1
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Jimenéz-Ruiz E, Li W, Meissner M. Where is the EXIT? Phenotypic screens for new egress factors in apicomplexan parasites. Mol Microbiol 2024; 121:359-367. [PMID: 37740453 DOI: 10.1111/mmi.15166] [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: 06/23/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/24/2023]
Abstract
Apicomplexans, such as Plasmodium and Toxoplasma are obligate intracellular parasites that invade, replicate and finally EXIT their host cell. During replication within a parasitophorous vacuole (PV), the parasites establish an extensive F-actin-containing network that connects individual parasites and is required for material exchange, recycling and the final steps of daughter cell assembly. After multiple rounds of replication, the parasites exit the host cell involving multiple signalling cascades, disassembly of the network, secretion of microneme proteins and activation of the acto-myosin motor. Blocking the host cell EXIT process leads to the formation of large PVs, making the screening for genes involved in exiting the cell relatively straightforward. Given that apicomplexans are highly diverse from other eukaryotes, approximately 30% of all genes are annotated as hypothetical, some apicomplexan-specific factors are likely to be critical during EXIT. This motivated several labs to design and perform forward genetic and phenotypic screens using various approaches, such as random insertion mutagenesis, temperature-sensitive mutants and, more recently, CRISPR/Cas9-mediated targeted editing and conditional mutagenesis. Here we will provide an overview of the technological developments over recent years and the most successful stories that led to the identification of new critical factors in Toxoplasma gondii.
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Affiliation(s)
- Elena Jimenéz-Ruiz
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
| | - Wei Li
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
| | - Markus Meissner
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
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2
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Sassmannshausen J, Bennink S, Distler U, Küchenhoff J, Minns AM, Lindner SE, Burda PC, Tenzer S, Gilberger TW, Pradel G. Comparative proteomics of vesicles essential for the egress of Plasmodium falciparum gametocytes from red blood cells. Mol Microbiol 2024; 121:431-452. [PMID: 37492994 DOI: 10.1111/mmi.15125] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/27/2023]
Abstract
Transmission of malaria parasites to the mosquito is mediated by sexual precursor cells, the gametocytes. Upon entering the mosquito midgut, the gametocytes egress from the enveloping erythrocyte while passing through gametogenesis. Egress follows an inside-out mode during which the membrane of the parasitophorous vacuole (PV) ruptures prior to the erythrocyte membrane. Membrane rupture requires exocytosis of specialized egress vesicles of the parasites; that is, osmiophilic bodies (OBs) involved in rupturing the PV membrane, and vesicles that harbor the perforin-like protein PPLP2 (here termed P-EVs) required for erythrocyte lysis. While some OB proteins have been identified, like G377 and MDV1/Peg3, the majority of egress vesicle-resident proteins is yet unknown. Here, we used high-resolution imaging and BioID methods to study the two egress vesicle types in Plasmodium falciparum gametocytes. We show that OB exocytosis precedes discharge of the P-EVs and that exocytosis of the P-EVs, but not of the OBs, is calcium sensitive. Both vesicle types exhibit distinct proteomes with the majority of proteins located in the OBs. In addition to known egress-related proteins, we identified novel components of OBs and P-EVs, including vesicle-trafficking proteins. Our data provide insight into the immense molecular machinery required for the inside-out egress of P. falciparum gametocytes.
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Affiliation(s)
- Juliane Sassmannshausen
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Ute Distler
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Juliane Küchenhoff
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Allen M Minns
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Scott E Lindner
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Stefan Tenzer
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
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3
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Quansah E, Chen Y, Yang S, Wang J, Sun D, Zhao Y, Chen M, Yu L, Zhang C. CRISPR-Cas13 in malaria parasite: Diagnosis and prospective gene function identification. Front Microbiol 2023; 14:1076947. [PMID: 36760507 PMCID: PMC9905151 DOI: 10.3389/fmicb.2023.1076947] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/03/2023] [Indexed: 01/26/2023] Open
Abstract
Malaria caused by Plasmodium is still a serious public health problem. Genomic editing is essential to understand parasite biology, elucidate mechanical pathways, uncover gene functions, identify novel therapeutic targets, and develop clinical diagnostic tools. Recent advances have seen the development of genomic diagnostic technologies and the emergence of genetic manipulation toolbox comprising a host of several systems for editing the genome of Plasmodium at the DNA, RNA, and protein level. Genomic manipulation at the RNA level is critical as it allows for the functional characterization of several transcripts. Of notice, some developed artificial RNA genome editing tools hinge on the endogenous RNA interference system of Plasmodium. However, Plasmodium lacks a robust RNAi machinery, hampering the progress of these editing tools. CRISPR-Cas13, which belongs to the VI type of the CRISPR system, can specifically bind and cut RNA under the guidance of crRNA, with no or minimal permanent genetic scar on genes. This review summarizes CRISPR-Cas13 system from its discovery, classification, principle of action, and diagnostic platforms. Further, it discusses the application prospects of Cas13-based systems in Plasmodium and highlights its advantages and drawbacks.
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Affiliation(s)
- Elvis Quansah
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Key Laboratory of Zoonoses, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yihuan Chen
- The Second Clinical Medical College, Anhui Medical University, Hefei, China
| | - Shijie Yang
- The Second Clinical Medical College, Anhui Medical University, Hefei, China
| | - Junyan Wang
- The Second Clinical Medical College, Anhui Medical University, Hefei, China
| | - Danhong Sun
- The Second Clinical Medical College, Anhui Medical University, Hefei, China
| | - Yangxi Zhao
- The First Clinical Medical College, Anhui Medical University, Hefei, China
| | - Ming Chen
- The Second Clinical Medical College, Anhui Medical University, Hefei, China
| | - Li Yu
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Key Laboratory of Zoonoses, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China,*Correspondence: Li Yu, ✉
| | - Chao Zhang
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Key Laboratory of Zoonoses, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China,Chao Zhang, ✉
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4
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Nedorezova DD, Dubovichenko MV, Belyaeva EP, Grigorieva ED, Peresadina AV, Kolpashchikov DM. Specificity of oligonucleotide gene therapy (OGT) agents. Theranostics 2022; 12:7132-7157. [PMID: 36276652 PMCID: PMC9576606 DOI: 10.7150/thno.77830] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/11/2022] [Indexed: 11/24/2022] Open
Abstract
Oligonucleotide gene therapy (OGT) agents (e. g. antisense, deoxyribozymes, siRNA and CRISPR/Cas) are promising therapeutic tools. Despite extensive efforts, only few OGT drugs have been approved for clinical use. Besides the problem of efficient delivery to targeted cells, hybridization specificity is a potential limitation of OGT agents. To ensure tight binding, a typical OGT agent hybridizes to the stretch of 15-25 nucleotides of a unique targeted sequence. However, hybrids of such lengths tolerate one or more mismatches under physiological conditions, the problem known as the affinity/specificity dilemma. Here, we assess the scale of this problem by analyzing OGT hybridization-dependent off-target effects (HD OTE) in vitro, in animal models and clinical studies. All OGT agents except deoxyribozymes exhibit HD OTE in vitro, with most thorough evidence of poor specificity reported for siRNA and CRISPR/Cas9. Notably, siRNA suppress non-targeted genes due to (1) the partial complementarity to mRNA 3'-untranslated regions (3'-UTR), and (2) the antisense activity of the sense strand. CRISPR/Cas9 system can cause hundreds of non-intended dsDNA breaks due to low specificity of the guide RNA, which can limit therapeutic applications of CRISPR/Cas9 by ex-vivo formats. Contribution of this effects to the observed in vivo toxicity of OGT agents is unclear and requires further investigation. Locked or peptide nucleic acids improve OGT nuclease resistance but not specificity. Approaches that use RNA marker dependent (conditional) activation of OGT agents may improve specificity but require additional validation in cell culture and in vivo.
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Affiliation(s)
- Daria D. Nedorezova
- Laboratory of Molecular Robotics and Biosensor Materials, International Institute SCAMT, ITMO University, 9 Lomonosov Str., St. Petersburg, 191002, Russian Federation
| | - Mikhail V. Dubovichenko
- Laboratory of Molecular Robotics and Biosensor Materials, International Institute SCAMT, ITMO University, 9 Lomonosov Str., St. Petersburg, 191002, Russian Federation
| | - Ekaterina P. Belyaeva
- Laboratory of Molecular Robotics and Biosensor Materials, International Institute SCAMT, ITMO University, 9 Lomonosov Str., St. Petersburg, 191002, Russian Federation
| | - Ekaterina D. Grigorieva
- Laboratory of Molecular Robotics and Biosensor Materials, International Institute SCAMT, ITMO University, 9 Lomonosov Str., St. Petersburg, 191002, Russian Federation
| | - Arina V. Peresadina
- Laboratory of Molecular Robotics and Biosensor Materials, International Institute SCAMT, ITMO University, 9 Lomonosov Str., St. Petersburg, 191002, Russian Federation
| | - Dmitry M. Kolpashchikov
- Laboratory of Molecular Robotics and Biosensor Materials, International Institute SCAMT, ITMO University, 9 Lomonosov Str., St. Petersburg, 191002, Russian Federation
- Chemistry Department, University of Central Florida, Orlando, FL 32816-2366, USA
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32816, USA
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5
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Ishizaki T, Hernandez S, Paoletta MS, Sanderson T, Bushell ES. CRISPR/Cas9 and genetic screens in malaria parasites: small genomes, big impact. Biochem Soc Trans 2022; 50:1069-1079. [PMID: 35621119 PMCID: PMC9246331 DOI: 10.1042/bst20210281] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/20/2022] [Accepted: 04/29/2022] [Indexed: 12/19/2022]
Abstract
The ∼30 Mb genomes of the Plasmodium parasites that cause malaria each encode ∼5000 genes, but the functions of the majority remain unknown. This is due to a paucity of functional annotation from sequence homology, which is compounded by low genetic tractability compared with many model organisms. In recent years technical breakthroughs have made forward and reverse genome-scale screens in Plasmodium possible. Furthermore, the adaptation of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-Associated protein 9 (CRISPR/Cas9) technology has dramatically improved gene editing efficiency at the single gene level. Here, we review the arrival of genetic screens in malaria parasites to analyse parasite gene function at a genome-scale and their impact on understanding parasite biology. CRISPR/Cas9 screens, which have revolutionised human and model organism research, have not yet been implemented in malaria parasites due to the need for more complex CRISPR/Cas9 gene targeting vector libraries. We therefore introduce the reader to CRISPR-based screens in the related apicomplexan Toxoplasma gondii and discuss how these approaches could be adapted to develop CRISPR/Cas9 based genome-scale genetic screens in malaria parasites. Moreover, since more than half of Plasmodium genes are required for normal asexual blood-stage reproduction, and cannot be targeted using knockout methods, we discuss how CRISPR/Cas9 could be used to scale up conditional gene knockdown approaches to systematically assign function to essential genes.
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Affiliation(s)
- Takahiro Ishizaki
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå, Sweden
| | - Sophia Hernandez
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå, Sweden
| | - Martina S. Paoletta
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå, Sweden
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA - CONICET, Hurlingham, Argentina
| | - Theo Sanderson
- Francis Crick Institute, 1 Midland Rd, London NW1 1AT, U.K
| | - Ellen S.C. Bushell
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå, Sweden
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6
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Kent RS, Briggs EM, Colon BL, Alvarez C, Silva Pereira S, De Niz M. Paving the Way: Contributions of Big Data to Apicomplexan and Kinetoplastid Research. Front Cell Infect Microbiol 2022; 12:900878. [PMID: 35734575 PMCID: PMC9207352 DOI: 10.3389/fcimb.2022.900878] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022] Open
Abstract
In the age of big data an important question is how to ensure we make the most out of the resources we generate. In this review, we discuss the major methods used in Apicomplexan and Kinetoplastid research to produce big datasets and advance our understanding of Plasmodium, Toxoplasma, Cryptosporidium, Trypanosoma and Leishmania biology. We debate the benefits and limitations of the current technologies, and propose future advancements that may be key to improving our use of these techniques. Finally, we consider the difficulties the field faces when trying to make the most of the abundance of data that has already been, and will continue to be, generated.
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Affiliation(s)
- Robyn S. Kent
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, United States
| | - Emma M. Briggs
- Institute for Immunology and Infection Research, School of Biological Sciences, University Edinburgh, Edinburgh, United Kingdom
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Beatrice L. Colon
- Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Catalina Alvarez
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Sara Silva Pereira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Mariana De Niz
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
- Institut Pasteur, Paris, France
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7
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Ratcliffe NA, Furtado Pacheco JP, Dyson P, Castro HC, Gonzalez MS, Azambuja P, Mello CB. Overview of paratransgenesis as a strategy to control pathogen transmission by insect vectors. Parasit Vectors 2022; 15:112. [PMID: 35361286 PMCID: PMC8969276 DOI: 10.1186/s13071-021-05132-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 12/13/2021] [Indexed: 12/12/2022] Open
Abstract
This article presents an overview of paratransgenesis as a strategy to control pathogen transmission by insect vectors. It first briefly summarises some of the disease-causing pathogens vectored by insects and emphasises the need for innovative control methods to counter the threat of resistance by both the vector insect to pesticides and the pathogens to therapeutic drugs. Subsequently, the state of art of paratransgenesis is described, which is a particularly ingenious method currently under development in many important vector insects that could provide an additional powerful tool for use in integrated pest control programmes. The requirements and recent advances of the paratransgenesis technique are detailed and an overview is given of the microorganisms selected for genetic modification, the effector molecules to be expressed and the environmental spread of the transgenic bacteria into wild insect populations. The results of experimental models of paratransgenesis developed with triatomines, mosquitoes, sandflies and tsetse flies are analysed. Finally, the regulatory and safety rules to be satisfied for the successful environmental release of the genetically engineered organisms produced in paratransgenesis are considered.
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Affiliation(s)
- Norman A Ratcliffe
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil. .,Department of Biosciences, Swansea University, Singleton Park, Swansea, UK.
| | - João P Furtado Pacheco
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Paul Dyson
- Institute of Life Science, Medical School, Swansea University, Singleton Park, Swansea, UK
| | - Helena Carla Castro
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Marcelo S Gonzalez
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Patricia Azambuja
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Cicero B Mello
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
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Hentzschel F, Obrova K, Marti M. No evidence for Ago2 translocation from the host erythrocyte into the Plasmodium parasite. Wellcome Open Res 2020; 5:92. [PMID: 33501380 PMCID: PMC7808052 DOI: 10.12688/wellcomeopenres.15852.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Plasmodium parasites rely on various host factors to grow and replicate within red blood cells (RBC). While many host proteins are known that mediate parasite adhesion and invasion, few examples of host enzymes co-opted by the parasite during intracellular development have been described. Recent studies suggested that the host protein Argonaute 2 (Ago2), which is involved in RNA interference, can translocate into the parasite and affect its development. Here, we investigated this hypothesis. Methods: We used several different monoclonal antibodies to test for Ago2 localisation in the human malaria parasite, P. falciparum and rodent P. berghei parasites. In addition, we biochemically fractionated infected red blood cells to localize Ago2. We also quantified parasite growth and sexual commitment in the presence of the Ago2 inhibitor BCI-137. Results: Ago2 localization by fluorescence microscopy produced inconclusive results across the three different antibodies, suggesting cross-reactivity with parasite targets. Biochemical separation of parasite and RBC cytoplasm detected Ago2 only in the RBC cytoplasm and not in the parasite. Inhibition of Ago2 using BCl-137 did not result in altered parasite development. Conclusion: Ago2 localization in infected RBCs by microscopy is confounded by non-specific binding of antibodies. Complementary results using biochemical fractionation and Ago2 detection by western blot did not detect the protein in the parasite cytosol, and growth assays using a specific inhibitor demonstrated that its catalytical activity is not required for parasite development. We therefore conclude that previous data localising Ago2 to parasite ring stages are due to antibody cross reactivity, and that Ago2 is not required for intracellular Plasmodium development.
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Affiliation(s)
- Franziska Hentzschel
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Klara Obrova
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Matthias Marti
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
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9
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Sassmannshausen J, Pradel G, Bennink S. Perforin-Like Proteins of Apicomplexan Parasites. Front Cell Infect Microbiol 2020; 10:578883. [PMID: 33042876 PMCID: PMC7522308 DOI: 10.3389/fcimb.2020.578883] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/13/2020] [Indexed: 11/23/2022] Open
Abstract
Perforins are secreted proteins of eukaryotes, which possess a membrane attack complex/perforin (MACPF) domain enabling them to form pores in the membranes of target cells. In higher eukaryotes, they are assigned to immune defense mechanisms required to kill invading microbes or infected cells. Perforin-like proteins (PLPs) are also found in apicomplexan parasites. Here they play diverse roles during lifecycle progression of the intracellularly replicating protozoans. The apicomplexan PLPs are best studied in Plasmodium and Toxoplasma, the causative agents of malaria and toxoplasmosis, respectively. The PLPs are expressed in the different lifecycle stages of the pathogens and can target and lyse a variety of cell membranes of the invertebrate and mammalian hosts. The PLPs thereby either function in host cell destruction during exit or in overcoming epithelial barriers during tissue passage. In this review, we summarize the various PLPs known for apicomplexan parasites and highlight their roles in Plasmodium and Toxoplasma lifecycle progression.
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Affiliation(s)
- Juliane Sassmannshausen
- Division of Cellular and Applied Infection Biology, Institute of Zoology, Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen, Germany
| | - Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen, Germany
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10
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Hentzschel F, Obrova K, Marti M. No evidence for Ago2 translocation from the host erythrocyte into the Plasmodium parasite. Wellcome Open Res 2020; 5:92. [PMID: 33501380 PMCID: PMC7808052 DOI: 10.12688/wellcomeopenres.15852.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2020] [Indexed: 02/15/2024] Open
Abstract
Background: Plasmodium parasites rely on various host factors to grow and replicate within red blood cells (RBC). While many host proteins are known that mediate parasite adhesion and invasion, few examples of host enzymes co-opted by the parasite during intracellular development have been described. Recent studies suggested that the host protein Argonaute 2 (Ago2), which is involved in RNA interference, can translocate into the parasite and affect its development. Here, we investigated this hypothesis. Methods: We used several different monoclonal antibodies to test for Ago2 localisation in the human malaria parasite, P. falciparum and rodent P. berghei parasites. In addition, we biochemically fractionated infected red blood cells to localize Ago2. We also quantified parasite growth and sexual commitment in the presence of the Ago2 inhibitor BCI-137. Results: Ago2 localization by fluorescence microscopy produced inconclusive results across the three different antibodies, suggesting cross-reactivity with parasite targets. Biochemical separation of parasite and RBC cytoplasm detected Ago2 only in the RBC cytoplasm and not in the parasite. Inhibition of Ago2 using BCl-137 did not result in altered parasite development. Conclusion: Ago2 localization in infected RBCs by microscopy is confounded by non-specific binding of antibodies. Complementary results using biochemical fractionation and Ago2 detection by western blot did not detect the protein in the parasite cytosol, and growth assays using a specific inhibitor demonstrated that its catalytical activity is not required for parasite development. We therefore conclude that previous data localising Ago2 to parasite ring stages are due to antibody cross reactivity, and that Ago2 is not required for intracellular Plasmodium development.
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Affiliation(s)
- Franziska Hentzschel
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Klara Obrova
- Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg, 69120, Germany
| | - Matthias Marti
- Wellcome Center for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
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