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6-Chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine. MOLBANK 2023. [DOI: 10.3390/m1573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
As part of our ongoing scaffold-hopping work on an antikinetoplastid 3-nitroimidazo[1,2-a]pyridine scaffold, we explored 3-nitroimidazo[1,2-b]pyridazine as a potential new antikinetoplastid series. Using conditions previously described by our lab, we obtained 6-chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine with 54% yield. In vitro activity of this compound was evaluated against both the promastigote form of Leishmania donovani, the axenic amastigote form of Leishmania infantum and the trypomastigote blood stream form of Trypanosomabrucei brucei, and its influence on cell viability was assessed on the HepG2 cell line. However, despite good activity against the trypomastigote blood stream form of T. b. brucei (EC50 = 0.38 µM), it showed poor solubility in both HepG2 (CC50 > 7.8 µM) and L. infantum axenic amastigotes (EC50 > 1.6 µM) culture media, associated with a loss of activity against the promastigote form of L. infantum (EC50 > 15.6 µM).
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Hänggeli KPA, Hemphill A, Müller N, Schimanski B, Olias P, Müller J, Boubaker G. Single- and duplex TaqMan-quantitative PCR for determining the copy numbers of integrated selection markers during site-specific mutagenesis in Toxoplasma gondii by CRISPR-Cas9. PLoS One 2022; 17:e0271011. [PMID: 36112587 PMCID: PMC9481009 DOI: 10.1371/journal.pone.0271011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/04/2022] [Indexed: 11/30/2022] Open
Abstract
Herein, we developed a single and a duplex TaqMan quantitative PCR (qPCR) for absolute quantification of copy numbers of integrated dihydrofolate reductase-thymidylate synthase (mdhfr-ts) drug selectable marker for pyrimethamine resistance in Toxoplasma gondii knockouts (KOs). The single TaqMan qPCR amplifies a 174 bp DNA fragment of the inserted mdhfr-ts and of the wild-type (WT) dhfr-ts (wtdhfr-ts) which is present as single copy gene in Toxoplasma and encodes a sensitive enzyme to pyrimethamine. Thus, the copy number of the dhfr-ts fragment in a given DNA quantity from KO parasites with a single site-specific integration should be twice the number of dhfr-ts copies recorded in the same DNA quantity from WT parasites. The duplex TaqMan qPCR allows simultaneous amplification of the 174 bp dhfr-ts fragment and the T. gondii 529-bp repeat element. Accordingly, for a WT DNA sample, the determined number of tachyzoites given by dhfr-ts amplification is equal to the number of tachyzoites determined by amplification of the Toxoplasma 529-bp, resulting thus in a ratio of 1. However, for a KO clone having a single site-specific integration of mdhfr-ts, the calculated ratio is 2. We then applied both approaches to test T. gondii RH mutants in which the major surface antigen (SAG1) was disrupted through insertion of mdhfr-ts using CRISPR-Cas9. Results from both assays were in correlation showing a high accuracy in detecting KOs with multiple integrated mdhfr-ts. Southern blot analyses using BsaBI and DraIII confirmed qPCRs results. Both TaqMan qPCRs are needed for reliable diagnostic of T. gondii KOs following CRISPR-Cas9-mediated mutagenesis, particularly with respect to off-target effects resulting from multiple insertions of mdhfr-ts. The principle of the duplex TaqMan qPCR is applicable for other selectable markers in Toxoplasma. TaqMan qPCR tools may contribute to more frequent use of WT Toxoplasma strains during functional genomics.
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Affiliation(s)
- Kai Pascal Alexander Hänggeli
- Department of Infectious Diseases and Pathobiology, Institute of Parasitology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Andrew Hemphill
- Department of Infectious Diseases and Pathobiology, Institute of Parasitology, University of Bern, Bern, Switzerland
- * E-mail: (GB); (AH)
| | - Norbert Müller
- Department of Infectious Diseases and Pathobiology, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Bernd Schimanski
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Philipp Olias
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Joachim Müller
- Department of Infectious Diseases and Pathobiology, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Ghalia Boubaker
- Department of Infectious Diseases and Pathobiology, Institute of Parasitology, University of Bern, Bern, Switzerland
- * E-mail: (GB); (AH)
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Doherty JF, Matthews BJ. Host Manipulation, Gene Editing, and Non-Traditional Model Organisms: A New Frontier for Behavioral Research? FRONTIERS IN INSECT SCIENCE 2022; 2:938644. [PMID: 38468779 PMCID: PMC10926399 DOI: 10.3389/finsc.2022.938644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 06/13/2022] [Indexed: 03/13/2024]
Abstract
Insects and parasites dominate the biosphere, in terms of known biodiversity and mode of life, respectively. Consequently, insects play a part in many host-parasite systems, either as parasite, host, or both. Moreover, a lot of these systems involve adaptive parasite-induced changes of host phenotype (typically behavior or morphology), which is commonly known as host manipulation. While many host manipulation systems have been described within the last few decades, the proximate mechanisms that underpin host phenotypic change are still largely unknown. Given the intimate co-evolutionary history of host-parasite systems, teasing apart the intricate network of biochemical reactions involved in host manipulation requires the integration of various complementary technologies. In this perspective, we stress the importance of multidisciplinary research on host manipulation, such as high-throughput sequencing methods (genomics and transcriptomics) to search for candidate mechanisms that are activated during a manipulation event. Then, we argue that gene editing technologies, specifically the CRISPR-Cas9 system, are a powerful way to test for the functional roles of candidate mechanisms, in both the parasite and the host. Finally, given the sheer diversity of unique host-parasite systems discovered to date, there is indeed a tremendous potential to create novel non-traditional model systems that could greatly expand our capacity to test the fundamental aspects of behavior and behavioral regulation.
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Ren B, Schmid M, Scheiner M, Mollenkopf HJ, Lucius R, Heitlinger E, Gupta N. Toxoplasma and Eimeria co-opt the host cFos expression for intracellular development in mammalian cells. Comput Struct Biotechnol J 2021; 19:719-731. [PMID: 33510872 PMCID: PMC7817532 DOI: 10.1016/j.csbj.2020.12.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 12/05/2022] Open
Abstract
Gene expression profiles differ significantly between Toxoplasma and Eimeria-infected host cells. Several distinct and shared host-signaling cascades are regulated by coccidian parasites. cFos is one of the few host transcripts mutually regulated during infection by both pathogens. Host cFos is required for optimal in vitro development of E. falciformis and T. gondii. Transcriptomics of parasitized wild-type and cFos-/- host cells reveals a perturbation of cFos network.
Successful asexual reproduction of intracellular pathogens depends on their potential to exploit host resources and subvert antimicrobial defense. In this work, we deployed two prevalent apicomplexan parasites of mammalian cells, namely Toxoplasma gondii and Eimeria falciformis, to identify potential host determinants of infection. Expression analyses of the young adult mouse colonic (YAMC) epithelial cells upon infection by either parasite showed regulation of several distinct transcripts, indicating that these two pathogens program their intracellular niches in a tailored manner. Conversely, parasitized mouse embryonic fibroblasts (MEFs) displayed a divergent transcriptome compared to corresponding YAMC epithelial cells, suggesting that individual host cells mount a fairly discrete response when encountering a particular pathogen. Among several host transcripts similarly altered by T. gondii and E. falciformis, we identified cFos, a master transcription factor, that was consistently induced throughout the infection. Indeed, asexual growth of both parasites was strongly impaired in MEF host cells lacking cFos expression. Last but not the least, our differential transcriptomics of the infected MEFs (parental and cFos-/- mutant) and YAMC epithelial cells disclosed a cFos-centered network, underlying signal cascades, as well as a repertoire of nucleotides- and ion-binding proteins, which presumably act in consort to acclimatize the mammalian cell and thereby facilitate the parasite development.
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Affiliation(s)
- Bingjian Ren
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Manuela Schmid
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Mattea Scheiner
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Hans-Joachim Mollenkopf
- Microarray and Genomics Core Facility, Max-Planck Institute for Infection Biology, Berlin, Germany
| | - Richard Lucius
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Emanuel Heitlinger
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany.,Research Group Ecology and Evolution of Parasite Host Interactions, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany.,Department of Biological Sciences, Birla Institute of Technology and Science Pilani (BITS-P), Hyderabad, India
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Hagen KD, McInally SG, Hilton ND, Dawson SC. Microtubule organelles in Giardia. ADVANCES IN PARASITOLOGY 2020; 107:25-96. [PMID: 32122531 DOI: 10.1016/bs.apar.2019.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Giardia lamblia is a widespread parasitic protist with a complex MT cytoskeleton that is critical for motility, attachment, mitosis and cell division, and transitions between its two life cycle stages-the infectious cyst and flagellated trophozoite. Giardia trophozoites have both highly dynamic and highly stable MT organelles, including the ventral disc, eight flagella, the median body and the funis. The ventral disc, an elaborate MT organelle, is essential for the parasite's attachment to the intestinal villi to avoid peristalsis. Giardia's four flagellar pairs enable swimming motility and may also promote attachment. They are maintained at different equilibrium lengths and are distinguished by their long cytoplasmic regions and novel extra-axonemal structures. The functions of the median body and funis, MT organelles unique to Giardia, remain less understood. In addition to conserved MT-associated proteins, the genome is enriched in ankyrins, NEKs, and novel hypothetical proteins that also associate with the MT cytoskeleton. High-resolution ultrastructural imaging and a current inventory of more than 300 proteins associated with Giardia's MT cytoskeleton lay the groundwork for future mechanistic analyses of parasite attachment to the host, motility, cell division, and encystation/excystation. Giardia's unique MT organelles exemplify the capacity of MT polymers to generate intricate structures that are diverse in both form and function. Thus, beyond its relevance to pathogenesis, the study of Giardia's MT cytoskeleton informs basic cytoskeletal biology and cellular evolution. With the availability of new molecular genetic tools to disrupt gene function, we anticipate a new era of cytoskeletal discovery in Giardia.
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Affiliation(s)
- Kari D Hagen
- Department of Microbiology and Molecular Genetics, UC Davis, Davis, CA, United States
| | - Shane G McInally
- Department of Microbiology and Molecular Genetics, UC Davis, Davis, CA, United States
| | - Nicholas D Hilton
- Department of Microbiology and Molecular Genetics, UC Davis, Davis, CA, United States
| | - Scott C Dawson
- Department of Microbiology and Molecular Genetics, UC Davis, Davis, CA, United States.
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Jex AR, Svärd S, Hagen KD, Starcevich H, Emery-Corbin SJ, Balan B, Nosala C, Dawson SC. Recent advances in functional research in Giardia intestinalis. ADVANCES IN PARASITOLOGY 2020; 107:97-137. [PMID: 32122532 PMCID: PMC7878119 DOI: 10.1016/bs.apar.2019.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review considers current advances in tools to investigate the functional biology of Giardia, it's coding and non-coding genes, features and cellular and molecular biology. We consider major gaps in current knowledge of the parasite and discuss the present state-of-the-art in its in vivo and in vitro cultivation. Advances in in silico tools, including for the modelling non-coding RNAs and genomic elements, as well as detailed exploration of coding genes through inferred homology to model organisms, have provided significant, primary level insight. Improved methods to model the three-dimensional structure of proteins offer new insights into their function, and binding interactions with ligands, other proteins or precursor drugs, and offer substantial opportunities to prioritise proteins for further study and experimentation. These approaches can be supplemented by the growing and highly accessible arsenal of systems-based methods now being applied to Giardia, led by genomic, transcriptomic and proteomic methods, but rapidly incorporating advanced tools for detection of real-time transcription, evaluation of chromatin states and direct measurement of macromolecular complexes. Methods to directly interrogate and perturb gene function have made major leaps in recent years, with CRISPr-interference now available. These approaches, coupled with protein over-expression, fluorescent labelling and in vitro and in vivo imaging, are set to revolutionize the field and herald an exciting time during which the field may finally realise Giardia's long proposed potential as a model parasite and eukaryote.
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Affiliation(s)
- Aaron R Jex
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
| | - Staffan Svärd
- Centre for Biomedicine, Uppsala University, Uppsala, Sweden
| | - Kari D Hagen
- College of Biological Sciences, University of California-Davis, Davis, CA, United States
| | - Hannah Starcevich
- College of Biological Sciences, University of California-Davis, Davis, CA, United States
| | - Samantha J Emery-Corbin
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia
| | - Balu Balan
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia
| | - Chris Nosala
- College of Biological Sciences, University of California-Davis, Davis, CA, United States
| | - Scott C Dawson
- College of Biological Sciences, University of California-Davis, Davis, CA, United States
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Shapiro RS, Chavez A, Collins JJ. CRISPR-based genomic tools for the manipulation of genetically intractable microorganisms. Nat Rev Microbiol 2019; 16:333-339. [PMID: 29599458 DOI: 10.1038/s41579-018-0002-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Genetic manipulation of microorganisms has been crucial in understanding their biology, yet for many microbial species, robust tools for comprehensive genetic analysis were lacking until the advent of CRISPR-Cas-based gene editing techniques. In this Progress article, we discuss advances in CRISPR-based techniques for the genetic analysis of genetically intractable microorganisms, with an emphasis on mycobacteria, fungi and parasites. We discuss how CRISPR-based analyses in these organisms have enabled the discovery of novel gene functions, the investigation of genetic interaction networks and the identification of virulence factors.
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Affiliation(s)
- Rebecca S Shapiro
- Department of Biological Engineering, Institute for Medical Engineering and Science, Synthetic Biology Center, MIT, Cambridge, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Alejandro Chavez
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - James J Collins
- Department of Biological Engineering, Institute for Medical Engineering and Science, Synthetic Biology Center, MIT, Cambridge, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
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Landfear SM. Protean permeases: Diverse roles for membrane transport proteins in kinetoplastid protozoa. Mol Biochem Parasitol 2018; 227:39-46. [PMID: 30590069 DOI: 10.1016/j.molbiopara.2018.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/13/2018] [Accepted: 12/19/2018] [Indexed: 11/26/2022]
Abstract
Kinetoplastid parasites such as Trypanosoma brucei, Trypanosoma cruzi, and Leishmania species rely upon their insect and vertebrate hosts to provide a plethora of nutrients throughout their life cycles. Nutrients and ions critical for parasite survival are taken up across the parasite plasma membrane by transporters and channels, polytopic membrane proteins that provide substrate-specific pores across the hydrophobic barrier. However, transporters and channels serve a wide range of biological functions beyond uptake of nutrients. This article highlights the diversity of activities that these integral membrane proteins serve and underscores the emerging complexity of their functions.
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Affiliation(s)
- Scott M Landfear
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA.
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McInally SG, Hagen KD, Nosala C, Williams J, Nguyen K, Booker J, Jones K, Dawson SC. Robust and stable transcriptional repression in Giardia using CRISPRi. Mol Biol Cell 2018; 30:119-130. [PMID: 30379614 PMCID: PMC6337905 DOI: 10.1091/mbc.e18-09-0605] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Giardia lamblia is a binucleate protistan parasite causing significant diarrheal disease worldwide. An inability to target Cas9 to both nuclei, combined with the lack of nonhomologous end joining and markers for positive selection, has stalled the adaptation of CRISPR/Cas9-mediated genetic tools for this widespread parasite. CRISPR interference (CRISPRi) is a modification of the CRISPR/Cas9 system that directs catalytically inactive Cas9 (dCas9) to target loci for stable transcriptional repression. Using a Giardia nuclear localization signal to target dCas9 to both nuclei, we developed efficient and stable CRISPRi-mediated transcriptional repression of exogenous and endogenous genes in Giardia. Specifically, CRISPRi knockdown of kinesin-2a and kinesin-13 causes severe flagellar length defects that mirror defects with morpholino knockdown. Knockdown of the ventral disk MBP protein also causes severe structural defects that are highly prevalent and persist in the population more than 5 d longer than defects associated with transient morpholino-based knockdown. By expressing two guide RNAs in tandem to simultaneously knock down kinesin-13 and MBP, we created a stable dual knockdown strain with both flagellar length and disk defects. The efficiency and simplicity of CRISPRi in polyploid Giardia allows rapid evaluation of knockdown phenotypes and highlights the utility of CRISPRi for emerging model systems.
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Affiliation(s)
- S G McInally
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - K D Hagen
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - C Nosala
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - J Williams
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - K Nguyen
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - J Booker
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - K Jones
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
| | - Scott C Dawson
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616
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Arroyo-Olarte RD, Thurow L, Kozjak-Pavlovic V, Gupta N. Illuminating pathogen-host intimacy through optogenetics. PLoS Pathog 2018; 14:e1007046. [PMID: 30001435 PMCID: PMC6042787 DOI: 10.1371/journal.ppat.1007046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The birth and subsequent evolution of optogenetics has resulted in an unprecedented advancement in our understanding of the brain. Its outstanding success does usher wider applications; however, the tool remains still largely relegated to neuroscience. Here, we introduce selected aspects of optogenetics with potential applications in infection biology that will not only answer long-standing questions about intracellular pathogens (parasites, bacteria, viruses) but also broaden the dimension of current research in entwined models. In this essay, we illustrate how a judicious integration of optogenetics with routine methods can illuminate the host–pathogen interactions in a way that has not been feasible otherwise.
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Affiliation(s)
- Ruben Dario Arroyo-Olarte
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Laura Thurow
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Vera Kozjak-Pavlovic
- Department of Microbiology, Biocenter, Julius Maximilian University, Würzburg, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- * E-mail:
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