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Ittiprasert W, Moescheid MF, Chaparro C, Mann VH, Quack T, Rodpai R, Miller A, Wisitpongpun P, Buakaew W, Mentink-Kane M, Schmid S, Popratiloff A, Grevelding CG, Grunau C, Brindley PJ. Targeted insertion and reporter transgene activity at a gene safe harbor of the human blood fluke, Schistosoma mansoni. CELL REPORTS METHODS 2023; 3:100535. [PMID: 37533651 PMCID: PMC10391569 DOI: 10.1016/j.crmeth.2023.100535] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/22/2023] [Accepted: 06/25/2023] [Indexed: 08/04/2023]
Abstract
The identification and characterization of genomic safe harbor sites (GSHs) can facilitate consistent transgene activity with minimal disruption to the host cell genome. We combined computational genome annotation and chromatin structure analysis to predict the location of four GSHs in the human blood fluke, Schistosoma mansoni, a major infectious pathogen of the tropics. A transgene was introduced via CRISPR-Cas-assisted homology-directed repair into one of the GSHs in the egg of the parasite. Gene editing efficiencies of 24% and transgene-encoded fluorescence of 75% of gene-edited schistosome eggs were observed. The approach advances functional genomics for schistosomes by providing a tractable path for generating transgenics using homology-directed, repair-catalyzed transgene insertion. We also suggest that this work will serve as a roadmap for the development of similar approaches in helminths more broadly.
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Affiliation(s)
- Wannaporn Ittiprasert
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
| | - Max F. Moescheid
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
- Institute of Parasitology, Biomedical Research Center Seltersberg, Justus Liebig University Giessen, Giessen, Germany
| | - Cristian Chaparro
- IHPE, University of Perpignan Via Domitia, CNRS, IFREMER, University Montpellier, Perpignan, France
| | - Victoria H. Mann
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
| | - Thomas Quack
- Institute of Parasitology, Biomedical Research Center Seltersberg, Justus Liebig University Giessen, Giessen, Germany
| | - Rutchanee Rodpai
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
- Department of Parasitology and Excellence in Medical Innovation, and Technology Research Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - André Miller
- Schistosomiasis Resource Center, Biomedical Research Institute, Rockville, MD 20850, USA
| | - Prapakorn Wisitpongpun
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
- Faculty of Medical Technology, Rangsit University, Pathum Thani 12000, Thailand
| | - Watunyoo Buakaew
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
- Department of Microbiology, Faculty of Medicine, Srinakharinwirot University, Bangkok 10110, Thailand
| | - Margaret Mentink-Kane
- Schistosomiasis Resource Center, Biomedical Research Institute, Rockville, MD 20850, USA
| | - Sarah Schmid
- Schistosomiasis Resource Center, Biomedical Research Institute, Rockville, MD 20850, USA
| | - Anastas Popratiloff
- Nanofabrication and Imaging Center, Science & Engineering Hall, George Washington University, Washington, DC 20052, USA
| | - Christoph G. Grevelding
- Institute of Parasitology, Biomedical Research Center Seltersberg, Justus Liebig University Giessen, Giessen, Germany
| | - Christoph Grunau
- IHPE, University of Perpignan Via Domitia, CNRS, IFREMER, University Montpellier, Perpignan, France
| | - Paul J. Brindley
- Department of Microbiology, Immunology & Tropical Medicine, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
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2
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Le Clec’h W, Chevalier FD, Jutzeler K, Anderson TJC. No evidence for schistosome parasite fitness trade-offs in the intermediate and definitive host. Parasit Vectors 2023; 16:132. [PMID: 37069704 PMCID: PMC10111729 DOI: 10.1186/s13071-023-05730-3] [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: 11/11/2022] [Accepted: 03/10/2023] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND The trematode parasite Schistosoma mansoni uses an aquatic snail intermediate and a vertebrate definitive host to complete its life cycle. We previously showed that a key transmission trait-the number of cercariae larvae shed from infected Biomphalaria spp. snails-varies significantly within and between different parasite populations and is genetically controlled by five loci. We investigated the hypothesis that the success of parasite genotypes showing high propagative fitness in the intermediate snail host may be offset by lower reproductive fitness in the definitive vertebrate host. METHODS We investigated this trade-off hypothesis by selecting parasite progeny producing high or low number of larvae in the snail and then comparing fitness parameters and virulence in the rodent host. We infected inbred BALB/c mice using two Schistosoma mansoni parasite lines [high shedder (HS) and low shedder (LS) lines] isolated from F2 progeny generated by genetic crosses between SmLE (HS parent) and SmBRE (LS parent) parasites. We used the F3 progeny to infect two populations of inbred Biomphalaria glabrata snails. We then compared life history traits and virulence of these two selected parasite lines in the rodent host to understand pleiotropic effects of genes determining cercarial shedding in parasites infecting the definitive host. RESULTS HS parasites shed high numbers of cercariae, which had a detrimental impact on snail physiology (measured by laccase-like activity and hemoglobin rate), regardless of the snail genetic background. In contrast, selected LS parasites shed fewer cercariae and had a lower impact on snail physiology. Similarly, HS worms have a higher reproductive fitness and produced more viable F3 miracidia larvae than LS parasites. This increase in transmission is correlated with an increase in virulence toward the rodent host, characterized by stronger hepato-splenomegaly and hepatic fibrosis. CONCLUSIONS These experiments revealed that schistosome parasite propagative and reproductive fitness was positively correlated in intermediate and definitive host (positive pleiotropy). Therefore, we rejected our trade-off hypothesis. We also showed that our selected schistosome lines exhibited low and high shedding phenotype regardless of the intermediate snail host genetic background. .
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Affiliation(s)
- Winka Le Clec’h
- Host Parasite Interaction Program, Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, TX 78245 USA
| | - Frédéric D. Chevalier
- Host Parasite Interaction Program, Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, TX 78245 USA
| | - Kathrin Jutzeler
- Host Parasite Interaction Program, Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, TX 78245 USA
- UT Health, Microbiology, Immunology and Molecular Genetics, San Antonio, TX 78229 USA
| | - Timothy J. C. Anderson
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, TX 78245 USA
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3
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Le Clec'h W, Chevalier FD, Mattos ACA, Strickland A, Diaz R, McDew-White M, Rohr CM, Kinung'hi S, Allan F, Webster BL, Webster JP, Emery AM, Rollinson D, Djirmay AG, Al Mashikhi KM, Al Yafae S, Idris MA, Moné H, Mouahid G, LoVerde P, Marchant JS, Anderson TJC. Genetic analysis of praziquantel response in schistosome parasites implicates a transient receptor potential channel. Sci Transl Med 2021; 13:eabj9114. [PMID: 34936381 DOI: 10.1126/scitranslmed.abj9114] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Winka Le Clec'h
- Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | | | - Ana Carolina A Mattos
- University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | | | - Robbie Diaz
- Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | | | - Claudia M Rohr
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Safari Kinung'hi
- National Institute for Medical Research, Mwanza, United Republic of Tanzania
| | - Fiona Allan
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial College, London, UK.,Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, UK
| | - Bonnie L Webster
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial College, London, UK.,Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, UK
| | - Joanne P Webster
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial College, London, UK.,Centre for Emerging, Endemic and Exotic Diseases (CEEED), Royal Veterinary College, University of London, London, UK
| | - Aidan M Emery
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial College, London, UK.,Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, UK
| | - David Rollinson
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial College, London, UK.,Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, UK
| | - Amadou Garba Djirmay
- Réseau International Schistosomiases Environnemental Aménagement et Lutte (RISEAL), Niamey, Niger.,World Health Organization, Geneva, Switzerland
| | - Khalid M Al Mashikhi
- Directorate General of Health Services, Dhofar Governorate, Salalah, Sultanate of Oman
| | - Salem Al Yafae
- Directorate General of Health Services, Dhofar Governorate, Salalah, Sultanate of Oman
| | | | - Hélène Moné
- Host-Pathogen-Environment Interactions Laboratory, University of Perpignan, Perpignan, France
| | - Gabriel Mouahid
- Host-Pathogen-Environment Interactions Laboratory, University of Perpignan, Perpignan, France
| | - Philip LoVerde
- University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Jonathan S Marchant
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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4
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Le Clec’h W, Chevalier FD, McDew-White M, Menon V, Arya GA, Anderson TJ. Genetic architecture of transmission stage production and virulence in schistosome parasites. Virulence 2021; 12:1508-1526. [PMID: 34167443 PMCID: PMC8237990 DOI: 10.1080/21505594.2021.1932183] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/06/2021] [Accepted: 05/14/2021] [Indexed: 12/30/2022] Open
Abstract
Both theory and experimental data from pathogens suggest that the production of transmission stages should be strongly associated with virulence, but the genetic bases of parasite transmission/virulence traits are poorly understood. The blood fluke Schistosoma mansoni shows extensive variation in numbers of cercariae larvae shed and in their virulence to infected snail hosts, consistent with expected trade-offs between parasite transmission and virulence. We crossed schistosomes from two populations that differ 8-fold in cercarial shedding and in their virulence to Biomphalaria glabrata snail hosts, and determined four-week cercarial shedding profiles in F0 parents, F1 parents and 376 F2 progeny from two independent crosses in inbred snails. Sequencing and linkage analysis revealed that cercarial production is polygenic and controlled by five QTLs (i.e. Quantitative Trait Loci). These QTLs act additively, explaining 28.56% of the phenotypic variation. These results demonstrate that the genetic architecture of key traits relevant to schistosome ecology can be dissected using classical linkage mapping approaches.
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Affiliation(s)
- Winka Le Clec’h
- Texas Biomedical Research Institute, San Antonio, Texas, USA
| | | | | | - Vinay Menon
- Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Grace-Ann Arya
- Texas Biomedical Research Institute, San Antonio, Texas, USA
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Stitz M, Chaparro C, Lu Z, Olzog VJ, Weinberg CE, Blom J, Goesmann A, Grunau C, Grevelding CG. Satellite-Like W-Elements: Repetitive, Transcribed, and Putative Mobile Genetic Factors with Potential Roles for Biology and Evolution of Schistosoma mansoni. Genome Biol Evol 2021; 13:6361599. [PMID: 34469545 PMCID: PMC8490949 DOI: 10.1093/gbe/evab204] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2021] [Indexed: 12/17/2022] Open
Abstract
A large portion of animal and plant genomes consists of noncoding DNA. This part includes tandemly repeated sequences and gained attention because it offers exciting insights into genome biology. We investigated satellite-DNA elements of the platyhelminth Schistosoma mansoni, a parasite with remarkable biological features. Schistosoma mansoni lives in the vasculature of humans causing schistosomiasis, a disease of worldwide importance. Schistosomes are the only trematodes that have evolved separate sexes, and the sexual maturation of the female depends on constant pairing with the male. The schistosome karyotype comprises eight chromosome pairs, males are homogametic (ZZ) and females are heterogametic (ZW). Part of the repetitive DNA of S. mansoni are W-elements (WEs), originally discovered as female-specific satellite DNAs in the heterochromatic block of the W-chromosome. Based on new genome and transcriptome data, we performed a reanalysis of the W-element families (WEFs). Besides a new classification of 19 WEFs, we provide first evidence for stage-, sex-, pairing-, gonad-, and strain-specific/preferential transcription of WEs as well as their mobile nature, deduced from autosomal copies of full-length and partial WEs. Structural analyses suggested roles as sources of noncoding RNA-like hammerhead ribozymes, for which we obtained functional evidence. Finally, the variable WEF occurrence in different schistosome species revealed remarkable divergence. From these results, we propose that WEs potentially exert enduring influence on the biology of S. mansoni. Their variable occurrence in different strains, isolates, and species suggests that schistosome WEs may represent genetic factors taking effect on variability and evolution of the family Schistosomatidae.
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Affiliation(s)
- Maria Stitz
- Institute of Parasitology, BFS, Justus Liebig University Giessen, Giessen, Germany
| | - Cristian Chaparro
- IHPE, CNRS, IFREMER, UPVD, University Montpellier, Perpignan, France
| | - Zhigang Lu
- Institute of Parasitology, BFS, Justus Liebig University Giessen, Giessen, Germany
| | | | | | - Jochen Blom
- Bioinformatics and Systems Biology, Justus Liebig University Giessen, Germany
| | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus Liebig University Giessen, Germany
| | - Christoph Grunau
- IHPE, CNRS, IFREMER, UPVD, University Montpellier, Perpignan, France
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LoVerde PT, Alwan SN, Taylor AB, Rhodes J, Chevalier FD, Anderson TJ, McHardy SF. Rational approach to drug discovery for human schistosomiasis. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 16:140-147. [PMID: 34111649 PMCID: PMC8193065 DOI: 10.1016/j.ijpddr.2021.05.002] [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] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/10/2021] [Accepted: 05/13/2021] [Indexed: 11/19/2022]
Abstract
Human schistosomiasis is a debilitating, life-threatening disease affecting more than 229 million people in as many as 78 countries. There is only one drug of choice effective against all three major species of Schistosoma, praziquantel (PZQ). However, as with many monotherapies, evidence for resistance is emerging in the field and can be selected for in the laboratory. Previously used therapies include oxamniquine (OXA), but shortcomings such as drug resistance and affordability resulted in discontinuation. Employing a genetic, biochemical and molecular approach, a sulfotransferase (SULT-OR) was identified as responsible for OXA drug resistance. By crystallizing SmSULT- OR with OXA, the mode of action of OXA was determined. This information allowed a rational approach to novel drug design. Our team approach with schistosome biologists, medicinal chemists, structural biologists and geneticists has enabled us to develop and test novel drug derivatives of OXA to treat this disease. Using an iterative process for drug development, we have successfully identified derivatives that are effective against all three species of the parasite. One derivative CIDD-0149830 kills 100% of all three human schistosome species within 5 days. The goal is to generate a second therapeutic with a different mode of action that can be used in conjunction with praziquantel to overcome the ever-growing threat of resistance and improve efficacy. The ability and need to design, screen, and develop future, affordable therapeutics to treat human schistosomiasis is critical for successful control program outcomes.
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Affiliation(s)
- Philip T LoVerde
- Departments of Biochemistry and Structural Biology, The University of Texas Health Science Center, San Antonio, TX, USA; Pathology and Laboratory Medicine, The University of Texas Health Science Center, San Antonio, TX, USA.
| | - Sevan N Alwan
- Departments of Biochemistry and Structural Biology, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Alexander B Taylor
- Departments of Biochemistry and Structural Biology, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Jayce Rhodes
- Center for Innovative Drug Discovery, Department of Chemistry, University of Texas at San Antonio, San Antonio, TX, USA
| | - Frédéric D Chevalier
- Program in Host-Pathogen Interactions, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Timothy Jc Anderson
- Program in Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Stanton F McHardy
- Center for Innovative Drug Discovery, Department of Chemistry, University of Texas at San Antonio, San Antonio, TX, USA
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7
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Lu DB, Yu QF, Zhang JY, Sun MT, Gu MM, Webster JP, Liang YS. Extended survival and reproductive potential of single-sex male and female Schistosoma japonicum within definitive hosts. Int J Parasitol 2021; 51:887-891. [PMID: 33905765 DOI: 10.1016/j.ijpara.2021.03.005] [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] [Received: 02/07/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 01/29/2023]
Abstract
Schistosomiasis is caused by dioecious helminths of the genus Schistosoma. Recent work indicated that unpaired female and male schistosomes can survive within their definitive host for at least 1 year, although the viability or fertility of these worms after subsequent pairing remained untested. We performed two experiments on laboratory mice, one with female Schistosoma japonicum exposure first and male schistosomes second and another vice versa. After surviving as single-sex unpaired forms for up to 1 year, 58.5% of male and 70% of female schistosomes were able to mate and produce viable eggs. This highlights an additional biological challenge in achieving elimination of schistosomiasis.
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Affiliation(s)
- Da-Bing Lu
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China; Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China.
| | - Qiu-Fu Yu
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China; Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Jie-Ying Zhang
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China; Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Meng-Tao Sun
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China; Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Man-Man Gu
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China; Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Joanne P Webster
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China; Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathology and Population Sciences, Royal Veterinary College, University of London, London, United Kingdom.
| | - You-Sheng Liang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
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Validation of a human-serum-based in vitro growth method for drug screening on juvenile development stages of Schistosoma mansoni. PLoS Negl Trop Dis 2021; 15:e0009313. [PMID: 33784302 PMCID: PMC8034724 DOI: 10.1371/journal.pntd.0009313] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 04/09/2021] [Accepted: 03/17/2021] [Indexed: 11/19/2022] Open
Abstract
Background Schistosomiasis affects over 200 million people worldwide but only praziquantel is available for treatment and control. Drug discovery is often based on phenotypic drug screening, involving different parasite stages retrieved from infected mice. Aiming to reduce animal use, we validated an in vitro growth method for juvenile Schistosoma mansoni for the purpose of drug sensitivity assays. Methodology/Principal findings We compared inter–batch variability of serum, worm size and organ development, gender distribution, and drug sensitivity between in vitro and in vivo grown worms over different life stages. In vitro developed S. mansoni in Hybridoma medium supplemented with 20% human serum were similar in size as in vivo worms until 28 days of incubation (males 1.4 ± 0.2 mm, females 1.1 ± 0.5 mm long). qPCR analysis revealed similar gender distribution both on newly transformed schistosomula and worms grown for 21 days. Worms developed in vitro and in vivo were similarly sensitive to praziquantel from 7 to 35 days of development with the exception of 21 days of development, where a slightly lower activity was observed for the in vitro grown worms (IC50: 0.54 μM in vitro, 0.14 μM in vivo 72 hours post-incubation). The evaluation of five additional drugs revealed a similar sensitivity on worms developed for 21 days, with the exception of mefloquine, where we observed a 10-fold lower sensitivity on in vitro developed schistosomes when compared to in vivo grown (IC50: 4.43 μM in vitro, 0.48 μM in vivo). Conclusion A large number of juvenile S. mansoni worms can be grown in vitro, which show similar drug sensitivity, gender distribution, size and morphology as the worms recovered from rodents, supporting the use of this method in drug screening efforts. Schistosomiasis is a water-borne disease affecting over 200 million people worldwide and praziquantel is the only drug available for treatment. Although this drug is effective on all Schistosoma species on the adult stage of development, its activity is only partial against early infection stages. In addition, this has been the only drug in use for over 40 years, a situation that poses selective pressure towards resistant worms and highlights the urgent need of new drugs. The discovery and development of new drugs is often based on drug screenings, performed on worms collected from infected mammals. In line with animal welfare recommendations and aiming to increase throughput and reduce the assay costs, we validated a recently established in vitro method to grow juvenile S. mansoni as a drug screening tool. The in vitro established worms have similar gender distribution, size and drug sensitivity as worms collected from mice.
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Liu S, Piao X, Hou N, Cai P, Ma Y, Chen Q. Duplex real-time PCR for sexing Schistosoma japonicum cercariae based on W chromosome-specific genes and its applications. PLoS Negl Trop Dis 2020; 14:e0008609. [PMID: 32822351 PMCID: PMC7467314 DOI: 10.1371/journal.pntd.0008609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 09/02/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023] Open
Abstract
As a unique feature among otherwise hermaphroditic trematodes, Schistosoma species are gonochoric parasites whose sex is genetically determined (ZZ for males and ZW for females). However, schistosome larvae are morphologically identical, and sex can only be discriminated by molecular methods. Here, we integrated published Schistosoma. japonicum transcriptome and genome data to identify W chromosome-specific genes as sex biomarkers. Three W chromosome-specific genes of S. japonicum were identified as sex biomarkers from a panel of 12 genes expressed only in females. An efficient duplex real-time PCR (qPCR) method for sexing cercariae was developed which could identify the sex of cercariae within 2 h without DNA extraction. Moreover, this method can be used to identify not only single-sex but also mixed-sex schistosome-infected snails. We observed a nearly equal proportion of single-male, single-female, and mixed-sex schistosome infections in artificially infected snails. Sex-known schistosome-infected snail models can be efficiently constructed with the aid of duplex qPCR. A field study revealed that single-sex schistosome infections were predominant among naturally infected snails. Finally, a schistosomiasis mouse model based on sex-known cercariae infection was shown to be more reliable than a model based on sex-unknown cercariae infection. The developed duplex qPCR method for sexing S. japonicum cercariae can be widely used for schistosomiasis modeling, genetic experiments, and field-based molecular epidemiological studies. Schistosoma japonicum is a major causative agent of human schistosomiasis. Unlike other parasitic worms, S. japonicum females are determined by the heterogametic sex chromosome (ZW) and males by the homogametic sex chromosome (ZZ). The life cycle of S. japonicum includes the egg, miracidium, mother sporocyst, daughter sporocyst, cercaria, schistosomulum, and adult stages. The sex of adult male and female worms can be morphologically distinguished, whereas the sex of larvae, such as cercariae, can only be discriminated by molecular methods. In this study, we established an efficient duplex real-time PCR method for sexing S. japonicum cercariae based on newly identified W chromosome-specific genes. The established duplex real-time PCR method will facilitate construction of sex-controlled schistosome-infected intermediate host or definitive host models for schistosome-host interplays and schistosomiasis studies. This method is also a powerful tool for investigating the epidemiology of single-sex and mixed-sex schistosome-infected snails in the field.
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Affiliation(s)
- Shuai Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
- * E-mail: (SL); (QC)
| | - Xianyu Piao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Nan Hou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Pengfei Cai
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Yu Ma
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Qijun Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agriculture University, Shenyang, P.R. China
- * E-mail: (SL); (QC)
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Le Clecʼh W, Diaz R, Chevalier FD, McDew-White M, Anderson TJC. Striking differences in virulence, transmission and sporocyst growth dynamics between two schistosome populations. Parasit Vectors 2019; 12:485. [PMID: 31619284 PMCID: PMC6796389 DOI: 10.1186/s13071-019-3741-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/04/2019] [Indexed: 11/12/2022] Open
Abstract
Background Parasite traits associated with transmission success, such as the number of infective stages released from the host, are expected to be optimized by natural selection. However, in the trematode parasite Schistosoma mansoni, a key transmission trait, i.e. the number of cercariae larvae shed from infected Biomphalaria spp. snails, varies significantly within and between different parasite populations and selection experiments demonstrate that this variation has a strong genetic basis. In this study, we compared the transmission strategies of two laboratory schistosome population and their consequences for their snail host. Methods We infected inbred Biomphalaria glabrata snails using two S. mansoni parasite populations (SmBRE and SmLE), both isolated from Brazil and maintained in the laboratory for decades. We compared life history traits of these two parasite populations by quantifying sporocyst growth within infected snails (assayed using qPCR), output of cercaria larvae and impact on snail host physiological response (i.e. hemoglobin rate, laccase-like activity) and survival. Results We identified striking differences in virulence and transmission between the two studied parasite populations. SmBRE (low shedder (LS) parasite population) sheds very low numbers of cercariae and causes minimal impact on the snail physiological response (i.e. laccase-like activity, hemoglobin rate and snail survival). In contrast, SmLE (high shedder (HS) parasite population) sheds 8-fold more cercariae (mean ± SE cercariae per shedding: 284 ± 19 vs 2352 ± 113), causes high snail mortality and has strong impact on snail physiology. We found that HS sporocysts grow more rapidly inside the snail host, comprising up to 60% of cells within infected snails, compared to LS sporocysts, which comprised up to 31%. Cercarial production is strongly correlated to the number of S. mansoni sporocyst cells present within the snail host tissue, although the proportion of sporocyst cells alone does not explain the low cercarial shedding of SmBRE. Conclusions We demonstrated the existence of alternative transmission strategies in the S. mansoni parasite consistent with trade-offs between parasite transmission and host survival: a “boom-bust” strategy characterized by high virulence, high transmission and short duration infections and a “slow and steady” strategy with low virulence, low transmission but long duration of snail host infections.![]()
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Affiliation(s)
- Winka Le Clecʼh
- Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, Texas, 78245, USA.
| | - Robbie Diaz
- Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, Texas, 78245, USA
| | - Frédéric D Chevalier
- Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, Texas, 78245, USA
| | - Marina McDew-White
- Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, Texas, 78245, USA
| | - Timothy J C Anderson
- Texas Biomedical Research Institute, P.O. Box 760549, San Antonio, Texas, 78245, USA
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11
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Xu J, Li C, Duan Z, Yu D, Zhang T, Ma H, Wang X, Zhan T, Xia C. Multiplex PCR for sexing Schistosoma japonicum cercariae and its utility. Parasitol Res 2019; 118:2885-2890. [PMID: 31448385 DOI: 10.1007/s00436-019-06431-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 08/15/2019] [Indexed: 11/26/2022]
Abstract
Accurate discrimination of the Schistosoma japonicum cercariae gender is very important for establishing monosexual infection animal models and for standardizing the real intensity of infection. In this study, a multiplex PCR technique consisting of two pairs of primers, of which one amplifies a 185-bp band specific for the W chromosome and the other amplifies a 420-bp band for the Z chromosome, was established to sex the S. japonicum cercariae. For male cercariae (ZZ), a single 420-bp band is expected, and for female cercariea (ZW), two distinct 185-bp and 420-bp bands can be observed. There was no cross-reaction with S. mansoni, S. haematobium, Clonorchis sinensis, Paragonimus westermani, and Trichinella spiralis. After sexing the cercariae escaped from a single snail, mice in group A were infected with 60 male cercariae and mice of group B were infected with 40 female cercariae. Meanwhile, mice in group C were infected with 10 male and 10 female cercariae that were sexed by multiplex PCR. At 45 days postinfection, male and female adult worms were recovered to verify the accuracy of multiplex PCR for sexing S. japonicum cercariae and to calculate the male and female survival rate and paired worm ratio. Our results showed that the multiplex PCR technique could distinguish male cercariae with 100% accuracy. However, sometimes the discrimination results of multiplex PCR mis-scored mixed sexual cercariae as female cercariae. The mean male adult worm burden in mice of group C was 10.7 ± 2.4, and the mean female adult worm burden was 7.7 ± 2.5. There was a significant difference between the male worm burden and female worm burden in group C. The P value was 0.013. The real paired worm ratio of group C was 74.2% (95%CI 56.6~91.8%). These results demonstrated a male-biased sex ratio in the mice model with equilibrated sex ratio cercariae infection, as predicted by our multiplex PCR technique. In conclusion, our multiplex PCR technique is an effective tool for sexing S. japonicum cercariae, especially for distinguishing male cercariae, which is of great value for establishing monosexual cercariae infection mice models to harvest male adult worms for anti-schistosomal drug screening.
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Affiliation(s)
- Jing Xu
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
| | - Chunxiang Li
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
| | - Zhongliang Duan
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
| | - Dan Yu
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
| | - Tingting Zhang
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
| | - Huihui Ma
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
| | - Xiaoli Wang
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
- Department of Microbiology and Parasitology, Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, China
| | - Tingzheng Zhan
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China
- Department of Parasitology, Guangxi Medical University, Nanning, China
| | - Chaoming Xia
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
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12
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Anderson TJC, LoVerde PT, Le Clec'h W, Chevalier FD. Genetic Crosses and Linkage Mapping in Schistosome Parasites. Trends Parasitol 2018; 34:982-996. [PMID: 30150002 DOI: 10.1016/j.pt.2018.08.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/27/2018] [Accepted: 08/02/2018] [Indexed: 12/14/2022]
Abstract
Linkage mapping - utilizing experimental genetic crosses to examine cosegregation of phenotypic traits with genetic markers - is now 100 years old. Schistosome parasites are exquisitely well suited to linkage mapping approaches because genetic crosses can be conducted in the laboratory, thousands of progeny are produced, and elegant experimental work over the last 75 years has revealed heritable genetic variation in multiple biomedically important traits such as drug resistance, host specificity, and virulence. Application of this approach is timely because the improved genome assembly for Schistosoma mansoni and developing molecular toolkit for schistosomes increase our ability to link phenotype with genotype. We describe current progress and potential future directions of linkage mapping in schistosomes.
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Affiliation(s)
| | | | - Winka Le Clec'h
- Texas Biomedical Research Institute, San Antonio, Texas 78227, USA
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13
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A method for single pair mating in an obligate parasitic nematode. Int J Parasitol 2017; 48:159-165. [PMID: 29111440 DOI: 10.1016/j.ijpara.2017.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/18/2017] [Accepted: 08/21/2017] [Indexed: 11/23/2022]
Abstract
Parasitic nematode species have extremely high levels of genetic diversity, presenting a number of experimental challenges for genomic and genetic work. Consequently, there is a need to develop inbred laboratory strains with reduced levels of polymorphism. The most efficient approach to inbred line development is single pair mating, but this is challenging for obligate parasites where the adult sexual reproductive stages are inside the host, and thus difficult to experimentally manipulate. This paper describes a successful approach to single pair mating of a parasitic nematode, Haemonchus contortus. The method allows for polyandrous mating behaviour and involves the surgical transplantation of a single adult male worm with multiple immature adult females directly into the sheep abomasum. We used a panel of microsatellite markers to monitor and validate the single pair mating crosses and to ensure that the genotypes of progeny and subsequent filial generations were consistent with those expected from a mating between a single female parent of known genotype and a single male parent of unknown genotype. We have established two inbred lines that both show a significant overall reduction in genetic diversity based on microsatellite genotyping and genome-wide single nucleotide polymorphism. There was an approximately 50% reduction in heterozygous SNP sites across the genome in the MHco3.N1 line compared with the MoHco3(ISE) parental strain. The MHco3.N1 inbred line has subsequently been used to provide DNA template for whole genome sequencing of H. contortus. This work provides proof of concept and methodologies for forward genetic analysis of obligate parasitic nematodes.
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14
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Kincaid-Smith J, Boissier J, Allienne JF, Oleaga A, Djuikwo-Teukeng F, Toulza E. A Genome Wide Comparison to Identify Markers to Differentiate the Sex of Larval Stages of Schistosoma haematobium, Schistosoma bovis and their Respective Hybrids. PLoS Negl Trop Dis 2016; 10:e0005138. [PMID: 27861520 PMCID: PMC5115654 DOI: 10.1371/journal.pntd.0005138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/25/2016] [Indexed: 11/28/2022] Open
Abstract
For scientists working on gonochoric organisms, determining sex can be crucial for many biological questions and experimental studies, such as crossbreeding, but it can also be a challenging task, particularly when no sexual dimorphism is visible or cannot be directly observed. In metazoan parasites of the genus Schistosoma responsible for schistosomiasis, sex is genetically determined in the zygote with a female heterogametic ZW/ZZ system. Adult flukes have a pronounced sexual dimorphism, whereas the sexes of the larval stages are morphologically indistinguishable but can be distinguished uniquely by using molecular methods. Therefore, reliable methods are needed to identify the sex of larvae individuals. Here, we present an endpoint PCR-based assay using female-specific sequences identified using a genome-wide comparative analysis between males and females. This work allowed us to identify sex-markers for Schistosoma haematobium and Schistosoma bovis but also the hybrid between both species that has recently emerged in Corsica (France). Five molecular sex-markers were identified and are female-specific in S. haematobium and the hybrid parasite, whereas three of them are also female-specific in S. bovis. These molecular markers will be useful to conduct studies, such as experimental crosses on these disease-causing blood flukes, which are still largely neglected but no longer restricted to tropical areas. Current global changes (environmental and anthropogenic) are expected to promote the spread and transmission of infectious diseases. One of the direct consequences of such changes is the modification of the geographical distribution of species, enabling natural hybridization. Such hybridization is already known to occur in schistosomes, and offspring have been shown to have superior virulence and invasive capacities. The recent outbreak of a hybrid between the human- and animal- infecting schistosomes, S. haematobium x S. bovis, in Europe (Corsica, France) clearly demonstrates this invasive capacity and raises the risk of zoonotic transmission. Therefore, it is important to study such hybrids, and experimental crosses are critical to address this issue. Here, we developed molecular sex markers for S. haematobium and S. bovis in order to distinguish gender and to be able to generate differentially introgressed hybrids, allowing us to investigate parasite fitness.
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Affiliation(s)
- Julien Kincaid-Smith
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, France
| | - Jérôme Boissier
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, France
| | - Jean-François Allienne
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, France
| | - Ana Oleaga
- Parasitology Laboratory, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, Spain
| | | | - Eve Toulza
- Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, France
- * E-mail:
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