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Mahanta PJ, Lhouvum K. Plasmodium falciparum proteases as new drug targets with special focus on metalloproteases. Mol Biochem Parasitol 2024; 258:111617. [PMID: 38554736 DOI: 10.1016/j.molbiopara.2024.111617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 02/15/2024] [Accepted: 03/10/2024] [Indexed: 04/02/2024]
Abstract
Malaria poses a significant global health threat particularly due to the prevalence of Plasmodium falciparum infection. With the emergence of parasite resistance to existing drugs including the recently discovered artemisinin, ongoing research seeks novel therapeutic avenues within the malaria parasite. Proteases are promising drug targets due to their essential roles in parasite biology, including hemoglobin digestion, merozoite invasion, and egress. While exploring the genomic landscape of Plasmodium falciparum, it has been revealed that there are 92 predicted proteases, with only approximately 14 of them having been characterized. These proteases are further distributed among 26 families grouped into five clans: aspartic proteases, cysteine proteases, metalloproteases, serine proteases, and threonine proteases. Focus on metalloprotease class shows further role in organelle processing for mitochondria and apicoplasts suggesting the potential of metalloproteases as viable drug targets. Holistic understanding of the parasite intricate life cycle and identification of potential drug targets are essential for developing effective therapeutic strategies against malaria and mitigating its devastating global impact.
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Affiliation(s)
| | - Kimjolly Lhouvum
- Department of Biotechnology, National Institute of Technology, Arunachal Pradesh, India.
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2
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Sassmannshausen J, Bennink S, Distler U, Küchenhoff J, Minns AM, Lindner SE, Burda PC, Tenzer S, Gilberger TW, Pradel G. Comparative proteomics of vesicles essential for the egress of Plasmodium falciparum gametocytes from red blood cells. Mol Microbiol 2024; 121:431-452. [PMID: 37492994 DOI: 10.1111/mmi.15125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/27/2023]
Abstract
Transmission of malaria parasites to the mosquito is mediated by sexual precursor cells, the gametocytes. Upon entering the mosquito midgut, the gametocytes egress from the enveloping erythrocyte while passing through gametogenesis. Egress follows an inside-out mode during which the membrane of the parasitophorous vacuole (PV) ruptures prior to the erythrocyte membrane. Membrane rupture requires exocytosis of specialized egress vesicles of the parasites; that is, osmiophilic bodies (OBs) involved in rupturing the PV membrane, and vesicles that harbor the perforin-like protein PPLP2 (here termed P-EVs) required for erythrocyte lysis. While some OB proteins have been identified, like G377 and MDV1/Peg3, the majority of egress vesicle-resident proteins is yet unknown. Here, we used high-resolution imaging and BioID methods to study the two egress vesicle types in Plasmodium falciparum gametocytes. We show that OB exocytosis precedes discharge of the P-EVs and that exocytosis of the P-EVs, but not of the OBs, is calcium sensitive. Both vesicle types exhibit distinct proteomes with the majority of proteins located in the OBs. In addition to known egress-related proteins, we identified novel components of OBs and P-EVs, including vesicle-trafficking proteins. Our data provide insight into the immense molecular machinery required for the inside-out egress of P. falciparum gametocytes.
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Affiliation(s)
- Juliane Sassmannshausen
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Ute Distler
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Juliane Küchenhoff
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Allen M Minns
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Scott E Lindner
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Stefan Tenzer
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
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3
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Mukherjee S, Nguyen S, Sharma E, Goldberg DE. Maturation and substrate processing topography of the Plasmodium falciparum invasion/egress protease plasmepsin X. Nat Commun 2022; 13:4537. [PMID: 35927261 PMCID: PMC9352755 DOI: 10.1038/s41467-022-32271-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 07/22/2022] [Indexed: 11/08/2022] Open
Abstract
The malaria parasite Plasmodium invades a host erythrocyte, multiplies within a parasitophorous vacuole (PV) and then ruptures the PV and erythrocyte membranes in a process known as egress. Both egress and invasion are controlled by effector proteins discharged from specialized secretory organelles. The aspartic protease plasmepsin X (PM X) regulates activity for many of these effectors, but it is unclear how PM X accesses its diverse substrates that reside in different organelles. PM X also autoprocesses to generate different isoforms. The function of this processing is not understood. We have mapped the self-cleavage sites and have constructed parasites with cleavage site mutations. Surprisingly, a quadruple mutant that remains full-length retains in vitro activity, is trafficked normally, and supports normal egress, invasion and parasite growth. The N-terminal half of the prodomain stays bound to the catalytic domain even after processing and is required for proper intracellular trafficking of PM X. We find that this enzyme cleaves microneme and exoneme substrates before discharge, while the rhoptry substrates that are dependent on PM X activity are cleaved after exoneme discharge into the PV. The data give insight into the temporal, spatial and biochemical control of this unusual but important aspartic protease.
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Affiliation(s)
- Sumit Mukherjee
- Division of Infectious Diseases, Department of Medicine, and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Suong Nguyen
- Division of Infectious Diseases, Department of Medicine, and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Eashan Sharma
- Division of Infectious Diseases, Department of Medicine, and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine, and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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4
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Collins CR, Hackett F, Howell SA, Snijders AP, Russell MRG, Collinson LM, Blackman MJ. The malaria parasite sheddase SUB2 governs host red blood cell membrane sealing at invasion. eLife 2020; 9:e61121. [PMID: 33287958 PMCID: PMC7723409 DOI: 10.7554/elife.61121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/26/2020] [Indexed: 12/26/2022] Open
Abstract
Red blood cell (RBC) invasion by malaria merozoites involves formation of a parasitophorous vacuole into which the parasite moves. The vacuole membrane seals and pinches off behind the parasite through an unknown mechanism, enclosing the parasite within the RBC. During invasion, several parasite surface proteins are shed by a membrane-bound protease called SUB2. Here we show that genetic depletion of SUB2 abolishes shedding of a range of parasite proteins, identifying previously unrecognized SUB2 substrates. Interaction of SUB2-null merozoites with RBCs leads to either abortive invasion with rapid RBC lysis, or successful entry but developmental arrest. Selective failure to shed the most abundant SUB2 substrate, MSP1, reduces intracellular replication, whilst conditional ablation of the substrate AMA1 produces host RBC lysis. We conclude that SUB2 activity is critical for host RBC membrane sealing following parasite internalisation and for correct functioning of merozoite surface proteins.
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Affiliation(s)
- Christine R Collins
- Malaria Biochemistry Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Fiona Hackett
- Malaria Biochemistry Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Steven A Howell
- Protein Analysis and Proteomics Platform, The Francis Crick InstituteLondonUnited Kingdom
| | - Ambrosius P Snijders
- Protein Analysis and Proteomics Platform, The Francis Crick InstituteLondonUnited Kingdom
| | - Matthew RG Russell
- Electron Microscopy Science Technology Platform, The Francis Crick InstituteLondonUnited Kingdom
| | - Lucy M Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick InstituteLondonUnited Kingdom
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Faculty of Infectious Diseases, London School of Hygiene & Tropical MedicineLondonUnited Kingdom
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5
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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: 73] [Impact Index Per Article: 18.3] [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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Hallée S, Counihan NA, Matthews K, Koning‐Ward TF, Richard D. The malaria parasite
Plasmodium falciparum
Sortilin is essential for merozoite formation and apical complex biogenesis. Cell Microbiol 2018; 20:e12844. [DOI: 10.1111/cmi.12844] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/22/2018] [Accepted: 03/17/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Stéphanie Hallée
- Centre de recherche en infectiologieCHU de Québec‐Université Laval Quebec City QC Canada
| | | | - Kathryn Matthews
- School of MedicineDeakin University Waurn Ponds 3216 VIC Australia
| | | | - Dave Richard
- Centre de recherche en infectiologieCHU de Québec‐Université Laval Quebec City QC Canada
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7
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Plasmodium berghei PIMMS2 Promotes Ookinete Invasion of the Anopheles gambiae Mosquito Midgut. Infect Immun 2017; 85:IAI.00139-17. [PMID: 28559405 PMCID: PMC5520436 DOI: 10.1128/iai.00139-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/11/2017] [Indexed: 12/21/2022] Open
Abstract
Mosquito midgut stages of the malaria parasite present an attractive biological system to study host-parasite interactions and develop interventions to block disease transmission. Mosquito infection ensues upon oocyst development that follows ookinete invasion and traversal of the mosquito midgut epithelium. Here, we report the characterization of PIMMS2 (Plasmodium invasion of mosquito midgut screen candidate 2), a Plasmodium berghei protein with structural similarities to subtilisin-like proteins. PIMMS2 orthologs are present in the genomes of all plasmodia and are mapped between the subtilisin-encoding genes SUB1 and SUB3. P. berghei PIMMS2 is specifically expressed in zygotes and ookinetes and is localized on the ookinete surface. Loss of PIMMS2 function through gene disruption by homologous recombination leads to normal development of motile ookinetes that exhibit a severely impaired capacity to traverse the mosquito midgut and transform to oocysts. Genetic complementation of the disrupted locus with a mutated PIMMS2 allele reveals that amino acid residues corresponding to the putative subtilisin-like catalytic triad are important but not essential for protein function. Our data demonstrate that PIMMS2 is a novel ookinete-specific protein that promotes parasite traversal of the mosquito midgut epithelium and establishment of mosquito infection.
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8
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Suárez-Cortés P, Sharma V, Bertuccini L, Costa G, Bannerman NL, Sannella AR, Williamson K, Klemba M, Levashina EA, Lasonder E, Alano P. Comparative Proteomics and Functional Analysis Reveal a Role of Plasmodium falciparum Osmiophilic Bodies in Malaria Parasite Transmission. Mol Cell Proteomics 2016; 15:3243-3255. [PMID: 27432909 DOI: 10.1074/mcp.m116.060681] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Indexed: 11/06/2022] Open
Abstract
An essential step in the transmission of the malaria parasite to the Anopheles vector is the transformation of the mature gametocytes into gametes in the mosquito gut, where they egress from the erythrocytes and mate to produce a zygote, which matures into a motile ookinete. Osmiophilic bodies are electron dense secretory organelles of the female gametocytes which discharge their contents during gamete formation, suggestive of a role in gamete egress. Only one protein with no functional annotation, Pfg377, is described to specifically reside in osmiophilic bodies in Plasmodium falciparum Importantly, Pfg377 defective gametocytes lack osmiophilic bodies and fail to infect mosquitoes, as confirmed here with newly produced pfg377 disrupted parasites. The unique feature of Pfg377 defective gametocytes of lacking osmiophilic bodies was here exploited to perform comparative, label free, global and affinity proteomics analyses of mutant and wild type gametocytes to identify components of these organelles. Subcellular localization studies with fluorescent reporter gene fusions and specific antibodies revealed an osmiophilic body localization for four out of five candidate gene products analyzed: the proteases PfSUB2 (subtilisin 2) and PfDPAP2 (Dipeptidyl aminopeptidase 2), the ortholog of the osmiophilic body component of the rodent malaria gametocytes PbGEST and a previously nonannotated 13 kDa protein. These results establish that osmiophilic bodies and their components are dispensable or marginally contribute (PfDPAP2) to gamete egress. Instead, this work reveals a previously unsuspected role of these organelles in P. falciparum development in the mosquito vector.
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Affiliation(s)
- Pablo Suárez-Cortés
- From the ‡Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena n.299, 00161 Roma, Italy
| | - Vikram Sharma
- §School of Biomedical and Healthcare Sciences, Plymouth University, Drake Circus, Plymouth, Devon, UK
| | - Lucia Bertuccini
- ¶Dipartimento Tecnologie e Salute, Istituto Superiore di Sanità, Viale Regina Elena n.299, 00161 Roma, Italy
| | - Giulia Costa
- ‖Department of Vector Biology, Max-Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Naa-Lamiley Bannerman
- §School of Biomedical and Healthcare Sciences, Plymouth University, Drake Circus, Plymouth, Devon, UK
| | - Anna Rosa Sannella
- From the ‡Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena n.299, 00161 Roma, Italy
| | - Kim Williamson
- **Department of Biology, Loyola University, 1032 West Sheridan Road, Chicago, Illinois 60660
| | - Michael Klemba
- ‡‡Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061
| | - Elena A Levashina
- ‖Department of Vector Biology, Max-Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Edwin Lasonder
- §School of Biomedical and Healthcare Sciences, Plymouth University, Drake Circus, Plymouth, Devon, UK
| | - Pietro Alano
- From the ‡Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena n.299, 00161 Roma, Italy;
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9
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Beeson JG, Drew DR, Boyle MJ, Feng G, Fowkes FJI, Richards JS. Merozoite surface proteins in red blood cell invasion, immunity and vaccines against malaria. FEMS Microbiol Rev 2016; 40:343-72. [PMID: 26833236 PMCID: PMC4852283 DOI: 10.1093/femsre/fuw001] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2016] [Indexed: 01/11/2023] Open
Abstract
Malaria accounts for an enormous burden of disease globally, with Plasmodium falciparum accounting for the majority of malaria, and P. vivax being a second important cause, especially in Asia, the Americas and the Pacific. During infection with Plasmodium spp., the merozoite form of the parasite invades red blood cells and replicates inside them. It is during the blood-stage of infection that malaria disease occurs and, therefore, understanding merozoite invasion, host immune responses to merozoite surface antigens, and targeting merozoite surface proteins and invasion ligands by novel vaccines and therapeutics have been important areas of research. Merozoite invasion involves multiple interactions and events, and substantial processing of merozoite surface proteins occurs before, during and after invasion. The merozoite surface is highly complex, presenting a multitude of antigens to the immune system. This complexity has proved challenging to our efforts to understand merozoite invasion and malaria immunity, and to developing merozoite antigens as malaria vaccines. In recent years, there has been major progress in this field, and several merozoite surface proteins show strong potential as malaria vaccines. Our current knowledge on this topic is reviewed, highlighting recent advances and research priorities. The authors summarize current knowledge of merozoite surface proteins of malaria parasites; their function in invasion, processing of surface proteins before, during and after invasion, their importance as targets of immunity, and the current status of malaria vaccines that target merozoite surface proteins.
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Affiliation(s)
- James G Beeson
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Microbiology, Monash University, Clayton, Victoria, Australia Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Damien R Drew
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Gaoqian Feng
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Epidemiology and Preventive Medicine, Monash University, Clayton, Victoria, Australia School of Population Health, University of Melbourne, Parkville, Victoria, Australia
| | - Jack S Richards
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Microbiology, Monash University, Clayton, Victoria, Australia Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
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10
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Andreadaki M, Morgan RN, Deligianni E, Kooij TWA, Santos JM, Spanos L, Matuschewski K, Louis C, Mair GR, Siden-Kiamos I. Genetic crosses and complementation reveal essential functions for the Plasmodium stage-specific actin2 in sporogonic development. Cell Microbiol 2014; 16:751-67. [PMID: 24471657 DOI: 10.1111/cmi.12274] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/18/2013] [Accepted: 01/22/2014] [Indexed: 11/30/2022]
Abstract
Malaria parasites have two actin isoforms, ubiquitous actin1 and specialized actin2. Actin2 is essential for late male gametogenesis, prior to egress from the host erythrocyte. Here, we examined whether the two actins fulfil overlapping functions in Plasmodium berghei. Replacement of actin2 with actin1 resulted in partial complementation of the defects in male gametogenesis and, thus, viable ookinetes were formed, able to invade the midgut epithelium and develop into oocysts. However, these remained small and their DNA was undetectable at day 8 after infection. As a consequence sporogony did not occur, resulting in a complete block of parasite transmission. Furthermore, we show that expression of actin2 is tightly controlled in female stages. The actin2 transcript is translationally repressed in female gametocytes, but translated in female gametes. The protein persists until mature ookinetes; this expression is strictly dependent on the maternally derived expression. Genetic crosses revealed that actin2 functions at an early stage of ookinete formation and that parasites lacking actin2 are unable to undergo sporogony in the mosquito midgut. Our results provide insights into the specialized role of actin2 in Plasmodium development in the mosquito and suggest that the two actin isoforms have distinct biological functions.
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Affiliation(s)
- Maria Andreadaki
- Institute of Molecular Biology and Biotechnology, FORTH, Heraklion, Greece; Department of Biology, University of Crete, Heraklion, Greece
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