and reveals how vesicular trafficking has been tuned to support a parasitic lifestyle.
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Affiliation(s)
- Alex W Chan
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Malgorzata Broncel
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Eden Yifrach
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Nicole R Haseley
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | | | - Elena Andree
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Alice L Herneisen
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Emily Shortt
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Moritz Treeck
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Sebastian Lourido
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
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7
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Chan AW, Broncel M, Yifrach E, Haseley N, Chakladar S, Andree E, Herneisen AL, Shortt E, Treeck M, Lourido S. Analysis of CDPK1 targets identifies a trafficking adaptor complex that regulates microneme exocytosis in Toxoplasma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523553. [PMID: 36712004 PMCID: PMC9882037 DOI: 10.1101/2023.01.11.523553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Apicomplexan parasites use Ca2+-regulated exocytosis to secrete essential virulence factors from specialized organelles called micronemes. Ca2+-dependent protein kinases (CDPKs) are required for microneme exocytosis; however, the molecular events that regulate trafficking and fusion of micronemes with the plasma membrane remain unresolved. Here, we combine sub-minute resolution phosphoproteomics and bio-orthogonal labeling of kinase substrates in Toxoplasma gondii to identify 163 proteins phosphorylated in a CDPK1-dependent manner. In addition to known regulators of secretion, we identify uncharacterized targets with predicted functions across signaling, gene expression, trafficking, metabolism, and ion homeostasis. One of the CDPK1 targets is a putative HOOK activating adaptor. In other eukaryotes, HOOK homologs form the FHF complex with FTS and FHIP to activate dynein-mediated trafficking of endosomes along microtubules. We show the FHF complex is partially conserved in T. gondii, consisting of HOOK, an FTS homolog, and two parasite-specific proteins (TGGT1_306920 and TGGT1_316650). CDPK1 kinase activity and HOOK are required for the rapid apical trafficking of micronemes as parasites initiate motility. Moreover, parasites lacking HOOK or FTS display impaired microneme protein secretion, leading to a block in the invasion of host cells. Taken together, our work provides a comprehensive catalog of CDPK1 targets and reveals how vesicular trafficking has been tuned to support a parasitic lifestyle.
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Affiliation(s)
- Alex W Chan
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Malgorzata Broncel
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, UK
| | - Eden Yifrach
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Nicole Haseley
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | | | - Elena Andree
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Alice L Herneisen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Moritz Treeck
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, UK
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
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8
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Qureshi A, Connolly JB. Bioinformatic and literature assessment of toxicity and allergenicity of a CRISPR-Cas9 engineered gene drive to control Anopheles gambiae the mosquito vector of human malaria. Malar J 2023; 22:234. [PMID: 37580703 PMCID: PMC10426224 DOI: 10.1186/s12936-023-04665-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 08/07/2023] [Indexed: 08/16/2023] Open
Abstract
BACKGROUND Population suppression gene drive is currently being evaluated, including via environmental risk assessment (ERA), for malaria vector control. One such gene drive involves the dsxFCRISPRh transgene encoding (i) hCas9 endonuclease, (ii) T1 guide RNA (gRNA) targeting the doublesex locus, and (iii) DsRed fluorescent marker protein, in genetically-modified mosquitoes (GMMs). Problem formulation, the first stage of ERA, for environmental releases of dsxFCRISPRh previously identified nine potential harms to the environment or health that could occur, should expressed products of the transgene cause allergenicity or toxicity. METHODS Amino acid sequences of hCas9 and DsRed were interrogated against those of toxins or allergens from NCBI, UniProt, COMPARE and AllergenOnline bioinformatic databases and the gRNA was compared with microRNAs from the miRBase database for potential impacts on gene expression associated with toxicity or allergenicity. PubMed was also searched for any evidence of toxicity or allergenicity of Cas9 or DsRed, or of the donor organisms from which these products were originally derived. RESULTS While Cas9 nuclease activity can be toxic to some cell types in vitro and hCas9 was found to share homology with the prokaryotic toxin VapC, there was no evidence from previous studies of a risk of toxicity to humans and other animals from hCas9. Although hCas9 did contain an 8-mer epitope found in the latex allergen Hev b 9, the full amino acid sequence of hCas9 was not homologous to any known allergens. Combined with a lack of evidence in the literature of Cas9 allergenicity, this indicated negligible risk to humans of allergenicity from hCas9. No matches were found between the gRNA and microRNAs from either Anopheles or humans. Moreover, potential exposure to dsxFCRISPRh transgenic proteins from environmental releases was assessed as negligible. CONCLUSIONS Bioinformatic and literature assessments found no convincing evidence to suggest that transgenic products expressed from dsxFCRISPRh were allergens or toxins, indicating that environmental releases of this population suppression gene drive for malaria vector control should not result in any increased allergenicity or toxicity in humans or animals. These results should also inform evaluations of other GMMs being developed for vector control and in vivo clinical applications of CRISPR-Cas9.
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Affiliation(s)
- Alima Qureshi
- Department of Life Sciences, Imperial College London, Silwood Park, Sunninghill, Ascot, UK
| | - John B Connolly
- Department of Life Sciences, Imperial College London, Silwood Park, Sunninghill, Ascot, UK.
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9
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Licon MH, Giuliano CJ, Chan AW, Chakladar S, Eberhard JN, Shallberg LA, Chandrasekaran S, Waldman BS, Koshy AA, Hunter CA, Lourido S. A positive feedback loop controls Toxoplasma chronic differentiation. Nat Microbiol 2023; 8:889-904. [PMID: 37081202 PMCID: PMC10520893 DOI: 10.1038/s41564-023-01358-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 03/07/2023] [Indexed: 04/22/2023]
Abstract
Successful infection strategies must balance pathogen amplification and persistence. In the obligate intracellular parasite Toxoplasma gondii this is accomplished through differentiation into dedicated cyst-forming chronic stages that avoid clearance by the host immune system. The transcription factor BFD1 is both necessary and sufficient for stage conversion; however, its regulation is not understood. In this study we examine five factors that are transcriptionally activated by BFD1. One of these is a cytosolic RNA-binding protein of the CCCH-type zinc-finger family, which we name bradyzoite formation deficient 2 (BFD2). Parasites lacking BFD2 fail to induce BFD1 and are consequently unable to fully differentiate in culture or in mice. BFD2 interacts with the BFD1 transcript under stress, and deletion of BFD2 reduces BFD1 protein levels but not messenger RNA abundance. The reciprocal effects on BFD2 transcription and BFD1 translation outline a positive feedback loop that enforces the chronic-stage gene-expression programme. Thus, our findings help explain how parasites both initiate and commit to chronic differentiation. This work provides new mechanistic insight into the regulation of T. gondii persistence, and can be exploited in the design of strategies to prevent and treat these key reservoirs of human infection.
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Affiliation(s)
| | - Christopher J Giuliano
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alex W Chan
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sundeep Chakladar
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Julia N Eberhard
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Lindsey A Shallberg
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Benjamin S Waldman
- Whitehead Institute, Cambridge, MA, USA
- Department of Microbiology and Immunology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Anita A Koshy
- BIO5 Institute, University of Arizona, Tucson, AZ, USA
- Department of Neurology, Department of Immunobiology, University of Arizona, Tucson, AZ, USA
| | - Christopher A Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sebastian Lourido
- Whitehead Institute, Cambridge, MA, USA.
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA.
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10
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Krishnamurthy S, Maru P, Wang Y, Bitew MA, Mukhopadhyay D, Yamaryo-Botté Y, Paredes-Santos TC, Sangaré LO, Swale C, Botté CY, Saeij JPJ. CRISPR Screens Identify Toxoplasma Genes That Determine Parasite Fitness in Interferon Gamma-Stimulated Human Cells. mBio 2023; 14:e0006023. [PMID: 36916910 PMCID: PMC10128063 DOI: 10.1128/mbio.00060-23] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 01/11/2023] [Indexed: 03/16/2023] Open
Abstract
Toxoplasma virulence depends on its ability to evade or survive the toxoplasmacidal mechanisms induced by interferon gamma (IFNγ). While many Toxoplasma genes involved in the evasion of the murine IFNγ response have been identified, genes required to survive the human IFNγ response are largely unknown. In this study, we used a genome-wide loss-of-function screen to identify Toxoplasma genes important for parasite fitness in IFNγ-stimulated primary human fibroblasts. We generated gene knockouts for the top six hits from the screen and confirmed their importance for parasite growth in IFNγ-stimulated human fibroblasts. Of these six genes, three have homology to GRA32, localize to dense granules, and coimmunoprecipitate with each other and GRA32, suggesting they might form a complex. Deletion of individual members of this complex leads to early parasite egress in IFNγ-stimulated cells. Thus, prevention of early egress is an important Toxoplasma fitness determinant in IFNγ-stimulated human cells. IMPORTANCE Toxoplasma infection causes serious complications in immunocompromised individuals and in the developing fetus. During infection, certain immune cells release a protein called interferon gamma that activates cells to destroy the parasite or inhibit its growth. While most Toxoplasma parasites are cleared by this immune response, some can survive by blocking or evading the IFNγ-induced restrictive environment. Many Toxoplasma genes that determine parasite survival in IFNγ-activated murine cells are known but parasite genes conferring fitness in IFNγ-activated human cells are largely unknown. Using a Toxoplasma adapted genome-wide loss-of-function screen, we identified many Toxoplasma genes that determine parasite fitness in IFNγ-activated human cells. The gene products of four top hits play a role in preventing early parasite egress in IFNγ-stimulated human cells. Understanding how IFNγ-stimulated human cells inhibit Toxoplasma growth and how Toxoplasma counteracts this, could lead to the development of novel therapeutics.
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Affiliation(s)
- Shruthi Krishnamurthy
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Parag Maru
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Yifan Wang
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Mebratu A. Bitew
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Yoshiki Yamaryo-Botté
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, Batiment Jean Roget, Grenoble, France
| | - Tatiana C. Paredes-Santos
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Lamba O. Sangaré
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Christopher Swale
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences (IAB), INSERM U1209, CNRS UMR5309, University Grenoble Alpes, Grenoble, France
| | - Cyrille Y. Botté
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, Batiment Jean Roget, Grenoble, France
| | - Jeroen P. J. Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, USA
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11
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Giuliano CJ, Wei KJ, Harling FM, Waldman BS, Farringer MA, Boydston EA, Lan TCT, Thomas RW, Herneisen AL, Sanderlin AG, Coppens I, Dvorin JD, Lourido S. Functional profiling of the Toxoplasma genome during acute mouse infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.05.531216. [PMID: 36945434 PMCID: PMC10028831 DOI: 10.1101/2023.03.05.531216] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Within a host, pathogens encounter a diverse and changing landscape of cell types, nutrients, and immune responses. Examining host-pathogen interactions in animal models can therefore reveal aspects of infection absent from cell culture. We use CRISPR-based screens to functionally profile the entire genome of the model apicomplexan parasite Toxoplasma gondii during mouse infection. Barcoded gRNAs were used to track mutant parasite lineages, enabling detection of bottlenecks and mapping of population structures. We uncovered over 300 genes that modulate parasite fitness in mice with previously unknown roles in infection. These candidates span multiple axes of host-parasite interaction, including determinants of tropism, host organelle remodeling, and metabolic rewiring. We mechanistically characterized three novel candidates, including GTP cyclohydrolase I, against which a small-molecule inhibitor could be repurposed as an antiparasitic compound. This compound exhibited antiparasitic activity against T. gondii and Plasmodium falciparum, the most lethal agent of malaria. Taken together, we present the first complete survey of an apicomplexan genome during infection of an animal host, and point to novel interfaces of host-parasite interaction that may offer new avenues for treatment.
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Affiliation(s)
| | - Kenneth J. Wei
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | - Faye M. Harling
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | | | - Madeline A. Farringer
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, USA
- Biological Sciences in Public Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | | | | | - Raina W. Thomas
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | - Alice L. Herneisen
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | | | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Jeffrey D. Dvorin
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Sebastian Lourido
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
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12
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Hoshizaki J, Jagoe H, Lee MCS. Efficient generation of mNeonGreen Plasmodium falciparum reporter lines enables quantitative fitness analysis. Front Cell Infect Microbiol 2022; 12:981432. [PMID: 36189342 PMCID: PMC9523114 DOI: 10.3389/fcimb.2022.981432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
CRISPR editing has enabled the rapid creation of fluorescent Plasmodium transgenic lines, facilitating a deeper understanding of parasite biology. The impact of genetic perturbations such as gene disruption or the introduction of drug resistance alleles on parasite fitness is typically quantified in competitive growth assays between the query line and a wild type reference. Although fluorescent reporter lines offer a facile and frequently used method to measure relative growth, this approach is limited by the strain background of the existing reporter, which may not match the growth characteristics of the query strains, particularly if these are slower-growing field isolates. Here, we demonstrate an efficient CRISPR-based approach to generate fluorescently labelled parasite lines using mNeonGreen derived from the LanYFP protein in Branchiostoma lanceolatum, which is one of the brightest monomeric green fluorescent proteins identified. Using a positive-selection approach by insertion of an in-frame blasticidin S deaminase marker, we generated a Dd2 reporter line expressing mNeonGreen under the control of the pfpare (P. falciparum Prodrug Activation and Resistance Esterase) locus. We selected the pfpare locus as an integration site because it is highly conserved across P. falciparum strains, expressed throughout the intraerythrocytic cycle, not essential, and offers the potential for negative selection to further enrich for integrants. The mNeonGreen@pare line demonstrates strong fluorescence with a negligible fitness defect. In addition, the construct developed can serve as a tool to fluorescently tag other P. falciparum strains for in vitro experimentation.
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13
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Herneisen AL, Li ZH, Chan AW, Moreno SNJ, Lourido S. Temporal and thermal profiling of the Toxoplasma proteome implicates parasite Protein Phosphatase 1 in the regulation of Ca 2+-responsive pathways. eLife 2022; 11:e80336. [PMID: 35976251 PMCID: PMC9436416 DOI: 10.7554/elife.80336] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Apicomplexan parasites cause persistent mortality and morbidity worldwide through diseases including malaria, toxoplasmosis, and cryptosporidiosis. Ca2+ signaling pathways have been repurposed in these eukaryotic pathogens to regulate parasite-specific cellular processes governing the replicative and lytic phases of the infectious cycle, as well as the transition between them. Despite the presence of conserved Ca2+-responsive proteins, little is known about how specific signaling elements interact to impact pathogenesis. We mapped the Ca2+-responsive proteome of the model apicomplexan Taxoplasma gondii via time-resolved phosphoproteomics and thermal proteome profiling. The waves of phosphoregulation following PKG activation and stimulated Ca2+ release corroborate known physiological changes but identify specific proteins operating in these pathways. Thermal profiling of parasite extracts identified many expected Ca2+-responsive proteins, such as parasite Ca2+-dependent protein kinases. Our approach also identified numerous Ca2+-responsive proteins that are not predicted to bind Ca2+, yet are critical components of the parasite signaling network. We characterized protein phosphatase 1 (PP1) as a Ca2+-responsive enzyme that relocalized to the parasite apex upon Ca2+ store release. Conditional depletion of PP1 revealed that the phosphatase regulates Ca2+ uptake to promote parasite motility. PP1 may thus be partly responsible for Ca2+-regulated serine/threonine phosphatase activity in apicomplexan parasites.
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Affiliation(s)
- Alice L Herneisen
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
| | - Alex W Chan
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
| | - Silvia NJ Moreno
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
| | - Sebastian Lourido
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
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14
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Touzdjian Pinheiro Kohlrausch Távora F, de Assis dos Santos Diniz F, de Moraes Rêgo-Machado C, Chagas Freitas N, Barbosa Monteiro Arraes F, Chumbinho de Andrade E, Furtado LL, Osiro KO, Lima de Sousa N, Cardoso TB, Márcia Mertz Henning L, Abrão de Oliveira Molinari P, Feingold SE, Hunter WB, Fátima Grossi de Sá M, Kobayashi AK, Lima Nepomuceno A, Santiago TR, Correa Molinari HB. CRISPR/Cas- and Topical RNAi-Based Technologies for Crop Management and Improvement: Reviewing the Risk Assessment and Challenges Towards a More Sustainable Agriculture. Front Bioeng Biotechnol 2022; 10:913728. [PMID: 35837551 PMCID: PMC9274005 DOI: 10.3389/fbioe.2022.913728] [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: 04/06/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated gene (Cas) system and RNA interference (RNAi)-based non-transgenic approaches are powerful technologies capable of revolutionizing plant research and breeding. In recent years, the use of these modern technologies has been explored in various sectors of agriculture, introducing or improving important agronomic traits in plant crops, such as increased yield, nutritional quality, abiotic- and, mostly, biotic-stress resistance. However, the limitations of each technique, public perception, and regulatory aspects are hindering its wide adoption for the development of new crop varieties or products. In an attempt to reverse these mishaps, scientists have been researching alternatives to increase the specificity, uptake, and stability of the CRISPR and RNAi system components in the target organism, as well as to reduce the chance of toxicity in nontarget organisms to minimize environmental risk, health problems, and regulatory issues. In this review, we discuss several aspects related to risk assessment, toxicity, and advances in the use of CRISPR/Cas and topical RNAi-based technologies in crop management and breeding. The present study also highlights the advantages and possible drawbacks of each technology, provides a brief overview of how to circumvent the off-target occurrence, the strategies to increase on-target specificity, the harm/benefits of association with nanotechnology, the public perception of the available techniques, worldwide regulatory frameworks regarding topical RNAi and CRISPR technologies, and, lastly, presents successful case studies of biotechnological solutions derived from both technologies, raising potential challenges to reach the market and being social and environmentally safe.
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Affiliation(s)
| | | | | | | | | | | | | | - Karen Ofuji Osiro
- Department of Phytopathology, University of Brasília, Brasília, Brazil
- Embrapa Agroenergy, Brasília, Brazil
| | | | | | | | | | | | - Wayne B. Hunter
- USDA-ARS, U.S. Horticultural Research Laboratory, Fort Pierce, FL, United States
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15
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Smith TA, Lopez-Perez GS, Herneisen AL, Shortt E, Lourido S. Screening the Toxoplasma kinome with high-throughput tagging identifies a regulator of invasion and egress. Nat Microbiol 2022; 7:868-881. [PMID: 35484233 PMCID: PMC9167752 DOI: 10.1038/s41564-022-01104-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/11/2022] [Indexed: 12/26/2022]
Abstract
Protein kinases regulate fundamental aspects of eukaryotic cell biology, making them attractive chemotherapeutic targets in parasites like Plasmodium spp. and Toxoplasma gondii. To systematically examine the parasite kinome, we developed a high-throughput tagging (HiT) strategy to endogenously label protein kinases with an auxin-inducible degron and fluorophore. Hundreds of tagging vectors were assembled from synthetic sequences in a single reaction and used to generate pools of mutants to determine localization and function. Examining 1,160 arrayed clones, we assigned 40 protein localizations and associated 15 kinases with distinct defects. The fitness of tagged alleles was also measured by pooled screening, distinguishing delayed from acute phenotypes. A previously unstudied kinase, associated with a delayed phenotype, was shown to be a regulator of invasion and egress. We named the kinase Store Potentiating/Activating Regulatory Kinase (SPARK), based on its impact on intracellular Ca2+ stores. Despite homology to mammalian 3-phosphoinositide-dependent protein kinase-1 (PDK1), SPARK lacks a lipid-binding domain, suggesting a rewiring of the pathway in parasites. HiT screening extends genome-wide approaches into complex cellular phenotypes, providing a scalable and versatile platform to dissect parasite biology.
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Affiliation(s)
- Tyler A Smith
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Alice L Herneisen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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16
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Horáčková V, Voleman L, Hagen KD, Petrů M, Vinopalová M, Weisz F, Janowicz N, Marková L, Motyčková A, Najdrová V, Tůmová P, Dawson SC, Doležal P. Efficient CRISPR/Cas9-mediated gene disruption in the tetraploid protist Giardia intestinalis. Open Biol 2022; 12:210361. [PMID: 35472287 PMCID: PMC9042576 DOI: 10.1098/rsob.210361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 03/14/2022] [Indexed: 01/07/2023] Open
Abstract
CRISPR/Cas9-mediated genome editing has become an extremely powerful technique used to modify gene expression in many organisms, including parasitic protists. Giardia intestinalis, a protist parasite that infects approximately 280 million people around the world each year, has been eluding the use of CRISPR/Cas9 to generate knockout cell lines due to its tetraploid genome. In this work, we show the ability of the in vitro assembled CRISPR/Cas9 components to successfully edit the genome of G. intestinalis. The cell line that stably expresses Cas9 in both nuclei of G. intestinalis showed effective recombination of the cassette containing the transcription units for the gRNA and the resistance marker. This highly efficient process led to the removal of all gene copies at once for three independent experimental genes, mem, cwp1 and mlf1. The method was also applicable to incomplete disruption of the essential gene, as evidenced by significantly reduced expression of tom40. Finally, testing the efficiency of Cas9-induced recombination revealed that homologous arms as short as 150 bp can be sufficient to establish a complete knockout cell line in G. intestinalis.
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Affiliation(s)
- Vendula Horáčková
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Luboš Voleman
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Kari D. Hagen
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, UC Davis, Davis, CA, USA
| | - Markéta Petrů
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Martina Vinopalová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Filip Weisz
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Natalia Janowicz
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Lenka Marková
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Alžběta Motyčková
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Vladimíra Najdrová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
| | - Pavla Tůmová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Scott C. Dawson
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, UC Davis, Davis, CA, USA
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Praha, Czech Republic
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17
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Dey A, Nandy S. CRISPER/Cas in Plant Natural Product Research: Therapeutics as Anticancer and other Drug Candidates and Recent Patents. Recent Pat Anticancer Drug Discov 2021; 16:460-468. [PMID: 34911411 DOI: 10.2174/1574892816666210706155602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/02/2021] [Accepted: 02/15/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR- associated9 (Cas9) endonuclease system is a facile, highly efficient and selective site-directed mutagenesis tool for RNA-guided genome-editing. CRISPR/Cas9 genome-editing strategy uses designed guide-RNAs that recognizes a 3 base-pair protospacer adjacent motif (PAM) sequence in the target-DNA. CRISPR/Cas-editing tools have mainly been employed in crop plants in relation to yield and stress tolerance. However, the immense potential of this technology has not yet been fully utilized in medicinal plants in deciphering or modulating secondary metabolic pathways producing therapeutically active phytochemicals against cancer and other diseases. OBJECTIVE The present review elucidates the use of CRISPR-Cas9 as a promising genome-editing tool in plants and plant-derived natural products with anticancer and other therapeutic applications. It also includes recent patents on the therapeutic applications of CRISPR-CAS systems implicated to cancer and other human medical conditions. METHODS Popular search engines, such as PubMed, Scopus, Google Scholar, Google Patents, Medline, ScienceDirect, SpringerLink, EMBASE, Mendeley, etc., were searched in order to retrieve literature using relevant keywords viz. CRISPER/Cas, plant natural product research, anticancer, therapeutics, etc., either singly or in various combinations. RESULTS Retrieved citations and further cross-referencing among the literature have resulted in a total number of 71 publications and 3 patents are being cited in this work. Information presented in this review aims to support further biotechnological and clinical strategies to be carried using CRISPER/ Cas mediated optimization of plant natural products against cancer and an array of other human medical conditions. CONCLUSION Off late, knock-in and knock-out, point mutation, controlled tuning of gene-expression and targeted mutagenesis have enabled the versatile CRISPR/Cas-editing device to engineer medicinal plants' genomes. In addition, by combining CRISPR/Cas-editing tool with next-generation sequencing (NGS) and various tools of system biology, many medicinal plants have been engineered genetically to optimize the production of valuable bioactive compounds of industrial significance.
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Affiliation(s)
- Abhijit Dey
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata 700073, India
| | - Samapika Nandy
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata 700073, India
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18
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Ghimire B, Saraiva M, Andersen CB, Gogoi A, Saleh M, Zic N, van West P, Brurberg MB. Transformation systems, gene silencing and gene editing technologies in oomycetes. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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19
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Markus BM, Boydston EA, Lourido S. CRISPR-Mediated Transcriptional Repression in Toxoplasma gondii. mSphere 2021; 6:e0047421. [PMID: 34643425 PMCID: PMC8513686 DOI: 10.1128/msphere.00474-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 09/23/2021] [Indexed: 11/20/2022] Open
Abstract
Tools for tuning endogenous gene expression are key to determining the genetic basis of diverse cellular phenotypes. Although synthetic regulatable promoters are available in Toxoplasma, scalable methods for targeted and combinatorial downregulation of gene expression-like RNA interference-have yet to be developed. To investigate the feasibility of CRISPR-mediated transcriptional regulation, we examined the function of two catalytically inactive Cas9 (dCas9) orthologs, from Streptococcus pyogenes and Streptococcus thermophilus, in Toxoplasma. Following the addition of single-guide RNAs (sgRNAs) targeting the promoter and 5' untranslated region (UTR) of the surface antigen gene SAG1, we profiled changes in protein abundance of targeted genes by flow cytometry for transcriptional reporters and immunoblotting. We found that the dCas9 orthologs generated a range of target gene expression levels, and the degree of repression was durable and stably inherited. Therefore, S. pyogenes and S. thermophilus dCas9 can effectively produce intermediate levels of gene expression in Toxoplasma. The distinct sgRNA scaffold requirements of the two dCas9s permit their orthogonal use for simultaneous examination of two distinct loci through transcriptional modulation, labeling for microscopy-based studies, or other dCas9-based approaches. Taking advantage of newly available genomic transcription start site data, these tools will aid in the development of new loss-of-function screening approaches in Toxoplasma. IMPORTANCE Toxoplasma gondii is a ubiquitous intracellular parasite of humans and animals that causes life-threatening disease in immunocompromised patients, fetal abnormalities when contracted during gestation, and recurrent eye lesions in some patients. Despite its health implications, about half of the Toxoplasma genome still lacks functional annotation. A particularly powerful tool for the investigation of an organism's cell biology is the modulation of gene expression, which can produce the subtle phenotypes often required for informing gene function. In Toxoplasma, such tools have limited throughput and versatility. Here, we detail the adaptation of a new set of tools based on CRISPR-Cas9, which allows the targeted downregulation of gene expression in Toxoplasma. With its scalability and adaptability to diverse genomic loci, this approach has the potential to greatly accelerate the functional characterization of the Toxoplasma genome.
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Affiliation(s)
- Benedikt M. Markus
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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20
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Ah‐Fong AM, Boyd AM, Matson ME, Judelson HS. A Cas12a-based gene editing system for Phytophthora infestans reveals monoallelic expression of an elicitor. MOLECULAR PLANT PATHOLOGY 2021; 22:737-752. [PMID: 33724663 PMCID: PMC8126191 DOI: 10.1111/mpp.13051] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 05/03/2023]
Abstract
Phytophthora infestans is a destructive pathogen of potato and a model for investigations of oomycete biology. The successful application of a CRISPR gene editing system to P. infestans is so far unreported. We discovered that it is difficult to express CRISPR/Cas9 but not a catalytically inactive form in transformants, suggesting that the active nuclease is toxic. We were able to achieve editing with CRISPR/Cas12a using vectors in which the nuclease and its guide RNA were expressed from a single transcript. Using the elicitor gene Inf1 as a target, we observed editing of one or both alleles in up to 13% of transformants. Editing was more efficient when guide RNA processing relied on the Cas12a direct repeat instead of ribozyme sequences. INF1 protein was not made when both alleles were edited in the same transformant, but surprisingly also when only one allele was altered. We discovered that the isolate used for editing, 1306, exhibited monoallelic expression of Inf1 due to insertion of a copia-like element in the promoter of one allele. The element exhibits features of active retrotransposons, including a target site duplication, long terminal repeats, and an intact polyprotein reading frame. Editing occurred more often on the transcribed allele, presumably due to differences in chromatin structure. The Cas12a system not only provides a tool for modifying genes in P. infestans, but also for other members of the genus by expanding the number of editable sites. Our work also highlights a natural mechanism that remodels oomycete genomes.
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Affiliation(s)
- Audrey M.V. Ah‐Fong
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - Amy M. Boyd
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - Michael E.H. Matson
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - Howard S. Judelson
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
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21
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Sakamoto H, Kita K, Matsuzaki M. A Novel 2A-peptide-containing Plasmid to Generate Stable Perkinsus marinus Cells Expressing Organelle-targeted Genes. J Eukaryot Microbiol 2021; 68:e12861. [PMID: 34051022 DOI: 10.1111/jeu.12861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetic manipulation techniques for marine protists are not well-established, despite immense efforts. However, Perkinsus marinus is an exception and can be developed as a genetically tractable model organism for related protists. Here, we designed a new plasmid for P. marinus that allows two proteins from a single mRNA to be differently localized using a self-cleaving 2A peptide. This enabled us to establish a stable transfectant expressing a mitochondrially targeted fluorescent protein. The system can be applied to any protein in theory and would make a powerful tool for investigating unique organelles in P. marinus and related dinoflagellates.
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Affiliation(s)
- Hirokazu Sakamoto
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.,Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Motomichi Matsuzaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,RIKEN Center for Advanced Intelligence Project, Tokyo, Japan
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22
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Yadavalli R, Umeda K, Waugh HA, Tracy AN, Sidhu AV, Hernández DE, Fernández Robledo JA. CRISPR/Cas9 Ribonucleoprotein-Based Genome Editing Methodology in the Marine Protozoan Parasite Perkinsus marinus. Front Bioeng Biotechnol 2021; 9:623278. [PMID: 33898400 PMCID: PMC8062965 DOI: 10.3389/fbioe.2021.623278] [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] [Received: 10/29/2020] [Accepted: 03/09/2021] [Indexed: 11/15/2022] Open
Abstract
Perkinsus marinus (Perkinsozoa), a close relative of apicomplexans, is an osmotrophic facultative intracellular marine protozoan parasite responsible for "Dermo" disease in oysters and clams. Although there is no clinical evidence of this parasite infecting humans, HLA-DR40 transgenic mice studies strongly suggest the parasite as a natural adjuvant in oral vaccines. P. marinus is being developed as a heterologous gene expression platform for pathogens of medical and veterinary relevance and a novel platform for delivering vaccines. We previously reported the transient expression of two rodent malaria genes Plasmodium berghei HAP2 and MSP8. In this study, we optimized the original electroporation-based protocol to establish a stable heterologous expression method. Using 20 μg of pPmMOE[MOE1]:GFP and 25.0 × 106 P. marinus cells resulted in 98% GFP-positive cells. Furthermore, using the optimized protocol, we report for the first time the successful knock-in of GFP at the C-terminus of the PmMOE1 using ribonucleoprotein (RNP)-based CRISPR/Cas9 gene editing methodology. The GFP was expressed 18 h post-transfection, and expression was observed for 8 months post-transfection, making it a robust and stable knock-in system.
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Affiliation(s)
| | - Kousuke Umeda
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Hannah A. Waugh
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
- Southern Maine Community College, South Portland, ME, United States
| | - Adrienne N. Tracy
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
- Colby College, Waterville, ME, United States
| | - Asha V. Sidhu
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
- Colby College, Waterville, ME, United States
| | - Derek E. Hernández
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
- Colby College, Waterville, ME, United States
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23
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Smith NC, Goulart C, Hayward JA, Kupz A, Miller CM, van Dooren GG. Control of human toxoplasmosis. Int J Parasitol 2020; 51:95-121. [PMID: 33347832 DOI: 10.1016/j.ijpara.2020.11.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/12/2020] [Accepted: 11/15/2020] [Indexed: 12/21/2022]
Abstract
Toxoplasmosis is caused by Toxoplasma gondii, an apicomplexan parasite that is able to infect any nucleated cell in any warm-blooded animal. Toxoplasma gondii infects around 2 billion people and, whilst only a small percentage of infected people will suffer serious disease, the prevalence of the parasite makes it one of the most damaging zoonotic diseases in the world. Toxoplasmosis is a disease with multiple manifestations: it can cause a fatal encephalitis in immunosuppressed people; if first contracted during pregnancy, it can cause miscarriage or congenital defects in the neonate; and it can cause serious ocular disease, even in immunocompetent people. The disease has a complex epidemiology, being transmitted by ingestion of oocysts that are shed in the faeces of definitive feline hosts and contaminate water, soil and crops, or by consumption of intracellular cysts in undercooked meat from intermediate hosts. In this review we examine current and future approaches to control toxoplasmosis, which encompass a variety of measures that target different components of the life cycle of T. gondii. These include: education programs about the parasite and avoidance of contact with infectious stages; biosecurity and sanitation to ensure food and water safety; chemo- and immunotherapeutics to control active infections and disease; prophylactic options to prevent acquisition of infection by livestock and cyst formation in meat; and vaccines to prevent shedding of oocysts by definitive feline hosts.
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Affiliation(s)
- Nicholas C Smith
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Research School of Biology, Australian National University, Canberra, ACT 0200, Australia.
| | - Cibelly Goulart
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Jenni A Hayward
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Andreas Kupz
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia
| | - Catherine M Miller
- College of Public Health, Medical and Veterinary Science, James Cook University, Cairns, QLD 4878, Australia
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
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24
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Wang Y, Sangaré LO, Paredes-Santos TC, Hassan MA, Krishnamurthy S, Furuta AM, Markus BM, Lourido S, Saeij JPJ. Genome-wide screens identify Toxoplasma gondii determinants of parasite fitness in IFNγ-activated murine macrophages. Nat Commun 2020; 11:5258. [PMID: 33067458 PMCID: PMC7567896 DOI: 10.1038/s41467-020-18991-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Macrophages play an essential role in the early immune response against Toxoplasma and are the cell type preferentially infected by the parasite in vivo. Interferon gamma (IFNγ) elicits a variety of anti-Toxoplasma activities in macrophages. Using a genome-wide CRISPR screen we identify 353 Toxoplasma genes that determine parasite fitness in naїve or IFNγ-activated murine macrophages, seven of which are further confirmed. We show that one of these genes encodes dense granule protein GRA45, which has a chaperone-like domain, is critical for correct localization of GRAs into the PVM and secretion of GRA effectors into the host cytoplasm. Parasites lacking GRA45 are more susceptible to IFNγ-mediated growth inhibition and have reduced virulence in mice. Together, we identify and characterize an important chaperone-like GRA in Toxoplasma and provide a resource for the community to further explore the function of Toxoplasma genes that determine fitness in IFNγ-activated macrophages.
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Affiliation(s)
- Yifan Wang
- grid.27860.3b0000 0004 1936 9684Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA USA
| | - Lamba Omar Sangaré
- grid.27860.3b0000 0004 1936 9684Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA USA
| | - Tatiana C. Paredes-Santos
- grid.27860.3b0000 0004 1936 9684Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA USA
| | - Musa A. Hassan
- grid.4305.20000 0004 1936 7988College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, UK ,grid.4305.20000 0004 1936 7988The Roslin Institute, The University of Edinburgh, Edinburgh, UK ,grid.4305.20000 0004 1936 7988Center for Tropical Livestock Health and Genetics, The University of Edinburgh, Edinburgh, UK
| | - Shruthi Krishnamurthy
- grid.27860.3b0000 0004 1936 9684Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA USA
| | - Anna M. Furuta
- grid.27860.3b0000 0004 1936 9684Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA USA
| | - Benedikt M. Markus
- grid.270301.70000 0001 2292 6283Whitehead Institute for Biomedical Research, Cambridge, MA USA ,grid.5963.9Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Sebastian Lourido
- grid.270301.70000 0001 2292 6283Whitehead Institute for Biomedical Research, Cambridge, MA USA ,grid.116068.80000 0001 2341 2786Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Jeroen P. J. Saeij
- grid.27860.3b0000 0004 1936 9684Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA USA
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25
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Harding CR, Sidik SM, Petrova B, Gnädig NF, Okombo J, Herneisen AL, Ward KE, Markus BM, Boydston EA, Fidock DA, Lourido S. Genetic screens reveal a central role for heme metabolism in artemisinin susceptibility. Nat Commun 2020; 11:4813. [PMID: 32968076 PMCID: PMC7511413 DOI: 10.1038/s41467-020-18624-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/03/2020] [Indexed: 01/26/2023] Open
Abstract
Artemisinins have revolutionized the treatment of Plasmodium falciparum malaria; however, resistance threatens to undermine global control efforts. To broadly explore artemisinin susceptibility in apicomplexan parasites, we employ genome-scale CRISPR screens recently developed for Toxoplasma gondii to discover sensitizing and desensitizing mutations. Using a sublethal concentration of dihydroartemisinin (DHA), we uncover the putative transporter Tmem14c whose disruption increases DHA susceptibility. Screens performed under high doses of DHA provide evidence that mitochondrial metabolism can modulate resistance. We show that disrupting a top candidate from the screens, the mitochondrial protease DegP2, lowers porphyrin levels and decreases DHA susceptibility, without significantly altering parasite fitness in culture. Deleting the homologous gene in P. falciparum, PfDegP, similarly lowers heme levels and DHA susceptibility. These results expose the vulnerability of heme metabolism to genetic perturbations that can lead to increased survival in the presence of DHA.
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Affiliation(s)
- Clare R Harding
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, UK
| | - Saima M Sidik
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Boryana Petrova
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Nina F Gnädig
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - John Okombo
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | | | - Kurt E Ward
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Benedikt M Markus
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
- Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA.
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26
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Al-Radhawi MA, Tran AP, Ernst EA, Chen T, Voigt CA, Sontag ED. Distributed Implementation of Boolean Functions by Transcriptional Synthetic Circuits. ACS Synth Biol 2020; 9:2172-2187. [PMID: 32589837 DOI: 10.1021/acssynbio.0c00228] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Starting in the early 2000s, sophisticated technologies have been developed for the rational construction of synthetic genetic networks that implement specified logical functionalities. Despite impressive progress, however, the scaling necessary in order to achieve greater computational power has been hampered by many constraints, including repressor toxicity and the lack of large sets of mutually orthogonal repressors. As a consequence, a typical circuit contains no more than roughly seven repressor-based gates per cell. A possible way around this scalability problem is to distribute the computation among multiple cell types, each of which implements a small subcircuit, which communicate among themselves using diffusible small molecules (DSMs). Examples of DSMs are those employed by quorum sensing systems in bacteria. This paper focuses on systematic ways to implement this distributed approach, in the context of the evaluation of arbitrary Boolean functions. The unique characteristics of genetic circuits and the properties of DSMs require the development of new Boolean synthesis methods, distinct from those classically used in electronic circuit design. In this work, we propose a fast algorithm to synthesize distributed realizations for any Boolean function, under constraints on the number of gates per cell and the number of orthogonal DSMs. The method is based on an exact synthesis algorithm to find the minimal circuit per cell, which in turn allows us to build an extensive database of Boolean functions up to a given number of inputs. For concreteness, we will specifically focus on circuits of up to 4 inputs, which might represent, for example, two chemical inducers and two light inputs at different frequencies. Our method shows that, with a constraint of no more than seven gates per cell, the use of a single DSM increases the total number of realizable circuits by at least 7.58-fold compared to centralized computation. Moreover, when allowing two DSM's, one can realize 99.995% of all possible 4-input Boolean functions, still with at most 7 gates per cell. The methodology introduced here can be readily adapted to complement recent genetic circuit design automation software. A toolbox that uses the proposed algorithm was created and made available at https://github.com/sontaglab/DBC/.
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Affiliation(s)
- M. Ali Al-Radhawi
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Anh Phong Tran
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Elizabeth A. Ernst
- Department of Mathematics, Statistics, and Computer Science, Macalester College, Saint Paul, Minnesota 55105, United States
| | - Tianchi Chen
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States
| | - Christopher A. Voigt
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Eduardo D. Sontag
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States
- Laboratory of Systems Pharmacology, Program in Therapeutic Science, Harvard Medical School, Boston, Massachusetts 02115, United States
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27
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Herneisen AL, Sidik SM, Markus BM, Drewry DH, Zuercher WJ, Lourido S. Identifying the Target of an Antiparasitic Compound in Toxoplasma Using Thermal Proteome Profiling. ACS Chem Biol 2020; 15:1801-1807. [PMID: 32597628 DOI: 10.1021/acschembio.0c00369] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Apicomplexan parasites include the causative agents of malaria and toxoplasmosis. Cell-based screens in Toxoplasma previously identified a chemical modulator of calcium signaling (ENH1) that blocked parasite egress from host cells and exhibited potent antiparasitic activity. To identify the targets of ENH1, we adapted thermal proteome profiling to Toxoplasma, which revealed calcium-dependent protein kinase 1 (CDPK1) as a target. We confirmed the inhibition of CDPK1 by ENH1 in vitro and in parasites by comparing alleles sensitive or resistant to ENH1. CDPK1 inhibition explained the block in egress; however, the effects of ENH1 on calcium homeostasis and parasite viability were CDPK1-independent, implicating additional targets. Thermal proteome profiling of lysates from parasites expressing the resistant allele of CDPK1 identified additional candidates associated with the mitochondria and the parasite pellicle-compartments that potentially function in calcium release and homeostasis. Our findings illustrate the promise of thermal profiling to identify druggable targets that modulate calcium signaling in apicomplexan parasites.
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Affiliation(s)
- Alice L. Herneisen
- Department of Biology, Massachusetts Institute of Technology, 30 Ames St, Cambridge, Massachusetts 02142, United States
- Whitehead Institute for Biomedical Research, 455 Main St, Cambridge, Massachusetts 02142, United States
| | - Saima M. Sidik
- Whitehead Institute for Biomedical Research, 455 Main St, Cambridge, Massachusetts 02142, United States
| | - Benedikt M. Markus
- Whitehead Institute for Biomedical Research, 455 Main St, Cambridge, Massachusetts 02142, United States
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, Freiburg 79104, Germany
| | - David H. Drewry
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - William J. Zuercher
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Sebastian Lourido
- Department of Biology, Massachusetts Institute of Technology, 30 Ames St, Cambridge, Massachusetts 02142, United States
- Whitehead Institute for Biomedical Research, 455 Main St, Cambridge, Massachusetts 02142, United States
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28
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Hu D, Tang X, Ben Mamoun C, Wang C, Wang S, Gu X, Duan C, Zhang S, Suo J, Deng M, Yu Y, Suo X, Liu X. Efficient Single-Gene and Gene Family Editing in the Apicomplexan Parasite Eimeria tenella Using CRISPR-Cas9. Front Bioeng Biotechnol 2020; 8:128. [PMID: 32158750 PMCID: PMC7052334 DOI: 10.3389/fbioe.2020.00128] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/10/2020] [Indexed: 12/26/2022] Open
Abstract
Eimeria species are pathogenic protozoa with a wide range of hosts and the cause of poultry coccidiosis, which results in huge economic losses to the poultry industry. These parasites encode a genome of ∼8000 genes that control a highly coordinated life cycle of asexual replication and sexual differentiation, transmission, and virulence. However, the function and physiological importance of the large majority of these genes remain unknown mostly due to the lack of tools for systematic analysis of gene functions. Here, we report the first application of CRISPR-Cas9 gene editing technology in Eimeria tenella for analysis of gene function at a single gene level as well as for systematic functional analysis of an entire gene family. Using a transgenic line constitutively expressing Cas9, we demonstrated successful and efficient loss of function through non-homologous end joining as well as guided homologous recombination. Application of this approach to the study of the localization of EtGRA9 revealed that the gene encodes a secreted protein whose cellular distribution varied during the life cycle. Systematic disruption of the ApiAp2 transcription factor gene family using this approach revealed that 23 of the 33 factors expressed by this parasite are essential for development and survival in the host. Our data thus establish CRISPR-Cas9 as a powerful technology for gene editing in Eimeria and will set the stage for systematic functional analysis of its genome to understand its biology and pathogenesis, and will make it possible to identify and validate new targets for coccidiosis therapy.
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Affiliation(s)
- Dandan Hu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xinming Tang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Choukri Ben Mamoun
- Department of Internal Medicine and Microbial Pathogenesis, School of Medicine, Yale University, New Haven, CT, United States
| | - Chaoyue Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Si Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiaolong Gu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Chunhui Duan
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Sixin Zhang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jinxia Suo
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Miner Deng
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yonglan Yu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xun Suo
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xianyong Liu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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29
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Krishnan A, Kloehn J, Lunghi M, Chiappino-Pepe A, Waldman BS, Nicolas D, Varesio E, Hehl A, Lourido S, Hatzimanikatis V, Soldati-Favre D. Functional and Computational Genomics Reveal Unprecedented Flexibility in Stage-Specific Toxoplasma Metabolism. Cell Host Microbe 2020; 27:290-306.e11. [PMID: 31991093 DOI: 10.1016/j.chom.2020.01.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/02/2019] [Accepted: 01/03/2020] [Indexed: 12/31/2022]
Abstract
To survive and proliferate in diverse host environments with varying nutrient availability, the obligate intracellular parasite Toxoplasma gondii reprograms its metabolism. We have generated and curated a genome-scale metabolic model (iTgo) for the fast-replicating tachyzoite stage, harmonized with experimentally observed phenotypes. To validate the importance of four metabolic pathways predicted by the model, we have performed in-depth in vitro and in vivo phenotyping of mutant parasites including targeted metabolomics and CRISPR-Cas9 fitness screening of all known metabolic genes. This led to unexpected insights into the remarkable flexibility of the parasite, addressing the dependency on biosynthesis or salvage of fatty acids (FAs), purine nucleotides (AMP and GMP), a vitamin (pyridoxal-5P), and a cofactor (heme) in both the acute and latent stages of infection. Taken together, our experimentally validated metabolic network leads to a deeper understanding of the parasite's biology, opening avenues for the development of therapeutic intervention against apicomplexans.
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Affiliation(s)
- Aarti Krishnan
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Joachim Kloehn
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Matteo Lunghi
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Anush Chiappino-Pepe
- Laboratory of Computational Systems Biotechnology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | | | - Damien Nicolas
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Emmanuel Varesio
- School of Pharmaceutical Sciences Geneva-Lausanne (EPGL), Geneva 1211, Switzerland; Mass Spectrometry Core Facility (MZ 2.0), University of Geneva, Geneva 1211, Switzerland
| | - Adrian Hehl
- Institute of Parasitology, University of Zürich, Zürich 8057, Switzerland
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Vassily Hatzimanikatis
- Laboratory of Computational Systems Biotechnology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland.
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