1
|
Bando H, Murata Y, Han Y, Sugi T, Fukuda Y, Bzik DJ, Fox BA, Kato K. Toxoplasma gondii chitinase-like protein TgCLP1 regulates the parasite cyst burden. Front Cell Infect Microbiol 2024; 14:1359888. [PMID: 38828265 PMCID: PMC11140023 DOI: 10.3389/fcimb.2024.1359888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/23/2024] [Indexed: 06/05/2024] Open
Abstract
Toxoplasma, an important intracellular parasite of humans and animals, causes life-threatening toxoplasmosis in immunocompromised individuals. Although Toxoplasma secretory proteins during acute infection (tachyzoite, which divides rapidly and causes inflammation) have been extensively characterized, those involved in chronic infection (bradyzoite, which divides slowly and is surrounded by a cyst wall) remain uncertain. Regulation of the cyst wall is essential to the parasite life cycle, and polysaccharides, such as chitin, in the cyst wall are necessary to sustain latent infection. Toxoplasma secretory proteins during the bradyzoite stage may have important roles in regulating the cyst wall via polysaccharides. Here, we focused on characterizing the hypothetical T. gondii chitinase, chitinase-like protein 1 (TgCLP1). We found that the chitinase-like domain containing TgCLP1 is partially present in the bradyzoite microneme and confirmed, albeit partially, its previous identification in the tachyzoite microneme. Furthermore, although parasites lacking TgCLP1 could convert from tachyzoites to bradyzoites and make an intact cyst wall, they failed to convert from bradyzoites to tachyzoites, indicating that TgCLP1 is necessary for bradyzoite reactivation. Taken together, our findings deepen our understanding of the molecular basis of recrudescence and could contribute to the development of novel strategies for the control of toxoplasmosis.
Collapse
Affiliation(s)
- Hironori Bando
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
- Department of Parasitology, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Yuho Murata
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Yongmei Han
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Tatsuki Sugi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
- Division of Collaboration and Education, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Yasuhiro Fukuda
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
| | - David J. Bzik
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Barbara A. Fox
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Kentaro Kato
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| |
Collapse
|
2
|
Kumar P, Tomita T, Gerken TA, Ballard CJ, Lee YS, Weiss LM, Samara NL. A Toxoplasma gondii O-glycosyltransferase that modulates bradyzoite cyst wall rigidity is distinct from host homologues. Nat Commun 2024; 15:3792. [PMID: 38710711 DOI: 10.1038/s41467-024-48253-w] [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: 09/27/2023] [Accepted: 04/23/2024] [Indexed: 05/08/2024] Open
Abstract
Infection with the apicomplexan protozoan Toxoplasma gondii can be life-threatening in immunocompromised hosts. Transmission frequently occurs through the oral ingestion of T. gondii bradyzoite cysts, which transition to tachyzoites, disseminate, and then form cysts containing bradyzoites in the central nervous system, resulting in latent infection. Encapsulation of bradyzoites by a cyst wall is critical for immune evasion, survival, and transmission. O-glycosylation of the protein CST1 by the mucin-type O-glycosyltransferase T. gondii (Txg) GalNAc-T3 influences cyst wall rigidity and stability. Here, we report X-ray crystal structures of TxgGalNAc-T3, revealing multiple features that are strictly conserved among its apicomplexan homologues. This includes a unique 2nd metal that is coupled to substrate binding and enzymatic activity in vitro and cyst wall O-glycosylation in T. gondii. The study illustrates the divergence of pathogenic protozoan GalNAc-Ts from their host homologues and lays the groundwork for studying apicomplexan GalNAc-Ts as therapeutic targets in disease.
Collapse
Affiliation(s)
- Pranav Kumar
- Structural Biochemistry Unit, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, 20892, USA
| | - Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, Bronx, 1300 Morris Park Avenue, New York, 10461, USA
| | - Thomas A Gerken
- Departments of Biochemistry and Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Collin J Ballard
- Departments of Biochemistry and Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Yong Sok Lee
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, 20892, USA
| | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, 1300 Morris Park Avenue, New York, 10461, USA
- Department of Medicine (Infectious Disease), Albert Einstein College of Medicine, Bronx 1300 Morris Park Avenue, New York, 10461, USA
| | - Nadine L Samara
- Structural Biochemistry Unit, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, 20892, USA.
| |
Collapse
|
3
|
Hasan T, Shimoda N, Nakamura S, Fox BA, Bzik DJ, Ushio-Watanabe N, Nishikawa Y. Protective efficacy of recombinant Toxoplasma gondii dense granule protein 15 against toxoplasmosis in C57BL/6 mice. Vaccine 2024; 42:2299-2309. [PMID: 38429153 DOI: 10.1016/j.vaccine.2024.02.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/03/2024]
Abstract
Toxoplasma gondii is a pervasive protozoan parasite that is responsible for significant zoonoses. A wide array of vaccines using different effector molecules of T. gondii have been studied worldwide to control toxoplasmosis. None of the existing vaccines are sufficiently effective to confer protective immunity. Among the different Toxoplasma-derived effector molecules, T. gondii dense granule protein 15 from the type II strain (GRA15 (II)) was recently characterized as an immunomodulatory molecule that induced host immunity via NF-κB. Therefore, we assessed the immunostimulatory and protective efficacy of recombinant GRA15 (II) (rGRA15) against T. gondii infection in a C57BL/6 mouse model. We observed that rGRA15 treatment increased the production of IL-12p40 from mouse peritoneal macrophages in vitro. Immunization of mice with rGRA15 induced the production of anti-TgGRA15-specific IgG, IgG1 and IgG2c antibodies. The rGRA15-sensitized spleen cells from mice inoculated with the same antigen strongly promoted spleen cell proliferation and IFN-γ production. Immunization with rGRA15 significantly enhanced the survival rate of mice and dramatically decreased parasite burden in mice challenged with the Pru (type II) strain. These results suggested that rGRA15 triggered humoral and cellular immune responses to control infection. However, all of the immunized mice died when challenged with the GRA15-deficient Pru strain or the RH (type I) strain. These results suggest that GRA15 (II)-dependent immunity plays a crucial role in protection against challenge infection with the type II strain of T. gondii. This study is the first report to show GRA15 (II) as a recombinant vaccine antigen against Toxoplasma infection.
Collapse
Affiliation(s)
- Tanjila Hasan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan; Department of Medicine and Surgery, Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Khulshi 4225, Chattogram, Bangladesh.
| | - Naomi Shimoda
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Shu Nakamura
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Barbara A Fox
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, 1 Medical Center Drive, Lebanon, NH 03756, USA.
| | - David J Bzik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, 1 Medical Center Drive, Lebanon, NH 03756, USA.
| | - Nanako Ushio-Watanabe
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| |
Collapse
|
4
|
Piro F, Masci S, Kannan G, Focaia R, Schultz TL, Thaprawat P, Carruthers VB, Di Cristina M. A Toxoplasma gondii putative amino acid transporter localizes to the plant-like vacuolar compartment and controls parasite extracellular survival and stage differentiation. mSphere 2024; 9:e0059723. [PMID: 38051073 PMCID: PMC10871165 DOI: 10.1128/msphere.00597-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 12/07/2023] Open
Abstract
Toxoplasma gondii is a protozoan parasite that infects a broad spectrum of hosts and can colonize many organs and cell types. The ability to reside within a wide range of different niches requires substantial adaptability to diverse microenvironments. Very little is known about how this parasite senses various milieus and adapts its metabolism to survive, replicate during the acute stage, and then differentiate to the chronic stage. T. gondii possesses a lysosome-like organelle known as the plant-like vacuolar compartment (PLVAC), which serves various functions, including digestion, ion storage and homeostasis, endocytosis, and autophagy. Lysosomes are critical for maintaining cellular health and function by degrading waste materials and recycling components. To supply the cell with the essential building blocks and energy sources required for the maintenance of its functions and structures, the digested solutes generated within the lysosome are transported into the cytosol by proteins embedded in the lysosomal membrane. Currently, a limited number of PLVAC transporters have been characterized, with TgCRT being the sole potential transporter of amino acids and small peptides identified thus far. To bridge this knowledge gap, we used lysosomal amino acid transporters from other organisms as queries to search the T. gondii proteome. This led to the identification of four potential amino acid transporters, which we have designated as TgAAT1-4. Assessing their expression and sub-cellular localization, we found that one of them, TgAAT1, localized to the PLVAC and is necessary for normal parasite extracellular survival and bradyzoite differentiation. Moreover, we present preliminary data showing the possible involvement of TgAAT1 in the PLVAC transport of arginine.IMPORTANCEToxoplasma gondii is a highly successful parasite infecting a broad range of warm-blooded organisms, including about one-third of all humans. Although Toxoplasma infections rarely result in symptomatic disease in individuals with a healthy immune system, the incredibly high number of persons infected, along with the risk of severe infection in immunocompromised patients and the potential link of chronic infection to mental disorders, makes this infection a significant public health concern. As a result, there is a pressing need for new treatment approaches that are both effective and well tolerated. The limitations in understanding how Toxoplasma gondii manages its metabolism to adapt to changing environments and triggers its transformation into bradyzoites have hindered the discovery of vulnerabilities in its metabolic pathways or nutrient acquisition mechanisms to identify new therapeutic targets. In this work, we have shown that the lysosome-like organelle plant-like vacuolar compartment (PLVAC), acting through the putative arginine transporter TgAAT1, plays a pivotal role in regulating the parasite's extracellular survival and differentiation into bradyzoites.
Collapse
Affiliation(s)
- Federica Piro
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Silvia Masci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Geetha Kannan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Riccardo Focaia
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Tracey L. Schultz
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Pariyamon Thaprawat
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Vern B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Manlio Di Cristina
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| |
Collapse
|
5
|
Lykins J, Moschitto MJ, Zhou Y, Filippova EV, Le HV, Tomita T, Fox BA, Bzik DJ, Su C, Rajagopala SV, Flores K, Spano F, Woods S, Roberts CW, Hua C, El Bissati K, Wheeler KM, Dovgin S, Muench SP, McPhillie M, Fishwick CW, Anderson WF, Lee PJ, Hickman M, Weiss LM, Dubey JP, Lorenzi HA, Silverman RB, McLeod RL. From TgO/GABA-AT, GABA, and T-263 Mutant to Conception of Toxoplasma. iScience 2024; 27:108477. [PMID: 38205261 PMCID: PMC10776954 DOI: 10.1016/j.isci.2023.108477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 04/28/2023] [Accepted: 11/13/2023] [Indexed: 01/12/2024] Open
Abstract
Toxoplasma gondii causes morbidity, mortality, and disseminates widely via cat sexual stages. Here, we find T. gondii ornithine aminotransferase (OAT) is conserved across phyla. We solve TgO/GABA-AT structures with bound inactivators at 1.55 Å and identify an inactivator selective for TgO/GABA-AT over human OAT and GABA-AT. However, abrogating TgO/GABA-AT genetically does not diminish replication, virulence, cyst-formation, or eliminate cat's oocyst shedding. Increased sporozoite/merozoite TgO/GABA-AT expression led to our study of a mutagenized clone with oocyst formation blocked, arresting after forming male and female gametes, with "Rosetta stone"-like mutations in genes expressed in merozoites. Mutations are similar to those in organisms from plants to mammals, causing defects in conception and zygote formation, affecting merozoite capacitation, pH/ionicity/sodium-GABA concentrations, drawing attention to cyclic AMP/PKA, and genes enhancing energy or substrate formation in TgO/GABA-AT-related-pathways. These candidates potentially influence merozoite's capacity to make gametes that fuse to become zygotes, thereby contaminating environments and causing disease.
Collapse
Affiliation(s)
- Joseph Lykins
- Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Matthew J. Moschitto
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, IL 60208-3113, USA
| | - Ying Zhou
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Ekaterina V. Filippova
- Center for Structural Genomics of Infectious Diseases and the Department of Biochemistry and Molecular Genetics, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Hoang V. Le
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, IL 60208-3113, USA
| | - Tadakimi Tomita
- Division of Parasitology, Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Barbara A. Fox
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
| | - David J. Bzik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
| | - Chunlei Su
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA
| | - Seesandra V. Rajagopala
- Department of Infectious Diseases, The J. Craig Venter Institute, 9704 Medical Center Drive, Rockville, MD 20850, USA
| | - Kristin Flores
- Center for Structural Genomics of Infectious Diseases and the Department of Biochemistry and Molecular Genetics, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Furio Spano
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Stuart Woods
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow Scotland, UK
| | - Craig W. Roberts
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow Scotland, UK
| | - Cong Hua
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Kamal El Bissati
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Kelsey M. Wheeler
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Sarah Dovgin
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Stephen P. Muench
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, The University of Leeds, Leeds, West York LS2 9JT, UK
| | - Martin McPhillie
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Colin W.G. Fishwick
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Wayne F. Anderson
- Center for Structural Genomics of Infectious Diseases and the Department of Biochemistry and Molecular Genetics, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Pharmacology, Northwestern University, Chicago, IL 60611, USA
| | - Patricia J. Lee
- Division of Experimental Therapeutics, Military Malaria Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Mark Hickman
- Division of Experimental Therapeutics, Military Malaria Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Louis M. Weiss
- Division of Parasitology, Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jitender P. Dubey
- Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA
| | - Hernan A. Lorenzi
- Department of Infectious Diseases, The J. Craig Venter Institute, 9704 Medical Center Drive, Rockville, MD 20850, USA
| | - Richard B. Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, and Center for Developmental Therapeutics, Northwestern University, Evanston, IL 60208-3113, USA
- Department of Pharmacology, Northwestern University, Chicago, IL 60611, USA
| | - Rima L. McLeod
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL 60637, USA
- Department of Pediatrics (Infectious Diseases), Institute of Genomics, Genetics, and Systems Biology, Global Health Center, Toxoplasmosis Center, CHeSS, The College, University of Chicago, Chicago, IL 60637, USA
| |
Collapse
|
6
|
Pan M, Ge CC, Niu SZ, Duan YY, Fan YM, Jin QW, Chen X, Tao JP, Huang SY. Functional analyses of Toxoplasma gondii dihydroorotase reveal a promising anti-parasitic target. FASEB J 2024; 38:e23397. [PMID: 38149908 DOI: 10.1096/fj.202301493r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/20/2023] [Accepted: 12/15/2023] [Indexed: 12/28/2023]
Abstract
Toxoplasma gondii relies heavily on the de novo pyrimidine biosynthesis pathway for fueling the high uridine-5'-monophosphate (UMP) demand during parasite growth. The third step of de novo pyrimidine biosynthesis is catalyzed by dihydroorotase (DHO), a metalloenzyme that catalyzes the reversible condensation of carbamoyl aspartate to dihydroorotate. Here, functional analyses of TgDHO reveal that tachyzoites lacking DHO are impaired in overall growth due to decreased levels of UMP, and the noticeably growth restriction could be partially rescued after supplementation with uracil or high concentrations of L-dihydroorotate in vitro. When pyrimidine salvage pathway is disrupted, both DHOH35A and DHOD284E mutant strains proliferated much slower than DHO-expressing parasites, suggesting an essential role of both TgDHO His35 and Asp284 residues in parasite growth. Additionally, DHO deletion causes the limitation of bradyzoite growth under the condition of uracil supplementation or uracil deprivation. During the infection in mice, the DHO-deficient parasites are avirulent, despite the generation of smaller tissue cysts. The results reveal that TgDHO contributes to parasite growth both in vitro and in vivo. The significantly differences between TgDHO and mammalian DHO reflect that DHO can be exploited to produce specific inhibitors targeting apicomplexan parasites. Moreover, potential DHO inhibitors exert beneficial effects on enzymatic activity of TgDHO and T. gondii growth in vitro. In conclusion, these data highlight the important role of TgDHO in parasite growth and reveal that it is a promising anti-parasitic target for future control of toxoplasmosis.
Collapse
Affiliation(s)
- Ming Pan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, PR China
| | - Ceng-Ceng Ge
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Shui-Zhu Niu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Yin-Yan Duan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Yi-Min Fan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Qi-Wang Jin
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, PR China
| | - Xiang Chen
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Jian-Ping Tao
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
| | - Si-Yang Huang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Jiangsu Key Laboratory of Zoonosis, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province, PR China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, PR China
| |
Collapse
|
7
|
Yamada K, Tazaki A, Ushio-Watanabe N, Usui Y, Takeda A, Matsunaga M, Suzumura A, Shimizu H, Zheng H, Ariefta NR, Yamamoto M, Hara H, Goto H, Sonoda KH, Nishiguchi KM, Kato M, Nishikawa Y, Toyokuni S, Kaneko H. Retinal ferroptosis as a critical mechanism for the induction of retinochoroiditis during ocular toxoplasmosis. Redox Biol 2023; 67:102890. [PMID: 37738924 PMCID: PMC10519826 DOI: 10.1016/j.redox.2023.102890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 09/13/2023] [Indexed: 09/24/2023] Open
Abstract
Toxoplasmosis is a major infectious disease, affecting approximately one-third of the world's population; its main clinical manifestation, ocular toxoplasmosis (OT), is a severe sight-threatening disease. Nevertheless, the diagnosis of OT is based on clinical findings, which needs improvement, even with biochemical tests, such as polymerase chain reaction and antibody detections. Furthermore, the efficacy of OT-targeted treatment is limited; thus, additional measures for diagnosis and treatments are needed. Here, we for the first time report a significantly reduced iron concentration in the vitreous humor (VH) of human patients infected with OT. To obtain further insights into molecular mechanisms, we established a mouse model of T. gondii infection, in which intravitreally injected tracer 57Fe, was accumulated in the neurosensory retina. T. gondii-infected eyes showed increased lipid peroxidation, reduction of glutathione peroxidase-4 expression and mitochondrial deformity in the photoreceptor as cristae loss. These findings strongly suggest the involvement of ferroptotic process in the photoreceptor of OT. In addition, deferiprone, an FDA-approved iron chelator, reduced the iron uptake but also ameliorated toxoplasma-induced retinochoroiditis by reducing retinal inflammation. In conclusion, the iron levels in the VH could serve as diagnostic markers and iron chelators as potential treatments for OT.
Collapse
Affiliation(s)
- Kazuhisa Yamada
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Akira Tazaki
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Nanako Ushio-Watanabe
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, 080-8555, Japan.
| | - Yoshihiko Usui
- Department of Ophthalmology, Tokyo Medical University, Tokyo, 160-8402, Japan.
| | - Atsunobu Takeda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Masaaki Matsunaga
- Department of Public Health, Fujita Health University School of Medicine, Toyoake, 470-1192, Japan.
| | - Ayana Suzumura
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Hideyuki Shimizu
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Hao Zheng
- Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Nanang R Ariefta
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, 080-8555, Japan.
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
| | - Hideaki Hara
- Department of Biofunctional Evaluation, Molecular Pharmacology, Gifu Pharmaceutical University, Gifu, 501-1196, Japan.
| | - Hiroshi Goto
- Department of Ophthalmology, Tokyo Medical University, Tokyo, 160-8402, Japan.
| | - Koh-Hei Sonoda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Koji M Nishiguchi
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Masashi Kato
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, 080-8555, Japan.
| | - Shinya Toyokuni
- Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan; Center for Low-Temperature Plasma Sciences, Nagoya University, Furo-Cho, Chikusa-ku, Nagoya, 464-8603, Japan.
| | - Hiroki Kaneko
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| |
Collapse
|
8
|
Vizcarra EA, Goerner AL, Ulu A, Hong DD, Bergersen KV, Talavera MA, Le Roch K, Wilson EH, White MW. An ex vivo model of Toxoplasma recrudescence reveals developmental plasticity of the bradyzoite stage. mBio 2023; 14:e0183623. [PMID: 37675999 PMCID: PMC10653814 DOI: 10.1128/mbio.01836-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 09/08/2023] Open
Abstract
IMPORTANCE The classical depiction of the Toxoplasma lifecycle is bradyzoite excystation conversion to tachyzoites, cell lysis, and immune control, followed by the reestablishment of bradyzoites and cysts. In contrast, we show that tachyzoite growth slows independent of the host immune response at a predictable time point following excystation. Furthermore, we demonstrate a host cell-dependent pathway of continuous amplification of the cyst-forming bradyzoite population. The developmental plasticity of the excysted bradyzoites further underlines the critical role the cyst plays in the flexibility of the lifecycle of this ubiquitous parasite. This revised model of Toxoplasma recrudescence uncovers previously unknown complexity in the clinically important bradyzoite stage of the parasite, which opens the door to further study these novel developmental features of the Toxoplasma intermediate life cycle.
Collapse
Affiliation(s)
- Edward A. Vizcarra
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Amber L. Goerner
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Arzu Ulu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - David D. Hong
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Kristina V. Bergersen
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Michael A. Talavera
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Karine Le Roch
- Department of Molecular, Cell, and Systems Biology, University of California, Riverside, California, USA
| | - Emma H. Wilson
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Michael W. White
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| |
Collapse
|
9
|
Thind AC, Mota CM, Gonçalves APN, Sha J, Wohlschlegel JA, Mineo TWP, Bradley PJ. The Toxoplasma gondii effector GRA83 modulates the host's innate immune response to regulate parasite infection. mSphere 2023; 8:e0026323. [PMID: 37768053 PMCID: PMC10597413 DOI: 10.1128/msphere.00263-23] [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: 05/12/2023] [Accepted: 08/07/2023] [Indexed: 09/29/2023] Open
Abstract
Toxoplasma gondii's propensity to infect its host and cause disease is highly dependent on its ability to modulate host cell functions. One of the strategies the parasite uses to accomplish this is via the export of effector proteins from the secretory dense granules. Dense granule (GRA) proteins are known to play roles in nutrient acquisition, host cell cycle manipulation, and immune regulation. Here, we characterize a novel dense granule protein named GRA83, which localizes to the parasitophorous vacuole (PV) in tachyzoites and bradyzoites. Disruption of GRA83 results in increased virulence, weight loss, and parasitemia during the acute infection, as well as a marked increase in the cyst burden during the chronic infection. This increased parasitemia was associated with an accumulation of inflammatory infiltrates in tissues in both acute and chronic infections. Murine macrophages infected with ∆gra83 tachyzoites produced less interleukin-12 (IL-12) in vitro, which was confirmed with reduced IL-12 and interferon-gamma in vivo. This dysregulation of cytokines correlates with reduced nuclear translocation of the p65 subunit of the nuclear factor-κB (NF-κB) complex. While GRA15 similarly regulates NF-κB, infection with ∆gra83/∆gra15 parasites did not further reduce p65 translocation to the host cell nucleus, suggesting these GRAs function in converging pathways. We also used proximity labeling experiments to reveal candidate GRA83 interacting T. gondii-derived partners. Taken together, this work reveals a novel effector that stimulates the innate immune response, enabling the host to limit the parasite burden. Importance Toxoplasma gondii poses a significant public health concern as it is recognized as one of the leading foodborne pathogens in the United States. Infection with the parasite can cause congenital defects in neonates, life-threatening complications in immunosuppressed patients, and ocular disease. Specialized secretory organelles, including the dense granules, play an important role in the parasite's ability to efficiently invade and regulate components of the host's infection response machinery to limit parasite clearance and establish an acute infection. Toxoplasma's ability to avoid early clearance, while also successfully infecting the host long enough to establish a persistent chronic infection, is crucial in allowing for its transmission to a new host. While multiple GRAs directly modulate host signaling pathways, they do so in various ways highlighting the parasite's diverse arsenal of effectors that govern infection. Understanding how parasite-derived effectors harness host functions to evade defenses yet ensure a robust infection is important for understanding the complexity of the pathogen's tightly regulated infection. In this study, we characterize a novel secreted protein named GRA83 that stimulates the host cell's response to limit infection.
Collapse
Affiliation(s)
- Amara C. Thind
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Caroline M. Mota
- Laboratory of Immunoparasitology “Dr. Mário Endsfeldz Camargo,” Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Ana Paula N. Gonçalves
- Laboratory of Immunoparasitology “Dr. Mário Endsfeldz Camargo,” Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Jihui Sha
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - James A. Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Tiago W. P. Mineo
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA
- Laboratory of Immunoparasitology “Dr. Mário Endsfeldz Camargo,” Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Peter J. Bradley
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| |
Collapse
|
10
|
Mani R, Abdelaziz MH, Ochiai E, Sa Q, Fox BA, Bzik DJ, Suzuki Y. Dense granule protein 3 of Toxoplasma gondii plays a crucial role in the capability of the tissue cysts of the parasite to persist in the presence of anti-cyst CD8 + T cells during the chronic stage of infection. Front Immunol 2023; 14:1272221. [PMID: 37868957 PMCID: PMC10585165 DOI: 10.3389/fimmu.2023.1272221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
Toxoplasma gondii establishes chronic infection by forming tissue cysts, and this chronic infection is one of the most common parasitic infections in humans. Our recent studies revealed that whereas CD8+ T cells of genetically resistant BALB/c mice have the capability to remove the tissue cysts of the parasite through their perforin-mediated activities, small portions of the cysts are capable of persisting in the presence of the anti-cyst CD8+ T cells. It is currently unknown how those small portions of the cysts resist or escape the T-cell immunity and persist in the hosts. In the present study, we discovered that the cysts, which persisted in the presence of the perforin-mediated CD8+ T-cell immunity, have significantly greater mRNA levels for four dense granule proteins, GRA1, GRA2, GRA3, and GRA7, and one rhoptry protein, ROP35, than the total population of the cysts present in the absence of the T cells. In addition, increased levels of mRNA for GRA1, GRA3, and ROP35 in the cysts significantly correlated with their successful persistence through the condition in which greater degrees of reduction of the cyst burden occurred through anti-cyst CD8+ T cells. In addition, GRA3-deficient T. gondii displayed significantly enhanced elimination of the cysts by anti-cyst CD8+ T cells when compared to the wild-type parasite. These results indicate that GRA3 is a key molecule that mediates in the capability of T. gondii cysts to persist by resisting or evading the anti-cyst activity of CD8+ T cells during the later stage of infection.
Collapse
Affiliation(s)
- Rajesh Mani
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Mohamed H. Abdelaziz
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Eri Ochiai
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Qila Sa
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Barbara A. Fox
- Deaprtment of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - David J. Bzik
- Deaprtment of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Yasuhiro Suzuki
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, United States
| |
Collapse
|
11
|
Sokol-Borrelli SL, Reilly SM, Holmes MJ, Orchanian SB, Massmann MD, Sharp KG, Cabo LF, Alrubaye HS, Martorelli Di Genova B, Lodoen MB, Sullivan WJ, Boyle JP. A transcriptional network required for bradyzoite development in Toxoplasma gondii is dispensable for recrudescent disease. Nat Commun 2023; 14:6078. [PMID: 37770433 PMCID: PMC10539341 DOI: 10.1038/s41467-023-40948-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 08/16/2023] [Indexed: 09/30/2023] Open
Abstract
Identification of regulators of Toxoplasma gondii bradyzoite development and cyst formation is the most direct way to address the importance of parasite development in long-term persistence and reactivation of this parasite. Here we show that a T. gondii gene (named Regulator of Cystogenesis 1; ROCY1) is sufficient for T. gondii bradyzoite formation in vitro and in vivo. ROCY1 encodes an RNA binding protein that has a preference for 3' regulatory regions of hundreds of T. gondii transcripts, and its RNA-binding domains are required to mediate bradyzoite development. Female mice infected with ΔROCY1 parasites have reduced (>90%) cyst burden. While viable parasites can be cultivated from brain tissue for up to 6 months post-infection, chronic brain-resident ΔROCY1 parasites have reduced oral infectivity compared to wild type. Despite clear defects in bradyzoite formation and oral infectivity, ΔROCY1 parasites were able to reactivate with similar timing and magnitude as wild type parasites for up to 5 months post-infection. Therefore while ROCY1 is a critical regulator of the bradyzoite developmental pathway, it is not required for parasite reactivation, raising new questions about the persisting life stage responsible for causing recrudescent disease.
Collapse
Affiliation(s)
- Sarah L Sokol-Borrelli
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sarah M Reilly
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael J Holmes
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 462022, USA
| | - Stephanie B Orchanian
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, USA
| | - Mackenzie D Massmann
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Katherine G Sharp
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leah F Cabo
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hisham S Alrubaye
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bruno Martorelli Di Genova
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Melissa B Lodoen
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, USA
| | - William J Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 462022, USA
| | - Jon P Boyle
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
12
|
Tarannum A, Rodríguez-Almonacid CC, Salazar-Bravo J, Karamysheva ZN. Molecular Mechanisms of Persistence in Protozoan Parasites. Microorganisms 2023; 11:2248. [PMID: 37764092 PMCID: PMC10534552 DOI: 10.3390/microorganisms11092248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Protozoan parasites are known for their remarkable capacity to persist within the bodies of vertebrate hosts, which frequently results in prolonged infections and the recurrence of diseases. Understanding the molecular mechanisms that underlie the event of persistence is of paramount significance to develop innovative therapeutic approaches, given that these pathways still need to be thoroughly elucidated. The present article provides a comprehensive overview of the latest developments in the investigation of protozoan persistence in vertebrate hosts. The focus is primarily on the function of persisters, their formation within the host, and the specific molecular interactions between host and parasite while they persist. Additionally, we examine the metabolomic, transcriptional, and translational changes that protozoan parasites undergo during persistence within vertebrate hosts, focusing on major parasites such as Plasmodium spp., Trypanosoma spp., Leishmania spp., and Toxoplasma spp. Key findings of our study suggest that protozoan parasites deploy several molecular and physiological strategies to evade the host immune surveillance and sustain their persistence. Furthermore, some parasites undergo stage differentiation, enabling them to acclimate to varying host environments and immune challenges. More often, stressors such as drug exposure were demonstrated to impact the formation of protozoan persisters significantly. Understanding the molecular mechanisms regulating the persistence of protozoan parasites in vertebrate hosts can reinvigorate our current insights into host-parasite interactions and facilitate the development of more efficacious disease therapeutics.
Collapse
Affiliation(s)
| | | | | | - Zemfira N. Karamysheva
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA; (A.T.); (C.C.R.-A.); (J.S.-B.)
| |
Collapse
|
13
|
Piro F, Masci S, Kannan G, Focaia R, Schultz TL, Carruthers VB, Di Cristina M. A Toxoplasma gondii putative arginine transporter localizes to the plant-like vacuolar compartment and controls parasite extracellular survival and stage differentiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.31.555807. [PMID: 37693549 PMCID: PMC10491228 DOI: 10.1101/2023.08.31.555807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Toxoplasma gondii is a protozoan parasite that infects a broad spectrum of hosts and can colonize many organs and cell types. The ability to reside within a wide range of different niches requires substantial adaptability to diverse microenvironments. Very little is known about how this parasite senses various milieus and adapts its metabolism to survive, replicate during the acute stage, and then differentiate to the chronic stage. Most eukaryotes, from yeast to mammals, rely on a nutrient sensing machinery involving the TORC complex as master regulator of cell growth and cell cycle progression. The lysosome functions as a signaling hub where TORC complex assembles and is activated by transceptors, which both sense and transport amino acids, including the arginine transceptor SLC38A9. While most of the TORC components are lost in T. gondii , indicating the evolution of a distinct nutrient sensing mechanism, the parasite's lysosomal plant-like vacuolar compartment (PLVAC) may still serve as a sensory platform for controlling parasite growth and differentiation. Using SLC38A9 to query the T. gondii proteome, we identified four putative amino acid transporters, termed TgAAT1-4, that structurally resemble the SLC38A9 arginine transceptor. Assessing their expression and sub-cellular localization, we found that one of them, TgAAT1, localized to the PLVAC and is necessary for normal parasite extracellular survival and bradyzoite differentiation. Moreover, we show that TgAAT1 is involved in the PLVAC efflux of arginine, an amino acid playing a key role in T. gondii differentiation, further supporting the hypothesis that TgAAT1 might play a role in nutrient sensing. IMPORTANCE T. gondii is a highly successful parasite infecting a broad range of warm-blood organisms including about one third of all humans. Although Toxoplasma infections rarely result in symptomatic disease in individuals with a healthy immune system, the incredibly high number of persons infected along with the risk of severe infection in immunocompromised patients and the potential link of chronic infection to mental disorders make this infection a significant public health concern. As a result, there is a pressing need for new treatment approaches that are both effective and well-tolerated. The limitations in understanding how Toxoplasma gondii manages its metabolism to adapt to changing environments and triggers its transformation into bradyzoites have hindered the discovery of vulnerabilities in its metabolic pathways or nutrient acquisition mechanisms to identify new therapeutic targets. In this work, we have shown that the lysosome-like organelle PLVAC, acting through the putative arginine transporter TgAAT1, plays a pivotal role in regulating the parasite's extracellular survival and differentiation into bradyzoites.
Collapse
|
14
|
Sanchez SG, Bassot E, Cerutti A, Mai Nguyen H, Aïda A, Blanchard N, Besteiro S. The apicoplast is important for the viability and persistence of Toxoplasma gondii bradyzoites. Proc Natl Acad Sci U S A 2023; 120:e2309043120. [PMID: 37590416 PMCID: PMC10450435 DOI: 10.1073/pnas.2309043120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 06/27/2023] [Indexed: 08/19/2023] Open
Abstract
Toxoplasma gondii is responsible for toxoplasmosis, a disease that can be serious when contracted during pregnancy, but can also be a threat for immunocompromised individuals. Acute infection is associated with the tachyzoite form that spreads rapidly within the host. However, under stress conditions, some parasites can differentiate into cyst-forming bradyzoites, residing mainly in the central nervous system, retina and muscle. Because this latent form of the parasite is resistant to all currently available treatments, and is central to persistence and transmission of the parasite, specific therapeutic strategies targeting this developmental stage need to be found. T. gondii contains a plastid of endosymbiotic origin called the apicoplast, which is an appealing drug target because it is essential for tachyzoite viability and contains several key metabolic pathways that are largely absent from the mammalian host. Its function in bradyzoites, however, is unknown. Our objective was thus to study the contribution of the apicoplast to the viability and persistence of bradyzoites during chronic toxoplasmosis. We have used complementary strategies based on stage-specific promoters to generate conditional bradyzoite mutants of essential apicoplast genes. Our results show that specifically targeting the apicoplast in both in vitro or in vivo-differentiated bradyzoites leads to a loss of long-term bradyzoite viability, highlighting the importance of this organelle for this developmental stage. This validates the apicoplast as a potential area to look for therapeutic targets in bradyzoites, with the aim to interfere with this currently incurable parasite stage.
Collapse
Affiliation(s)
- Syrian G. Sanchez
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| | - Emilie Bassot
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, University of Toulouse, CNRS, Inserm, Université Paul Sabatier, 31059Toulouse, France
| | - Aude Cerutti
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| | - Hoa Mai Nguyen
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| | - Amel Aïda
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, University of Toulouse, CNRS, Inserm, Université Paul Sabatier, 31059Toulouse, France
| | - Nicolas Blanchard
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, University of Toulouse, CNRS, Inserm, Université Paul Sabatier, 31059Toulouse, France
| | - Sébastien Besteiro
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| |
Collapse
|
15
|
Lockyer EJ, Torelli F, Butterworth S, Song OR, Howell S, Weston A, East P, Treeck M. A heterotrimeric complex of Toxoplasma proteins promotes parasite survival in interferon gamma-stimulated human cells. PLoS Biol 2023; 21:e3002202. [PMID: 37459303 PMCID: PMC10373997 DOI: 10.1371/journal.pbio.3002202] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/27/2023] [Accepted: 06/16/2023] [Indexed: 07/28/2023] Open
Abstract
Toxoplasma gondii secretes protein effectors to subvert the human immune system sufficiently to establish a chronic infection. Relative to murine infections, little is known about which parasite effectors disarm human immune responses. Here, we used targeted CRISPR screening to identify secreted protein effectors required for parasite survival in IFNγ-activated human cells. Independent screens were carried out using 2 Toxoplasma strains that differ in virulence in mice, leading to the identification of effectors required for survival in IFNγ-activated human cells. We identify the secreted protein GRA57 and 2 other proteins, GRA70 and GRA71, that together form a complex which enhances the ability of parasites to persist in IFNγ-activated human foreskin fibroblasts (HFFs). Components of the protein machinery required for export of Toxoplasma proteins into the host cell were also found to be important for parasite resistance to IFNγ in human cells, but these export components function independently of the identified protein complex. Host-mediated ubiquitination of the parasite vacuole has previously been associated with increased parasite clearance from human cells, but we find that vacuoles from GRA57, GRA70, and GRA71 knockout strains are surprisingly less ubiquitinated by the host cell. We hypothesise that this is likely a secondary consequence of deletion of the complex, unlinked to the IFNγ resistance mediated by these effectors.
Collapse
Affiliation(s)
- Eloise J Lockyer
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Francesca Torelli
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Simon Butterworth
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ok-Ryul Song
- High-Throughput Screening Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Steven Howell
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Anne Weston
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Philip East
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Cell Biology of Host-Pathogen Interaction Laboratory, Instituto Gulbenkian Ciência, Oeiras, Portugal
| |
Collapse
|
16
|
Wilde ML, Ruparel U, Klemm T, Lee VV, Calleja DJ, Komander D, Tonkin CJ. Characterisation of the OTU domain deubiquitinase complement of Toxoplasma gondii. Life Sci Alliance 2023; 6:e202201710. [PMID: 36958824 PMCID: PMC10038098 DOI: 10.26508/lsa.202201710] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 03/15/2023] [Accepted: 03/15/2023] [Indexed: 03/25/2023] Open
Abstract
The phylum Apicomplexa contains several parasitic species of medical and agricultural importance. The ubiquitination machinery remains, for the most part, uncharacterised in apicomplexan parasites, despite the important roles that it plays in eukaryotic biology. Bioinformatic analysis of the ubiquitination machinery in apicomplexan parasites revealed an expanded ovarian tumour domain-containing (OTU) deubiquitinase (DUB) family in Toxoplasma, potentially reflecting functional importance in apicomplexan parasites. This study presents comprehensive characterisation of Toxoplasma OTU DUBs. AlphaFold-guided structural analysis not only confirmed functional orthologues found across eukaryotes, but also identified apicomplexan-specific enzymes, subsequently enabling discovery of a cryptic OTU DUB in Plasmodium species. Comprehensive biochemical characterisation of 11 Toxoplasma OTU DUBs revealed activity against ubiquitin- and NEDD8-based substrates and revealed ubiquitin linkage preferences for Lys6-, Lys11-, Lys48-, and Lys63-linked chain types. We show that accessory domains in Toxoplasma OTU DUBs impose linkage preferences, and in case of apicomplexan-specific TgOTU9, we discover a cryptic ubiquitin-binding domain that is essential for TgOTU9 activity. Using the auxin-inducible degron (AID) to generate knockdown parasite lines, TgOTUD6B was found to be important for Toxoplasma growth.
Collapse
Affiliation(s)
- Mary-Louise Wilde
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Ushma Ruparel
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Theresa Klemm
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - V Vern Lee
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
- Bio21 Molecular Science and Biotechnology Institute, Parkville, Australia; and Department of Biochemistry and Pharmacology, The University of Melbourne, Melbourne, Australia
| | - Dale J Calleja
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - David Komander
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Christopher J Tonkin
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; and Department of Medical Biology, University of Melbourne, Melbourne, Australia
| |
Collapse
|
17
|
Thind AC, Mota CM, Gonçalves APN, Sha J, Wohlschlegel JA, Mineo TWP, Bradley PJ. The Toxoplasma gondii effector GRA83 modulates the host's innate immune response to regulate parasite infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543158. [PMID: 37398161 PMCID: PMC10312501 DOI: 10.1101/2023.05.31.543158] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Toxoplasma gondii 's propensity to infect its host and cause disease is highly dependent on its ability to modulate host cell functions. One of the strategies the parasite uses to accomplish this is via the export of effector proteins from the secretory dense granules. Dense granule (GRA) proteins are known to play roles in nutrient acquisition, host cell cycle manipulation, and immune regulation. Here, we characterize a novel dense granule protein named GRA83, which localizes to the parasitophorous vacuole in tachyzoites and bradyzoites. Disruption of GRA83 results in increased virulence, weight loss, and parasitemia during the acute infection, as well as a marked increase in the cyst burden during the chronic infection. This increased parasitemia was associated with an accumulation of inflammatory infiltrates in tissues in both the acute and chronic infection. Murine macrophages infected with Δ gra83 tachyzoites produced less interleukin-12 (IL-12) in vitro , which was confirmed with reduced IL-12 and interferon gamma (IFN-γ) in vivo . This dysregulation of cytokines correlates with reduced nuclear translocation of the p65 subunit of the NF-κB complex. While GRA15 similarly regulates NF-κB, infection with Δ gra83/ Δ gra15 parasites did not further reduce p65 translocation to the host cell nucleus, suggesting these GRAs function in converging pathways. We also used proximity labelling experiments to reveal candidate GRA83 interacting T. gondii derived partners. Taken together, this work reveals a novel effector that stimulates the innate immune response, enabling the host to limit parasite burden. Importance Toxoplasma gondii poses a significant public health concern as it is recognized as one of the leading foodborne pathogens in the United States. Infection with the parasite can cause congenital defects in neonates, life-threatening complications in immunosuppressed patients, and ocular disease. Specialized secretory organelles, including the dense granules, play an important role in the parasite's ability to efficiently invade and regulate components of the host's infection response machinery to limit parasite clearance and establish an acute infection. Toxoplasma' s ability to avoid early clearance, while also successfully infecting the host long enough to establish a persistent chronic infection, is crucial in allowing for its transmission to a new host. While multiple GRAs directly modulate host signaling pathways, they do so in various ways highlighting the parasite's diverse arsenal of effectors that govern infection. Understanding how parasite-derived effectors harness host functions to evade defenses yet ensure a robust infection are important for understanding the complexity of the pathogen's tightly regulated infection. In this study, we characterize a novel secreted protein named GRA83 that stimulates the host cell's response to limit infection.
Collapse
|
18
|
Tedford E, Badya NB, Laing C, Asaoka N, Kaneko S, Filippi BM, McConkey GA. Infection-induced extracellular vesicles evoke neuronal transcriptional and epigenetic changes. Sci Rep 2023; 13:6913. [PMID: 37106020 PMCID: PMC10140046 DOI: 10.1038/s41598-023-34074-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 04/24/2023] [Indexed: 04/29/2023] Open
Abstract
Infection with the protozoan Toxoplasma gondii induces changes in neurotransmission, neuroinflammation, and behavior, yet it remains elusive how these changes come about. In this study we investigated how norepinephrine levels are altered by infection. TINEV (Toxoplasma-induced neuronal extracellular vesicles) isolated from infected noradrenergic cells down-regulated dopamine ß-hydroxylase (DBH) gene expression in human and rodent cells. Here we report that intracerebral injection of TINEVs into the brain is sufficient to induce DBH down-regulation and distrupt catecholaminergic signalling. Further, TINEV treatment induced hypermethylation upstream of the DBH gene. An antisense lncRNA to DBH was found in purified TINEV preparations. Paracrine signalling to induce transcriptional gene silencing and DNA methylation may be a common mode to regulate neurologic function.
Collapse
Affiliation(s)
- Ellen Tedford
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Norhidayah Binti Badya
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Conor Laing
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Nozomi Asaoka
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-Cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shuji Kaneko
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-Cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Beatrice Maria Filippi
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Glenn Alan McConkey
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
| |
Collapse
|
19
|
Invasion of Toxoplasma gondii bradyzoites: Molecular dissection of the moving junction proteins and effective vaccination targets. Proc Natl Acad Sci U S A 2023; 120:e2219533120. [PMID: 36693095 PMCID: PMC9945962 DOI: 10.1073/pnas.2219533120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Toxoplasmosis is a neglected parasitic disease necessitating public health control. Host cell invasion by Toxoplasma occurs at different stages of the parasite's life cycle and is crucial for survival and establishment of infection. In tachyzoites, which are responsible for acute toxoplasmosis, invasion involves the formation of a molecular bridge between the parasite and host cell membranes, referred to as the moving junction (MJ). The MJ is shaped by the assembly of AMA1 and RON2, as part of a complex involving additional RONs. While this essential process is well characterized in tachyzoites, the invasion process remains unexplored in bradyzoites, which form cysts and are responsible for chronic toxoplasmosis and contribute to the dissemination of the parasite between hosts. Here, we show that bradyzoites invade host cells in an MJ-dependent fashion but differ in protein composition from the tachyzoite MJ, relying instead on the paralogs AMA2 and AMA4. Functional characterization of AMA4 reveals its key role for cysts burden during the onset of chronic infection, while being dispensable for the acute phase. Immunizations with AMA1 and AMA4, alone or in complex with their rhoptry neck respective partners RON2 and RON2L1, showed that the AMA1-RON2 pair induces strong protection against acute and chronic infection, while the AMA4-RON2L1 complex targets more selectively the chronic form. Our study provides important insights into the molecular players of bradyzoite invasion and indicates that invasion of cyst-forming bradyzoites contributes to cyst burden. Furthermore, we validate AMA-RON complexes as potential vaccine candidates to protect against toxoplasmosis.
Collapse
|
20
|
Smith D, Lunghi M, Olafsson EB, Hatton O, Di Cristina M, Carruthers VB. A High-Throughput Amenable Dual Luciferase System for Measuring Toxoplasma gondii Bradyzoite Viability after Drug Treatment. Anal Chem 2023; 95:668-676. [PMID: 36548400 PMCID: PMC9850410 DOI: 10.1021/acs.analchem.2c02174] [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: 05/19/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
It is estimated that more than 2 billion people are chronically infected with the intracellular protozoan parasite Toxoplasma gondii (T. gondii). Despite this, there is currently no vaccine to prevent infection in humans, and there is no recognized curative treatment to clear tissue cysts. A major hurdle for identifying effective drug candidates against chronic-stage cysts has been the low throughput of existing in vitro assays for testing the survival of bradyzoites. We have developed a luciferase-based platform for specifically determining bradyzoite survival within in vitro cysts in a 96-well plate format. We engineered a cystogenic type II T. gondii PruΔku80Δhxgpr strain for stage-specific expression of firefly luciferase in the cytosol of bradyzoites and nanoluciferase for secretion into the lumen of the cyst (DuaLuc strain). Using this DuaLuc strain, we found that the ratio of firefly luciferase to nanoluciferase decreased upon treatment with atovaquone or LHVS, two compounds that are known to compromise bradyzoite viability. The 96-well format allowed us to test several additional compounds and generate dose-response curves for calculation of EC50 values indicating relative effectiveness of a compound. Accordingly, this DuaLuc system should be suitable for screening libraries of diverse compounds and defining the potency of hits or other compounds with a putative antibradyzoite activity.
Collapse
Affiliation(s)
- David Smith
- University of Michigan Medical School, Ann Arbor 734 763 2081, United States
- Moredun Research Institute, Penicuik EH26 0PZ, U.K.
| | - Matteo Lunghi
- Università degli Studi di Perugia, Perugia 06123, Italy
| | - Einar B. Olafsson
- University of Michigan Medical School, Ann Arbor 734 763 2081, United States
- University of Uppsala, Uppsala 751 05, Sweden
| | - Olivia Hatton
- University of Michigan Medical School, Ann Arbor 734 763 2081, United States
| | | | - Vern B. Carruthers
- University of Michigan Medical School, Ann Arbor 734 763 2081, United States
| |
Collapse
|
21
|
A. PORTES JULIANA, C. VOMMARO ROSSIANE, AYRES CALDAS LUCIO, S. MARTINS-DUARTE ERICA. Intracellular life of protozoan Toxoplasma gondii: Parasitophorous vacuole establishment and survival strategies. BIOCELL 2023. [DOI: 10.32604/biocell.2023.026629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
|
22
|
Butterworth S, Torelli F, Lockyer EJ, Wagener J, Song OR, Broncel M, Russell MRG, Moreira-Souza ACA, Young JC, Treeck M. Toxoplasma gondii virulence factor ROP1 reduces parasite susceptibility to murine and human innate immune restriction. PLoS Pathog 2022; 18:e1011021. [PMID: 36476844 PMCID: PMC9762571 DOI: 10.1371/journal.ppat.1011021] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/19/2022] [Accepted: 11/24/2022] [Indexed: 12/12/2022] Open
Abstract
Toxoplasma gondii is an intracellular parasite that can infect many host species and is a cause of significant human morbidity worldwide. T. gondii secretes a diverse array of effector proteins into the host cell which are critical for infection. The vast majority of these secreted proteins have no predicted functional domains and remain uncharacterised. Here, we carried out a pooled CRISPR knockout screen in the T. gondii Prugniaud strain in vivo to identify secreted proteins that contribute to parasite immune evasion in the host. We demonstrate that ROP1, the first-identified rhoptry protein of T. gondii, is essential for virulence and has a previously unrecognised role in parasite resistance to interferon gamma-mediated innate immune restriction. This function is conserved in the highly virulent RH strain of T. gondii and contributes to parasite growth in both murine and human macrophages. While ROP1 affects the morphology of rhoptries, from where the protein is secreted, it does not affect rhoptry secretion. Finally, we show that ROP1 co-immunoprecipitates with the host cell protein C1QBP, an emerging regulator of innate immune signaling. In summary, we identify putative in vivo virulence factors in the T. gondii Prugniaud strain and show that ROP1 is an important and previously overlooked effector protein that counteracts both murine and human innate immunity.
Collapse
Affiliation(s)
- Simon Butterworth
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Francesca Torelli
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Eloise J. Lockyer
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Jeanette Wagener
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ok-Ryul Song
- High-Throughput Screening Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Malgorzata Broncel
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Matt R. G. Russell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | | | - Joanna C. Young
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Moritz Treeck
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| |
Collapse
|
23
|
Mayoral J, Guevara RB, Rivera-Cuevas Y, Tu V, Tomita T, Romano JD, Gunther-Cummins L, Sidoli S, Coppens I, Carruthers VB, Weiss LM. Dense Granule Protein GRA64 Interacts with Host Cell ESCRT Proteins during Toxoplasma gondii Infection. mBio 2022; 13:e0144222. [PMID: 35730903 PMCID: PMC9426488 DOI: 10.1128/mbio.01442-22] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 05/31/2022] [Indexed: 11/21/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii adapts to diverse host cell environments within a replicative compartment that is heavily decorated by secreted proteins. In an attempt to identify novel parasite secreted proteins that influence host cell activity, we identified and characterized a transmembrane dense granule protein dubbed GRA64 (TGME49_202620). We found that GRA64 is on the parasitophorous vacuolar membrane (PVM) and is partially exposed to the host cell cytoplasm in both tachyzoite and bradyzoite parasitophorous vacuoles. Using co-immunoprecipitation and proximity-based biotinylation approaches, we demonstrated that GRA64 appears to interact with components of the host endosomal sorting complexes required for transport (ESCRT). Genetic disruption of GRA64 does not affect acute Toxoplasma virulence or encystation in mice, as observed via tissue cyst burdens in mice during chronic infection. However, ultrastructural analysis of Δgra64 tissue cysts using electron tomography revealed enlarged vesicular structures underneath the cyst membrane, suggesting a role for GRA64 in organizing the recruitment of ESCRT proteins and subsequent intracystic vesicle formation. This study uncovers a novel host-parasite interaction that contributes to an emerging paradigm in which specific host ESCRT proteins are recruited to the limiting membranes (PVMs) of tachyzoite and bradyzoite vacuoles formed during acute and chronic Toxoplasma infection. IMPORTANCE Toxoplasma gondii is a widespread foodborne parasite that causes congenital disease and life-threatening complications in immunocompromised individuals. Part of this parasite's success lies in its ability to infect diverse organisms and host cells and to persist as a latent infection within parasite-constructed structures called tissue cysts. In this study, we characterized a protein that is secreted by T. gondii into its parasitophorous vacuole during intracellular infection, which we dub GRA64. On the vacuolar membrane, this protein is exposed to the host cell cytosol and interacts with specific host ESCRT proteins. Parasites lacking the GRA64 protein exhibit ultrastructural changes in tissue cysts during chronic infection. This study lays the foundation for future studies on the mechanics and consequences of host ESCRT-parasite protein interactions.
Collapse
Affiliation(s)
- Joshua Mayoral
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rebekah B. Guevara
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Yolanda Rivera-Cuevas
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Julia D. Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Leslie Gunther-Cummins
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Simone Sidoli
- Departments of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Vernon B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| |
Collapse
|
24
|
Deleting ku80 improves the efficiency of targeted gene editing in Neospora caninum. Mol Biochem Parasitol 2022; 251:111508. [PMID: 35963548 DOI: 10.1016/j.molbiopara.2022.111508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 07/16/2022] [Accepted: 08/01/2022] [Indexed: 11/24/2022]
Abstract
CRISPR/Cas9 technology has been widely used for gene editing in organisms. Gene deletion of the ku80/ku70 complex can improve the efficiency of gene replacement in Arabidopsis thaliana, Cryptococcus neoformans, and Toxoplasma gondii, which remained elusive in Neospora caninum. Here, we knock out the ku80 gene in Nc1 strain by using CRISPR/Cas9, detect the growth rate and virulence of NcΔku80. Then we compare the efficiency of gene replacements between NcΔku80 and Nc1 strains by transfected with the same HA-tagged plasmids, and the percentage of HA-tagged parasites was investigated by IFA. The results showed that gene targeting efficiency was increased in the NcΔku80 strain via double crossover at several genetic loci, but its growth rate and virulence were unaffected. In conclusion, the NcΔku80 strain can be used as an effective strain for rapid gene editing of N. caninum.
Collapse
|
25
|
Tian X, Wang M, Xie T, Wan G, Sun H, Mei X, Zhang Z, Li X, Wang S. A recombinant protein vaccine encoding Toxoplasma gondii Cyst wall 2 (dense granule protein 47) provides partial protection against acute and chronic T. gondii infection in BALB/c mice. Acta Trop 2022; 232:106514. [PMID: 35580637 DOI: 10.1016/j.actatropica.2022.106514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/26/2022]
Abstract
Toxoplasma gondii poses a major threat to economies and public health, and there are still no available vaccines for human against T. gondii infection. T. gondii cyst wall 2 (TgCST2, also known as dense granule protein-47) is a critical molecule in the establishment of chronic infection, making it a potential vaccine candidate. In this research, the recombinant TgCST2 (rTgCST2) was employed to evaluate the protective efficacy of TgCST2 antigen using BALB/c mice model against T. gondii infections via active immunization trials. First, the strong immunogenicity of TgCST2 was indicated by immunoblotting and immunofluorescence, which mean that TgCST2 might elicit robust immune responses in the organism. Then, after triply subcutaneous immunization with rTgCST2/ISA 201 emulsion, high levels of Toxoplasma-specific IgG, IgG1, IgG2a and cytokines (Interferon γ and interleukin 10) further suggested that TgCST2 was a promising immunogenic antigen. More importantly, this antigen could prolong survival in RH strain infected mice and resulted in the lower brain cysts size and number of PRU strain infected mice. These preliminary results demonstrated the immunoprophylactic effects of TgCST2 antigen and will inform new studies in developing subunit recombinant vaccines against T. gondii.
Collapse
|
26
|
Deletion of Toxoplasma Rhoptry Protein 38 (PruΔ rop38) as a Vaccine Candidate for Toxoplasmosis in a Murine Model. Biomedicines 2022; 10:biomedicines10061336. [PMID: 35740356 PMCID: PMC9220005 DOI: 10.3390/biomedicines10061336] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/03/2022] [Accepted: 06/04/2022] [Indexed: 11/16/2022] Open
Abstract
Toxoplasmosis is a serious zoonotic disease that threatens human and animal health. Here, we evaluated the vaccine potential of the deletion of Toxoplasma rhoptry protein 38 (PruΔrop38) through its pathogenicity and immunoprotective efficacy in mice. Mice inoculated intraperitoneally with 1 × 103, 2 × 103, or 4 × 103 PruΔrop38 showed no visible signs, whereas mice inoculated with 1 × 103 parental Pru strain showed obvious wasting and bow-back, suggesting a significantly lower pathogenicity of PruΔrop38 in mice. Vaccination with 1 × 102 PruΔrop38 triggered a mixed Th1/Th2 response (Th1 response predominant), with higher IgG, IgG2a, and IgG1 levels in serum from week 3 to week 12, and a significant increase in IFN-γ, IL-12, and IL-10 in suspensions of splenocytes at 30 or 60 days post-immunization. All vaccinated mice survived when infected intraperitoneally with tachyzoites (RH, Pru, VEG, or TgcatBJ1) or when infected orally with cysts (Pru or ME49). The brain parasite burden during Pru tachyzoite, Pru cyst and ME49 cyst challenges were significantly reduced in vaccinated mice. The duration of immunization showed that vaccination with PruΔrop38 could protect mice from challenge with different varied genotypes of Toxoplasma strains against different routes of infection. Collectively, these findings indicate that PruΔrop38 is an attenuated strain that provides long-term protective efficacy against acute or chronic toxoplasmosis in mice.
Collapse
|
27
|
Zhu L, Qi W, Yang G, Yang Y, Wang Y, Zheng L, Fu Y, Cheng X. Toxoplasma gondii Rhoptry Protein 7 (ROP7) Interacts with NLRP3 and Promotes Inflammasome Hyperactivation in THP-1-Derived Macrophages. Cells 2022; 11:cells11101630. [PMID: 35626667 PMCID: PMC9139738 DOI: 10.3390/cells11101630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/07/2022] [Accepted: 05/11/2022] [Indexed: 12/24/2022] Open
Abstract
Toxoplasma gondii is a common opportunistic protozoan pathogen that can parasitize the karyocytes of humans and virtually all other warm-blooded animals. In the host’s innate immune response to T. gondii infection, inflammasomes can mediate the maturation of pro-IL-1β and pro-IL-18, which further enhances the immune response. However, how intercellular parasites specifically provoke inflammasome activation remains unclear. In this study, we found that the T. gondii secretory protein, rhoptry protein 7 (ROP7), could interact with the NACHT domain of NLRP3 through liquid chromatography-mass spectrometry analysis and co-immunoprecipitation assays. When expressing ROP7 in differentiated THP-1 cells, there was significant up-regulation in NF-κB and continuous release of IL-1β. This process is pyroptosis-independent and leads to inflammasome hyperactivation through the IL-1β/NF-κB/NLRP3 feedback loop. The loss of ROP7 in tachyzoites did not affect parasite proliferation in host cells but did attenuate parasite-induced inflammatory activity. In conclusion, these findings unveil that a T. gondii-derived protein is able to promote inflammasome activation, and further study of ROP7 will deepen our understanding of host innate immunity to parasites.
Collapse
Affiliation(s)
- Lijun Zhu
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (L.Z.); (W.Q.); (X.C.)
| | - Wanjun Qi
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (L.Z.); (W.Q.); (X.C.)
| | - Guang Yang
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China;
| | - Yurong Yang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China;
| | - Yuwen Wang
- Engineering Research Center of Optical Instrument and System, The Ministry of Education, Shanghai Key Laboratory of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China; (Y.W.); (L.Z.)
| | - Lulu Zheng
- Engineering Research Center of Optical Instrument and System, The Ministry of Education, Shanghai Key Laboratory of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China; (Y.W.); (L.Z.)
| | - Yongfeng Fu
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (L.Z.); (W.Q.); (X.C.)
- Correspondence:
| | - Xunjia Cheng
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; (L.Z.); (W.Q.); (X.C.)
| |
Collapse
|
28
|
Gubbels MJ, Ferguson DJP, Saha S, Romano JD, Chavan S, Primo VA, Michaud C, Coppens I, Engelberg K. Toxoplasma gondii's Basal Complex: The Other Apicomplexan Business End Is Multifunctional. Front Cell Infect Microbiol 2022; 12:882166. [PMID: 35573773 PMCID: PMC9103881 DOI: 10.3389/fcimb.2022.882166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/30/2022] [Indexed: 01/08/2023] Open
Abstract
The Apicomplexa are famously named for their apical complex, a constellation of organelles at their apical end dedicated to invasion of their host cells. In contrast, at the other end of the cell, the basal complex (BC) has been overshadowed since it is much less prominent and specific functions were not immediately obvious. However, in the past decade a staggering array of functions have been associated with the BC and strides have been made in understanding its structure. Here, these collective insights are supplemented with new data to provide an overview of the understanding of the BC in Toxoplasma gondii. The emerging picture is that the BC is a dynamic and multifunctional complex, with a series of (putative) functions. The BC has multiple roles in cell division: it is the site where building blocks are added to the cytoskeleton scaffold; it exerts a two-step stretch and constriction mechanism as contractile ring; and it is key in organelle division. Furthermore, the BC has numerous putative roles in 'import', such as the recycling of mother cell remnants, the acquisition of host-derived vesicles, possibly the uptake of lipids derived from the extracellular medium, and the endocytosis of micronemal proteins. The latter process ties the BC to motility, whereas an additional role in motility is conferred by Myosin C. Furthermore, the BC acts on the assembly and/or function of the intravacuolar network, which may directly or indirectly contribute to the establishment of chronic tissue cysts. Here we provide experimental support for molecules acting in several of these processes and identify several new BC proteins critical to maintaining the cytoplasmic bridge between divided parasites. However, the dispensable nature of many BC components leaves many questions unanswered regarding its function. In conclusion, the BC in T. gondii is a dynamic and multifunctional structure at the posterior end of the parasite.
Collapse
Affiliation(s)
- Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - David J. P. Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford John Radcliffe Hospital, Oxford, United Kingdom
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford, United Kingdom
| | - Sudeshna Saha
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Julia D. Romano
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Suyog Chavan
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Vincent A. Primo
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Cynthia Michaud
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Klemens Engelberg
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| |
Collapse
|
29
|
Allred DR. Integration of DNA Repair, Antigenic Variation, Cytoadhesion, and Chance in Babesia Survival: A Perspective. Front Cell Infect Microbiol 2022; 12:869696. [PMID: 35493746 PMCID: PMC9047050 DOI: 10.3389/fcimb.2022.869696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/24/2022] [Indexed: 11/13/2022] Open
Abstract
Apicomplexan parasites live in hostile environments in which they are challenged chemically and their hosts attempt in many ways to kill them. In response, the parasites have evolved multiple mechanisms that take advantage of these challenges to enhance their survival. Perhaps the most impressive example is the evolutionary co-option of DNA repair mechanisms by the parasites as a means to rapidly manipulate the structure, antigenicity, and expression of the products of specific multigene families. The purpose of variant proteins that mediate cytoadhesion has long been thought to be primarily the avoidance of splenic clearance. Based upon known biology, I present an alternative perspective in which it is survival of the oxidative environment within which Babesia spp. parasites live that has driven integration of DNA repair, antigenic variation, and cytoadhesion, and speculate on how genome organization affects that integration. This perspective has ramifications for the development of parasite control strategies.
Collapse
Affiliation(s)
- David R. Allred
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL, United States
- Genetics Institute, University of Florida, Gainesville, FL, United States
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- *Correspondence: David R. Allred,
| |
Collapse
|
30
|
Christiansen C, Maus D, Hoppenz E, Murillo-León M, Hoffmann T, Scholz J, Melerowicz F, Steinfeldt T, Seeber F, Blume M. In vitro maturation of Toxoplasma gondii bradyzoites in human myotubes and their metabolomic characterization. Nat Commun 2022; 13:1168. [PMID: 35246532 PMCID: PMC8897399 DOI: 10.1038/s41467-022-28730-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 02/02/2022] [Indexed: 12/15/2022] Open
Abstract
The apicomplexan parasite Toxoplasma gondii forms bradyzoite-containing tissue cysts that cause chronic and drug-tolerant infections. However, current in vitro models do not allow long-term culture of these cysts to maturity. Here, we developed a human myotube-based in vitro culture model of functionally mature tissue cysts that are orally infectious to mice and tolerate exposure to a range of antibiotics and temperature stresses. Metabolomic characterization of purified cysts reveals global changes that comprise increased levels of amino acids and decreased abundance of nucleobase- and tricarboxylic acid cycle-associated metabolites. In contrast to fast replicating tachyzoite forms of T. gondii these tissue cysts tolerate exposure to the aconitase inhibitor sodium fluoroacetate. Direct access to persistent stages of T. gondii under defined cell culture conditions will be essential for the dissection of functionally important host-parasite interactions and drug evasion mechanisms. It will also facilitate the identification of new strategies for therapeutic intervention. Bradyzoites are a quiescent form of Toxoplasma gondii enclosed in cysts during chronic infections. Here, Christiansen et al. develop a human myotube-based in vitro culture model of cysts that are infectious to mice and characterize their metabolism in comparison to fast replicating tachyzoites.
Collapse
Affiliation(s)
- Céline Christiansen
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Deborah Maus
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Ellen Hoppenz
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Mateo Murillo-León
- Institute of Virology, Medical Center University of Freiburg, 79104, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.,Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Tobias Hoffmann
- ZBS 4: Advanced Light and Electron Microscopy, Centre for Biological Threats and Special Pathogens 4, Robert Koch-Institute, 13353, Berlin, Germany
| | - Jana Scholz
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Florian Melerowicz
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany
| | - Tobias Steinfeldt
- Institute of Virology, Medical Center University of Freiburg, 79104, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany
| | - Frank Seeber
- FG 16: Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, 13353, Berlin, Germany
| | - Martin Blume
- NG2: Metabolism of Microbial Pathogens, Robert Koch-Institute, 13353, Berlin, Germany.
| |
Collapse
|
31
|
Seizova S, Ruparel U, Garnham AL, Bader SM, Uboldi AD, Coffey MJ, Whitehead LW, Rogers KL, Tonkin CJ. Transcriptional modification of host cells harboring Toxoplasma gondii bradyzoites prevents IFN gamma-mediated cell death. Cell Host Microbe 2021; 30:232-247.e6. [PMID: 34921775 DOI: 10.1016/j.chom.2021.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/05/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022]
Abstract
Toxoplasma gondii develops a latent infection in the muscle and central nervous system that acts as a reservoir for acute-stage reactivation in vulnerable patients. Little is understood about how parasites manipulate host cells during latent infection and the impact this has on survival. We show that bradyzoites impart a unique transcriptional signature on infected host cells. Many of these transcriptional changes rely on protein export and result in the suppression of type I interferon (IFN) and IFNγ signaling more so than in acute stages. Loss of the protein export component, MYR1, abrogates transcriptional remodeling and prevents suppression of IFN signaling. Among the exported proteins, the inhibitor of STAT1 transcription (IST) plays a key role in limiting IFNγ signaling in bradyzoites. Furthermore, bradyzoite protein export protects host cells from IFNγ-mediated cell death, even when export is restricted to latent stages. These findings highlight the functional importance of host manipulation in Toxoplasma's bradyzoite stages.
Collapse
Affiliation(s)
- Simona Seizova
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia; Wellcome Center for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee DD1 5EH, UK
| | - Ushma Ruparel
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Alexandra L Garnham
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Stefanie M Bader
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Alessandro D Uboldi
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael J Coffey
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia; Poseida Therapeutics, San Diego, CA, USA
| | - Lachlan W Whitehead
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Kelly L Rogers
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Christopher J Tonkin
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia.
| |
Collapse
|
32
|
Dard C, Leforestier B, Francisco Hilário F, Traoré MDM, Lespinasse MA, Pérès B, Molina MC, Pereira de Freitas R, Milet A, Maubon D, Wong YS. Crossing of the Cystic Barriers of Toxoplasma gondii by the Fluorescent Coumarin Tetra-Cyclopeptide. Molecules 2021; 26:7506. [PMID: 34946588 PMCID: PMC8708940 DOI: 10.3390/molecules26247506] [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: 11/10/2021] [Revised: 11/28/2021] [Accepted: 12/05/2021] [Indexed: 01/11/2023] Open
Abstract
FR235222 is a natural tetra-cyclopeptide with a strong inhibition effect on histone deacetylases, effective on mammalian cells as well as on intracellular apicomplexan parasites, such as Toxoplasma gondii, in the tachyzoite and bradyzoite stages. This molecule is characterized by two parts: the zinc-binding group, responsible for the binding to the histone deacetylase, and the cyclic tetrapeptide moiety, which plays a crucial role in cell permeability. Recently, we have shown that the cyclic tetrapeptide coupled with a fluorescent diethyl-amino-coumarin was able to maintain properties of cellular penetration on human cells. Here, we show that this property can be extended to the crossing of the Toxoplasma gondii cystic cell wall and the cell membrane of the parasite in its bradyzoite form, while maintaining a high efficacy as a histone deacetylase inhibitor. The investigation by molecular modeling allows a better understanding of the penetration mechanism.
Collapse
Affiliation(s)
- Céline Dard
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM, CNRSINSERM U1209, CNRS UMR 5309, Univ. Grenoble Alpes, 38000 Grenoble, France; (C.D.); (D.M.)
| | - Baptiste Leforestier
- Team SITH, CNRS UMR 5250, Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France; (B.L.); (A.M.)
| | - Flaviane Francisco Hilário
- Team COMET, CNRS UMR 5063, Univ. Grenoble Alpes, CNRS, DPM, 38000 Grenoble, France; (F.F.H.); (M.D.M.T.); (M.-A.L.); (B.P.); (M.-C.M.)
| | - Mohamed Dit Mady Traoré
- Team COMET, CNRS UMR 5063, Univ. Grenoble Alpes, CNRS, DPM, 38000 Grenoble, France; (F.F.H.); (M.D.M.T.); (M.-A.L.); (B.P.); (M.-C.M.)
| | - Marie-Ange Lespinasse
- Team COMET, CNRS UMR 5063, Univ. Grenoble Alpes, CNRS, DPM, 38000 Grenoble, France; (F.F.H.); (M.D.M.T.); (M.-A.L.); (B.P.); (M.-C.M.)
| | - Basile Pérès
- Team COMET, CNRS UMR 5063, Univ. Grenoble Alpes, CNRS, DPM, 38000 Grenoble, France; (F.F.H.); (M.D.M.T.); (M.-A.L.); (B.P.); (M.-C.M.)
| | - Marie-Carmen Molina
- Team COMET, CNRS UMR 5063, Univ. Grenoble Alpes, CNRS, DPM, 38000 Grenoble, France; (F.F.H.); (M.D.M.T.); (M.-A.L.); (B.P.); (M.-C.M.)
| | - Rossimiriam Pereira de Freitas
- Departamento de Química, Universidade Federal de Minas Gerais, Av Pres Antônio Carlos, 6627, Pampulha, Belo Horizonte 31270-901, MG, Brazil;
| | - Anne Milet
- Team SITH, CNRS UMR 5250, Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France; (B.L.); (A.M.)
| | - Danièle Maubon
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM, CNRSINSERM U1209, CNRS UMR 5309, Univ. Grenoble Alpes, 38000 Grenoble, France; (C.D.); (D.M.)
| | - Yung-Sing Wong
- Departamento de Química, Universidade Federal de Minas Gerais, Av Pres Antônio Carlos, 6627, Pampulha, Belo Horizonte 31270-901, MG, Brazil;
| |
Collapse
|
33
|
Analogs of marinopyrrole A show enhancement to observed in vitro potency against acute Toxoplasma gondii infection. Antimicrob Agents Chemother 2021; 66:e0079421. [PMID: 34662196 DOI: 10.1128/aac.00794-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The apicomplexan parasite Toxoplasma gondii is the causative agent of toxoplasmosis, a globally distributed infection with severe clinical consequences for immunocompromised individuals and developing fetuses. There are few available treatments, and these are associated with potentially severe adverse effects. Marinopyrrole A, a compound discovered in a marine Streptomyces species, has previously been found to exhibit potent antimicrobial activity, prompting our interest in exploring efficacy against Toxoplasma gondii. We found that marinopyrrole A was a highly potent anti-Toxoplasma molecule, with an in vitro 50% maximal inhibitory concentration (IC50) of 0.31 μM corresponding to a higher potency than that of the current standard of care (pyrimethamine); however, addition of 20% serum led to abrogation of potency, and toxicity to human cell lines was observed. Yet, application of marinopyrrole A to an in vivo lethal acute infection model facilitated significantly enhanced survival at doses of 5, 10, and 20 mg/kg. We then tested a series of marinopyrrole A analogs-RL002, RL003, and RL125-demonstrating significantly increased potency in vitro, with IC50 values ranging from 0.09-0.17 μM (3.6-6.8X increase relative to pyrimethamine). No detectable cytotoxicity was observed up to 50 μM in human foreskin fibroblasts, with cytotoxicity in HepG2 cells ranging from ∼28-50 μM, corresponding to >200X selectivity for parasites over host cells. All analogs additionally showed reduced sensitivity to serum. Further, RL003 potently inhibited in vitro-generated bradyzoites at 0.245 μM. Taken together, these data support further development of marinopyrrole A analogs as promising anti-Toxoplasma molecules to further combat this prevalent infection.
Collapse
|
34
|
Abou-El-Naga IF, Gomaa MM, ElAchy SN. Effect of HIV aspartyl protease inhibitors on experimental infection with a cystogenic Me49 strain of Toxoplasma gondii. Pathog Glob Health 2021; 116:107-118. [PMID: 34420500 DOI: 10.1080/20477724.2021.1967628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Toxoplasmosis is a zoonotic disease of major significant perspectives in public health and veterinary medicine. So far, the available drugs control only the active infection, once the parasite encysts in the tissues, they lose their efficacy. Cytokines; IFN-γ and IL-10, play a critical role in the modulation of toxoplasmic encephalitis and neuro-inflammation in chronic toxoplasmosis. Antiretroviral protease inhibitors applied in the treatment of acquired immunodeficiency syndrome, revealed activity against multiple parasites. Aluvia (lopinavir/ritonavir) (L/R); an aspartyl protease inhibitor, had efficiently treated T. gondii RH strain infection. We investigated the potential activity of L/R against experimental T. gondii infection with a cystogenic Me49 strain in mice, considering the role of IFN-γ and IL-10 in the neuropathology versus pyrimethamine-sulfadiazine combination therapy. Three aluvia regimens were applied; starting on the day of infection (acute phase), 2-week PI (early chronic phase) and eight weeks PI (late chronic phase). L/R reduced the brain-tissue cyst burden significantly in all treatment regimens. It impaired the parasite infectivity markedly in the late chronic phase. Ultrastructural changes were detected in Toxoplasma cyst membrane and wall, bradyzoite membrane and nuclear envelope. The signs of bradyzoite paraptosis and cytoplasmic lipid droplets were observed. L/R had significantly reduced the brain-homogenate levels of IFN-γ and IL-10 in its three regimens however, they could not reach the normal level in chronic phases. Cerebral hypercellularity, perivascular inflammatory response, lymphoplasmacytic infiltrates and glial cellular reaction were ameliorated by L/R treatment. Herein, L/R was proved to possess promising preventive and therapeutic perspectives in chronic cerebral toxoplasmosis.
Collapse
Affiliation(s)
- Iman Fathy Abou-El-Naga
- Department Of Medical Parasitology, Faculty Of Medicine, Alexandria University, Alexandria, Egypt
| | - Maha Mohamed Gomaa
- Department Of Medical Parasitology, Faculty Of Medicine, Alexandria University, Alexandria, Egypt
| | - Samar Nabil ElAchy
- Department Of Pathology, Faculty Of Medicine, Alexandria University, Alexandria, Egypt
| |
Collapse
|
35
|
Rajendran E, Clark M, Goulart C, Steinhöfel B, Tjhin ET, Gross S, Smith NC, Kirk K, van Dooren GG. Substrate-mediated regulation of the arginine transporter of Toxoplasma gondii. PLoS Pathog 2021; 17:e1009816. [PMID: 34352043 PMCID: PMC8370653 DOI: 10.1371/journal.ppat.1009816] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/17/2021] [Accepted: 07/22/2021] [Indexed: 12/13/2022] Open
Abstract
Intracellular parasites, such as the apicomplexan Toxoplasma gondii, are adept at scavenging nutrients from their host. However, there is little understanding of how parasites sense and respond to the changing nutrient environments they encounter during an infection. TgApiAT1, a member of the apicomplexan ApiAT family of amino acid transporters, is the major uptake route for the essential amino acid L-arginine (Arg) in T. gondii. Here, we show that the abundance of TgApiAT1, and hence the rate of uptake of Arg, is regulated by the availability of Arg in the parasite's external environment, increasing in response to decreased [Arg]. Using a luciferase-based 'biosensor' strain of T. gondii, we demonstrate that the expression of TgApiAT1 varies between different organs within the host, indicating that parasites are able to modulate TgApiAT1-dependent uptake of Arg as they encounter different nutrient environments in vivo. Finally, we show that Arg-dependent regulation of TgApiAT1 expression is post-transcriptional, mediated by an upstream open reading frame (uORF) in the TgApiAT1 transcript, and we provide evidence that the peptide encoded by this uORF is critical for mediating regulation. Together, our data reveal the mechanism by which an apicomplexan parasite responds to changes in the availability of a key nutrient.
Collapse
Affiliation(s)
- Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australia
| | - Morgan Clark
- Research School of Biology, Australian National University, Canberra, Australia
| | - Cibelly Goulart
- Research School of Biology, Australian National University, Canberra, Australia
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Birte Steinhöfel
- Research School of Biology, Australian National University, Canberra, Australia
| | - Erick T. Tjhin
- Research School of Biology, Australian National University, Canberra, Australia
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Simon Gross
- Research School of Biology, Australian National University, Canberra, Australia
| | - Nicholas C. Smith
- Research School of Biology, Australian National University, Canberra, Australia
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, Australia
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, Australia
| |
Collapse
|
36
|
Alday PH, McConnell EV, Boitz Zarella JM, Dodean RA, Kancharla P, Kelly JX, Doggett JS. Acridones Are Highly Potent Inhibitors of Toxoplasma gondii Tachyzoites. ACS Infect Dis 2021; 7:1877-1884. [PMID: 33723998 DOI: 10.1021/acsinfecdis.1c00016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acridone derivatives, which have been shown to have in vitro and in vivo activity against Plasmodium spp, inhibit Toxoplasma gondii proliferation at picomolar concentrations. Using enzymatic assays, we show that acridones inhibit both T. gondii cytochrome bc1 and dihydroorotate dehydrogenase and identify acridones that bind preferentially to the Qi site of cytochrome bc1. We identify acridones that have efficacy in a murine model of systemic toxoplasmosis. Acridones have potent activity against T. gondii and represent a promising new class of preclinical compounds.
Collapse
Affiliation(s)
- P. Holland Alday
- Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Erin V. McConnell
- Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Jan M. Boitz Zarella
- Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Rozalia A. Dodean
- Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Papireddy Kancharla
- Department of Chemistry, Portland State University, Portland, Oregon 97201, United States
| | - Jane X. Kelly
- Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
- Department of Chemistry, Portland State University, Portland, Oregon 97201, United States
| | - J. Stone Doggett
- Portland VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| |
Collapse
|
37
|
You H, Mayer JU, Johnston RL, Sivakumaran H, Ranasinghe S, Rivera V, Kondrashova O, Koufariotis LT, Du X, Driguez P, French JD, Waddell N, Duke MG, Ittiprasert W, Mann VH, Brindley PJ, Jones MK, McManus DP. CRISPR/Cas9-mediated genome editing of Schistosoma mansoni acetylcholinesterase. FASEB J 2021; 35:e21205. [PMID: 33337558 DOI: 10.1096/fj.202001745rr] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/16/2020] [Accepted: 11/03/2020] [Indexed: 12/21/2022]
Abstract
CRISPR/Cas9-mediated genome editing shows cogent potential for the genetic modification of helminth parasites. We report successful gene knock-in (KI) into the genome of the egg of Schistosoma mansoni by combining CRISPR/Cas9 with single-stranded oligodeoxynucleotides (ssODNs). We edited the acetylcholinesterase (AChE) gene of S. mansoni targeting two guide RNAs (gRNAs), X5 and X7, located on exon 5 and exon 7 of Smp_154600, respectively. Eggs recovered from livers of experimentally infected mice were transfected by electroporation with a CRISPR/Cas9-vector encoding gRNA X5 or X7 combining with/ without a ssODN donor. Next generation sequencing analysis of reads of amplicon libraries spanning targeted regions revealed that the major modifications induced by CRISPR/Cas9 in the eggs were generated by homology directed repair (HDR). Furthermore, soluble egg antigen from AChE-edited eggs exhibited markedly reduced AChE activity, indicative that programed Cas9 cleavage mutated the AChE gene. Following injection of AChE-edited schistosome eggs into the tail veins of mice, an significantly enhanced Th2 response involving IL-4, -5, -10, and-13 was detected in lung cells and splenocytes in mice injected with X5-KI eggs in comparison to control mice injected with unmutated eggs. A Th2-predominant response, with increased levels of IL-4, -13, and GATA3, also was induced by X5 KI eggs in small intestine-draining mesenteric lymph node cells when the gene-edited eggs were introduced into the subserosa of the ileum of the mice. These findings confirmed the potential and the utility of CRISPR/Cas9-mediated genome editing for functional genomics in schistosomes.
Collapse
Affiliation(s)
- Hong You
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | | | - Rebecca L Johnston
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Haran Sivakumaran
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Shiwanthi Ranasinghe
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Vanessa Rivera
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Olga Kondrashova
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Lambros T Koufariotis
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Xiaofeng Du
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Patrick Driguez
- King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Juliet D French
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Nicola Waddell
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Mary G Duke
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Wannaporn Ittiprasert
- Department of Microbiology, Immunology & Tropical Medicine, & Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC, USA
| | - Victoria H Mann
- Department of Microbiology, Immunology & Tropical Medicine, & Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC, USA
| | - Paul J Brindley
- Department of Microbiology, Immunology & Tropical Medicine, & Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC, USA
| | - Malcolm K Jones
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia
| | - Donald P McManus
- Immunology Department, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| |
Collapse
|
38
|
Guo H, Gao Y, N'Da DD, Xuan X. In vitro anti-Toxoplasma gondii efficacy of synthesised benzyltriazole derivatives. ACTA ACUST UNITED AC 2021; 88:e1-e8. [PMID: 34212734 PMCID: PMC8252180 DOI: 10.4102/ojvr.v88i1.1898] [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: 08/05/2020] [Revised: 03/18/2021] [Accepted: 04/12/2021] [Indexed: 11/21/2022]
Abstract
Toxoplasma gondii, an obligate intracellular parasite, is the aetiological agent of toxoplasmosis, a disease that affects approximately 25% – 30% of the world’s population. At present, no safe and effective vaccine exists for the prevention of toxoplasmosis. Current treatment options for toxoplasmosis are active only against tachyzoites and may also cause bone marrow toxicity. To contribute to the global search for novel agents for the treatment of toxoplasmosis, we herein report the in vitro activities of previously synthesised benzyltriazole derivatives. The effects of these compounds against T. gondii in vitro were evaluated by using a expressing green fluorescent protein (GFP) type I strain parasite (RH-GFP) and a type II cyst-forming strain of parasite (PruΔku80Δhxgprt). The frontline antitubercular drug isoniazid, designated as Frans J. Smit -isoniazid (FJS-INH), was also included in the screening as a preliminary test in view of future repurposing of this agent. Of the compounds screened, FJS-302, FJS-303, FJS-403 and FJS-INH demonstrated > 80% parasite growth inhibition with IC50 values of 5.6 µg/mL, 6.8 µg/µL, 7.0 µg/mL and 19.8 µg/mL, respectively. FJS-302, FJS-303 and FJS-403 inhibited parasite invasion and replication, whereas, sulphadiazine (SFZ), the positive control, was only effective against parasite replication. In addition, SFZ induced bradyzoite differentiation in vitro, whilst FJS-302, FJS-303 and FJS-403 did not increase the bradyzoite number. These results indicate that FJS-302, FJS-303 and FJS-403 have the potential to act as a viable source of antiparasitic therapeutic agents.
Collapse
Affiliation(s)
- Huanping Guo
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro.
| | | | | | | |
Collapse
|
39
|
Tomita T, Mukhopadhyay D, Han B, Yakubu R, Tu V, Mayoral J, Sugi T, Ma Y, Saeij JPJ, Weiss LM. Toxoplasma gondii Matrix Antigen 1 Is a Secreted Immunomodulatory Effector. mBio 2021; 12:mBio.00603-21. [PMID: 34006649 PMCID: PMC8262993 DOI: 10.1128/mbio.00603-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Our studies on novel cyst wall proteins serendipitously led us to the discovery that cyst wall and vacuolar matrix protein MAG1, first identified a quarter of a century ago, functions as a secreted immunomodulatory effector. MAG1 is a dense granular protein that is found in the parasitophorous vacuolar matrix in tachyzoite vacuoles and the cyst wall and matrix in bradyzoite vacuoles. In the current study, we demonstrated that MAG1 is secreted beyond the parasitophorous vacuole into the host cytosol in both tachyzoites and bradyzoites. Secretion of MAG1 gradually decreases as the parasitophorous vacuole matures, but prominent MAG1 puncta are present inside host cells even at 4 and 6 days following infection. During acute murine infection, Δmag1 parasites displayed significantly reduced virulence and dissemination. In the chronic stage of infection, Δmag1 parasites generated almost no brain cysts. To identify the mechanism behind the attenuated pathology seen with Δmag1 parasites, various immune responses were screened in vitro using bone marrow-derived macrophages (BMDM). Infection of BMDM with Δmag1 parasites induced a significant increase in interleukin 1β (IL-1β) secretion, which is a hallmark of inflammasome activation. Heterologous complementation of MAG1 in BMDM cells prevented this Δmag1 parasite-induced IL-1β release, indicating that secreted MAG1 in host cytosol dampens inflammasome activation. Furthermore, knocking out GRA15 (an inducer of IL-1β release) in Δmag1 parasites completely inhibited all IL-1β release by host cells following infection. These data suggest that MAG1 has a role as an immunomodulatory molecule and that by suppressing inflammasome activation, it would favor survival of the parasite and the establishment of latent infection.IMPORTANCEToxoplasma gondii is an Apicomplexan that infects a third of humans, causing encephalitis in AIDS patients and intellectual disabilities in congenitally infected patients. We determined that one of the cyst matrix proteins, MAG1, which had been thought to be an innate structural protein, can be secreted into the host cell and suppress the host immune reaction. This particular immune reaction is initiated by another parasite-secreted protein, GRA15. The intricate balance of inflammasome activation by GRA15 and suppression by MAG1 protects mice from acute death while enabling parasites to disseminate and establish chronic cysts. Our finding contributes to our understanding of how parasites persist in the host and how T. gondii modulates the host immune system.
Collapse
Affiliation(s)
- Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Bing Han
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Rama Yakubu
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Joshua Mayoral
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Tatsuki Sugi
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Yanfen Ma
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
| | - Jeroen P J Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, New York, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA
| |
Collapse
|
40
|
Abstract
Toxoplasma gondii causes a chronic infection that renders the immunocompromised human host susceptible to toxoplasmic encephalitis triggered by cyst reactivation in the central nervous system. The dense granule protein GRA12 is a major parasite virulence factor required for parasite survival during acute infection. Here, we characterized the role of four GRA12-related genes in acute and chronic stages of infection. While GRA12A, GRA12B, and GRA12D were highly expressed in asexual stage tachyzoites and bradyzoites, expression of GRA12C appeared to be restricted to the sexual stages. In contrast to deletion of GRA12 (Δgra12), no major defects in acute virulence were observed in Δgra12A, Δgra12B, or Δgra12D parasites, though Δgra12B parasites exhibited an increased tachyzoite replication rate. Bradyzoites secreted GRA12A, GRA12B, and GRA12D and incorporated these molecules into the developing cyst wall, as well as the cyst matrix in distinct patterns. Similar to GRA12, GRA12A, GRA12B, and GRA12D colocalized with the dense granules in extracellular tachyzoites, with GRA2 and the intravacuolar network in the tachyzoite stage parasitophorous vacuole and with GRA2 in the cyst matrix and cyst wall. Chronic stage cyst burdens were decreased in mice infected with Δgra12A parasites and were increased in mice infected with Δgra12B parasites. However, Δgra12B cysts were not efficiently maintained in vivo Δgra12A, Δgra12B, and Δgra12D in vitro cysts displayed a reduced reactivation efficiency, and reactivation of Δgra12A cysts was delayed. Collectively, our results suggest that a family of genes related to GRA12 play significant roles in the formation, maintenance, and reactivation of chronic stage cysts.IMPORTANCE If host immunity weakens, Toxoplasma gondii cysts recrudesce in the central nervous system and cause a severe toxoplasmic encephalitis. Current therapies target acute stage infection but do not eliminate chronic cysts. Parasite molecules that mediate the development and persistence of chronic infection are poorly characterized. Dense granule (GRA) proteins such as GRA12 are key virulence factors during acute infection. Here, we investigated four GRA12-related genes. GRA12-related genes were not major virulence factors during acute infection. Instead, GRA12-related proteins localized at the cyst wall and cyst matrix and played significant roles in cyst development, persistence, and reactivation during chronic infection. Similar to GRA12, the GRA12-related proteins selectively associated with the intravacuolar network of membranes inside the vacuole. Collectively, our results support the hypothesis that GRA12 proteins associated with the intravacuolar membrane system support parasite virulence during acute infection and cyst development, persistence, and reactivation during chronic infection.
Collapse
|
41
|
Kochanowsky JA, Thomas KK, Koshy AA. ROP16-Mediated Activation of STAT6 Suppresses Host Cell Reactive Oxygen Species Production, Facilitating Type III Toxoplasma gondii Growth and Survival. mBio 2021; 12:e03305-20. [PMID: 33653884 PMCID: PMC8092286 DOI: 10.1128/mbio.03305-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/22/2021] [Indexed: 12/21/2022] Open
Abstract
Polymorphic effector proteins determine the susceptibility of Toxoplasma gondii strains to IFN-γ-mediated clearance mechanisms deployed by murine host cells. However, less is known about the influence of these polymorphic effector proteins on IFN-γ-independent clearance mechanisms. Here, we show that deletion of one such polymorphic effector protein, ROP16, from a type III background leads to a defect in parasite growth and survival in unstimulated human fibroblasts and murine macrophages. Rescue of these defects requires a ROP16 with a functional kinase domain and the ability to activate a specific family of host cell transcription factors (STAT3, 5a, and 6). The growth and survival defects correlate with an accumulation of host cell reactive oxygen species (ROS) and are prevented by treatment with an ROS inhibitor. Exogenous activation of STAT3 and 6 suppresses host cell ROS production during infection with ROP16-deficient parasites and depletion of STAT6, but not STAT3 or 5a, causes an accumulation of ROS in cells infected with wild-type parasites. Pharmacological inhibition of NOX2 and mitochondrially derived ROS also rescues growth and survival of ROP16-deficient parasites. Collectively, these findings reveal an IFN-γ-independent mechanism of parasite restriction in human cells that is subverted by injection of ROP16 by type III parasites.IMPORTANCEToxoplasma gondii is an obligate intracellular parasite that infects up to one-third of the world's population. Control of the parasite is largely accomplished by IFN-γ-dependent mechanisms that stimulate innate and adaptive immune responses. Parasite suppression of IFN-γ-stimulated responses has been linked to proteins that the parasite secretes into its host cell. These secreted proteins vary by T. gondii strain and determine strain-specific lethality in mice. How these strain-specific polymorphic effector proteins affect IFN-γ-independent parasite control mechanisms in human and murine cells is not well known. This study shows that one such secreted protein, ROP16, enables efficient parasite growth and survival by suppressing IFN-γ-independent production of ROS by human and mouse cells.
Collapse
Affiliation(s)
| | | | - Anita A Koshy
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
- Department of Neurology, University of Arizona, Tucson, Arizona, USA
| |
Collapse
|
42
|
Updates in Paracoccidioides Biology and Genetic Advances in Fungus Manipulation. J Fungi (Basel) 2021; 7:jof7020116. [PMID: 33557381 PMCID: PMC7915485 DOI: 10.3390/jof7020116] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/30/2021] [Accepted: 02/02/2021] [Indexed: 12/28/2022] Open
Abstract
The dimorphic fungi of the Paracoccidioides genus are the causative agents of paracoccidioidomycosis (PCM). This disease is endemic in Latin America and primarily affects workers in rural areas. PCM is considered a neglected disease, despite being a disabling disease that has a notable impact on the public health system. Paracoccidioides spp. are thermally dimorphic fungi that present infective mycelia at 25 °C and differentiate into pathogenic yeast forms at 37 °C. This transition involves a series of morphological, structural, and metabolic changes which are essential for their survival inside hosts. As a pathogen, the fungus is subjected to several varieties of stress conditions, including the host immune response, which involves the production of reactive nitrogen and oxygen species, thermal stress due to temperature changes during the transition, pH alterations within phagolysosomes, and hypoxia inside granulomas. Over the years, studies focusing on understanding the establishment and development of PCM have been conducted with several limitations due to the low effectiveness of strategies for the genetic manipulation of Paracoccidioides spp. This review describes the most relevant biological features of Paracoccidioides spp., including aspects of the phylogeny, ecology, stress response, infection, and evasion mechanisms of the fungus. We also discuss the genetic aspects and difficulties of fungal manipulation, and, finally, describe the advances in molecular biology that may be employed in molecular research on this fungus in the future.
Collapse
|
43
|
PCR Screening of Toxoplasma gondii Single Clones Directly from 96-Well Plates Without DNA Purification. Methods Mol Biol 2021; 2071:117-123. [PMID: 31758449 DOI: 10.1007/978-1-4939-9857-9_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Toxoplasma gondii has become a model for studying the phylum Apicomplexa, and more in general parasite-host interactions, thanks to its ease of growth in culture and availability of a broad array of genetics tools. Assigning gene function typically involves genetic techniques such as gene knockout, conditional expression, or protein tagging. These approaches generally require isolation of single clones that have correctly introduced the desired genetic modification into the target genomic locus. The frequency of positive clones carrying these genetic manipulations depends on the particular parasite strain and the impact that these genome modifications have on parasite fitness. An adverse effect on parasite viability or growth would result in a low abundancy of the correct transgenic parasites within the transfected population. This in turn will account for a low rate of positive clones after population cloning, requiring the genetic analysis of a high number of single clones. We have developed a simple and fast method to screen single clones of T. gondii directly from the 96-well plates without previous parasite expansion or time-consuming genomic extraction. This approach permits screening at an earlier point than previously possible, thus allowing for faster movement toward assessing gene function.
Collapse
|
44
|
Mayoral J, Tomita T, Tu V, Aguilan JT, Sidoli S, Weiss LM. Toxoplasma gondii PPM3C, a secreted protein phosphatase, affects parasitophorous vacuole effector export. PLoS Pathog 2020; 16:e1008771. [PMID: 33370417 PMCID: PMC7793252 DOI: 10.1371/journal.ppat.1008771] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/08/2021] [Accepted: 11/23/2020] [Indexed: 12/19/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii infects a large proportion of humans worldwide and can cause adverse complications in the settings of immune-compromise and pregnancy. T. gondii thrives within many different cell types due in part to its residence within a specialized and heavily modified compartment in which the parasite divides, termed the parasitophorous vacuole. Within this vacuole, numerous proteins optimize intracellular survival following their secretion by the parasite. We investigated the contribution of one of these proteins, TgPPM3C, predicted to contain a PP2C-class serine/threonine phosphatase domain and previously shown to interact with the protein MYR1, an essential component of a putative vacuolar translocon that mediates effector export into the host cell. Parasites lacking the TgPPM3C gene exhibit a minor growth defect in vitro, are avirulent during acute infection in mice, and form fewer cysts in mouse brain during chronic infection. Phosphoproteomic assessment of TgPPM3C deleted parasite cultures demonstrated alterations in the phosphorylation status of many secreted vacuolar proteins including two exported effector proteins, GRA16 and GRA28, as well as MYR1. Parasites lacking TgPPM3C are defective in GRA16 and GRA28 export, but not in the export of other MYR1-dependant effectors. Phosphomimetic mutation of two GRA16 serine residues results in export defects, suggesting that de-phosphorylation is a critical step in the process of GRA16 export. These findings provide another example of the emerging role of phosphatases in regulating the complex environment of the T. gondii parasitophorous vacuole and influencing the export of specific effector proteins from the vacuolar lumen into the host cell. The flexible life cycle of the intracellular parasite Toxoplasma gondii allows it to infect many different types of warm-blooded hosts, as well as diverse cell types once inside the host organism. This formidable achievement is partly mediated by the establishment of a unique compartment following host cell invasion, termed the parasitophorous vacuole. While advancements have been made in cataloguing Toxoplasma secreted proteins that reside within this vacuole, the specific functions and contributions of many of these secreted parasite “tools” remain elusive. Here, we assessed the contribution of a parasite vacuolar protein called TgPPM3C, predicted to function as an enzyme that dephosphorylates other proteins. We found that deleting the TgPPM3C gene in the parasite results in a profound virulence defect during infection in mice, likely due to the dysregulated phosphorylation status of many vacuolar proteins detected by phosphoproteomic analysis of TgPPM3C-deleted parasites. We found that the phosphorylation status of one such protein, GRA16, influences its ability to cross the parasitophorous vacuole membrane and enter the host cell, where it is known to induce host transcriptional changes that benefit parasite growth. These findings illustrate the emerging role of Toxoplasma vacuolar phosphatases in regulating host-parasite interactions during infection.
Collapse
Affiliation(s)
- Joshua Mayoral
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Jennifer T. Aguilan
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Simone Sidoli
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
| |
Collapse
|
45
|
Du X, McManus DP, French JD, Jones MK, You H. CRISPR/Cas9: A new tool for the study and control of helminth parasites. Bioessays 2020; 43:e2000185. [PMID: 33145822 DOI: 10.1002/bies.202000185] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022]
Abstract
Recent reports of CRISPR/Cas9 genome editing in parasitic helminths open up new avenues for research on these dangerous pathogens. However, the complex morphology and life cycles inherent to these parasites present obstacles for the efficient application of CRISPR/Cas9-targeted mutagenesis. This is especially true with the trematode flukes where only modest levels of gene mutation efficiency have been achieved. Current major challenges in the application of CRISPR/Cas9 for study of parasitic worms thus lie in enhancing gene mutation efficiency and overcoming issues involved in host passage so that mutated parasites survive. Strategies developed for CRISPR/Cas9 studies on Caenorhabditis elegans, protozoa and mammalian cells, including novel delivery methods, the choice of selectable markers, and refining mutation precision represent novel tactics whereby these impediments can be overcome. Furthermore, employing CRISPR/Cas9-mediated gene drive to interfere with vector transmission represents a novel approach for the control of parasitic worms that is worthy of further exploration.
Collapse
Affiliation(s)
- Xiaofeng Du
- Immunology Department, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia.,Faculty of Medicine, The University of Queensland, Herston, Brisbane, Queensland, Australia
| | - Donald P McManus
- Immunology Department, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia.,Faculty of Medicine, The University of Queensland, Herston, Brisbane, Queensland, Australia
| | - Juliet D French
- Genetics & Computational Biology Department, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia
| | - Malcolm K Jones
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Hong You
- Immunology Department, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia
| |
Collapse
|
46
|
Zhao P, Zhang N, Dong J, Li J, Wang X, Li X, Li X, Yang J, Gong P, Zhang X. Effects of Dense Granular Protein 6 (GRA6) Disruption on Neospora caninum Virulence. Front Vet Sci 2020; 7:562730. [PMID: 33195538 PMCID: PMC7536263 DOI: 10.3389/fvets.2020.562730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/26/2020] [Indexed: 12/17/2022] Open
Abstract
Neospora caninum (N. caninum) is a major cause of abortions in cattle. During its invasion of host cells, a parasitophorous vacuole (PV) is formed, accompanied by an intravacuolar network (IVN). The IVN takes part in parasite ingesting of nutrients from hosts. The dense granular proteins of N. caninum (NcGRAs) play a key role in forming the PV and the IVN, which may influence virulence during N. caninum invasion. The present study aimed to explore the biological function of NcGRA6 in N. caninum by disrupting the NcGRA6 gene in the Nc-1 strain. We successfully constructed an NcGRA6-targeting CRISPR plasmid (pNc-SAG1-Cas9:U6-SgGRA6) and amplified the DHFR-TS DNA donor. The NcGRA6 knockout mutation (ΔNcGRA6) was generated by co-electroporation of the pNc-SAG1::CAS9-U6::sgGRA6 plasmid and the DHFR-TS DNA donor into the Nc-1 strain, which was then cultured under pyrimethamine selection pressure. The ΔNcGRA6 mutation was further verified by identification of NcGRA6 gene disruption using PCR, measurement of NcGRA6 gene transcription levels using qPCR, assessment of NcGRA6 protein expression levels using western blotting, and observation of NcGRA6 protein location using immunofluorescence and immunoelectron microscopy. The results of in vitro virulence assays, including plaque, invasion, egress, and replication assays, showed that the ΔNcGRA6 strain had smaller plaques, similar invasion and egress ability, and slower intracellular replication ability than the Nc-1 strain. The results of in vivo virulence assays showed that the ΔNcGRA6 strain exhibited reduced virulence and improved survival ability in mice compared with the Nc-1 strain. The parasite burden in ΔNcGRA6 strain-infected mouse tissues, including the heart, brain, liver, spleen, lung, and kidney, was significantly reduced compared with that in mice infected with the Nc-1 strain. These data suggest that we successfully constructed a ΔNcGRA6 strain and verify that NcGRA6 is a critical virulence factor. NcGRA6 gene disruption can slow down N. caninum proliferation and lower the pathogenicity to hosts. Our findings provide a foundation for future research on other targeted N. caninum protein functions and may help in exploring the interaction mechanisms between parasites and hosts.
Collapse
Affiliation(s)
- Panpan Zhao
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China.,Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
| | - Nan Zhang
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jingquan Dong
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China.,Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
| | - Jianhua Li
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xiaocen Wang
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xin Li
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xiangrui Li
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Ju Yang
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Pengtao Gong
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xichen Zhang
- Key Laboratory of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| |
Collapse
|
47
|
Young JC, Broncel M, Teague H, Russell MRG, McGovern OL, Renshaw M, Frith D, Snijders AP, Collinson L, Carruthers VB, Ewald SE, Treeck M. Phosphorylation of Toxoplasma gondii Secreted Proteins during Acute and Chronic Stages of Infection. mSphere 2020; 5:e00792-20. [PMID: 32907954 PMCID: PMC7485689 DOI: 10.1128/msphere.00792-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 01/07/2023] Open
Abstract
The intracellular parasite Toxoplasma gondii resides within a membrane-bound parasitophorous vacuole (PV) and secretes an array of proteins to establish this replicative niche. It has been shown previously that Toxoplasma secretes kinases and that numerous proteins are phosphorylated after secretion. Here, we assess the role of the phosphorylation of strand-forming protein 1 (SFP1) and the related protein GRA29, two secreted proteins with unknown function. We show that both proteins form stranded structures in the PV that are independent of the previously described intravacuolar network or actin. SFP1 and GRA29 can each form these structures independently of other Toxoplasma secreted proteins, although GRA29 appears to regulate SFP1 strands. We show that an unstructured region at the C termini of SFP1 and GRA29 is required for the formation of strands and that mimicking the phosphorylation of this domain of SFP1 negatively regulates strand development. When tachyzoites convert to chronic-stage bradyzoites, both proteins show a dispersed localization throughout the cyst matrix. Many secreted proteins are reported to dynamically redistribute as the cyst forms, and secreted kinases are known to play a role in cyst formation. Using quantitative phosphoproteome and proteome analyses comparing tachyzoite and early bradyzoite stages, we reveal widespread differential phosphorylation of secreted proteins. While we found no direct evidence for phosphorylation playing a dominant role for SFP1/GRA29 redistribution in the cyst, these data support a model in which secreted kinases and phosphatases contribute to the regulation of secreted proteins during stage conversion.IMPORTANCEToxoplasma gondii is a common parasite that infects up to one-third of the human population. Initially, the parasite grows rapidly, infecting and destroying cells of the host, but subsequently switches to a slow-growing form and establishes chronic infection. In both stages, the parasite lives within a membrane-bound vacuole within the host cell, but in the chronic stage, a durable cyst wall is synthesized, which provides protection to the parasite during transmission to a new host. Toxoplasma secretes proteins into the vacuole to build its replicative niche, and previous studies identified many of these proteins as phosphorylated. We investigate two secreted proteins and show that a phosphorylated region plays an important role in their regulation in acute stages. We also observed widespread phosphorylation of secreted proteins when parasites convert from acute to chronic stages, providing new insight into how the cyst wall may be dynamically regulated.
Collapse
Affiliation(s)
- Joanna C Young
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Malgorzata Broncel
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Helena Teague
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Matt R G Russell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Olivia L McGovern
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Matt Renshaw
- Advanced Light Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - David Frith
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Ambrosius P Snijders
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Sarah E Ewald
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
- Carter Immunology Center, University of Virginia, Charlottesville, Virginia, USA
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| |
Collapse
|
48
|
Mack EA, Tagliamonte MS, Xiao YP, Quesada S, Allred DR. Babesia bovis Rad51 ortholog influences switching of ves genes but is not essential for segmental gene conversion in antigenic variation. PLoS Pathog 2020; 16:e1008772. [PMID: 32866214 PMCID: PMC7485966 DOI: 10.1371/journal.ppat.1008772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/11/2020] [Accepted: 08/13/2020] [Indexed: 01/04/2023] Open
Abstract
The tick-borne apicomplexan parasite, Babesia bovis, a highly persistent bovine pathogen, expresses VESA1 proteins on the infected erythrocyte surface to mediate cytoadhesion. The cytoadhesion ligand, VESA1, which protects the parasite from splenic passage, is itself protected from a host immune response by rapid antigenic variation. B. bovis relies upon segmental gene conversion (SGC) as a major mechanism to vary VESA1 structure. Gene conversion has been considered a form of homologous recombination (HR), a process for which Rad51 proteins are considered pivotal components. This could make BbRad51 a choice target for development of inhibitors that both interfere with parasite genome integrity and disrupt HR-dependent antigenic variation. Previously, we knocked out the Bbrad51 gene from the B. bovis haploid genome, resulting in a phenotype of sensitivity to methylmethane sulfonate (MMS) and apparent loss of HR-dependent integration of exogenous DNA. In a further characterization of BbRad51, we demonstrate here that ΔBbrad51 parasites are not more sensitive than wild-type to DNA damage induced by γ-irradiation, and repair their genome with similar kinetics. To assess the need for BbRad51 in SGC, RT-PCR was used to observe alterations to a highly variant region of ves1α transcripts over time. Mapping of these amplicons to the genome revealed a significant reduction of in situ transcriptional switching (isTS) among ves loci, but not cessation. By combining existing pipelines for analysis of the amplicons, we demonstrate that SGC continues unabated in ΔBbrad51 parasites, albeit at an overall reduced rate, and a reduction in SGC tract lengths was observed. By contrast, no differences were observed in the lengths of homologous sequences at which recombination occurred. These results indicate that, whereas BbRad51 is not essential to babesial antigenic variation, it influences epigenetic control of ves loci, and its absence significantly reduces successful variation. These results necessitate a reconsideration of the likely enzymatic mechanism(s) underlying SGC and suggest the existence of additional targets for development of small molecule inhibitors. B. bovis establishes highly persistent infections in cattle, in part by using cytoadhesion to avoid passage through the spleen. While protective, a host antibody response targeting the cytoadhesion ligand is quickly rendered ineffective by antigenic variation. In B. bovis, antigenic variation relies heavily upon segmental gene conversion (SGC), presumed to be a form of homologous recombination (HR), to generate variants. As Rad51 is generally considered essential to HR, we investigated its contribution to SGC. While diminishing the parasite’s capacity for HR-dependent integration of exogenous DNA, the loss of BbRad51 did not affect the parasite’s sensitivity to ionizing radiation, overall genome stability, or competence for SGC. Instead, loss of BbRad51 diminished the extent of in situ transcriptional switching (isTS) among ves gene loci, the accumulation of SGC recombinants, and the mean lengths of SGC sequence tracts. Given the overall reductions in VESA1 variability, compromise of the parasite’s capacity for in vivo persistence is predicted.
Collapse
Affiliation(s)
- Erin A. Mack
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, Florida, United States of America
| | - Massimiliano S. Tagliamonte
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Yu-Ping Xiao
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, Florida, United States of America
| | - Samantha Quesada
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, Florida, United States of America
| | - David R. Allred
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, Florida, United States of America
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Genetics Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| |
Collapse
|
49
|
Salvioni A, Belloy M, Lebourg A, Bassot E, Cantaloube-Ferrieu V, Vasseur V, Blanié S, Liblau RS, Suberbielle E, Robey EA, Blanchard N. Robust Control of a Brain-Persisting Parasite through MHC I Presentation by Infected Neurons. Cell Rep 2020; 27:3254-3268.e8. [PMID: 31189109 DOI: 10.1016/j.celrep.2019.05.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 03/03/2019] [Accepted: 05/15/2019] [Indexed: 12/27/2022] Open
Abstract
Control of CNS pathogens by CD8 T cells is key to avoid fatal neuroinflammation. Yet, the modalities of MHC I presentation in the brain are poorly understood. Here, we analyze the antigen presentation mechanisms underlying CD8 T cell-mediated control of the Toxoplasma gondii parasite in the CNS. We show that MHC I presentation of an efficiently processed model antigen (GRA6-OVA), even when not expressed in the bradyzoite stage, reduces cyst burden and dampens encephalitis in C57BL/6 mice. Antigen presentation assays with infected primary neurons reveal a correlation between lower MHC I presentation of tachyzoite antigens by neurons and poor parasite control in vivo. Using conditional MHC I-deficient mice, we find that neuronal MHC I presentation is required for robust restriction of T. gondii in the CNS during chronic phase, showing the importance of MHC I presentation by CNS neurons in the control of a prevalent brain pathogen.
Collapse
Affiliation(s)
- Anna Salvioni
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Marcy Belloy
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Aurore Lebourg
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Emilie Bassot
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Vincent Cantaloube-Ferrieu
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Virginie Vasseur
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Sophie Blanié
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Roland S Liblau
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Elsa Suberbielle
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France
| | - Ellen A Robey
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Nicolas Blanchard
- Center for Pathophysiology Toulouse-Purpan (CPTP), INSERM, CNRS, University of Toulouse, 31024 Toulouse, France.
| |
Collapse
|
50
|
Mukhopadhyay D, Arranz-Solís D, Saeij JPJ. Toxoplasma GRA15 and GRA24 are important activators of the host innate immune response in the absence of TLR11. PLoS Pathog 2020; 16:e1008586. [PMID: 32453782 PMCID: PMC7274473 DOI: 10.1371/journal.ppat.1008586] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/05/2020] [Accepted: 04/30/2020] [Indexed: 12/13/2022] Open
Abstract
The murine innate immune response against Toxoplasma gondii is predominated by the interaction of TLR11/12 with Toxoplasma profilin. However, mice lacking Tlr11 or humans, who do not have functional TLR11 or TLR12, still elicit a strong innate immune response upon Toxoplasma infection. The parasite factors that determine this immune response are largely unknown. Herein, we investigated two dense granule proteins (GRAs) secreted by Toxoplasma, GRA15 and GRA24, for their role in stimulating the innate immune response in Tlr11-/- mice and in human cells, which naturally lack TLR11/TLR12. Our results show that GRA15 and GRA24 synergistically shape the early immune response and parasite virulence in Tlr11-/- mice, with GRA15 as the predominant effector. Nevertheless, acute virulence in Tlr11-/- mice is still dominated by allelic combinations of ROP18 and ROP5, which are effectors that determine evasion of the immunity-related GTPases. In human macrophages, GRA15 and GRA24 play a major role in the induction of IL12, IL18 and IL1β secretion. We further show that GRA15/GRA24-mediated IL12, IL18 and IL1β secretion activates IFNγ secretion by peripheral blood mononuclear cells (PBMCs), which controls Toxoplasma proliferation. Taken together, our study demonstrates the important role of GRA15 and GRA24 in activating the innate immune response in hosts lacking TLR11.
Collapse
Affiliation(s)
- Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - David Arranz-Solís
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Jeroen P. J. Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
- * E-mail:
| |
Collapse
|