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Freville A, Stewart LB, Tetteh KKA, Treeck M, Cortes A, Voss TS, Tarr SJ, Baker DA, Conway DJ. Expression of the MSPDBL2 antigen in a discrete subset of Plasmodium falciparum schizonts is regulated by GDV1 but may not be linked to sexual commitment. mBio 2024; 15:e0314023. [PMID: 38530030 PMCID: PMC11077968 DOI: 10.1128/mbio.03140-23] [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: 11/21/2023] [Accepted: 03/04/2024] [Indexed: 03/27/2024] Open
Abstract
The Plasmodium falciparum merozoite surface protein MSPDBL2 is a polymorphic antigen targeted by acquired immune responses, and normally expressed in only a minority of mature schizonts. The potential relationship of MSPDBL2 to sexual commitment is examined, as variable mspdbl2 transcript levels and proportions of MSPDBL2-positive mature schizonts in clinical isolates have previously correlated with levels of many sexual stage parasite gene transcripts, although not with the master regulator ap2-g. It is demonstrated that conditional overexpression of the gametocyte development protein GDV1, which promotes sexual commitment, also substantially increases the proportion of MSPDBL2-positive schizonts in culture. Conversely, truncation of the gdv1 gene is shown to prevent any expression of MSPDBL2. However, across diverse P. falciparum cultured lines, the variable proportions of MSPDBL2 positivity in schizonts do not correlate significantly with variable gametocyte conversion rates, indicating it is not involved in sexual commitment. Confirming this, examining a line with endogenous hemagglutinin-tagged AP2-G showed that the individual schizonts expressing MSPDBL2 are mostly different from those expressing AP2-G. Using a selection-linked integration system, modified P. falciparum lines were engineered to express an intact or disrupted version of MSPDBL2, showing the protein is not required for sexual commitment or early gametocyte development. Asexual parasite multiplication rates were also not affected by expression of either intact or disrupted MSPDBL2 in a majority of schizonts. Occurring alongside sexual commitment, the role of the discrete MSPDBL2-positive schizont subpopulation requires further investigation in natural infections where it is under immune selection. IMPORTANCE Malaria parasites in the blood are remarkably variable, able to switch antigenic targets so they may survive within humans who have already developed specific immune responses. This is one of the challenges in developing vaccines against malaria. MSPDBL2 is a target of naturally acquired immunity expressed in minority proportions of schizonts, the end stages of each 2-day replication cycle in red blood cells which contain merozoites prepared to invade new red blood cells. Results show that the proportion of schizonts expressing MSPDBL2 is positively controlled by the expression of the regulatory gametocyte development protein GDV1. It was previously known that expression of GDV1 leads to increased expression of AP2-G which causes parasites to switch to sexual development, so a surprising finding here is that MSPDBL2-positive parasites are mostly distinct from those that express AP2-G. This discrete antigenic subpopulation of mostly asexual parasites is regulated alongside sexually committed parasites, potentially enabling survival under stress conditions.
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Affiliation(s)
- Aline Freville
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Lindsay B. Stewart
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Kevin K. A. Tetteh
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Alfred Cortes
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia, Spain
- ICREA, Barcelona, Catalonia, Spain
| | - Till S. Voss
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Sarah J. Tarr
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David A. Baker
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David J. Conway
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Akoniyon OP, Akiibinu M, Adeleke MA, Maharaj R, Okpeku M. A Comparative Study of Genetic Diversity and Multiplicity of Infection in Uncomplicated Plasmodium falciparum Infections in Selected Regions of Pre-Elimination and High Transmission Settings Using MSP1 and MSP2 Genes. Pathogens 2024; 13:172. [PMID: 38392910 PMCID: PMC10891941 DOI: 10.3390/pathogens13020172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/22/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Understanding the genetic structure of P. falciparum population in different regions is pivotal to malaria elimination. Genetic diversity and the multiplicity of infection are indicators used for measuring malaria endemicity across different transmission settings. Therefore, this study characterized P. falciparum infections from selected areas constituting pre-elimination and high transmission settings in South Africa and Nigeria, respectively. METHODS Parasite genomic DNA was extracted from 129 participants with uncomplicated P. falciparum infections. Isolates were collected from 78 participants in South Africa (southern Africa) and 51 in Nigeria (western Africa). Allelic typing of the msp1 and msp2 genes was carried out using nested PCR. RESULTS In msp1, the K1 allele (39.7%) was the most common allele among the South African isolates, while the RO33 allele (90.2%) was the most common allele among the Nigerian isolates. In the msp2 gene, FC27 and IC3D7 showed almost the same percentage distribution (44.9% and 43.6%) in the South African isolates, whereas FC27 had the highest percentage distribution (60.8%) in the Nigerian isolates. The msp2 gene showed highly distinctive genotypes, indicating high genetic diversity in the South African isolates, whereas msp1 showed high genetic diversity in the Nigerian isolates. The RO33 allelic family displayed an inverse relationship with participants' age in the Nigerian isolates. The overall multiplicity of infection (MOI) was significantly higher in Nigeria (2.87) than in South Africa (2.44) (p < 0.000 *). In addition, heterozygosity was moderately higher in South Africa (1.46) than in Nigeria (1.13). CONCLUSIONS The high genetic diversity and MOI in P. falciparum that were observed in this study could provide surveillance data, on the basis of which appropriate control strategies should be adopted.
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Affiliation(s)
- Olusegun Philip Akoniyon
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (M.A.A.)
| | - Moses Akiibinu
- Department of Biochemistry and Chemistry, Caleb University, Lagos 11379, Nigeria;
| | - Matthew A. Adeleke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (M.A.A.)
| | - Rajendra Maharaj
- Office of Malaria Research, South African Medical Research Council, Cape Town 7505, South Africa;
| | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa; (O.P.A.); (M.A.A.)
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3
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Alves-Rosa MF, Tayler NM, Dorta D, Coronado LM, Spadafora C. P. falciparum Invasion and Erythrocyte Aging. Cells 2024; 13:334. [PMID: 38391947 PMCID: PMC10887143 DOI: 10.3390/cells13040334] [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: 01/16/2024] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/24/2024] Open
Abstract
Plasmodium parasites need to find red blood cells (RBCs) that, on the one hand, expose receptors for the pathogen ligands and, on the other hand, maintain the right geometry to facilitate merozoite attachment and entry into the red blood cell. Both characteristics change with the maturation of erythrocytes. Some Plasmodia prefer younger vs. older erythrocytes. How does the life evolution of the RBC affect the invasion of the parasite? What happens when the RBC ages? In this review, we present what is known up until now.
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Affiliation(s)
| | | | | | | | - Carmenza Spadafora
- Center of Cellular and Molecular Biology of Diseases, Instituto de Investigaciones Científicas y Servicio de Alta Tecnología (INDICASAT AIP), City of Knowledge, Panama City 0843-01103, Panama; (M.F.A.-R.); (N.M.T.); (D.D.); (L.M.C.)
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Evbuomwan IO, Alejolowo OO, Elebiyo TC, Nwonuma CO, Ojo OA, Edosomwan EU, Chikwendu JI, Elosiuba NV, Akulue JC, Dogunro FA, Rotimi DE, Osemwegie OO, Ojo AB, Ademowo OG, Adeyemi OS, Oluba OM. In silico modeling revealed phytomolecules derived from Cymbopogon citratus (DC.) leaf extract as promising candidates for malaria therapy. J Biomol Struct Dyn 2024; 42:101-118. [PMID: 36974933 DOI: 10.1080/07391102.2023.2192799] [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: 01/02/2023] [Accepted: 03/10/2023] [Indexed: 03/29/2023]
Abstract
The emergence of varying levels of resistance to currently available antimalarial drugs significantly threatens global health. This factor heightens the urgency to explore bioactive compounds from natural products with a view to discovering and developing newer antimalarial drugs with novel mode of actions. Therefore, we evaluated the inhibitory effects of sixteen phytocompounds from Cymbopogon citratus leaf extract against Plasmodium falciparum drug targets such as P. falciparum circumsporozoite protein (PfCSP), P. falciparum merozoite surface protein 1 (PfMSP1) and P. falciparum erythrocyte membrane protein 1 (PfEMP1). In silico approaches including molecular docking, pharmacophore modeling and 3D-QSAR were adopted to analyze the inhibitory activity of the compounds under consideration. The molecular docking results indicated that a compound swertiajaponin from C. citratus exhibited a higher binding affinity (-7.8 kcal/mol) to PfMSP1 as against the standard artesunate-amodiaquine (-6.6 kcal/mol). Swertiajaponin also formed strong hydrogen bond interactions with LYS29, CYS30, TYR34, ASN52, GLY55 and CYS28 amino acid residues. In addition, quercetin another compound from C. citratus exhibited significant binding energies -6.8 and -8.3 kcal/mol with PfCSP and PfEMP1, respectively but slightly lower than the standard artemether-lumefantrine with binding energies of -7.4 kcal/mol against PfCSP and -8.7 kcal/mol against PfEMP1. Overall, the present study provides evidence that swertiajaponin and other phytomolecules from C. citratus have modulatory properties toward P. falciparum drug targets and thus may warrant further exploration in early drug discovery efforts against malaria. Furthermore, these findings lend credence to the folkloric use of C. citratus for malaria treatment.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ikponmwosa Owen Evbuomwan
- SDG #03 Group - Good Health and Well-Being Research Cluster, Landmark University, Omu-Aran, Nigeria
- Department of Biochemistry, Landmark University, Omu-Aran, Nigeria
- Department of Food Science and Microbiology, Landmark University, Omu-Aran, Nigeria
| | - Omokolade Oluwaseyi Alejolowo
- SDG #03 Group - Good Health and Well-Being Research Cluster, Landmark University, Omu-Aran, Nigeria
- Department of Biochemistry, Landmark University, Omu-Aran, Nigeria
| | | | - Charles Obiora Nwonuma
- SDG #03 Group - Good Health and Well-Being Research Cluster, Landmark University, Omu-Aran, Nigeria
- Department of Biochemistry, Landmark University, Omu-Aran, Nigeria
| | - Oluwafemi Adeleke Ojo
- Phytomedicine, Molecular Toxicology and Computational Biochemistry Research Group, Department of Biochemistry, Bowen University, Iwo, Nigeria
| | - Evelyn Uwa Edosomwan
- Department of Animal and Environmental Biology, University of Benin, Benin City, Nigeria
| | | | | | | | | | - Damilare Emmanuel Rotimi
- SDG #03 Group - Good Health and Well-Being Research Cluster, Landmark University, Omu-Aran, Nigeria
- Department of Biochemistry, Landmark University, Omu-Aran, Nigeria
| | | | | | - Olusegun George Ademowo
- Department of Pharmacology and Therapeutics, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, Nigeria
- Drug Research Laboratory, Institute of Advanced Medical Research and Training (IMRAT), College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Oluyomi Stephen Adeyemi
- SDG #03 Group - Good Health and Well-Being Research Cluster, Landmark University, Omu-Aran, Nigeria
- Department of Biochemistry, Landmark University, Omu-Aran, Nigeria
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
| | - Olarewaju Michael Oluba
- SDG #03 Group - Good Health and Well-Being Research Cluster, Landmark University, Omu-Aran, Nigeria
- Department of Biochemistry, Landmark University, Omu-Aran, Nigeria
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Rosenkranz M, Fürle K, Hibbert J, Ulmer A, Ali A, Giese T, Blank A, Haefeli WE, Böhnlein E, Lanzer M, Thomson-Luque R. Multifunctional IgG/IgM antibodies and cellular cytotoxicity are elicited by the full-length MSP1 SumayaVac-1 malaria vaccine. NPJ Vaccines 2023; 8:112. [PMID: 37558673 PMCID: PMC10412566 DOI: 10.1038/s41541-023-00701-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 06/27/2023] [Indexed: 08/11/2023] Open
Abstract
Radical control of malaria likely requires a vaccine that targets both the asymptomatic liver stages and the disease-causing blood stages of the human malaria parasite Plasmodium falciparum. While substantial progress has been made towards liver stage vaccines, the development of a blood stage vaccine is lagging behind. We have recently conducted a first-in-human clinical trial to evaluate the safety and immunogenicity of the recombinant, full-length merozoite surface protein 1 (MSP1FL) formulated with GLA-SE as adjuvant. Here, we show that the vaccine, termed SumayaVac-1, elicited both a humoral and cellular immune response as well as a recall T cell memory. The induced IgG and IgM antibodies were able to stimulate various Fc-mediated effector mechanisms associated with protection against malaria, including phagocytosis, release of reactive oxygen species, production of IFN-γ as well as complement activation and fixation. The multifunctional activity of the humoral immune response remained for at least 6 months after vaccination and was comparable to that of naturally acquired anti-MSP1 antibodies from semi-immune adults from Kenya. We further present evidence of SumayaVac-1 eliciting a recallable cellular cytotoxicity by IFN-γ producing CD8+ T cells. Our study revitalizes MSP1FL as a relevant blood stage vaccine candidate and warrants further evaluation of SumayaVac-1 in a phase II efficacy trial.
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Affiliation(s)
- Micha Rosenkranz
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Kristin Fürle
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Julia Hibbert
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Anne Ulmer
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Arin Ali
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Giese
- Institute for Immunology, Heidelberg University Hospital and German Center for Infection Research (DZIF), Heidelberg, Germany
| | - Antje Blank
- Clinical Pharmacology and Pharmacoepidemiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Walter E Haefeli
- Clinical Pharmacology and Pharmacoepidemiology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Michael Lanzer
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Richard Thomson-Luque
- Center for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany.
- Sumaya-Biotech GmbH & Co. KG, Heidelberg, Germany.
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Computational Clues of Immunogenic Hotspots in Plasmodium falciparum Erythrocytic Stage Vaccine Candidate Antigens: In Silico Approach. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5886687. [PMID: 36277884 PMCID: PMC9584662 DOI: 10.1155/2022/5886687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 09/27/2022] [Indexed: 11/30/2022]
Abstract
Malaria is the most pernicious parasitic infection, and Plasmodium falciparum is the most virulent species with substantial morbidity and mortality worldwide. The present in silico investigation was performed to reveal the biophysical characteristics and immunogenic epitopes of the 14 blood-stage proteins of the P. falciparum using comprehensive immunoinformatics approaches. For this aim, various web servers were employed to predict subcellular localization, antigenicity, allergenicity, solubility, physicochemical properties, posttranslational modification sites (PTMs), the presence of signal peptide, and transmembrane domains. Moreover, structural analysis for secondary and 3D model predictions were performed for all and stable proteins, respectively. Finally, human helper T lymphocyte (HTL) epitopes were predicted using HLA reference set of IEDB server and screened in terms of antigenicity, allergenicity, and IFN-γ induction as well as population coverage. Also, a multiserver B-cell epitope prediction was done with subsequent screening for antigenicity, allergenicity, and solubility. Altogether, these proteins showed appropriate antigenicity, abundant PTMs, and many B-cell and HTL epitopes, which could be directed for future vaccination studies in the context of multiepitope vaccine design.
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Putaporntip C, Kuamsab N, Rojrung R, Seethamchai S, Jongwutiwes S. Structural organization and sequence diversity of the complete nucleotide sequence encoding the Plasmodium malariae merozoite surface protein-1. Sci Rep 2022; 12:15591. [PMID: 36114242 PMCID: PMC9481586 DOI: 10.1038/s41598-022-19049-z] [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: 03/15/2022] [Accepted: 08/23/2022] [Indexed: 11/28/2022] Open
Abstract
The merozoite surface protein-1 (MSP1) is a prime candidate for an asexual blood stage vaccine against malaria. However, polymorphism in this antigen could compromise the vaccine’s efficacy. Although the extent of sequence variation in MSP1 has been analyzed from various Plasmodium species, little is known about structural organization and diversity of this locus in Plasmodium malariae (PmMSP1). Herein, we have shown that PmMSP1 contained five conserved and four variable blocks based on analysis of the complete coding sequences. Variable blocks were characterized by short insertion and deletion variants (block II), polymorphic nonrepeat sequences (block IV), complex repeat structure with size variation (block VI) and degenerate octapeptide repeats (block VIII). Like other malarial MSP1s, evidences of intragenic recombination have been found in PmMSP1. The rate of nonsynonymous nucleotide substitutions significantly exceeded that of synonymous nucleotide substitutions in block IV, suggesting positive selection in this region. Codon-based analysis of deviation from neutrality has identified a codon under purifying selection located in close proximity to the homologous region of the 38 kDa/42 kDa cleavage site of P. falciparum MSP1. A number of predicted linear B-cell epitopes were identified across both conserved and variable blocks of the protein. However, polymorphism in repeat-containing blocks resulted in alteration of the predicted linear B-cell epitope scores across variants. Although a number of predicted HLA-class II-binding peptides were identified in PmMSP1, all variants of block IV seemed not to be recognized by common HLA-class II alleles among Thai population, suggesting that diversity in this positive selection region could probably affect host immune recognition. The data on structural diversity in PmMSP1 could be useful for further studies such as vaccine development and strain characterization of this neglected malaria parasite.
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Aleshnick M, Florez-Cuadros M, Martinson T, Wilder BK. Monoclonal antibodies for malaria prevention. Mol Ther 2022; 30:1810-1821. [PMID: 35395399 PMCID: PMC8979832 DOI: 10.1016/j.ymthe.2022.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/04/2022] [Accepted: 04/01/2022] [Indexed: 11/29/2022] Open
Abstract
Monoclonal antibodies are highly specific proteins that are cloned from a single B cell and bind to a single epitope on a pathogen. These laboratory-made molecules can serve as prophylactics or therapeutics for infectious diseases and have an impressive capacity to modulate the progression of disease, as demonstrated for the first time on a large scale during the COVID-19 pandemic. The high specificity and natural starting point of monoclonal antibodies afford an encouraging safety profile, yet the high cost of production remains a major limitation to their widespread use. While a monoclonal antibody approach to abrogating malaria infection is not yet available, the unique life cycle of the malaria parasite affords many opportunities for such proteins to act, and preliminary research into the efficacy of monoclonal antibodies in preventing malaria infection, disease, and transmission is encouraging. This review examines the current status and future outlook for monoclonal antibodies against malaria in the context of the complex life cycle and varied antigenic targets expressed in the human and mosquito hosts, and provides insight into the strengths and limitations of this approach to curtailing one of humanity’s oldest and deadliest diseases.
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Affiliation(s)
- Maya Aleshnick
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | | | - Thomas Martinson
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Brandon K Wilder
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA; Department of Parasitology, U.S. Naval Medical Research 6 (NAMRU-6), Lima, Peru
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Aguttu C, Okech BA, Mukisa A, Lubega GW. Screening and characterization of hypothetical proteins of Plasmodium falciparum as novel vaccine candidates in the fight against malaria using reverse vaccinology. J Genet Eng Biotechnol 2021; 19:103. [PMID: 34269931 PMCID: PMC8283385 DOI: 10.1186/s43141-021-00199-y] [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: 04/07/2021] [Accepted: 06/16/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND Plasmodium falciparum is the most deadly and leading cause of morbidity and mortality in Africa. About 90% of all malaria deaths in the world today occur in Sub-Saharan Africa especially in children aged < 5 years. In 2018, it was reported that there were 228 million malaria cases that resulted in 405,000 deaths from 91 countries. Currently, a fully effective and long-lasting preventive malaria vaccine is still elusive therefore more effort is needed to identify better effective vaccine candidates. The aim of this study was to identify and characterize hypothetical proteins as vaccine candidates derived from Plasmodium falciparum 3D7 genome by reverse vaccinology. RESULTS Of the 23 selected hypothetical proteins, 5 were predicted on the extracellular localization by WoLFPSORTv.2.0 program and all the 5 had less than 2 transmembrane regions that were predicted by TMHMMv2.0 and HMMTOP programs at default settings. Two out of the five proteins lacked secretory signal peptides as predicted by SignalP program. Among the 5 extracellular proteins, 3 were predicted to be antigenic by VaxiJen (score ≥ 0.5) and had negative GRAVY values ranging from - 1.156 to - 0.440. B cell epitope prediction by ABCpred and BCpred programs revealed a total of 15 antigenic epitopes. A total of 13 cytotoxic T cells were predicted from the 3 proteins using CTLPred online server. Only 2 out of the 13 CTL were antigenic, immunogenic, non-allergenic, and non-toxic using VaxiJen, IEDB, AllergenFp, and Toxinpred servers respectively in that order. Five HTL peptides from XP_001351030.1 protein are predicted inducers of all the three cytokines. STRING protein-protein network analysis of HPs revealed XP_001350955.1 closely interacts with nucleoside diphosphate kinase (PF13-0349) at 0.704, XP_001351030.1 interacts with male development protein1 (Mdv-1) at 0.645, and XP_001351047.1 with an uncharacterized protein (MAL8P1.53) at 0.400. CONCLUSION Reverse vaccinology is a promising strategy for the screening and identification of antigenic antigens with potential capacity to elicit cellular and humoral immune responses against P. falciparum infection. In this study, potential vaccine candidates of Plasmodium falciparum were identified and screened using standard bioinformatics tools. The vaccine candidates contained antigenic and immunogenic epitopes which could be considered for novel and effective vaccine targets. However, we strongly recommend in vivo and in vitro experiments to validate their immunogenicity and protective efficacy to completely decipher the vaccine targets against malaria.
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Affiliation(s)
- Claire Aguttu
- Department of Biochemistry and Sports Science, College of Natural Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda
| | | | - Ambrose Mukisa
- Department of Biochemistry and Sports Science, College of Natural Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda
| | - George William Lubega
- Department of Bio-molecular Resources and Bio-lab Sciences, School of Biosecurity, Biotechnology and Laboratory Sciences (SBLS), College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O Box 7062, Kampala, Uganda
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Dijkman PM, Marzluf T, Zhang Y, Chang SYS, Helm D, Lanzer M, Bujard H, Kudryashev M. Structure of the merozoite surface protein 1 from Plasmodium falciparum. SCIENCE ADVANCES 2021; 7:eabg0465. [PMID: 34078606 PMCID: PMC11210306 DOI: 10.1126/sciadv.abg0465] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
The merozoite surface protein 1 (MSP-1) is the most abundant protein on the surface of the erythrocyte-invading Plasmodium merozoite, the causative agent of malaria. MSP-1 is essential for merozoite formation, entry into and escape from erythrocytes, and is a promising vaccine candidate. Here, we present monomeric and dimeric structures of full-length MSP-1. MSP-1 adopts an unusual fold with a large central cavity. Its fold includes several coiled-coils and shows structural homology to proteins associated with membrane and cytoskeleton interactions. MSP-1 formed dimers through these domains in a concentration-dependent manner. Dimerization is affected by the presence of the erythrocyte cytoskeleton protein spectrin, which may compete for the dimerization interface. Our work provides structural insights into the possible mode of interaction of MSP-1 with erythrocytes and establishes a framework for future investigations into the role of MSP-1 in Plasmodium infection and immunity.
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Affiliation(s)
- Patricia M Dijkman
- Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University of Frankfurt, Frankfurt am Main, Germany
| | - Tanja Marzluf
- Centre for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg University, Heidelberg, Germany
- MS-based Protein Analysis Unit, Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Yingyi Zhang
- Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University of Frankfurt, Frankfurt am Main, Germany
| | - Shih-Ying Scott Chang
- Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University of Frankfurt, Frankfurt am Main, Germany
| | - Dominic Helm
- MS-based Protein Analysis Unit, Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Lanzer
- Centre for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Heidelberg University, Heidelberg, Germany
| | - Hermann Bujard
- Sumaya Biotech GmbH & Co. KG, Heidelberg, Germany
- Centre for Molecular Biology Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Mikhail Kudryashev
- Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University of Frankfurt, Frankfurt am Main, Germany
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Diversify and Conquer: The Vaccine Escapism of Plasmodium falciparum. Microorganisms 2020; 8:microorganisms8111748. [PMID: 33171746 PMCID: PMC7694999 DOI: 10.3390/microorganisms8111748] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 12/14/2022] Open
Abstract
Over the last century, a great deal of effort and resources have been poured into the development of vaccines to protect against malaria, particularly targeting the most widely spread and deadly species of the human-infecting parasites: Plasmodium falciparum. Many of the known proteins the parasite uses to invade human cells have been tested as vaccine candidates. However, precisely because of the importance and immune visibility of these proteins, they tend to be very diverse, and in many cases redundant, which limits their efficacy in vaccine development. With the advent of genomics and constantly improving sequencing technologies, an increasingly clear picture is emerging of the vast genomic diversity of parasites from different geographic areas. This diversity is distributed throughout the genome and includes most of the vaccine candidates tested so far, playing an important role in the low efficacy achieved. Genomics is a powerful tool to search for genes that comply with the most desirable attributes of vaccine targets, allowing us to evaluate function, immunogenicity and also diversity in the worldwide parasite populations. Even predicting how this diversity might evolve and spread in the future becomes possible, and can inform novel vaccine efforts.
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12
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Artemisinin-Ginkgo biloba extract combination therapy for Plasmodium yoelii. Parasitol Int 2020; 80:102226. [PMID: 33137498 DOI: 10.1016/j.parint.2020.102226] [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: 01/01/2020] [Revised: 03/02/2020] [Accepted: 10/22/2020] [Indexed: 11/21/2022]
Abstract
Malaria remains a widespread life-threatening infectious disease, leading to an estimated 219 million cases and around 435,000 deaths. After an unprecedented success, the antimalarial progress is at a standstill. Therefore, new methods are urgently needed to decrease drug resistant and enhance antimalarial efficacy. According to the alteration of erythrocyte biomechanical properties and the immune evasion mechanism of parasites, drugs, which can improve blood circulation, can be chosen to combine with antimalarial drugs for malaria treatment. Ginkgo biloba extract (GBE), one of drug for vascular disease, was used to combine with artemisinin for Plasmodium yoelii therapy. Artemisinin-GBE combination therapy (AGCT) demonstrated remarkable antimalarial efficacy by decreasing infection rate, improving blood microcirculation and modulating immune system. Besides, the expression of invasion related genes, such as AMA1, MSP1 and Py01365, can be suppressed by AGCT, hindering invasion process of merozoites. This new antimalarial strategy, combining antimalarial drugs with drugs that improve blood circulation, may enhance the antimalarial efficacy and ameliorate restoration ability, proving a potential method for finding ideal compatible drugs to improve malaria therapy.
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13
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Anam ZE, Joshi N, Gupta S, Yadav P, Chaurasiya A, Kahlon AK, Kaushik S, Munde M, Ranganathan A, Singh S. A De novo Peptide from a High Throughput Peptide Library Blocks Myosin A -MTIP Complex Formation in Plasmodium falciparum. Int J Mol Sci 2020; 21:ijms21176158. [PMID: 32859024 PMCID: PMC7503848 DOI: 10.3390/ijms21176158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/09/2020] [Accepted: 05/15/2020] [Indexed: 01/09/2023] Open
Abstract
Apicomplexan parasites, through their motor machinery, produce the required propulsive force critical for host cell-entry. The conserved components of this so-called glideosome machinery are myosin A and myosin A Tail Interacting Protein (MTIP). MTIP tethers myosin A to the inner membrane complex of the parasite through 20 amino acid-long C-terminal end of myosin A that makes direct contacts with MTIP, allowing the invasion of Plasmodium falciparum in erythrocytes. Here, we discovered through screening a peptide library, a de-novo peptide ZA1 that binds the myosin A tail domain. We demonstrated that ZA1 bound strongly to myosin A tail and was able to disrupt the native myosin A tail MTIP complex both in vitro and in vivo. We then showed that a shortened peptide derived from ZA1, named ZA1S, was able to bind myosin A and block parasite invasion. Overall, our study identified a novel anti-malarial peptide that could be used in combination with other antimalarials for blocking the invasion of Plasmodium falciparum.
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Affiliation(s)
- Zill e Anam
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
| | - Nishant Joshi
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201304, India;
| | - Sakshi Gupta
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (S.G.); (M.M.)
| | - Preeti Yadav
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
| | - Ayushi Chaurasiya
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
| | - Amandeep Kaur Kahlon
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
| | - Shikha Kaushik
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
| | - Manoj Munde
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (S.G.); (M.M.)
| | - Anand Ranganathan
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
- Correspondence: (A.R.); (S.S.)
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; (Z.e.A.); (P.Y.); (A.C.); (A.K.K.); (S.K.)
- Correspondence: (A.R.); (S.S.)
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14
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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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15
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Blank A, Fürle K, Jäschke A, Mikus G, Lehmann M, Hüsing J, Heiss K, Giese T, Carter D, Böhnlein E, Lanzer M, Haefeli WE, Bujard H. Immunization with full-length Plasmodium falciparum merozoite surface protein 1 is safe and elicits functional cytophilic antibodies in a randomized first-in-human trial. NPJ Vaccines 2020; 5:10. [PMID: 32025341 PMCID: PMC6994672 DOI: 10.1038/s41541-020-0160-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/14/2020] [Indexed: 12/20/2022] Open
Abstract
A vaccine remains a priority in the global fight against malaria. Here, we report on a single-center, randomized, double-blind, placebo and adjuvant-controlled, dose escalation phase 1a safety and immunogenicity clinical trial of full-length Plasmodium falciparum merozoite surface protein 1 (MSP1) in combination with GLA-SE adjuvant. Thirty-two healthy volunteers were vaccinated at least three times with MSP1 plus adjuvant, adjuvant alone, or placebo (24:4:4) to evaluate the safety and immunogenicity. MSP1 was safe, well tolerated and immunogenic, with all vaccinees sero-converting independent of the dose. The MSP1-specific IgG and IgM titers persisted above levels found in malaria semi-immune humans for at least 6 months after the last immunization. The antibodies were variant- and strain-transcending and stimulated respiratory activity in granulocytes. Furthermore, full-length MSP1 induced memory T-cells. Our findings encourage challenge studies as the next step to evaluate the efficacy of full-length MSP1 as a vaccine candidate against falciparum malaria (EudraCT 2016-002463-33).
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Affiliation(s)
- Antje Blank
- Klinische Pharmakologie und Pharmakoepidemiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Kristin Fürle
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Anja Jäschke
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Gerd Mikus
- Klinische Pharmakologie und Pharmakoepidemiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Monika Lehmann
- Koordinierungszentrum für Klinische Studien (KKS), Universitätsklinikum Heidelberg, Im Neuenheimer Feld 130.3, 69120 Heidelberg, Germany
| | - Johannes Hüsing
- Koordinierungszentrum für Klinische Studien (KKS), Universitätsklinikum Heidelberg, Im Neuenheimer Feld 130.3, 69120 Heidelberg, Germany
| | - Kirsten Heiss
- PEPperPRINT GmbH, Rischerstrasse 12, 69123 Heidelberg, Germany
| | - Thomas Giese
- Institut für Immunologie, Universitätsklinikum Heidelberg und Deutsches Zentrum für Infektionsforschung (DZIF) Standort Heidelberg, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany
| | - Darrick Carter
- PAI Life Sciences, 1616 Eastlake Ave E, Suite 550, Seattle, WA 98102 USA
| | - Ernst Böhnlein
- Sumaya Biotech GmbH & Co. KG, Im Neuenheimer Feld 582, 69120 Heidelberg, Germany
| | - Michael Lanzer
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Walter E. Haefeli
- Klinische Pharmakologie und Pharmakoepidemiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Hermann Bujard
- Sumaya Biotech GmbH & Co. KG, Im Neuenheimer Feld 582, 69120 Heidelberg, Germany
- Zentrum für Molekulare Biologie Heidelberg, Universität Heidelberg, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
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16
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Cheng Y, Wang B, Lu F, Ahmed MA, Han JH, Na SH, Ha KS, Park WS, Hong SH, Han ET. Identification and characterization of Pv50, a novel Plasmodium vivax merozoite surface protein. Parasit Vectors 2019; 12:176. [PMID: 30999945 PMCID: PMC6474066 DOI: 10.1186/s13071-019-3434-7] [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: 01/04/2019] [Accepted: 04/04/2019] [Indexed: 11/27/2022] Open
Abstract
Background Plasmodium vivax contains approximately 5400 coding genes, more than 40% of which code for hypothetical proteins that have not been functionally characterized. In a previous preliminary screening using pooled serum samples, numerous hypothetical proteins were selected from among those that were highly transcribed in the schizont-stage of parasites, and highly antigenic P. vivax candidates including hypothetical proteins were identified. However, their immunological and functional activities in P. vivax remain unclear. From these candidates, we investigated a P. vivax 50-kDa protein (Pv50, PVX_087140) containing a highly conserved signal peptide that shows high transcription levels in blood-stage parasites. Results Recombinant Pv50 was expressed in a cell-free expression system and used for IgG prevalence analysis of patients with vivax malaria and healthy individuals. Immune responses were analyzed in immunized mice and mouse antibodies were used to detect the subcellular localization of the protein in blood-stage parasites by immunofluorescence assay. A protein array method was used to evaluate protein-protein interactions to predict protein functional activities during the invasion of parasites into erythrocytes. Recombinant Pv50 showed IgG prevalence in patient samples with a sensitivity of 42.9% and specificity of 93.8% compared to that in healthy individuals. The non-cytophilic antibodies IgG1 and IgG3 were the major components involved in the antibody response in Pv50-immunized mice. Pv50 localized on the surface of merozoites and a specific interaction between Pv50 and PvMSP1 was detected, suggesting that Pv50-PvMSP1 forms a heterodimeric complex in P. vivax. Conclusions Increased immune responses caused by native P. vivax parasites were detected, confirming its immunogenic effects. This study provides a method for detecting new malaria antigens, and Pv50 may be a vivax malaria vaccine candidate with PvMSP1. Electronic supplementary material The online version of this article (10.1186/s13071-019-3434-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yang Cheng
- Department of Public Health and Preventive Medicine, Laboratory of Pathogen Infection and Immunity, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, People's Republic of China. .,Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea.
| | - Bo Wang
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea.,Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Feng Lu
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea.,Department of Pathogen Biology and Immunology, School of Medicine, Yangzhou University, Yangzhou, People's Republic of China
| | - Md Atique Ahmed
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Sung Hun Na
- Department of Obstetrics and Gynecology, Kangwon National University Hospital, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Won Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Seok-Ho Hong
- Department of Internal Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea.
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17
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Plasmodium falciparum MSP3 Exists in a Complex on the Merozoite Surface and Generates Antibody Response during Natural Infection. Infect Immun 2018; 86:IAI.00067-18. [PMID: 29760216 DOI: 10.1128/iai.00067-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022] Open
Abstract
Plasmodium falciparum merozoite surface protein 3 (MSP3) is an abundantly expressed secreted merozoite surface protein and a leading malaria vaccine candidate antigen. However, it is unclear how MSP3 is retained on the surface of merozoites without a glycosylphosphatidylinositol (GPI) anchor or a transmembrane domain. In the present study, we identified an MSP3-associated network on the Plasmodium merozoite surface by immunoprecipitation of Plasmodium merozoite lysate using antibody to the N terminus of MSP3 (anti-MSP3N) followed by mass spectrometry analysis. The results suggested the association of MSP3 with other merozoite surface proteins: MSP1, MSP6, MSP7, RAP2, and SERA5. Protein-protein interaction studies by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) analysis showed that MSP3 complex consists of MSP1, MSP6, and MSP7 proteins. Immunological characterization of MSP3 revealed that MSP3N is strongly recognized by hyperimmune serum from African and Asian populations. Furthermore, we demonstrate that human antibodies, affinity purified against recombinant MSP3N (rMSP3N), promote opsonic phagocytosis of merozoites in cooperation with monocytes. At nonphysiological concentrations, anti-MSP3N antibodies inhibited the growth of P. falciparum in vitro Together, the data suggest that MSP3 and especially its N-terminal region containing known B/T cell epitopes are targets of naturally acquired immunity against malaria and also comprise an important candidate for a multisubunit malaria vaccine.
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18
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Arévalo-Pinzón G, González-González M, Suárez CF, Curtidor H, Carabias-Sánchez J, Muro A, LaBaer J, Patarroyo MA, Fuentes M. Self-assembling functional programmable protein array for studying protein-protein interactions in malaria parasites. Malar J 2018; 17:270. [PMID: 30016987 PMCID: PMC6050706 DOI: 10.1186/s12936-018-2414-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 07/10/2018] [Indexed: 12/30/2022] Open
Abstract
Background Plasmodium vivax is the most widespread malarial species, causing significant morbidity worldwide. Knowledge is limited regarding the molecular mechanism of invasion due to the lack of a continuous in vitro culture system for these species. Since protein–protein and host–cell interactions play an essential role in the microorganism’s invasion and replication, elucidating protein function during invasion is critical when developing more effective control methods. Nucleic acid programmable protein array (NAPPA) has thus become a suitable technology for studying protein–protein and host–protein interactions since producing proteins through the in vitro transcription/translation (IVTT) method overcomes most of the drawbacks encountered to date, such as heterologous protein production, stability and purification. Results Twenty P. vivax proteins on merozoite surface or in secretory organelles were selected and successfully cloned using gateway technology. Most constructs were displayed in the array expressed in situ, using the IVTT method. The Pv12 protein was used as bait for evaluating array functionality and co-expressed with P. vivax cDNA display in the array. It was found that Pv12 interacted with Pv41 (as previously described), as well as PvMSP142kDa, PvRBP1a, PvMSP8 and PvRAP1. Conclusions NAPPA is a high-performance technique enabling co-expression of bait and query in situ, thereby enabling interactions to be analysed rapidly and reproducibly. It offers a fresh alternative for studying protein–protein and ligand–receptor interactions regarding a parasite which is difficult to cultivate (i.e. P. vivax). Electronic supplementary material The online version of this article (10.1186/s12936-018-2414-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gabriela Arévalo-Pinzón
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia.,PhD Programme in Biomedical and Biological Sciences, Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia
| | - María González-González
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain.,Department of Medicine and General Cytometry Service-Nucleus, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain
| | - Carlos Fernando Suárez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia.,Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A.), Calle 222 # 55-37, Bogotá, Colombia
| | - Hernando Curtidor
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia.,School of Medicine and Health Sciences, Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia
| | | | - Antonio Muro
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Campus Universitario Miguel de Unamuno s/n, 37007, Salamanca, Spain
| | - Joshua LaBaer
- Virginia G. Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Manuel Alfonso Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia.,School of Medicine and Health Sciences, Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia
| | - Manuel Fuentes
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain. .,Department of Medicine and General Cytometry Service-Nucleus, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain.
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19
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Protein-protein interaction studies reveal the Plasmodium falciparum merozoite surface protein-1 region involved in a complex formation that binds to human erythrocytes. Biochem J 2018; 475:1197-1209. [PMID: 29511044 DOI: 10.1042/bcj20180017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/23/2018] [Accepted: 03/05/2018] [Indexed: 11/17/2022]
Abstract
Plasmodium falciparum merozoite surface protein (PfMSP) 1 has been studied extensively as a vaccine candidate antigen. PfMSP-1 undergoes proteolytic processing into four major products, such as p83, p30, p38, and p42, that are associated in the form of non-covalent complex(s) with other MSPs. To delineate MSP1 regions involved in the interaction with other MSPs, here we expressed recombinant proteins (PfMSP-165) encompassing part of p38 and p42 regions and PfMSP-119 PfMSP-165 interacted strongly with PfMSP-3, PfMSP-6, PfMSP-7, and PfMSP-9, whereas PfMSP-119 did not interact with any of these proteins. Since MSP-1 complex binds human erythrocytes, we examined the ability of these proteins to bind human erythrocyte. Among the proteins of MSP-1 complex, PfMSP-6 and PfMSP-9 bound to human erythrocytes. Serological studies showed that PfMSP-165 was frequently recognized by sera from malaria endemic regions, whereas this was not the case for PfMSP-119 In contrast, antibodies against PfMSP-119 showed much higher inhibition of merozoite invasion compared with antibodies against the larger PfMSP-165 fragment. Importantly, anti-PfMSP-119 antibodies recognized both recombinant proteins, PfMSP-119 and PfMSP-165; however, anti-PfMSP-165 antibody failed to recognize the PfMSP-119 protein. Taken together, these results demonstrate that PfMSP-1 sequences upstream of the 19 kDa C-terminal region are involved in molecular interactions with other MSPs, and these sequences may probably serve as a smoke screen to evade antibody response to the membrane-bound C-terminal 19 kDa region.
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20
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Kumar K, Srinivasan P, Nold MJ, Moch JK, Reiter K, Sturdevant D, Otto TD, Squires RB, Herrera R, Nagarajan V, Rayner JC, Porcella SF, Geromanos SJ, Haynes JD, Narum DL. Profiling invasive Plasmodium falciparum merozoites using an integrated omics approach. Sci Rep 2017; 7:17146. [PMID: 29215067 PMCID: PMC5719419 DOI: 10.1038/s41598-017-17505-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
The symptoms of malaria are brought about by blood-stage parasites, which are established when merozoites invade human erythrocytes. Our understanding of the molecular events that underpin erythrocyte invasion remains hampered by the short-period of time that merozoites are invasive. To address this challenge, a Plasmodium falciparum gamma-irradiated long-lived merozoite (LLM) line was developed and investigated. Purified LLMs invaded erythrocytes by an increase of 10-300 fold compared to wild-type (WT) merozoites. Using an integrated omics approach, we investigated the basis for the phenotypic difference. Only a few single nucleotide polymorphisms within the P. falciparum genome were identified and only marginal differences were observed in the merozoite transcriptomes. By contrast, using label-free quantitative mass-spectrometry, a significant change in protein abundance was noted, of which 200 were proteins of unknown function. We determined the relative molar abundance of over 1100 proteins in LLMs and further characterized the major merozoite surface protein complex. A unique processed MSP1 intermediate was identified in LLM but not observed in WT suggesting that delayed processing may be important for the observed phenotype. This integrated approach has demonstrated the significant role of the merozoite proteome during erythrocyte invasion, while identifying numerous unknown proteins likely to be involved in invasion.
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Affiliation(s)
- Krishan Kumar
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Prakash Srinivasan
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, USA.
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - J Kathleen Moch
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Dan Sturdevant
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - R Burke Squires
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Raul Herrera
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Vijayaraj Nagarajan
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Stephen F Porcella
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | | | - J David Haynes
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA.
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21
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Mechanisms of naturally acquired immunity to P. falciparum and approaches to identify merozoite antigen targets. Parasitology 2017; 145:839-847. [PMID: 29144217 DOI: 10.1017/s0031182017001949] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Malaria is one the most serious infectious diseases with over 200 million clinical cases annually. Most cases of the severe disease are caused by Plasmodium falciparum. The blood stage of Plasmodium parasite is entirely responsible for malaria-associated pathology. The population most susceptible to severe malaria are children under the age of 5, with low levels of immunity. It is only after many years of repeated exposure that individuals living in endemic areas develop clinical immunity. This form of protection prevents clinical episodes by substantially reducing parasite burden. Naturally acquired immunity predominantly targets blood-stage parasites with antibody responses being the main mediators of protection. The targets of clinical immunity are the extracellular merozoite and the infected erythrocyte surface, with the extremely diverse PfEMP1 proteins the main target here. This observation provides a strong rationale that an effective anti-malaria vaccine targeting blood-stage parasites is achievable. Thus the identification of antigenic targets of naturally acquired immunity remains an important step towards the formulation of novel vaccine combinations before testing their efficacy in clinical trials. This review summarizes the main findings to date defining antigenic targets present on the extracellular merozoite associated with naturally acquired immunity to P. falciparum malaria.
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22
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Molecular mechanisms that mediate invasion and egress of malaria parasites from red blood cells. Curr Opin Hematol 2017; 24:208-214. [PMID: 28306665 DOI: 10.1097/moh.0000000000000334] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Malaria parasites invade and multiply in diverse host cells during their complex life cycle. Some blood stage parasites transform into male and female gametocytes that are transmitted by female anopheline mosquitoes. The gametocytes are activated in the mosquito midgut to form male and female gametes, which egress from RBCs to mate and form a zygote. Here, we will review our current understanding of the molecular mechanisms that mediate invasion and egress by malaria parasites at different life cycle stages. RECENT FINDINGS A number of key effector molecules such as parasite protein ligands for receptor-engagement during invasion as well as proteases and perforin-like proteins that mediate egress have been identified. Interestingly, these parasite-encoded effectors are located in internal, vesicular organelles and are secreted in a highly regulated manner during invasion and egress. Here, we will review our current understanding of the functional roles of these effectors as well as the signaling pathways that regulate their timely secretion with accurate spatiotemporal coordinates. SUMMARY Understanding the molecular basis of key processes such as host cell invasion and egress by malaria parasites could provide novel targets for development of inhibitors to block parasite growth and transmission.
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23
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Acharya P, Garg M, Kumar P, Munjal A, Raja KD. Host-Parasite Interactions in Human Malaria: Clinical Implications of Basic Research. Front Microbiol 2017; 8:889. [PMID: 28572796 PMCID: PMC5435807 DOI: 10.3389/fmicb.2017.00889] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 05/02/2017] [Indexed: 12/21/2022] Open
Abstract
The malaria parasite, Plasmodium, is one of the oldest parasites documented to infect humans and has proven particularly hard to eradicate. One of the major hurdles in designing an effective subunit vaccine against the malaria parasite is the insufficient understanding of host–parasite interactions within the human host during infections. The success of the parasite lies in its ability to evade the human immune system and recruit host responses as physiological cues to regulate its life cycle, leading to rapid acclimatization of the parasite to its immediate host environment. Hence understanding the environmental niche of the parasite is crucial in developing strategies to combat this deadly infectious disease. It has been increasingly recognized that interactions between parasite proteins and host factors are essential to establishing infection and virulence at every stage of the parasite life cycle. This review reassesses all of these interactions and discusses their clinical importance in designing therapeutic approaches such as design of novel vaccines. The interactions have been followed from the initial stages of introduction of the parasite under the human dermis until asexual and sexual blood stages which are essential for transmission of malaria. We further classify the interactions as “direct” or “indirect” depending upon their demonstrated ability to mediate direct physical interactions of the parasite with host factors or their indirect manipulation of the host immune system since both forms of interactions are known to have a crucial role during infections. We also discuss the many ways in which this understanding has been taken to the field and the success of these strategies in controlling human malaria.
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Affiliation(s)
- Pragyan Acharya
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - Manika Garg
- Department of Biochemistry, Jamia Hamdard UniversityNew Delhi, India
| | - Praveen Kumar
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - Akshay Munjal
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - K D Raja
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
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24
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Kennedy AT, Wijeyewickrema LC, Huglo A, Lin C, Pike R, Cowman AF, Tham WH. Recruitment of Human C1 Esterase Inhibitor Controls Complement Activation on Blood StagePlasmodium falciparumMerozoites. THE JOURNAL OF IMMUNOLOGY 2017; 198:4728-4737. [DOI: 10.4049/jimmunol.1700067] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/10/2017] [Indexed: 11/19/2022]
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25
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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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26
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Abstract
PURPOSE OF REVIEW Red cell receptors provide unique entry points for Plasmodium parasites to initiate blood-stage malaria infection. Parasites encode distinct ligands that bind specifically to both highly abundant and low-copy receptors. Recent advances in the understanding of molecular and structural mechanisms of these interactions provide fundamental insights into receptor-ligand biology and molecular targets for intervention. RECENT FINDINGS The review focuses on the requirements for known interactions, insight derived from complex structures, and mechanisms of receptor/ligand engagement. Further, novel roles for established red cell membrane proteins, parasite ligands and associated interacting partners have recently been established in red cell invasion. SUMMARY The new knowledge underlines the intricacies involved in invasion by a eukaryotic parasite into a eukaryotic host cell demonstrated by expanded parasite ligand families, redundancy in red cell receptor engagement, multitiered temporal binding, and the breadth of receptors engaged.
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27
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Jackson AP. Gene family phylogeny and the evolution of parasite cell surfaces. Mol Biochem Parasitol 2016; 209:64-75. [DOI: 10.1016/j.molbiopara.2016.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/18/2016] [Accepted: 03/19/2016] [Indexed: 11/30/2022]
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28
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Das S, Hertrich N, Perrin AJ, Withers-Martinez C, Collins CR, Jones ML, Watermeyer JM, Fobes ET, Martin SR, Saibil HR, Wright GJ, Treeck M, Epp C, Blackman MJ. Processing of Plasmodium falciparum Merozoite Surface Protein MSP1 Activates a Spectrin-Binding Function Enabling Parasite Egress from RBCs. Cell Host Microbe 2016; 18:433-44. [PMID: 26468747 PMCID: PMC4608996 DOI: 10.1016/j.chom.2015.09.007] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/17/2015] [Accepted: 09/18/2015] [Indexed: 11/09/2022]
Abstract
The malaria parasite Plasmodium falciparum replicates within erythrocytes, producing progeny merozoites that are released from infected cells via a poorly understood process called egress. The most abundant merozoite surface protein, MSP1, is synthesized as a large precursor that undergoes proteolytic maturation by the parasite protease SUB1 just prior to egress. The function of MSP1 and its processing are unknown. Here we show that SUB1-mediated processing of MSP1 is important for parasite viability. Processing modifies the secondary structure of MSP1 and activates its capacity to bind spectrin, a molecular scaffold protein that is the major component of the host erythrocyte cytoskeleton. Parasites expressing an inefficiently processed MSP1 mutant show delayed egress, and merozoites lacking surface-bound MSP1 display a severe egress defect. Our results indicate that interactions between SUB1-processed merozoite surface MSP1 and the spectrin network of the erythrocyte cytoskeleton facilitate host erythrocyte rupture to enable parasite egress. Merozoite surface protein MSP1 processing is important for P. falciparum viability Proteolytic processing activates MSP1’s heparin and spectrin-binding functions The rate of MSP1 processing governs the kinetics of parasite egress Loss of parasite surface MSP1 results in a severe egress defect
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Affiliation(s)
- Sujaan Das
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Nadine Hertrich
- Department für Infektiologie, Parasitologie, Universitätsklinikum Heidelberg, D-69120 Heidelberg, Germany
| | - Abigail J Perrin
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1HH, UK
| | | | - Christine R Collins
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Matthew L Jones
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Jean M Watermeyer
- Department of Crystallography, Birkbeck College, London, WC1E 7HX, UK
| | - Elmar T Fobes
- Department für Infektiologie, Parasitologie, Universitätsklinikum Heidelberg, D-69120 Heidelberg, Germany
| | - Stephen R Martin
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Helen R Saibil
- Department of Crystallography, Birkbeck College, London, WC1E 7HX, UK
| | - Gavin J Wright
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1HH, UK
| | - Moritz Treeck
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Christian Epp
- Department für Infektiologie, Parasitologie, Universitätsklinikum Heidelberg, D-69120 Heidelberg, Germany
| | - Michael J Blackman
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK; Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
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29
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Merozoite Antigens of Plasmodium falciparum Elicit Strain-Transcending Opsonizing Immunity. Infect Immun 2016; 84:2175-2184. [PMID: 27185785 DOI: 10.1128/iai.00145-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/11/2016] [Indexed: 02/06/2023] Open
Abstract
It is unclear whether naturally acquired immunity to Plasmodium falciparum results from the acquisition of antibodies to multiple, diverse antigens or to fewer, highly conserved antigens. Moreover, the specific antibody functions required for malaria immunity are unknown, and hence informative immunological assays are urgently needed to address these knowledge gaps and guide vaccine development. In this study, we investigated whether merozoite-opsonizing antibodies are associated with protection from malaria in a strain-specific or strain-transcending manner by using a novel field isolate and an immune plasma-matched cohort from Papua New Guinea with our validated assay of merozoite phagocytosis. Highly correlated opsonization responses were observed across the 15 parasite strains tested, as were strong associations with protection (composite phagocytosis score across all strains in children uninfected at baseline: hazard ratio of 0.15, 95% confidence interval of 0.04 to 0.63). Opsonizing antibodies had a strong strain-transcending component, and the opsonization of transgenic parasites deficient for MSP3, MSP6, MSPDBL1, or P. falciparum MSP1-19 (PfMSP1-19) was similar to that of wild-type parasites. We have provided the first evidence that merozoite opsonization is predominantly strain transcending, and the highly consistent associations with protection against diverse parasite strains strongly supports the use of merozoite opsonization as a correlate of immunity for field studies and vaccine trials. These results demonstrate that conserved domains within merozoite antigens targeted by opsonization generate strain-transcending immune responses and represent promising vaccine candidates.
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30
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Na+ Influx Induced by New Antimalarials Causes Rapid Alterations in the Cholesterol Content and Morphology of Plasmodium falciparum. PLoS Pathog 2016; 12:e1005647. [PMID: 27227970 PMCID: PMC4881962 DOI: 10.1371/journal.ppat.1005647] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/28/2016] [Indexed: 12/27/2022] Open
Abstract
Among the several new antimalarials discovered over the past decade are at least three clinical candidate drugs, each with a distinct chemical structure, that disrupt Na+ homeostasis resulting in a rapid increase in intracellular Na+ concentration ([Na+]i) within the erythrocytic stages of Plasmodium falciparum. At present, events triggered by Na+ influx that result in parasite demise are not well-understood. Here we report effects of two such drugs, a pyrazoleamide and a spiroindolone, on intraerythrocytic P. falciparum. Within minutes following the exposure to these drugs, the trophozoite stage parasite, which normally contains little cholesterol, was made permeant by cholesterol-dependent detergents, suggesting it acquired a substantial amount of the lipid. Consistently, the merozoite surface protein 1 and 2 (MSP1 and MSP2), glycosylphosphotidylinositol (GPI)-anchored proteins normally uniformly distributed in the parasite plasma membrane, coalesced into clusters. These alterations were not observed following drug treatment of P. falciparum parasites adapted to grow in a low [Na+] growth medium. Both cholesterol acquisition and MSP1 coalescence were reversible upon the removal of the drugs, implicating an active process of cholesterol exclusion from trophozoites that we hypothesize is inhibited by high [Na+]i. Electron microscopy of drug-treated trophozoites revealed substantial morphological changes normally seen at the later schizont stage including the appearance of partial inner membrane complexes, dense organelles that resemble "rhoptries" and apparent nuclear division. Together these results suggest that [Na+]i disruptor drugs by altering levels of cholesterol in the parasite, dysregulate trophozoite to schizont development and cause parasite demise.
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31
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Crosnier C, Iqbal Z, Knuepfer E, Maciuca S, Perrin AJ, Kamuyu G, Goulding D, Bustamante LY, Miles A, Moore SC, Dougan G, Holder AA, Kwiatkowski DP, Rayner JC, Pleass RJ, Wright GJ. Binding of Plasmodium falciparum Merozoite Surface Proteins DBLMSP and DBLMSP2 to Human Immunoglobulin M Is Conserved among Broadly Diverged Sequence Variants. J Biol Chem 2016; 291:14285-14299. [PMID: 27226583 PMCID: PMC4933183 DOI: 10.1074/jbc.m116.722074] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Indexed: 11/17/2022] Open
Abstract
Diversity at pathogen genetic loci can be driven by host adaptive immune selection pressure and may reveal proteins important for parasite biology. Population-based genome sequencing of Plasmodium falciparum, the parasite responsible for the most severe form of malaria, has highlighted two related polymorphic genes called dblmsp and dblmsp2, which encode Duffy binding-like (DBL) domain-containing proteins located on the merozoite surface but whose function remains unknown. Using recombinant proteins and transgenic parasites, we show that DBLMSP and DBLMSP2 directly and avidly bind human IgM via their DBL domains. We used whole genome sequence data from over 400 African and Asian P. falciparum isolates to show that dblmsp and dblmsp2 exhibit extreme protein polymorphism in their DBL domain, with multiple variants of two major allelic classes present in every population tested. Despite this variability, the IgM binding function was retained across diverse sequence representatives. Although this interaction did not seem to have an effect on the ability of the parasite to invade red blood cells, binding of DBLMSP and DBLMSP2 to IgM inhibited the overall immunoreactivity of these proteins to IgG from patients who had been exposed to the parasite. This suggests that IgM binding might mask these proteins from the host humoral immune system.
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Affiliation(s)
- Cécile Crosnier
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom; Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - Zamin Iqbal
- Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, United Kingdom
| | - Ellen Knuepfer
- Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, United Kingdom
| | - Sorina Maciuca
- Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, United Kingdom
| | - Abigail J Perrin
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom; Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - Gathoni Kamuyu
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - David Goulding
- Microbial Pathogenesis Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - Leyla Y Bustamante
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - Alistair Miles
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom; Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, United Kingdom
| | - Shona C Moore
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom; Warwick Systems Biology Centre, Senate House, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Gordon Dougan
- Microbial Pathogenesis Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - Anthony A Holder
- Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, United Kingdom
| | - Dominic P Kwiatkowski
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom; Wellcome Trust Centre for Human Genetics, Oxford OX3 7BN, United Kingdom
| | - Julian C Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom
| | - Richard J Pleass
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Gavin J Wright
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom; Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, United Kingdom.
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32
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Weiss GE, Crabb BS, Gilson PR. Overlaying Molecular and Temporal Aspects of Malaria Parasite Invasion. Trends Parasitol 2016; 32:284-295. [DOI: 10.1016/j.pt.2015.12.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/02/2015] [Accepted: 12/10/2015] [Indexed: 12/31/2022]
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33
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Abstract
PURPOSE OF REVIEW Malaria is caused by the infection and proliferation of parasites from the genus Plasmodium in red blood cells (RBCs). A free Plasmodium parasite, or merozoite, released from an infected RBC must invade another RBC host cell to sustain a blood-stage infection. Here, we review recent advances on RBC invasion by Plasmodium merozoites, focusing on specific molecular interactions between host and parasite. RECENT FINDINGS Recent work highlights the central role of host-parasite interactions at virtually every stage of RBC invasion by merozoites. Biophysical experiments have for the first time measured the strength of merozoite-RBC attachment during invasion. For P. falciparum, there have been many key insights regarding the invasion ligand PfRh5 in particular, including its influence on host species tropism, a co-crystal structure with its RBC receptor basigin, and its suitability as a vaccine target. For P. vivax, researchers identified the origin and emergence of the parasite from Africa, demonstrating a natural link to the Duffy-negative RBC variant in African populations. For the simian parasite P. knowlesi, zoonotic invasion into human cells is linked to RBC age, which has implications for parasitemia during an infection and thus malaria. SUMMARY New studies of the molecular and cellular mechanisms governing RBC invasion by Plasmodium parasites have shed light on various aspects of parasite biology and host cell tropism, and indicate opportunities for malaria control.
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34
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Lin CS, Uboldi AD, Epp C, Bujard H, Tsuboi T, Czabotar PE, Cowman AF. Multiple Plasmodium falciparum Merozoite Surface Protein 1 Complexes Mediate Merozoite Binding to Human Erythrocytes. J Biol Chem 2016; 291:7703-15. [PMID: 26823464 DOI: 10.1074/jbc.m115.698282] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Indexed: 11/06/2022] Open
Abstract
Successful invasion of human erythrocytes byPlasmodium falciparummerozoites is required for infection of the host and parasite survival. The early stages of invasion are mediated via merozoite surface proteins that interact with human erythrocytes. The nature of these interactions are currently not well understood, but it is known that merozoite surface protein 1 (MSP1) is critical for successful erythrocyte invasion. Here we show that the peripheral merozoite surface proteins MSP3, MSP6, MSPDBL1, MSPDBL2, and MSP7 bind directly to MSP1, but independently of each other, to form multiple forms of the MSP1 complex on the parasite surface. These complexes have overlapping functions that interact directly with human erythrocytes. We also show that targeting the p83 fragment of MSP1 using inhibitory antibodies inhibits all forms of MSP1 complexes and disrupts parasite growthin vitro.
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Affiliation(s)
- Clara S Lin
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia, the Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Alessandro D Uboldi
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Christian Epp
- the Department of Infectious Diseases, Parasitology, Universität Heidelberg, INF 324, 69120 Heidelberg, Germany
| | - Hermann Bujard
- the Zentrum für Molekulare Biologie der Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany, and
| | - Takafumi Tsuboi
- the Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Peter E Czabotar
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia, the Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Alan F Cowman
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia, the Department of Medical Biology, University of Melbourne, Melbourne, Australia,
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35
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Koch M, Baum J. The mechanics of malaria parasite invasion of the human erythrocyte - towards a reassessment of the host cell contribution. Cell Microbiol 2016; 18:319-29. [PMID: 26663815 PMCID: PMC4819681 DOI: 10.1111/cmi.12557] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 11/30/2015] [Accepted: 12/07/2015] [Indexed: 01/15/2023]
Abstract
Despite decades of research, we still know little about the mechanics of Plasmodium host cell invasion. Fundamentally, while the essential or non‐essential nature of different parasite proteins is becoming clearer, their actual function and how each comes together to govern invasion are poorly understood. Furthermore, in recent years an emerging world view is shifting focus away from the parasite actin–myosin motor being the sole force responsible for entry to an appreciation of host cell dynamics and forces and their contribution to the process. In this review, we discuss merozoite invasion of the erythrocyte, focusing on the complex set of pre‐invasion events and how these might prime the red cell to facilitate invasion. While traditionally parasite interactions at this stage have been viewed simplistically as mediating adhesion only, recent work makes it apparent that by interacting with a number of host receptors and signalling pathways, combined with secretion of parasite‐derived lipid material, that the merozoite may initiate cytoskeletal re‐arrangements and biophysical changes in the erythrocyte that greatly reduce energy barriers for entry. Seen in this light Plasmodium invasion may well turn out to be a balance between host and parasite forces, much like that of other pathogen infection mechanisms.
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Affiliation(s)
- Marion Koch
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, SW7 2AZ, UK
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, SW7 2AZ, UK
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36
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von Bohl A, Kuehn A, Simon N, Ngongang VN, Spehr M, Baumeister S, Przyborski JM, Fischer R, Pradel G. A WD40-repeat protein unique to malaria parasites associates with adhesion protein complexes and is crucial for blood stage progeny. Malar J 2015; 14:435. [PMID: 26537493 PMCID: PMC4634918 DOI: 10.1186/s12936-015-0967-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 10/27/2015] [Indexed: 11/16/2022] Open
Abstract
Background During development in human erythrocytes, Plasmodium falciparum parasites display a remarkable number of adhesive proteins on their plasma membrane. In the invasive merozoites, these include members of the PfMSP1 and PfAMA1/RON complexes, which facilitate contact between merozoites and red blood cells. In gametocytes, sexual precursor cells mediating parasite transmission to the mosquito vector, plasma membrane-associated proteins primarily belong to the PfCCp and 6-cys families with roles in fertilization. This study describes a newly identified WD40-repeat protein unique to Plasmodium species that associates with adhesion protein complexes of both merozoites and gametocytes. Methods The WD40-repeat protein-like protein PfWLP1 was identified via co-immunoprecipitation assays followed by mass spectrometry and characterized using biochemical and immunohistochemistry methods. Reverse genetics were employed for functional analysis. Results PfWLP1 is expressed both in schizonts and gametocytes. In mature schizonts, the protein localizes underneath the merozoite micronemes and interacts with PfAMA1, while in gametocytes PfWLP1 primarily accumulates underneath the plasma membrane and associates with PfCCp1 and Pfs230. Reverse genetics failed to disrupt the pfwlp1 gene, while haemagglutinin-tagging was feasible, suggesting a crucial function for PfWLP1 during blood stage replication. Conclusions This is the first report on a plasmodial WD40-repeat protein associating with cell adhesion proteins. Since WD40 domains are known to mediate protein–protein contact by serving as a rigid scaffold for protein interactions, the presented data suggest that PfWLP1 supports the stability of adhesion protein complexes of the plasmodial blood stages. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0967-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andreas von Bohl
- Division of Cellular and Applied Infection Biology, Institute for Biology II, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany. .,Institute of Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
| | - Andrea Kuehn
- Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Straße 2/D15, 97080, Würzburg, Germany.
| | - Nina Simon
- Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Straße 2/D15, 97080, Würzburg, Germany.
| | - Vanesa Nkwouano Ngongang
- Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Straße 2/D15, 97080, Würzburg, Germany.
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, 52074, Aachen, Germany.
| | - Stefan Baumeister
- Parasitology Section, Faculty of Biology, Philipps University Marburg, Karl-von-Frisch-Straße 8, 35043, Marburg, Germany.
| | - Jude M Przyborski
- Parasitology Section, Faculty of Biology, Philipps University Marburg, Karl-von-Frisch-Straße 8, 35043, Marburg, Germany.
| | - Rainer Fischer
- Institute of Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute for Biology II, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
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37
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Groat-Carmona AM, Kain H, Brownell J, Douglass AN, Aly ASI, Kappe SHI. A Plasmodium α/β-hydrolase modulates the development of invasive stages. Cell Microbiol 2015; 17:1848-67. [PMID: 26118838 DOI: 10.1111/cmi.12477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 06/19/2015] [Accepted: 06/23/2015] [Indexed: 11/26/2022]
Abstract
The bud emergence (BEM)46 proteins are evolutionarily conserved members of the α/β-hydrolase superfamily, which includes enzymes with diverse functions and a wide range of substrates. Here, we identified a Plasmodium BEM46-like protein (PBLP) and characterized it throughout the life cycle of the rodent malaria parasite Plasmodium yoelii. The Plasmodium BEM46-like protein is shown to be closely associated with the parasite plasma membrane of asexual erythrocytic stage schizonts and exo-erythrocytic schizonts; however, PBLP localizes to unique intracellular structures in sporozoites. Generation and analysis of P. yoelii knockout (Δpblp) parasite lines showed that PBLP has an important role in erythrocytic stage merozoite development with Δpblp parasites forming fewer merozoites during schizogony, which results in decreased parasitemia when compared with wild-type (WT) parasites. Δpblp parasites showed no defects in gametogenesis or transmission to mosquitoes; however, because they formed fewer oocysts there was a reduction in the number of developed sporozoites in infected mosquitoes when compared with WT. Although Δpblp sporozoites showed no apparent defect in mosquito salivary gland infection, they showed decreased infectivity in hepatocytes in vitro. Similarly, mice infected with Δpblp sporozoites exhibited a delay in the onset of blood-stage patency, which is likely caused by reduced sporozoite infectivity and a discernible delay in exo-erythrocytic merozoite formation. These data are consistent with the model that PBLP has an important role in parasite invasive-stage morphogenesis throughout the parasite life cycle.
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Affiliation(s)
- Anna M Groat-Carmona
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Heather Kain
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Jessica Brownell
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Alyse N Douglass
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Ahmed S I Aly
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Stefan H I Kappe
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA.,Department of Global Health, University of Washington, Seattle, WA, USA
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38
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Merozoite surface protein 1 recognition of host glycophorin A mediates malaria parasite invasion of red blood cells. Blood 2015; 125:2704-11. [PMID: 25778531 DOI: 10.1182/blood-2014-11-611707] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/05/2015] [Indexed: 01/15/2023] Open
Abstract
Plasmodium falciparum invasion of human red blood cells (RBCs) is an intricate process requiring a number of distinct ligand-receptor interactions at the merozoite-erythrocyte interface. Merozoite surface protein 1 (MSP1), a highly abundant ligand coating the merozoite surface in all species of malaria parasites, is essential for RBC invasion and considered a leading candidate for inclusion in a multiple-subunit vaccine against malaria. Our previous studies identified an interaction between the carboxyl-terminus of MSP1 and RBC band 3. Here, by employing phage display technology, we report a novel interaction between the amino-terminus of MSP1 and RBC glycophorin A (GPA). Mapping of the binding domains established a direct interaction between malaria MSP1 and human GPA within a region of MSP1 known to potently inhibit P falciparum invasion of human RBCs. Furthermore, a genetically modified mouse model lacking the GPA- band 3 complex in RBCs is completely resistant to malaria infection in vivo. These findings suggest an essential role of the MSP1-GPA-band 3 complex during the initial adhesion phase of malaria parasite invasion of RBCs.
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Chiu CYH, Hodder AN, Lin CS, Hill DL, Li Wai Suen CSN, Schofield L, Siba PM, Mueller I, Cowman AF, Hansen DS. Antibodies to the Plasmodium falciparum Proteins MSPDBL1 and MSPDBL2 Opsonize Merozoites, Inhibit Parasite Growth, and Predict Protection From Clinical Malaria. J Infect Dis 2015; 212:406-15. [PMID: 25646353 DOI: 10.1093/infdis/jiv057] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/15/2015] [Indexed: 11/13/2022] Open
Abstract
Increasing evidence suggests that antibodies against merozoite surface proteins (MSPs) play an important role in clinical immunity to malaria. Two unusual members of the MSP-3 family, merozoite surface protein duffy binding-like (MSPDBL)1 and MSPDBL2, have been shown to be extrinsically associated to MSP-1 on the parasite surface. In addition to a secreted polymorphic antigen associated with merozoite (SPAM) domain characteristic of MSP-3 family members, they also contain Duffy binding-like (DBL) domain and were found to bind to erythrocytes, suggesting that they play a role in parasite invasion. Antibody responses to these proteins were investigated in a treatment-reinfection study conducted in an endemic area of Papua New Guinea to determine their contribution to naturally acquired immunity. Antibodies to the SPAM domains of MSPDBL1 and MSPDBL2 as well as the DBL domain of MSPDBL1 were found to be associated with protection from Plasmodium falciparum clinical episodes. Moreover, affinity-purified anti-MSPDBL1 and MSPDBL2 were found to inhibit in vitro parasite growth and had strong merozoite opsonizing capacity, suggesting that protection targeting these antigens results from ≥2 distinct effector mechanisms. Together these results indicate that MSPDBL1 and MSPDBL2 are important targets of naturally acquired immunity and might constitute potential vaccine candidates.
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Affiliation(s)
- Chris Y H Chiu
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, University of Melbourne, Parkville, Victoria
| | - Anthony N Hodder
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, University of Melbourne, Parkville, Victoria
| | - Clara S Lin
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, University of Melbourne, Parkville, Victoria
| | - Danika L Hill
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, University of Melbourne, Parkville, Victoria
| | | | - Louis Schofield
- The Walter and Eliza Hall Institute of Medical Research Australian Institute of Tropical Health and Medicine, James Cook University, Douglas, Queensland, Australia
| | - Peter M Siba
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Eastern Highlands Province, Goroka
| | - Ivo Mueller
- The Walter and Eliza Hall Institute of Medical Research Barcelona Center for International Health, University of Barcelona, Spain
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, University of Melbourne, Parkville, Victoria
| | - Diana S Hansen
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, University of Melbourne, Parkville, Victoria
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