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Marothia M, Behl A, Maurya P, Saini M, Shoaib R, Garg S, Kumari G, Biswas S, Munjal A, Anand S, Kahlon AK, Gupta P, Biswas S, Goswami B, Abdulhameed Almuqdadi HT, Bhowmick IP, Shevtsov M, Ramalingam S, Ranganathan A, Singh S. Targeting PfProhibitin 2-Hu-Hsp70A1A complex as a unique approach towards malaria vaccine development. iScience 2024; 27:109918. [PMID: 38812541 PMCID: PMC11134565 DOI: 10.1016/j.isci.2024.109918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/13/2024] [Accepted: 05/03/2024] [Indexed: 05/31/2024] Open
Abstract
Malaria parasite invasion to host erythrocytes is mediated by multiple interactions between merozoite ligands and erythrocyte receptors that contribute toward the development of disease pathology. Here, we report a novel antigen Plasmodium prohibitin "PfPHB2" and identify its cognate partner "Hsp70A1A" in host erythrocyte that plays a crucial role in mediating host-parasite interaction during merozoite invasion. Using small interfering RNA (siRNA)- and glucosamine-6-phosphate riboswitch (glmS) ribozyme-mediated approach, we show that loss of Hsp70A1A in red blood cells (RBCs) or PfPHB2 in infected red blood cells (iRBCs), respectively, inhibit PfPHB2-Hsp70A1A interaction leading to invasion inhibition. Antibodies targeting PfPHB2 and monoclonal antibody therapeutics against Hsp70A1A efficiently block parasite invasion. Recombinant PfPHB2 binds to RBCs which is inhibited by anti-PfPHB2 antibody and monoclonal antibody against Hsp70A1A. The validation of PfPHB2 to serve as antigen is further supported by detection of anti-PfPHB2 antibody in patient sera. Overall, this study proposes PfPHB2 as vaccine candidate and highlights the use of monoclonal antibody therapeutics for future malaria treatment.
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Affiliation(s)
- Manisha Marothia
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Ankita Behl
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Preeti Maurya
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Monika Saini
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Rumaisha Shoaib
- Department of Bioscience, Jamia Millia Islamia, New Delhi, India
| | - Swati Garg
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Geeta Kumari
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Shreeja Biswas
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Akshay Munjal
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Sakshi Anand
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Amandeep Kaur Kahlon
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Pragya Gupta
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi 110025, India
| | - Saurav Biswas
- Regional Medical Research Center-Northeast Region (RMRC-NE)-ICMR, Dibrugarh 786001, India
| | - Bidhan Goswami
- Multidisciplinary Research Unit, Agartala Government Medical College, Agartala, Tripura (West), India
| | - Haider Thaer Abdulhameed Almuqdadi
- Department of Bioscience, Jamia Millia Islamia, New Delhi, India
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq
| | - Ipsita Pal Bhowmick
- Regional Medical Research Center-Northeast Region (RMRC-NE)-ICMR, Dibrugarh 786001, India
| | - Maxim Shevtsov
- Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany
- Institute of Cytology of the Russian Academy of Sciences (RAS), 194064 St. Petersburg, Russia
- Personalized Medicine Centre, Almazov National Medical Research Centre, Akkuratova Str. 2, 197341 St. Petersburg, Russia
| | - Sivaprakash Ramalingam
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi 110025, India
| | - Anand Ranganathan
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
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2
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Kanyal A, Deshmukh B, Davies H, Mamatharani DV, Farheen D, Treeck M, Karmodiya K. PfHDAC1 is an essential regulator of P. falciparum asexual proliferation and host cell invasion genes with a dynamic genomic occupancy responsive to artemisinin stress. mBio 2024; 15:e0237723. [PMID: 38709067 DOI: 10.1128/mbio.02377-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/26/2024] [Indexed: 05/07/2024] Open
Abstract
Plasmodium falciparum, the deadly protozoan parasite responsible for malaria, has a tightly regulated gene expression profile closely linked to its intraerythrocytic development cycle. Epigenetic modifiers of the histone acetylation code have been identified as key regulators of the parasite's transcriptome but require further investigation. In this study, we map the genomic distribution of Plasmodium falciparum histone deacetylase 1 (PfHDAC1) across the erythrocytic asexual development cycle and find it has a dynamic occupancy over a wide array of developmentally relevant genes. Overexpression of PfHDAC1 results in a progressive increment in parasite load over consecutive rounds of the asexual infection cycle and is associated with enhanced gene expression of multiple families of host cell invasion factors (merozoite surface proteins, rhoptry proteins, etc.) and with increased merozoite invasion efficiency. With the use of class-specific inhibitors, we demonstrate that PfHDAC1 activity in parasites is crucial for timely intraerythrocytic development. Interestingly, overexpression of PfHDAC1 results in decreased sensitivity to frontline-drug dihydroartemisinin in parasites. Furthermore, we identify that artemisinin exposure can interfere with PfHDAC1 abundance and chromatin occupancy, resulting in enrichment over genes implicated in response/resistance to artemisinin. Finally, we identify that dihydroartemisinin exposure can interrupt the in vitro catalytic deacetylase activity and post-translational phosphorylation of PfHDAC1, aspects that are crucial for its genomic function. Collectively, our results demonstrate PfHDAC1 to be a regulator of critical functions in asexual parasite development and host invasion, which is responsive to artemisinin exposure stress and deterministic of resistance to it. IMPORTANCE Malaria is a major public health problem, with the parasite Plasmodium falciparum causing most of the malaria-associated mortality. It is spread by the bite of infected mosquitoes and results in symptoms such as cyclic fever, chills, and headache. However, if left untreated, it can quickly progress to a more severe and life-threatening form. The World Health Organization currently recommends the use of artemisinin combination therapy, and it has worked as a gold standard for many years. Unfortunately, certain countries in southeast Asia and Africa, burdened with a high prevalence of malaria, have reported cases of drug-resistant infections. One of the major problems in controlling malaria is the emergence of artemisinin resistance. Population genomic studies have identified mutations in the Kelch13 gene as a molecular marker for artemisinin resistance. However, several reports thereafter indicated that Kelch13 is not the main mediator but rather hinted at transcriptional deregulation as a major determinant of drug resistance. Earlier, we identified PfGCN5 as a global regulator of stress-responsive genes, which are known to play a central role in artemisinin resistance generation. In this study, we have identified PfHDAC1, a histone deacetylase as a cell cycle regulator, playing an important role in artemisinin resistance generation. Taken together, our study identified key transcriptional regulators that play an important role in artemisinin resistance generation.
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Affiliation(s)
- Abhishek Kanyal
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra, India
| | - Bhagyashree Deshmukh
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra, India
| | - Heledd Davies
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - D V Mamatharani
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra, India
| | - Dilsha Farheen
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra, India
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Krishanpal Karmodiya
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra, India
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3
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Cabral G, Moss WJ, Brown KM. Proteomic approaches for protein kinase substrate identification in Apicomplexa. Mol Biochem Parasitol 2024; 259:111633. [PMID: 38821187 DOI: 10.1016/j.molbiopara.2024.111633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/10/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Apicomplexa is a phylum of protist parasites, notable for causing life-threatening diseases including malaria, toxoplasmosis, cryptosporidiosis, and babesiosis. Apicomplexan pathogenesis is generally a function of lytic replication, dissemination, persistence, host cell modification, and immune subversion. Decades of research have revealed essential roles for apicomplexan protein kinases in establishing infections and promoting pathogenesis. Protein kinases modify their substrates by phosphorylating serine, threonine, tyrosine, or other residues, resulting in rapid functional changes in the target protein. Post-translational modification by phosphorylation can activate or inhibit a substrate, alter its localization, or promote interactions with other proteins or ligands. Deciphering direct kinase substrates is crucial to understand mechanisms of kinase signaling, yet can be challenging due to the transient nature of kinase phosphorylation and potential for downstream indirect phosphorylation events. However, with recent advances in proteomic approaches, our understanding of kinase function in Apicomplexa has improved dramatically. Here, we discuss methods that have been used to identify kinase substrates in apicomplexan parasites, classifying them into three main categories: i) kinase interactome, ii) indirect phosphoproteomics and iii) direct labeling. We briefly discuss each approach, including their advantages and limitations, and highlight representative examples from the Apicomplexa literature. Finally, we conclude each main category by introducing prospective approaches from other fields that would benefit kinase substrate identification in Apicomplexa.
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Affiliation(s)
- Gabriel Cabral
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - William J Moss
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kevin M Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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4
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Charles S, Mahapatra RK. Artificial intelligence based de-novo design for novel Plasmodium falciparum plasmepsin (PM) X inhibitors. J Biomol Struct Dyn 2023:1-16. [PMID: 37943000 DOI: 10.1080/07391102.2023.2279700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 10/27/2023] [Indexed: 11/10/2023]
Abstract
Plasmodium falciparum is the leading cause of malaria with 627,000 deaths annually. Invasion and egress are critical stages for successful infection of the host yet depend on proteins that are extensively pre-processed by various maturases. Plasmepsins (Plasmodium pepsins, abbreviated PM, I-X) are pepsin-like aspartic proteases that are involved in almost all stages of the life cycle. The goal of this study was to use de-novo generative modeling techniques to create novel potential PfPMX inhibitors. A total of 4325 compounds were virtually screened by structural-based docking methods. The obtained hits were utilized to refine a structure-based Ligand Neural Network (L-Net) generative model to generate related compounds. The obtained optimal L-Net Compounds with smina scores ≤ -5.00KCalmol-1 and QED ≥ 0.35 were further taken for amplification utilizing Ligand Based Transformer modeling using Deep generative learning (Drug Explorer/DrugEx). The resulting hits were then subjected to XP Glide conventional Molecular docking and QikProp ADMET screening; molecules with XP Docking score ≤ -7.00KCalmol-1 were retained. Based on their Glide ligand efficiency, originality, and uniqueness, 30 compounds were chosen for binding affinity and MM_GBSA energy determination. Following Induced Fit docking (IFD), 7 compounds were taken for 50 ns MD simulations and FEP/MD calculations. This study reported novel potential PfPMX inhibitors with acceptable ADMET profiles and reasonable synthetic accessibility scores, as well as sufficient docking scores against other PMs were generated. The PfPMX inhibitors reported in this article are promising antimalarials for the next stages of drug development, and the first of their kind to be investigated thoroughly.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ssemuyiga Charles
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar, Odisha, India
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5
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Hart MN, Mohring F, DonVito SM, Thomas JA, Muller-Sienerth N, Wright GJ, Knuepfer E, Saibil HR, Moon RW. Sequential roles for red blood cell binding proteins enable phased commitment to invasion for malaria parasites. Nat Commun 2023; 14:4619. [PMID: 37528099 PMCID: PMC10393984 DOI: 10.1038/s41467-023-40357-z] [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: 09/26/2022] [Accepted: 07/20/2023] [Indexed: 08/03/2023] Open
Abstract
Invasion of red blood cells (RBCs) by Plasmodium merozoites is critical to their continued survival within the host. Two major protein families, the Duffy binding-like proteins (DBPs/EBAs) and the reticulocyte binding like proteins (RBLs/RHs) have been studied extensively in P. falciparum and are hypothesized to have overlapping, but critical roles just prior to host cell entry. The zoonotic malaria parasite, P. knowlesi, has larger invasive merozoites and contains a smaller, less redundant, DBP and RBL repertoire than P. falciparum. One DBP (DBPα) and one RBL, normocyte binding protein Xa (NBPXa) are essential for invasion of human RBCs. Taking advantage of the unique biological features of P. knowlesi and iterative CRISPR-Cas9 genome editing, we determine the precise order of key invasion milestones and demonstrate distinct roles for each family. These distinct roles support a mechanism for phased commitment to invasion and can be targeted synergistically with invasion inhibitory antibodies.
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Affiliation(s)
- Melissa N Hart
- Department of Infection Biology, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, AL9 7TA, UK
| | - Franziska Mohring
- Department of Infection Biology, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Sophia M DonVito
- Department of Infection Biology, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - James A Thomas
- Department of Infection Biology, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | | | - Gavin J Wright
- Wellcome Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK
- Department of Biology, Hull York Medical School, York Biomedical Research Institute, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Ellen Knuepfer
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, AL9 7TA, UK
- Malaria Parasitology Laboratory, Francis Crick Institute, London, NW1 1AT, UK
| | - Helen R Saibil
- ISMB, Biological Sciences, Birkbeck, University of London, Malet St, London, WC1E 7HX, UK
| | - Robert W Moon
- Department of Infection Biology, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
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6
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Triglia T, Scally SW, Seager BA, Pasternak M, Dagley LF, Cowman AF. Plasmepsin X activates the PCRCR complex of Plasmodium falciparum by processing PfRh5 for erythrocyte invasion. Nat Commun 2023; 14:2219. [PMID: 37072430 PMCID: PMC10113190 DOI: 10.1038/s41467-023-37890-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/04/2023] [Indexed: 04/20/2023] Open
Abstract
Plasmodium falciparum causes the most severe form of malaria in humans. The protozoan parasite develops within erythrocytes to mature schizonts, that contain more than 16 merozoites, which egress and invade fresh erythrocytes. The aspartic protease plasmepsin X (PMX), processes proteins and proteases essential for merozoite egress from the schizont and invasion of the host erythrocyte, including the leading vaccine candidate PfRh5. PfRh5 is anchored to the merozoite surface through a 5-membered complex (PCRCR), consisting of Plasmodium thrombospondin-related apical merozoite protein, cysteine-rich small secreted protein, Rh5-interacting protein and cysteine-rich protective antigen. Here, we show that PCRCR is processed by PMX in micronemes to remove the N-terminal prodomain of PhRh5 and this activates the function of the complex unmasking a form that can bind basigin on the erythrocyte membrane and mediate merozoite invasion. The ability to activate PCRCR at a specific time in merozoite invasion most likely masks potential deleterious effects of its function until they are required. These results provide an important understanding of the essential role of PMX and the fine regulation of PCRCR function in P. falciparum biology.
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Affiliation(s)
- Tony Triglia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Stephen W Scally
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Benjamin A Seager
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Michał Pasternak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Laura F Dagley
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.
- University of Melbourne, Melbourne, VIC, 3010, Australia.
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7
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Functional inactivation of Plasmodium falciparum glycogen synthase kinase GSK3 modulates erythrocyte invasion and blocks gametocyte maturation. J Biol Chem 2022; 298:102360. [PMID: 35961464 PMCID: PMC9478393 DOI: 10.1016/j.jbc.2022.102360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/23/2022] Open
Abstract
Malaria is responsible for hundreds of thousands of deaths every year. The lack of an effective vaccine and the global spread of multidrug resistant parasites hampers the fight against the disease and underlines the need for new antimalarial drugs. Central to the pathogenesis of malaria is the proliferation of Plasmodium parasites within human erythrocytes. Parasites invade erythrocytes via a coordinated sequence of receptor–ligand interactions between the parasite and the host cell. Posttranslational modifications such as protein phosphorylation are known to be key regulators in this process and are mediated by protein kinases. For several parasite kinases, including the Plasmodium falciparum glycogen synthase kinase 3 (PfGSK3), inhibitors have been shown to block erythrocyte invasion. Here, we provide an assessment of PfGSK3 function by reverse genetics. Using targeted gene disruption, we show the active gene copy, PfGSK3β, is not essential for asexual blood stage proliferation, although it modulates efficient erythrocyte invasion. We found functional inactivation leads to a 69% decreased growth rate and confirmed this growth defect by rescue experiments with wildtype and catalytically inactive mutants. Functional knockout of PfGSK3β does not lead to transcriptional upregulation of the second copy of PfGSK3. We further analyze expression, localization, and function of PfGSK3β during gametocytogenesis using a parasite line allowing conditional induction of sexual commitment. We demonstrate PfGSK3β-deficient gametocytes show a strikingly malformed morphology leading to the death of parasites in later stages of gametocyte development. Taken together, these findings are important for our understanding and the development of PfGSK3 as an antimalarial target.
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8
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Introini V, Govendir MA, Rayner JC, Cicuta P, Bernabeu M. Biophysical Tools and Concepts Enable Understanding of Asexual Blood Stage Malaria. Front Cell Infect Microbiol 2022; 12:908241. [PMID: 35711656 PMCID: PMC9192966 DOI: 10.3389/fcimb.2022.908241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/27/2022] [Indexed: 12/02/2022] Open
Abstract
Forces and mechanical properties of cells and tissues set constraints on biological functions, and are key determinants of human physiology. Changes in cell mechanics may arise from disease, or directly contribute to pathogenesis. Malaria gives many striking examples. Plasmodium parasites, the causative agents of malaria, are single-celled organisms that cannot survive outside their hosts; thus, thost-pathogen interactions are fundamental for parasite’s biological success and to the host response to infection. These interactions are often combinations of biochemical and mechanical factors, but most research focuses on the molecular side. However, Plasmodium infection of human red blood cells leads to changes in their mechanical properties, which has a crucial impact on disease pathogenesis because of the interaction of infected red blood cells with other human tissues through various adhesion mechanisms, which can be probed and modelled with biophysical techniques. Recently, natural polymorphisms affecting red blood cell biomechanics have also been shown to protect human populations, highlighting the potential of understanding biomechanical factors to inform future vaccines and drug development. Here we review biophysical techniques that have revealed new aspects of Plasmodium falciparum invasion of red blood cells and cytoadhesion of infected cells to the host vasculature. These mechanisms occur differently across Plasmodium species and are linked to malaria pathogenesis. We highlight promising techniques from the fields of bioengineering, immunomechanics, and soft matter physics that could be beneficial for studying malaria. Some approaches might also be applied to other phases of the malaria lifecycle and to apicomplexan infections with complex host-pathogen interactions.
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Affiliation(s)
- Viola Introini
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Viola Introini,
| | - Matt A. Govendir
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
| | - Julian C. Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Pietro Cicuta
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Maria Bernabeu
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
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9
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Towards rainbow portable Cytophone with laser diodes for global disease diagnostics. Sci Rep 2022; 12:8671. [PMID: 35606373 PMCID: PMC9126638 DOI: 10.1038/s41598-022-11452-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 04/18/2022] [Indexed: 11/08/2022] Open
Abstract
In vivo, Cytophone has demonstrated the capability for the early diagnosis of cancer, infection, and cardiovascular disorders through photoacoustic detection of circulating disease markers directly in the bloodstream with an unprecedented 1,000-fold improvement in sensitivity. Nevertheless, a Cytophone with higher specificity and portability is urgently needed. Here, we introduce a novel Cytophone platform that integrates a miniature multispectral laser diode array, time-color coding, and high-speed time-resolved signal processing. Using two-color (808 nm/915 nm) laser diodes, we demonstrated spectral identification of white and red clots, melanoma cells, and hemozoin in malaria-infected erythrocytes against a blood background and artifacts. Data from a Plasmodium yoelii murine model and cultured human P. falciparum were verified in vitro with confocal photothermal and fluorescent microscopy. With these techniques, we detected infected cells within 4 h after invasion, which makes hemozoin promising as a spectrally selective marker at the earliest stages of malaria progression. Along with the findings from our previous application of Cytophone with conventional lasers for the diagnosis of melanoma, bacteremia, sickle anemia, thrombosis, stroke, and abnormal hemoglobin forms, this current finding suggests the potential for the development of a portable rainbow Cytophone with multispectral laser diodes for the identification of these and other diseases.
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10
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Basis for drug selectivity of plasmepsin IX and X inhibition in Plasmodium falciparum and vivax. Structure 2022; 30:947-961.e6. [PMID: 35460613 DOI: 10.1016/j.str.2022.03.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 03/02/2022] [Accepted: 03/29/2022] [Indexed: 11/20/2022]
Abstract
Plasmepsins IX (PMIX) and X (PMX) are essential aspartyl proteases for Plasmodium spp. egress, invasion, and development. WM4 and WM382 inhibit PMIX and PMX in Plasmodium falciparum and P. vivax. WM4 inhibits PMX, while WM382 is a dual inhibitor of PMIX and PMX. To understand their function, we identified protein substrates. Enzyme kinetic and structural analyses identified interactions responsible for drug specificity. PMIX and PMX have similar substrate specificity; however, there are distinct differences for peptide and protein substrates. Differences in WM4 and WM382 binding for PMIX and PMX map to variations in the S' region and engagement of the active site S3 pocket. Structures of PMX reveal interactions and mechanistic detail of drug binding important for development of clinical candidates against these targets.
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11
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Groomes PV, Kanjee U, Duraisingh MT. RBC membrane biomechanics and Plasmodium falciparum invasion: probing beyond ligand-receptor interactions. Trends Parasitol 2022; 38:302-315. [PMID: 34991983 PMCID: PMC8917059 DOI: 10.1016/j.pt.2021.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 10/19/2022]
Abstract
A critical step in malaria blood-stage infections is the invasion of red blood cells (RBCs) by merozoite forms of the Plasmodium parasite. Much progress has been made in defining the parasite ligands and host receptors that mediate this critical step. However, less well understood are the RBC biophysical determinants that influence parasite invasion. In this review we explore how Plasmodium falciparum merozoites interact with the RBC membrane during invasion to modulate RBC deformability and facilitate invasion. We further highlight RBC biomechanics-related polymorphisms that might have been selected for in human populations due to their ability to reduce parasite invasion. Such an understanding will reveal the translational potential of targeting host pathways affecting RBC biomechanical properties for the treatment of malaria.
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Affiliation(s)
- Patrice V Groomes
- Department of Immunology & Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Usheer Kanjee
- Department of Immunology & Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Manoj T Duraisingh
- Department of Immunology & Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
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12
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Shaikh MS, Ali B, Janjua M, Akbar A, Haider SA, Moiz B, Raheem A, Baird JK, Beg MA. Plasmodium in the bone marrow: case series from a hospital in Pakistan, 2007-2015. Malar J 2021; 20:254. [PMID: 34103036 PMCID: PMC8186108 DOI: 10.1186/s12936-021-03792-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/29/2021] [Indexed: 12/12/2022] Open
Abstract
Background Malaria is a life-threatening, multisystem disease caused by the plasmodial parasite with a global incidence of approximately 229 million annually. The parasites are known to have unique and crucial interactions with various body tissues during its life cycle, notably the liver, spleen, and recent work has shown the bone marrow to be a reservoir of infection. Methods This study is a case series of patients in whom examination of bone marrow revealed malarial parasites. A retrospective record review of 35 parasite-positive bone marrow specimens examined at Aga Khan University Hospital (AKUH), Karachi, Pakistan, over the years 2007 to 2015 was conducted. Bone marrow aspirates were collected as per International Council for Standardization in Haematology (ICSH) guidelines. Results The median age of patients was 22 years (range 1–75), and 60 % (n = 21) were male. 22 patients had evidence of Plasmodium falciparum, 12 had evidence of Plasmodium vivax and 1 patient had a mixed infection. Gametocytes and trophozoites were the most common stages identified on both peripheral blood and bone marrow examinations. Indications for bone marrow examination included fever of unknown origin and the workup of cytopenias and malignancies. Conclusions The incidental finding of Plasmodium in samples of bone marrow suggests the reticuloendothelial system may be regularly harbour these parasites, be the infection acute or chronic in character.
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Affiliation(s)
- Muhammad Shariq Shaikh
- Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Stadium Road, 74800, Karachi, Pakistan
| | - Basim Ali
- Aga Khan University, Karachi, Pakistan
| | | | | | | | - Bushra Moiz
- Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Stadium Road, 74800, Karachi, Pakistan
| | - Ahmed Raheem
- Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Stadium Road, 74800, Karachi, Pakistan
| | - John Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mohammad Asim Beg
- Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Stadium Road, 74800, Karachi, Pakistan.
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13
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Liffner B, Balbin JM, Wichers JS, Gilberger TW, Wilson DW. The Ins and Outs of Plasmodium Rhoptries, Focusing on the Cytosolic Side. Trends Parasitol 2021; 37:638-650. [PMID: 33941492 DOI: 10.1016/j.pt.2021.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/19/2021] [Accepted: 03/15/2021] [Indexed: 01/13/2023]
Abstract
Parasites of the genus Plasmodium cause human and animal malaria, leading to significant health and economic impacts. A key aspect of the complex life cycle of Plasmodium parasites is the invasion of the parasite into its host cell, which is mediated by secretory organelles. The largest of these organelles, the rhoptry, undergoes rapid and profound physiological changes when it secretes its contents during merozoite and sporozoite invasion of the host erythrocyte and hepatocyte, respectively. Here we discuss recent advancements in our understanding of the dynamic rhoptry biology during the parasite's invasive stages, with a focus on the roles of cytosolically exposed rhoptry-interacting proteins (C-RIPs). We explore potential similarities between the molecular mechanisms driving merozoite and sporozoite rhoptry function.
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Affiliation(s)
- Benjamin Liffner
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Juan Miguel Balbin
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Jan Stephan Wichers
- Centre for Structural Systems Biology, 22607, Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Tim-Wolf Gilberger
- Centre for Structural Systems Biology, 22607, Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; Biology Department, University of Hamburg, 20146 Hamburg, Germany
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia; Burnet Institute, 85 Commercial Road, Melbourne 3004, Victoria, Australia.
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14
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Thiam LG, Nyarko PB, Kusi KA, Niang M, Aniweh Y, Awandare GA. Blood donor variability is a modulatory factor for P. falciparum invasion phenotyping assays. Sci Rep 2021; 11:7129. [PMID: 33782439 PMCID: PMC8007732 DOI: 10.1038/s41598-021-86438-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 03/12/2021] [Indexed: 11/26/2022] Open
Abstract
Human erythrocytes are indispensable for Plasmodium falciparum development. Unlike other eukaryotic cells, there is no existing erythroid cell line capable of supporting long-term P. falciparum in vitro experiments. Consequently, invasion phenotyping experiments rely on erythrocytes of different individuals. However, the contribution of the erythrocytes variation in influencing invasion rates remains unknown, which represents a challenge for conducting large-scale comparative studies. Here, we used erythrocytes of different blood groups harboring different hemoglobin genotypes to assess the relative contribution of blood donor variability in P. falciparum invasion phenotyping assays. For each donor, we investigated the relationship between parasite invasion phenotypes and erythrocyte phenotypic characteristics, including the expression levels of surface receptors (e.g. the human glycophorins A and C, the complement receptor 1 and decay accelerating factor), blood groups (e.g. ABO/Rh system), and hemoglobin genotypes (e.g. AA, AS and AC). Across all donors, there were significant differences in invasion efficiency following treatment with either neuraminidase, trypsin or chymotrypsin relative to the control erythrocytes. Primarily, we showed that the levels of key erythrocyte surface receptors and their sensitivity to enzyme treatment significantly differed across donors. However, invasion efficiency did not correlate with susceptibility to enzyme treatment or with the levels of the selected erythrocyte surface receptors. Furthermore, we found no relationship between P. falciparum invasion phenotype and blood group or hemoglobin genotype. Altogether, our findings demonstrate the need to consider erythrocyte donor uniformity and anticipate challenges associated with blood donor variability in early stages of large-scale study design.
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Affiliation(s)
- Laty G Thiam
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.,Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.,G4 MEGA Vaccines, Institut Pasteur de Dakar, Dakar, Senegal
| | - Prince B Nyarko
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.,Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.,Laboratory of Pathogen-Host Interaction, UMR5235, CNRS, University of Montpellier, Montpellier, France
| | - Kwadwo A Kusi
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.,Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Makhtar Niang
- Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana. .,Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana. .,Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.
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15
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Hitz E, Grüninger O, Passecker A, Wyss M, Scheurer C, Wittlin S, Beck HP, Brancucci NMB, Voss TS. The catalytic subunit of Plasmodium falciparum casein kinase 2 is essential for gametocytogenesis. Commun Biol 2021; 4:336. [PMID: 33712726 PMCID: PMC7954856 DOI: 10.1038/s42003-021-01873-0] [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] [Received: 06/24/2020] [Accepted: 02/17/2021] [Indexed: 01/31/2023] Open
Abstract
Casein kinase 2 (CK2) is a pleiotropic kinase phosphorylating substrates in different cellular compartments in eukaryotes. In the malaria parasite Plasmodium falciparum, PfCK2 is vital for asexual proliferation of blood-stage parasites. Here, we applied CRISPR/Cas9-based gene editing to investigate the function of the PfCK2α catalytic subunit in gametocytes, the sexual forms of the parasite that are essential for malaria transmission. We show that PfCK2α localizes to the nucleus and cytoplasm in asexual and sexual parasites alike. Conditional knockdown of PfCK2α expression prevented the transition of stage IV into transmission-competent stage V gametocytes, whereas the conditional knockout of pfck2a completely blocked gametocyte maturation already at an earlier stage of sexual differentiation. In summary, our results demonstrate that PfCK2α is not only essential for asexual but also sexual development of P. falciparum blood-stage parasites and encourage studies exploring PfCK2α as a potential target for dual-active antimalarial drugs.
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Affiliation(s)
- Eva Hitz
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Olivia Grüninger
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Armin Passecker
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Matthias Wyss
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Christian Scheurer
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Sergio Wittlin
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Hans-Peter Beck
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Nicolas M. B. Brancucci
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
| | - Till S. Voss
- grid.416786.a0000 0004 0587 0574Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland ,grid.6612.30000 0004 1937 0642University of Basel, 4001 Basel, Switzerland
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16
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Adderley J, Williamson T, Doerig C. Parasite and Host Erythrocyte Kinomics of Plasmodium Infection. Trends Parasitol 2021; 37:508-524. [PMID: 33593681 DOI: 10.1016/j.pt.2021.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/06/2023]
Abstract
Malaria remains a heavy public health and socioeconomic burden in tropical and subtropical regions. Increasing resistance against front-line treatments implies that novel targets for antimalarial intervention are urgently required. Protein kinases of both the parasites and their host cells possess strong potential in this respect. We present an overview of the updated kinome of Plasmodium falciparum, the species that is the largest contributor to malaria mortality, and of current knowledge pertaining to the function of parasite-encoded protein kinases during the parasite's life cycle. Furthermore, we detail recent advances in drug initiatives targeting Plasmodium kinases and outline the potential of protein kinases in the context of the growing field of host-directed therapies, which is currently being explored as a novel way to combat parasite drug resistance.
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Affiliation(s)
- Jack Adderley
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Tayla Williamson
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Christian Doerig
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia.
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17
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Blake TCA, Haase S, Baum J. Actomyosin forces and the energetics of red blood cell invasion by the malaria parasite Plasmodium falciparum. PLoS Pathog 2020; 16:e1009007. [PMID: 33104759 PMCID: PMC7644091 DOI: 10.1371/journal.ppat.1009007] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/05/2020] [Accepted: 09/28/2020] [Indexed: 11/29/2022] Open
Abstract
All symptoms of malaria disease are associated with the asexual blood stages of development, involving cycles of red blood cell (RBC) invasion and egress by the Plasmodium spp. merozoite. Merozoite invasion is rapid and is actively powered by a parasite actomyosin motor. The current accepted model for actomyosin force generation envisages arrays of parasite myosins, pushing against short actin filaments connected to the external milieu that drive the merozoite forwards into the RBC. In Plasmodium falciparum, the most virulent human malaria species, Myosin A (PfMyoA) is critical for parasite replication. However, the precise function of PfMyoA in invasion, its regulation, the role of other myosins and overall energetics of invasion remain unclear. Here, we developed a conditional mutagenesis strategy combined with live video microscopy to probe PfMyoA function and that of the auxiliary motor PfMyoB in invasion. By imaging conditional mutants with increasing defects in force production, based on disruption to a key PfMyoA phospho-regulation site, the absence of the PfMyoA essential light chain, or complete motor absence, we define three distinct stages of incomplete RBC invasion. These three defects reveal three energetic barriers to successful entry: RBC deformation (pre-entry), mid-invasion initiation, and completion of internalisation, each requiring an active parasite motor. In defining distinct energetic barriers to invasion, these data illuminate the mechanical challenges faced in this remarkable process of protozoan parasitism, highlighting distinct myosin functions and identifying potential targets for preventing malaria pathogenesis.
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Affiliation(s)
- Thomas C. A. Blake
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Silvia Haase
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Jake Baum
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
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18
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Favuzza P, de Lera Ruiz M, Thompson JK, Triglia T, Ngo A, Steel RWJ, Vavrek M, Christensen J, Healer J, Boyce C, Guo Z, Hu M, Khan T, Murgolo N, Zhao L, Penington JS, Reaksudsan K, Jarman K, Dietrich MH, Richardson L, Guo KY, Lopaticki S, Tham WH, Rottmann M, Papenfuss T, Robbins JA, Boddey JA, Sleebs BE, Sabroux HJ, McCauley JA, Olsen DB, Cowman AF. Dual Plasmepsin-Targeting Antimalarial Agents Disrupt Multiple Stages of the Malaria Parasite Life Cycle. Cell Host Microbe 2020; 27:642-658.e12. [PMID: 32109369 PMCID: PMC7146544 DOI: 10.1016/j.chom.2020.02.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/22/2019] [Accepted: 02/11/2020] [Indexed: 01/07/2023]
Abstract
Artemisin combination therapy (ACT) is the main treatment option for malaria, which is caused by the intracellular parasite Plasmodium. However, increased resistance to ACT highlights the importance of finding new drugs. Recently, the aspartic proteases Plasmepsin IX and X (PMIX and PMX) were identified as promising drug targets. In this study, we describe dual inhibitors of PMIX and PMX, including WM382, that block multiple stages of the Plasmodium life cycle. We demonstrate that PMX is a master modulator of merozoite invasion and direct maturation of proteins required for invasion, parasite development, and egress. Oral administration of WM382 cured mice of P. berghei and prevented blood infection from the liver. In addition, WM382 was efficacious against P. falciparum asexual infection in humanized mice and prevented transmission to mosquitoes. Selection of resistant P. falciparum in vitro was not achievable. Together, these show that dual PMIX and PMX inhibitors are promising candidates for malaria treatment and prevention.
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Affiliation(s)
- Paola Favuzza
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Jennifer K Thompson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Tony Triglia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Anna Ngo
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Ryan W J Steel
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Marissa Vavrek
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | - Janni Christensen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Julie Healer
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Zhuyan Guo
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | - Mengwei Hu
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | - Tanweer Khan
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | - Nicholas Murgolo
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | - Lianyun Zhao
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | | | - Kitsanapong Reaksudsan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kate Jarman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Melanie H Dietrich
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Lachlan Richardson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kai-Yuan Guo
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Sash Lopaticki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Wai-Hong Tham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Tony Papenfuss
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Justin A Boddey
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - Hélène Jousset Sabroux
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia
| | - John A McCauley
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA
| | - David B Olsen
- Merck & Co., Inc., 770 Sumneytown Pike, West Point, PA 19486, USA.
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; University of Melbourne, Melbourne, VIC 3010, Australia.
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19
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Dans MG, Weiss GE, Wilson DW, Sleebs BE, Crabb BS, de Koning-Ward TF, Gilson PR. Screening the Medicines for Malaria Venture Pathogen Box for invasion and egress inhibitors of the blood stage of Plasmodium falciparum reveals several inhibitory compounds. Int J Parasitol 2020; 50:235-252. [PMID: 32135179 DOI: 10.1016/j.ijpara.2020.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/30/2019] [Accepted: 01/05/2020] [Indexed: 12/14/2022]
Abstract
With emerging resistance to frontline treatments, it is vital that new drugs are identified to target Plasmodium falciparum. One of the most critical processes during parasites asexual lifecycle is the invasion and subsequent egress of red blood cells (RBCs). Many unique parasite ligands, receptors and enzymes are employed during egress and invasion that are essential for parasite proliferation and survival, therefore making these processes druggable targets. To identify potential inhibitors of egress and invasion, we screened the Medicines for Malaria Venture Pathogen Box, a 400 compound library against neglected tropical diseases, including 125 with antimalarial activity. For this screen, we utilised transgenic parasites expressing a bioluminescent reporter, nanoluciferase (Nluc), to measure inhibition of parasite egress and invasion in the presence of the Pathogen Box compounds. At a concentration of 2 µM, we found 15 compounds that inhibited parasite egress by >40% and 24 invasion-specific compounds that inhibited invasion by >90%. We further characterised 11 of these inhibitors through cell-based assays and live cell microscopy, and found two compounds that inhibited merozoite maturation in schizonts, one compound that inhibited merozoite egress, one compound that directly inhibited parasite invasion and one compound that slowed down invasion and arrested ring formation. The remaining compounds were general growth inhibitors that acted during the egress and invasion phase of the cell cycle. We found the sulfonylpiperazine, MMV020291, to be the most invasion-specific inhibitor, blocking successful merozoite internalisation within human RBCs and having no substantial effect on other stages of the cell cycle. This has significant implications for the possible development of an invasion-specific inhibitor as an antimalarial in a combination based therapy, in addition to being a useful tool for studying the biology of the invading parasite.
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Affiliation(s)
- Madeline G Dans
- Burnet Institute, Melbourne, Victoria 3004, Australia; School of Medicine, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Greta E Weiss
- Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, The University of Adelaide, Adelaide, South Australia 5005, Australia; Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia; The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, Victoria 3004, Australia; The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Paul R Gilson
- Burnet Institute, Melbourne, Victoria 3004, Australia.
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20
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Mapping and functional analysis of heterochromatin protein 1 phosphorylation in the malaria parasite Plasmodium falciparum. Sci Rep 2019; 9:16720. [PMID: 31723180 PMCID: PMC6853920 DOI: 10.1038/s41598-019-53325-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 10/30/2019] [Indexed: 01/01/2023] Open
Abstract
Previous studies in model eukaryotes have demonstrated that phosphorylation of heterochromatin protein 1 (HP1) is important for dynamically regulating its various functions. However, in the malaria parasite Plasmodium falciparum both the function of HP1 phosphorylation and the identity of the protein kinases targeting HP1 are still elusive. In order to functionally analyze phosphorylation of P. falciparum HP1 (PfHP1), we first mapped PfHP1 phosphorylation sites by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis of native PfHP1, which identified motifs from which potential kinases could be predicted; in particular, several phosphorylated residues were embedded in motifs rich in acidic residues, reminiscent of targets for P. falciparum casein kinase 2 (PfCK2). Secondly, we tested recombinant PfCK2 and a number of additional protein kinases for their ability to phosphorylate PfHP1 in in vitro kinase assays. These experiments validated our prediction that PfHP1 acts as a substrate for PfCK2. Furthermore, LC-MS/MS analysis showed that PfCK2 phosphorylates three clustered serine residues in an acidic motif within the central hinge region of PfHP1. To study the role of PfHP1 phosphorylation in live parasites we used CRISPR/Cas9-mediated genome editing to generate a number of conditional PfHP1 phosphomutants based on the DiCre/LoxP system. Our studies revealed that neither PfCK2-dependent phosphorylation of PfHP1, nor phosphorylation of the hinge domain in general, affect PfHP1's ability to localize to heterochromatin, and that PfHP1 phosphorylation in this region is dispensable for the proliferation of P. falciparum blood stage parasites.
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21
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Phosphorylation of the VAR2CSA extracellular region is associated with enhanced adhesive properties to the placental receptor CSA. PLoS Biol 2019; 17:e3000308. [PMID: 31181082 PMCID: PMC6586358 DOI: 10.1371/journal.pbio.3000308] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/20/2019] [Accepted: 05/16/2019] [Indexed: 12/26/2022] Open
Abstract
Plasmodium falciparum is the main cause of disease and death from malaria. P. falciparum virulence resides in the ability of infected erythrocytes (IEs) to sequester in various tissues through the interaction between members of the polymorphic P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesin family to various host receptors. Here, we investigated the effect of phosphorylation of variant surface antigen 2-CSA (VAR2CSA), a member of the PfEMP1 family associated to placental sequestration, on its capacity to adhere to chondroitin sulfate A (CSA) present on the placental syncytium. We showed that phosphatase treatment of IEs impairs cytoadhesion to CSA. MS analysis of recombinant VAR2CSA phosphosites prior to and after phosphatase treatment, as well as of native VAR2CSA expressed on IEs, identified critical phosphoresidues associated with CSA binding. Site-directed mutagenesis on recombinant VAR2CSA of 3 phosphoresidues localised within the CSA-binding region confirmed in vitro their functional importance. Furthermore, using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 nuclease (CRISPR/Cas9), we generated a parasite line in which the phosphoresidue T934 is changed to alanine and showed that this mutation strongly impairs IEs cytoadhesion to CSA. Taken together, these results demonstrate that phosphorylation of the extracellular region of VAR2CSA plays a major role in IEs cytoadhesion to CSA and provide new molecular insights for strategies aiming to reduce the morbidity and mortality of PM.
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22
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Salinas ND, Tang WK, Tolia NH. Blood-Stage Malaria Parasite Antigens: Structure, Function, and Vaccine Potential. J Mol Biol 2019; 431:4259-4280. [PMID: 31103771 DOI: 10.1016/j.jmb.2019.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/22/2019] [Accepted: 05/08/2019] [Indexed: 10/26/2022]
Abstract
Plasmodium parasites are the causative agent of malaria, a disease that kills approximately 450,000 individuals annually, with the majority of deaths occurring in children under the age of 5 years and the development of a malaria vaccine is a global health priority. Plasmodium parasites undergo a complex life cycle requiring numerous diverse protein families. The blood stage of parasite development results in the clinical manifestation of disease. A vaccine that disrupts the blood stage is highly desired and will aid in the control of malaria. The blood stage comprises multiple steps: invasion of, asexual growth within, and egress from red blood cells. This review focuses on blood-stage antigens with emphasis on antigen structure, antigen function, neutralizing antibodies, and vaccine potential.
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Affiliation(s)
- Nichole D Salinas
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA
| | - Wai Kwan Tang
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA
| | - Niraj H Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA.
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23
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Evidence against a Role of Elevated Intracellular Ca 2+ during Plasmodium falciparum Preinvasion. Biophys J 2019; 114:1695-1706. [PMID: 29642038 DOI: 10.1016/j.bpj.2018.02.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/19/2018] [Accepted: 02/09/2018] [Indexed: 12/11/2022] Open
Abstract
Severe malaria is primarily caused by Plasmodium falciparum parasites during their asexual reproduction cycle within red blood cells. One of the least understood stages in this cycle is the brief preinvasion period during which merozoite-red cell contacts lead to apical alignment of the merozoite in readiness for penetration, a stage of major relevance in the control of invasion efficiency. Red blood cell deformations associated with this process were suggested to be active plasma membrane responses mediated by transients of elevated intracellular calcium. Few studies have addressed this hypothesis because of technical challenges, and the results remained inconclusive. Here, Fluo-4 was used as a fluorescent calcium indicator with optimized protocols to investigate the distribution of the dye in red blood cell populations used as P. falciparum invasion targets in egress-invasion assays. Preinvasion dynamics was observed simultaneously under bright-field and fluorescence microscopy by recording egress-invasion events. All the egress-invasion sequences showed red blood cell deformations of varied intensities during the preinvasion period and the echinocytic changes that follow during invasion. Intraerythrocytic calcium signals were absent throughout this interval in over half the records and totally absent during the preinvasion period, regardless of deformation strength. When present, calcium signals were of a punctate modality, initiated within merozoites already poised for invasion. These results argue against a role of elevated intracellular calcium during the preinvasion stage. We suggest an alternative mechanism of merozoite-induced preinvasion deformations based on passive red cell responses to transient agonist-receptor interactions associated with the formation of adhesive coat filaments.
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24
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Abstract
Plasmodium species cause malaria by proliferating in human erythrocytes. Invasion of immunologically privileged erythrocytes provides a relatively protective niche as well as access to a rich source of nutrients. Plasmodium spp. target erythrocytes of different ages, but share a common mechanism of invasion. Specific engagement of erythrocyte receptors defines target cell tropism, activating downstream events and resulting in the physical penetration of the erythrocyte, powered by the parasite's actinomyosin-based motor. Here we review the latest in our understanding of the molecular composition of this highly complex and fascinating biological process.
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25
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Human Cyclophilin B forms part of a multi-protein complex during erythrocyte invasion by Plasmodium falciparum. Nat Commun 2017; 8:1548. [PMID: 29146974 PMCID: PMC5691159 DOI: 10.1038/s41467-017-01638-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 10/04/2017] [Indexed: 12/13/2022] Open
Abstract
Invasion of human erythrocytes by Plasmodium falciparum merozoites involves multiple interactions between host receptors and their merozoite ligands. Here we report human Cyclophilin B as a receptor for PfRhopH3 during merozoite invasion. Localization and binding studies show that Cyclophilin B is present on the erythrocytes and binds strongly to merozoites. We demonstrate that PfRhopH3 binds to the RBCs and their treatment with Cyclosporin A prevents merozoite invasion. We also show a multi-protein complex involving Cyclophilin B and Basigin, as well as PfRhopH3 and PfRh5 that aids the invasion. Furthermore, we report identification of a de novo peptide CDP3 that binds Cyclophilin B and blocks invasion by up to 80%. Collectively, our data provide evidence of compounded interactions between host receptors and merozoite surface proteins and paves the way for developing peptide and small-molecules that inhibit the protein−protein interactions, individually or in toto, leading to abrogation of the invasion process. Invasion of red blood cells by Plasmodium falciparum is a complex process and relies on several receptor-ligand interactions. Here, the authors show that human cyclophilin B binds Plasmodium surface protein PfRhopH3 and that interruption of this interaction reduces invasion by 80%.
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26
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Abstract
Complications arising from malaria are a concern for public health authorities worldwide, since the annual caseload in humans usually exceeds millions. Of more than 160 species of Plasmodium, only 4 infect humans, with the most severe cases ascribed to Plasmodium falciparum and the most prevalent to Plasmodium vivax. Over the past 70 years, since World War II, when the first antimalarial drugs were widely used, many efforts have been made to combat this disease, including vectorial control, new drug discoveries and genetic and molecular approaches. Molecular approaches, such as glycobiology, may lead to new therapeutic targets (both in the host and the parasites), since all interactions are mediated by carbohydrates or glycan moieties decorating both cellular surfaces from parasite and host cells. In this review, we address the carbohydrate-mediated glycobiology that directly affects Plasmodium survival or host resistance.
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Affiliation(s)
- Pollyanna S Gomes
- Departamento de Imunologia, Instituto de Microbiologia, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Daniel F Feijó
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz)Salvador, Brazil
| | - Alexandre Morrot
- Departamento de Imunologia, Instituto de Microbiologia, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil.,Instituto Oswaldo CruzFiocruz, Rio de Janeiro, Brazil
| | - Celio G Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
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27
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Plasmodium falciparum erythrocyte-binding antigen 175 triggers a biophysical change in the red blood cell that facilitates invasion. Proc Natl Acad Sci U S A 2017; 114:4225-4230. [PMID: 28373555 DOI: 10.1073/pnas.1620843114] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Invasion of the red blood cell (RBC) by the Plasmodium parasite defines the start of malaria disease pathogenesis. To date, experimental investigations into invasion have focused predominantly on the role of parasite adhesins or signaling pathways and the identity of binding receptors on the red cell surface. A potential role for signaling pathways within the erythrocyte, which might alter red cell biophysical properties to facilitate invasion, has largely been ignored. The parasite erythrocyte-binding antigen 175 (EBA175), a protein required for entry in most parasite strains, plays a key role by binding to glycophorin A (GPA) on the red cell surface, although the function of this binding interaction is unknown. Here, using real-time deformability cytometry and flicker spectroscopy to define biophysical properties of the erythrocyte, we show that EBA175 binding to GPA leads to an increase in the cytoskeletal tension of the red cell and a reduction in the bending modulus of the cell's membrane. We isolate the changes in the cytoskeleton and membrane and show that reduction in the bending modulus is directly correlated with parasite invasion efficiency. These data strongly imply that the malaria parasite primes the erythrocyte surface through its binding antigens, altering the biophysical nature of the target cell and thus reducing a critical energy barrier to invasion. This finding would constitute a major change in our concept of malaria parasite invasion, suggesting it is, in fact, a balance between parasite and host cell physical forces working together to facilitate entry.
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28
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McCoy JM, Stewart RJ, Uboldi AD, Li D, Schröder J, Scott NE, Papenfuss AT, Lehane AM, Foster LJ, Tonkin CJ. A forward genetic screen identifies a negative regulator of rapid Ca 2+-dependent cell egress (MS1) in the intracellular parasite Toxoplasma gondii. J Biol Chem 2017; 292:7662-7674. [PMID: 28258212 DOI: 10.1074/jbc.m117.775114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/27/2017] [Indexed: 12/20/2022] Open
Abstract
Toxoplasma gondii, like all apicomplexan parasites, uses Ca2+ signaling pathways to activate gliding motility to power tissue dissemination and host cell invasion and egress. A group of "plant-like" Ca2+-dependent protein kinases (CDPKs) transduces cytosolic Ca2+ flux into enzymatic activity, but how they function is poorly understood. To investigate how Ca2+ signaling activates egress through CDPKs, we performed a forward genetic screen to isolate gain-of-function mutants from an egress-deficient cdpk3 knockout strain. We recovered mutants that regained the ability to egress from host cells that harbored mutations in the gene Suppressor of Ca2+-dependent Egress 1 (SCE1). Global phosphoproteomic analysis showed that SCE1 deletion restored many Δcdpk3-dependent phosphorylation events to near wild-type levels. We also show that CDPK3-dependent SCE1 phosphorylation is required to relieve its suppressive activity to potentiate egress. In summary, our work has uncovered a novel component and suppressor of Ca2+-dependent cell egress during Toxoplasma lytic growth.
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Affiliation(s)
- James M McCoy
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,Computing and Information Systems,University of Melbourne, Victoria 3010, Australia
| | - Rebecca J Stewart
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,Computing and Information Systems,University of Melbourne, Victoria 3010, Australia
| | - Alessandro D Uboldi
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,Computing and Information Systems,University of Melbourne, Victoria 3010, Australia
| | - Dongdi Li
- the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Jan Schröder
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,the Peter MacCallum Cancer Institute, Victoria 3000, Australia, and
| | - Nicollas E Scott
- the University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Anthony T Papenfuss
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,the Peter MacCallum Cancer Institute, Victoria 3000, Australia, and
| | - Adele M Lehane
- the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Leonard J Foster
- the University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Christopher J Tonkin
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia, .,the Departments of Medical Biology
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29
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Sisquella X, Nebl T, Thompson JK, Whitehead L, Malpede BM, Salinas ND, Rogers K, Tolia NH, Fleig A, O'Neill J, Tham WH, David Horgen F, Cowman AF. Plasmodium falciparum ligand binding to erythrocytes induce alterations in deformability essential for invasion. eLife 2017; 6. [PMID: 28226242 PMCID: PMC5333951 DOI: 10.7554/elife.21083] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/09/2017] [Indexed: 12/31/2022] Open
Abstract
The most lethal form of malaria in humans is caused by Plasmodium falciparum. These parasites invade erythrocytes, a complex process involving multiple ligand-receptor interactions. The parasite makes initial contact with the erythrocyte followed by dramatic deformations linked to the function of the Erythrocyte binding antigen family and P. falciparum reticulocyte binding-like families. We show EBA-175 mediates substantial changes in the deformability of erythrocytes by binding to glycophorin A and activating a phosphorylation cascade that includes erythrocyte cytoskeletal proteins resulting in changes in the viscoelastic properties of the host cell. TRPM7 kinase inhibitors FTY720 and waixenicin A block the changes in the deformability of erythrocytes and inhibit merozoite invasion by directly inhibiting the phosphorylation cascade. Therefore, binding of P. falciparum parasites to the erythrocyte directly activate a signaling pathway through a phosphorylation cascade and this alters the viscoelastic properties of the host membrane conditioning it for successful invasion.
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Affiliation(s)
- Xavier Sisquella
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Thomas Nebl
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Jennifer K Thompson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Brian M Malpede
- Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, United States.,Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States
| | - Nichole D Salinas
- Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, United States.,Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States
| | - Kelly Rogers
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Niraj H Tolia
- Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, United States.,Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States
| | - Andrea Fleig
- The Queen's Medical Center and John A. Burns School of Medicine, University of Hawaii, Honolulu, United States
| | - Joseph O'Neill
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Wai-Hong Tham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, United States
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Australia
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30
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Chen L, Xu Y, Wong W, Thompson JK, Healer J, Goddard-Borger ED, Lawrence MC, Cowman AF. Structural basis for inhibition of erythrocyte invasion by antibodies to Plasmodium falciparum protein CyRPA. eLife 2017; 6. [PMID: 28195530 PMCID: PMC5349848 DOI: 10.7554/elife.21347] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/31/2017] [Indexed: 02/01/2023] Open
Abstract
Plasmodium falciparum causes malaria in humans with over 450,000 deaths annually. The asexual blood stage involves invasion of erythrocytes by merozoites, in which they grow and divide to release daughter merozoites, which in turn invade new erythrocytes perpetuating the cycle responsible for malaria. A key step in merozoite invasion is the essential binding of PfRh5/CyRPA/PfRipr complex to basigin, a step linked to the formation of a pore between merozoites and erythrocytes. We show CyRPA interacts directly with PfRh5. An invasion inhibitory monoclonal antibody to CyRPA blocks binding of CyRPA to PfRh5 and complex formation thus illuminating the molecular mechanism for inhibition of parasite growth. We determined the crystal structures of CyRPA alone and in complex with an antibody Fab fragment. CyRPA has a six-bladed β-propeller fold, and we identify the region that interacts with PfRh5. This functionally conserved epitope is a potential target for vaccines against P. falciparum.
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Affiliation(s)
- Lin Chen
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Yibin Xu
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Wilson Wong
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Jennifer K Thompson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Julie Healer
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Ethan D Goddard-Borger
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Michael C Lawrence
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
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31
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Tools for attenuation of gene expression in malaria parasites. Int J Parasitol 2017; 47:385-398. [PMID: 28153780 DOI: 10.1016/j.ijpara.2016.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/15/2016] [Accepted: 11/28/2016] [Indexed: 12/30/2022]
Abstract
An understanding of the biology of Plasmodium parasites, which are the causative agents of the disease malaria, requires study of gene function. Various reverse genetic tools have been described for determining gene function. These tools can be broadly grouped as trans- and cis-acting. Trans-acting tools control gene functions through synthetic nucleic acid probe molecules matching the sequence of the gene of interest. Once delivered to the parasite, the probe engages with the mRNA of the target gene and attenuates its function. Cis-acting tools control gene function through elements introduced into the gene of interest by DNA transfection. The expression of the modified gene can be controlled using external agents, typically small molecule ligands. In this review, we discuss the strengths and weaknesses of these tools to guide researchers in selecting the appropriate tool for studies of gene function, and for guiding future refinements of these tools.
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32
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Malaria: Biology and Disease. Cell 2016; 167:610-624. [PMID: 27768886 DOI: 10.1016/j.cell.2016.07.055] [Citation(s) in RCA: 438] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/17/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.
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33
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Jacot D, Tosetti N, Pires I, Stock J, Graindorge A, Hung YF, Han H, Tewari R, Kursula I, Soldati-Favre D. An Apicomplexan Actin-Binding Protein Serves as a Connector and Lipid Sensor to Coordinate Motility and Invasion. Cell Host Microbe 2016; 20:731-743. [PMID: 27978434 DOI: 10.1016/j.chom.2016.10.020] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/16/2016] [Accepted: 10/27/2016] [Indexed: 01/06/2023]
Abstract
Apicomplexa exhibit a unique form of substrate-dependent gliding motility central for host cell invasion and parasite dissemination. Gliding is powered by rearward translocation of apically secreted transmembrane adhesins via their interaction with the parasite actomyosin system. We report a conserved armadillo and pleckstrin homology (PH) domain-containing protein, termed glideosome-associated connector (GAC), that mediates apicomplexan gliding motility, invasion, and egress by connecting the micronemal adhesins with the actomyosin system. TgGAC binds to and stabilizes filamentous actin and specifically associates with the transmembrane adhesin TgMIC2. GAC localizes to the apical pole in invasive stages of Toxoplasma gondii and Plasmodium berghei, and apical positioning of TgGAC depends on an apical lysine methyltransferase, TgAKMT. GAC PH domain also binds to phosphatidic acid, a lipid mediator associated with microneme exocytosis. Collectively, these findings indicate a central role for GAC in spatially and temporally coordinating gliding motility and invasion.
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Affiliation(s)
- Damien Jacot
- Department of Microbiology & Molecular Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland
| | - Nicolò Tosetti
- Department of Microbiology & Molecular Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland
| | - Isa Pires
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7, 90220 Oulu, Finland
| | - Jessica Stock
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham NG2 7UH, UK
| | - Arnault Graindorge
- Department of Microbiology & Molecular Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland
| | - Yu-Fu Hung
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7, 90220 Oulu, Finland
| | - Huijong Han
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7, 90220 Oulu, Finland
| | - Rita Tewari
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham NG2 7UH, UK
| | - Inari Kursula
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7, 90220 Oulu, Finland; Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway.
| | - Dominique Soldati-Favre
- Department of Microbiology & Molecular Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland.
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Hierarchical phosphorylation of apical membrane antigen 1 is required for efficient red blood cell invasion by malaria parasites. Sci Rep 2016; 6:34479. [PMID: 27698395 PMCID: PMC5048298 DOI: 10.1038/srep34479] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/08/2016] [Indexed: 12/03/2022] Open
Abstract
Central to the pathogenesis of malaria is the proliferation of Plasmodium falciparum parasites within human erythrocytes. Parasites invade erythrocytes via a coordinated sequence of receptor-ligand interactions between the parasite and host cell. One key ligand, Apical Membrane Antigen 1 (AMA1), is a leading blood-stage vaccine and previous work indicates that phosphorylation of its cytoplasmic domain (CPD) is important to its function during invasion. Here we investigate the significance of each of the six available phospho-sites in the CPD. We confirm that the cyclic AMP/protein kinase A (PKA) signalling pathway elicits a phospho-priming step upon serine 610 (S610), which enables subsequent phosphorylation in vitro of a conserved, downstream threonine residue (T613) by glycogen synthase kinase 3 (GSK3). Both phosphorylation steps are required for AMA1 to function efficiently during invasion. This provides the first evidence that the functions of key invasion ligands of the malaria parasite are regulated by sequential phosphorylation steps.
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35
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Plasmodium vivax Reticulocyte Binding Proteins Are Key Targets of Naturally Acquired Immunity in Young Papua New Guinean Children. PLoS Negl Trop Dis 2016; 10:e0005014. [PMID: 27677183 PMCID: PMC5038947 DOI: 10.1371/journal.pntd.0005014] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/30/2016] [Indexed: 11/19/2022] Open
Abstract
Background Major gaps in our understanding of Plasmodium vivax biology and the acquisition of immunity to this parasite hinder vaccine development. P. vivax merozoites exclusively invade reticulocytes, making parasite proteins that mediate reticulocyte binding and/or invasion potential key vaccine or drug targets. While protein interactions that mediate invasion are still poorly understood, the P. vivax Reticulocyte-Binding Protein family (PvRBP) is thought to be involved in P. vivax restricted host-cell selectivity. Methodology/Principal findings We assessed the binding specificity of five members of the PvRBP family (PvRBP1a, PvRBP1b, PvRBP2a, PvRBP2b, PvRBP2-P2 and a non-binding fragment of PvRBP2c) to normocytes or reticulocytes. PvRBP2b was identified as the only reticulocyte-specific binder (P<0.001), whereas the others preferentially bound to normocytes (PvRBP1a/b P≤0.034), or showed comparable binding to both (PvRBP2a/2-P2, P = 0.38). Furthermore, we measured levels of total and IgG subclasses 1, 2, 3 and 4 to the six PvRBPs in a cohort of young Papua New Guinean children, and assessed their relationship with prospective risk of P. vivax malaria. Children had substantial, highly correlated (rho = 0.49–0.82, P<0.001) antibody levels to all six PvRBPs, with dominant IgG1 and IgG3 subclasses. Both total IgG (Incidence Rate Ratio [IRR] 0.63–0.73, P = 0.008–0.041) and IgG1 (IRR 0.56–0.69, P = 0.001–0.035) to PvRBP2b and PvRBP1a were strongly associated with reduced risk of vivax-malaria, independently of age and exposure. Conclusion/Significance These results demonstrate a diversity of erythrocyte-binding phenotypes of PvRBPs, indicating binding to both reticulocyte-specific and normocyte-specific ligands. Our findings provide further insights into the naturally acquired immunity to P. vivax and highlight the importance of PvRBP proteins as targets of naturally acquired humoral immunity. In-depth studies of the role of PvRBPs in P. vivax invasion and functional validation of the role of anti-PvRBP antibodies in clinical immunity against P. vivax are now required to confirm the potential of the reticulocyte-binding PvRBP2b and PvRBP1a as vaccine candidate antigens. In parallel with the tremendous reduction in malaria burden, Plasmodium vivax (Pv) is now the predominant malaria species in the Asia-Pacific and Americas. Pv can only invade young erythrocytes (reticulocytes) and this restriction is thought to involve the Reticulocyte-Binding Protein family (PvRBP). Given their predicted role, PvRBPs are potentially interesting vaccine targets. However, the acquisition of immunity to Pv in general (PvRBPs in particular) is poorly understood, hindering vaccine development. Here, we show that out of five PvRBPs, only one (PvRBP2b) binds exclusively to reticulocytes. Furthermore, we measured antibody levels to all six PvRBPs in a cohort of young Papua New Guinean children, assessing the relationship between antibodies to PvRBPs and risk of malaria disease. Both total and specific antibody subclass levels (IgG1 and IgG3) to the reticulocyte-specific binder PvRBP2b, and the non-specific binder PvRBP1a were strongly associated with lower risk of clinical disease. Our findings indicate a diversity of roles of PvRBPs in erythrocyte invasion and highlight their importance as targets of the naturally acquired immunity to Pv. Functional studies of the role of PvRBPs in reticulocyte invasion will be required to fully understand the potential of PvRBP1a and PvRBP2b as vaccine candidates.
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36
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Diaz SA, Martin SR, Howell SA, Grainger M, Moon RW, Green JL, Holder AA. The Binding of Plasmodium falciparum Adhesins and Erythrocyte Invasion Proteins to Aldolase Is Enhanced by Phosphorylation. PLoS One 2016; 11:e0161850. [PMID: 27607074 PMCID: PMC5015959 DOI: 10.1371/journal.pone.0161850] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/14/2016] [Indexed: 02/07/2023] Open
Abstract
Aldolase has been implicated as a protein coupling the actomyosin motor and cell surface adhesins involved in motility and host cell invasion in the human malaria parasite Plasmodium falciparum. It binds to the cytoplasmic domain (CTD) of type 1 membrane proteins of the thrombospondin-related anonymous protein (TRAP) family. Other type 1 membrane proteins located in the apical organelles of merozoites, the form of the parasite that invades red blood cells, including apical membrane antigen 1 (AMA1) and members of the erythrocyte binding ligand (EBL) and reticulocyte binding homologue (RH) protein families have been implicated in host cell binding and invasion. Using a direct binding method we confirm that TRAP and merozoite TRAP (MTRAP) bind aldolase and show that the interaction is mediated by more than just the C-terminal six amino acid residues identified previously. Single amino acid substitutions in the MTRAP CTD abolished binding to aldolase. The CTDs of AMA1 and members of the EBL and RH protein families also bound to aldolase. MTRAP competed with AMA1 and RH4 for binding to aldolase, indicating overlapping binding sites. MTRAP CTD was phosphorylated in vitro by both calcium dependent kinase 1 (CDPK1) and protein kinase A, and this modification increased the affinity of binding to aldolase by ten-fold. Phosphorylation of the CTD of members of the EBL and RH protein families also increased their affinity for aldolase in some cases. To examine whether or not MTRAP expressed in asexual blood stage parasites is phosphorylated, it was tagged with GFP, purified and analysed, however no phosphorylation was detected. We propose that CTD binding to aldolase may be dynamically modulated by phosphorylation, and there may be competition for aldolase binding between different CTDs. The use and efficiency of alternate invasion pathways may be determined by the affinity of adhesins and cell invasion proteins for aldolase, in addition to their host ligand specificity.
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Affiliation(s)
- Suraya A. Diaz
- Malaria Parasitology Laboratory, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Stephen R. Martin
- Structural Biology Science Technology Platform The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Steven A. Howell
- Mass Spectrometry Science Technology Platform, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Munira Grainger
- Malaria Parasitology Laboratory, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Robert W. Moon
- Malaria Parasitology Laboratory, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Judith L. Green
- Malaria Parasitology Laboratory, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Anthony A. Holder
- Malaria Parasitology Laboratory, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
- * E-mail:
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Aniweh Y, Gao X, Gunalan K, Preiser PR. PfRH2b specific monoclonal antibodies inhibit merozoite invasion. Mol Microbiol 2016; 102:386-404. [DOI: 10.1111/mmi.13468] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Yaw Aniweh
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
| | - Xiaohong Gao
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
| | - Karthigayan Gunalan
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
| | - Peter R. Preiser
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
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Essential Role of the PfRh5/PfRipr/CyRPA Complex during Plasmodium falciparum Invasion of Erythrocytes. Cell Host Microbe 2016; 20:60-71. [DOI: 10.1016/j.chom.2016.06.004] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 04/05/2016] [Accepted: 05/18/2016] [Indexed: 01/30/2023]
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Development and Application of a Simple Plaque Assay for the Human Malaria Parasite Plasmodium falciparum. PLoS One 2016; 11:e0157873. [PMID: 27332706 PMCID: PMC4917082 DOI: 10.1371/journal.pone.0157873] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/06/2016] [Indexed: 02/03/2023] Open
Abstract
Malaria is caused by an obligate intracellular protozoan parasite that replicates within and destroys erythrocytes. Asexual blood stages of the causative agent of the most virulent form of human malaria, Plasmodium falciparum, can be cultivated indefinitely in vitro in human erythrocytes, facilitating experimental analysis of parasite cell biology, biochemistry and genetics. However, efforts to improve understanding of the basic biology of this important pathogen and to develop urgently required new antimalarial drugs and vaccines, suffer from a paucity of basic research tools. This includes a simple means of quantifying the effects of drugs, antibodies and gene modifications on parasite fitness and replication rates. Here we describe the development and validation of an extremely simple, robust plaque assay that can be used to visualise parasite replication and resulting host erythrocyte destruction at the level of clonal parasite populations. We demonstrate applications of the plaque assay by using it for the phenotypic characterisation of two P. falciparum conditional mutants displaying reduced fitness in vitro.
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Carvalho TG, Morahan B, John von Freyend S, Boeuf P, Grau G, Garcia-Bustos J, Doerig C. The ins and outs of phosphosignalling in Plasmodium: Parasite regulation and host cell manipulation. Mol Biochem Parasitol 2016; 208:2-15. [PMID: 27211241 DOI: 10.1016/j.molbiopara.2016.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 05/16/2016] [Indexed: 12/15/2022]
Abstract
Signal transduction and kinomics have been rapidly expanding areas of investigation within the malaria research field. Here, we provide an overview of phosphosignalling pathways that operate in all stages of the Plasmodium life cycle. We review signalling pathways in the parasite itself, in the cells it invades, and in other cells of the vertebrate host with which it interacts. We also discuss the potential of these pathways as novel targets for antimalarial intervention.
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Affiliation(s)
- Teresa Gil Carvalho
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Belinda Morahan
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Simona John von Freyend
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Philippe Boeuf
- Burnet Institute, Melbourne, Victoria 3004, Australia; The University of Melbourne, Department of Medicine, Melbourne, Victoria 3010, Australia; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Georges Grau
- Vascular Immunology Unit, Department of Pathology, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2050, Australia
| | - Jose Garcia-Bustos
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Christian Doerig
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia.
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