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Kundu P, Naskar D, McKie SJ, Dass S, Kanjee U, Introini V, Ferreira MU, Cicuta P, Duraisingh M, Deane JE, Rayner JC. The structure of a Plasmodium vivax Tryptophan Rich Antigen domain suggests a lipid binding function for a pan-Plasmodium multi-gene family. Nat Commun 2023; 14:5703. [PMID: 37709739 PMCID: PMC10502043 DOI: 10.1038/s41467-023-40885-8] [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: 10/24/2022] [Accepted: 08/10/2023] [Indexed: 09/16/2023] Open
Abstract
Tryptophan Rich Antigens (TRAgs) are encoded by a multi-gene family found in all Plasmodium species, but are significantly expanded in P. vivax and closely related parasites. We show that multiple P. vivax TRAgs are expressed on the merozoite surface and that one, PVP01_0000100 binds red blood cells with a strong preference for reticulocytes. Using X-ray crystallography, we solved the structure of the PVP01_0000100 C-terminal tryptophan rich domain, which defines the TRAg family, revealing a three-helical bundle that is conserved across Plasmodium and has structural homology with lipid-binding BAR domains involved in membrane remodelling. Biochemical assays confirm that the PVP01_0000100 C-terminal domain has lipid binding activity with preference for sulfatide, a glycosphingolipid present in the outer leaflet of plasma membranes. Deletion of the putative orthologue in P. knowlesi, PKNH_1300500, impacts invasion in reticulocytes, suggesting a role during this essential process. Together, this work defines an emerging molecular function for the Plasmodium TRAg family.
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Affiliation(s)
- Prasun Kundu
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Deboki Naskar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Shannon J McKie
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Sheena Dass
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Viola Introini
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- Global Health and Tropical Medicine, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Lisbon, Portugal
| | - Pietro Cicuta
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Manoj Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Janet E Deane
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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Oduma CO, Koepfli C. Plasmodium falciparum and Plasmodium vivax Adjust Investment in Transmission in Response to Change in Transmission Intensity: A Review of the Current State of Research. Front Cell Infect Microbiol 2021; 11:786317. [PMID: 34956934 PMCID: PMC8692836 DOI: 10.3389/fcimb.2021.786317] [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: 09/30/2021] [Accepted: 11/19/2021] [Indexed: 12/02/2022] Open
Abstract
Malaria parasites can adjust the proportion of parasites that develop into gametocytes, and thus the probability for human-to-vector transmission, through changes in the gametocyte conversion rate. Understanding the factors that impact the commitment of malaria parasites to transmission is required to design better control interventions. Plasmodium spp. persist across countries with vast differences in transmission intensities, and in sites where transmission is highly seasonal. Mounting evidence shows that Plasmodium spp. adjusts the investment in transmission according to seasonality of vector abundance, and transmission intensity. Various techniques to determine the investment in transmission are available, i.e., short-term culture, where the conversion rate can be measured most directly, genome and transcriptome studies, quantification of mature gametocytes, and mosquito feeding assays. In sites with seasonal transmission, the proportion of gametocytes, their densities and infectivity are higher during the wet season, when vectors are plentiful. When countries with pronounced differences in transmission intensity were compared, the investment in transmission was higher when transmission was low, thus maximizing the parasite’s chances to be transmitted to mosquitoes. Increased transmissibility of residual infections after a successful reduction of malaria transmission levels need to be considered when designing intervention measures.
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Affiliation(s)
- Colins O Oduma
- Department of Biochemistry and Molecular Biology, Egerton University, Nakuru, Kenya.,Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Cristian Koepfli
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States
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3
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Henry NB, Sermé SS, Siciliano G, Sombié S, Diarra A, Sagnon N, Traoré AS, Sirima SB, Soulama I, Alano P. Biology of Plasmodium falciparum gametocyte sex ratio and implications in malaria parasite transmission. Malar J 2019; 18:70. [PMID: 30866941 PMCID: PMC6417185 DOI: 10.1186/s12936-019-2707-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/05/2019] [Indexed: 11/10/2022] Open
Abstract
While significant advances have been made in understanding Plasmodium falciparum gametocyte biology and its relationship with malaria parasite transmission, the gametocyte sex ratio contribution to this process still remains a relevant research question. The present review discusses the biology of sex determination in P. falciparum, the underlying host and parasite factors, the sex specific susceptibility to drugs, the effect of sex ratio dynamics on malaria parasite transmission and the development of gametocyte sex specific diagnosis tools. Despite the inherent differences across several studies and approaches, the emerging picture highlights a potentially relevant contribution of the P. falciparum gametocyte sex ratio in the modulation of malaria parasite transmission. The increasing availability of molecular methods to measure gametocyte sex ratio will enable evaluation of important parameters, such as the impact of drug treatment on gametocyte sex ratio in vitro and in vivo as well as the changes of gametocyte sex ratios in natural infections, key steps towards elucidating how these parameters affect parasite infectiousness to the mosquito vectors.
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Affiliation(s)
- Noëlie Béré Henry
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Samuel Sindié Sermé
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Giulia Siciliano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Salif Sombié
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - N'fale Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | | | - Sodiomon Bienvenu Sirima
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.,Groupe de Recherche Action Santé, Ouagadougou, Burkina Faso
| | - Issiaka Soulama
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy.
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4
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Lee SM, Plieskatt J, King CR. Disulfide bond mapping of Pfs25, a recombinant malaria transmission blocking vaccine candidate. Anal Biochem 2018; 542:20-23. [PMID: 29162427 PMCID: PMC5825383 DOI: 10.1016/j.ab.2017.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 10/28/2017] [Accepted: 11/15/2017] [Indexed: 11/26/2022]
Abstract
A liquid chromatography tandem-mass spectrometry method was developed to map the eleven disulfide bonds in Pfs25, a malaria transmission-blocking vaccine candidate. The compact and complex nature of Pfs25 has led to difficulties in prior peptide mapping efforts. Here, we report confirmation of proper disulfide pairing of a recombinant Pfs25, by optimizing denaturation and digestion with trypsin/Lys-C. The digested peptides were separated by reversed phase HPLC to obtain the peptide map and elucidate the disulfide linkages. MSE fragmentation confirmed the digested peptides and disulfide bonds. The eleven disulfide bonds and locations matched the predicted Pvs25 crystal structure, a Pfs25 homologue.
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Affiliation(s)
- Shwu-Maan Lee
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC 20001-2621, USA.
| | - Jordan Plieskatt
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC 20001-2621, USA.
| | - C Richter King
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC 20001-2621, USA.
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5
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Lee SM, Wu CK, Plieskatt J, McAdams DH, Miura K, Ockenhouse C, King CR. Assessment of Pfs25 expressed from multiple soluble expression platforms for use as transmission-blocking vaccine candidates. Malar J 2016; 15:405. [PMID: 27515826 PMCID: PMC4982271 DOI: 10.1186/s12936-016-1464-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 07/29/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transmission-blocking vaccines (TBVs) have become a focus of strategies to control and eventually eliminate malaria as they target the entry of sexual stage into the Anopheles stephensi mosquito thereby preventing transmission, an essential component of the parasite life cycle. Such vaccines are envisioned as complements to vaccines that target human infection, such as RTS,S as well as drug treatment, and vector control strategies. A number of conserved proteins, including Pfs25, have been identified as promising TBV targets in research or early stage development. Pfs25 is a 25 kDa protein of Plasmodium falciparum expressed on the surface of zygotes and ookinetes. Its complex tertiary structure, including numerous cysteines, has led to difficulties in the expression of a recombinant protein that is homogeneous, with proper conformation, and free of glycosylation, a phenomenon not found in native parasite machinery. METHODS While the expression and purification of Pfs25 in various systems, has been previously independently reported, here a parallel analysis of Pfs25 is presented to inform on the biochemical features of Pfs25 and their impact on functionality. Three scalable expression systems were used to express, purify, and evaluate Pfs25 both in vitro and in vivo, including the ability of each protein to produce functional antibodies through the standard membrane feeding assay. RESULTS Through numerous attempts, soluble, monomeric Pfs25 derived from Escherichia coli was not achieved, while Pichia pastoris presented Pfs25 as an inhomogeneous product with glycosylation. In comparison, baculovirus produced a pure, monomeric protein free of glycosylation. The glycosylation present for Pichia produced Pfs25, showed no notable decrease in the ability to elicit transmission reducing antibodies in functional evaluation, while a reduced and alkylated Pfs25 (derived from plant and used as a control) was found to have significantly decreased transmission reducing activity, emphasizing the importance of ensuring correct disulfide stabilized conformation during vaccine design and production. CONCLUSIONS In this study, the biochemical features of Pfs25, produced from different expression systems, are described along with their impact on the ability of the protein to elicit functional antibodies. Pfs25 expressed using baculovirus and Pichia showed promise as candidates for vaccine development.
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Affiliation(s)
- Shwu-Maan Lee
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA.
| | - Chia-Kuei Wu
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
| | - Jordan Plieskatt
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
| | - David H McAdams
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Chris Ockenhouse
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
| | - C Richter King
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
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6
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Schneider P, Reece SE, van Schaijk BCL, Bousema T, Lanke KHW, Meaden CSJ, Gadalla A, Ranford-Cartwright LC, Babiker HA. Quantification of female and male Plasmodium falciparum gametocytes by reverse transcriptase quantitative PCR. Mol Biochem Parasitol 2015; 199:29-33. [PMID: 25827756 DOI: 10.1016/j.molbiopara.2015.03.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 11/15/2022]
Abstract
The transmission of malaria parasites depends on the presence of sexual stages (gametocytes) in the blood, making the ratio and densities of female and male gametocytes important determinants of parasite fitness. This manuscript describes the development of reverse transcriptase quantitative PCR (RT-qPCR) assays to separately quantify mature female and male gametocytes of the human malaria parasite Plasmodium falciparum, and reveals that Pfs25 mRNA is expressed only in female gametocytes. The female (Pfs25) and male (Pfs230p) gametocyte specific RT-qPCR assays have lower detection limits of 0.3 female and 1.8 male gametocytes per microlitre of blood, respectively, making them more sensitive than microscopy. Accurate quantification of the ratio and densities of female and male gametocytes will increase understanding of P. falciparum transmission and improve the evaluation of transmission blocking interventions.
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Affiliation(s)
- Petra Schneider
- Institutes of Evolution, Immunology and Infection Research, United Kingdom.
| | - Sarah E Reece
- Institutes of Evolution, Immunology and Infection Research, United Kingdom; Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
| | - Ben C L van Schaijk
- Department of Medical Microbiology, Radboud University Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands.
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands.
| | - Kjerstin H W Lanke
- Department of Medical Microbiology, Radboud University Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands.
| | - Cora S J Meaden
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, United Kingdom.
| | - Amal Gadalla
- College of Medicine and Health Sciences, Sultan Qaboos University, PO Box 35, Alkhoud 123, Sultanate of Oman; Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan.
| | - Lisa C Ranford-Cartwright
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, United Kingdom.
| | - Hamza A Babiker
- College of Medicine and Health Sciences, Sultan Qaboos University, PO Box 35, Alkhoud 123, Sultanate of Oman.
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7
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González-Cerón L, Alvarado-Delgado A, Martínez-Barnetche J, Rodríguez MH, Ovilla-Muñoz M, Pérez F, Hernandez-Avila JE, Sandoval MA, Rodríguez MDC, Villarreal-Treviño C. Sequence variation of ookinete surface proteins Pvs25 and Pvs28 of Plasmodium vivax isolates from Southern Mexico and their association to local anophelines infectivity. INFECTION GENETICS AND EVOLUTION 2010; 10:645-54. [DOI: 10.1016/j.meegid.2010.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 03/24/2010] [Accepted: 03/25/2010] [Indexed: 10/19/2022]
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8
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Saxena AK, Wu Y, Garboczi DN. Plasmodium p25 and p28 surface proteins: potential transmission-blocking vaccines. EUKARYOTIC CELL 2007; 6:1260-5. [PMID: 17557884 PMCID: PMC1951121 DOI: 10.1128/ec.00060-07] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Ajay K Saxena
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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9
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Mohmmed A, Kishore S, Patra KP, Dasaradhi PVN, Malhotra P, Chauhan VS. Identification of karyopherin beta as an immunogenic antigen of the malaria parasite using immune mice and human sera. Parasite Immunol 2005; 27:197-203. [PMID: 15987343 DOI: 10.1111/j.1365-3024.2005.00759.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A differential immunoscreening of the lambdagt11 Plasmodium falciparum genomic expression library was carried out using anti-P. yoelii sera (convalescent-phase mouse sera) and immune sera collected from healthy adults, to identify novel cross-reactive and possibly protective antigens of the parasite. One clone, with an insert size of 1132 bp that reacted strongly with both the sera was selected. The insert was found to be a part of the P. falciparum karyopherin beta (PfKbeta) homologue. RT-PCR and Northern blot analysis confirmed the expression of PfKbeta in the blood stages of the parasite. The approximately 110 kDa protein was localized in the cytoplasm at the ring and trophozoite, and in the parasitophorous vacuole at the schizont stage. Two large fragments of PfKbeta representing the N- and C-terminal halves were expressed in E. coli. The recombinant proteins were highly immunogenic in mice, and also found to be the target for immune response in natural infections of Plasmodium spp. Anti-sera against the protein showed a low level of anti-parasitic activity. Immunization with recombinant PfKbeta fragments was only partially protective against a heterologous challenge infection in mice. Our results show that the parasite releases a highly immunogenic, cytoplasmic protein into the host which may not contribute to the development of protective immunity.
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Affiliation(s)
- Asif Mohmmed
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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10
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Abstract
The sexual stages of the malaria parasite are highly specialized cells adapted to withstand major environmental changes during their development. They also induce immune responses that may affect the outcome of the infection in the mosquito. In this review Pietro Alano considers the nature and the role of the antigens expressed by Plasmodium sexual stages.
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Affiliation(s)
- P Alano
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanita, viale Regina Elena 299, 00161 Rome, Italy
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11
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Baton LA, Ranford-Cartwright LC. Do malaria ookinete surface proteins P25 and P28 mediate parasite entry into mosquito midgut epithelial cells? Malar J 2005; 4:15. [PMID: 15733320 PMCID: PMC555762 DOI: 10.1186/1475-2875-4-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2005] [Accepted: 02/25/2005] [Indexed: 11/30/2022] Open
Abstract
Background P25 and P28 are related ookinete surface proteins highly conserved throughout the Plasmodium genus that are under consideration as candidates for inclusion in transmission-blocking vaccines. Previous research using transgenic rodent malaria parasites lacking P25 and P28 has demonstrated that these proteins have multiple partially redundant functions during parasite infection of the mosquito vector, including an undefined role in ookinete traversal of the mosquito midgut epithelium, and it has been suggested that, unlike wild-type parasites, Dko P25/P28 parasites migrate across the midgut epithelium via an intercellular, rather than intracellular, route. Presentation of the hypothesis This paper presents an alternative interpretation for the previous observations of Dko P25/P28 parasites, based upon a recently published model of the route of ookinete invasion across the midgut epithelium. This model claims ookinete invasion is intracellular, with entry occurring through the lateral apical plasma membrane of midgut epithelial cells, and is associated with significant invagination of the midgut epithelium localised at the site of parasite penetration. Following this model, it is hypothesized that: (1) a sub-population of Dko P25/P28 ookinetes invaginate, but do not penetrate, the apical surface of the midgut epithelium and thus remain within the midgut lumen; and (2) another sub-population of Dko P25/P28 parasites successfully enters and migrates across the midgut epithelium via an intracellular route similar to wild-type parasites and subsequently develops into oocysts. Testing the hypothesis These hypotheses are tested by showing how they can account for previously published observations and incorporate them into a coherent and consistent explanatory framework. Based upon these hypotheses, several quantitative predictions are made, which can be experimentally tested, about the relationship between the densities of invading Dko P25/P28 ookinetes in different regions of the midgut epithelium and the number of oocyst stage parasites to which these mutant ookinetes give rise. Implications of the hypothesis The recently published model of ookinete invasion implies that Dko P25/P28 parasites are greatly, although not completely, impaired in their ability to enter the midgut epithelium. Therefore, P25 and/or P28 have a novel, previously unrecognized, function in mediating ookinete entry into midgut epithelial cells, suggesting that one mode of action of transmission-blocking antibodies to these ookinete surface proteins is to inhibit this function.
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Affiliation(s)
- Luke A Baton
- Division of Infection and Immunity, Institute of Biomedical and Life Sciences, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Lisa C Ranford-Cartwright
- Division of Infection and Immunity, Institute of Biomedical and Life Sciences, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
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12
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Abstract
Malaria remains one of the leading causes of both morbidity and mortality of humans residing in tropical countries. For many malarious regions outside of Africa, development of effective transmission-blocking vaccines will require coverage against both Plasmodium falciparum and Plasmodium vivax. The genes coding for two potential P. vivax transmission-blocking antigens, Pvs25 and Pvs28, have been cloned. Mice vaccinated with yeast-produced recombinant proteins Pvs25 and Pvs28 adsorbed to aluminum hydroxide developed strong antibody responses against the immunogens. The development of oocysts in mosquitoes was completely inhibited when these antisera were ingested with the P. vivax Salvador (Sal) I strain-infected chimpanzee blood. In a large collection of P. vivax field isolates, we found only 5 nucleotide changes that would result in amino acid substitutions in Pvs25. In contrast, the Pvs28 gene had 22 nucleotide changes that would result in conservative amino acid substitutions. How the antigenic polymorphism of Pvs25 and Pvs28 would affect the efficacy of Sal I based vaccine remains to be elucidated. Clinical trials with Pvs25 and the P. falciparum ortholog Pfs25 are in preparation.
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Affiliation(s)
- Takafumi Tsuboi
- Department of Molecular Parasitology, Ehime University School of Medicine, Shigenobu-cho, Ehime 791-0295, Japan.
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13
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Abstract
Our understanding of the intricate interactions between the malarial parasite and the mosquito vector is complicated both by the number and diversity of parasite and vector species, and by the experimental inaccessibility of phenomena under investigation. Steady developments in techniques to study the parasite in the mosquito have recently been augmented by methods to culture in their entirety the sporogonic stages of some parasite species. These, together with the new saturation technologies, and genetic transformation of both parasite and vector will permit penetrating studies into an exciting and largely unknown area of parasite-host interactions, an understanding of which must result in the development of new intervention strategies. This microreview highlights key areas of current basic molecular interest, and identifies numerous lacunae in our knowledge that must be filled if we are to make rational decisions for future control strategies. It will conclude by trying to explain why in the opinion of this reviewer understanding malaria-mosquito interactions may be critical to our future attempts to limit a disease of growing global importance.
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Affiliation(s)
- R E Sinden
- Biological Sciences Department, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK.
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14
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Tachibana M, Tsuboi T, Kaneko O, Khuntirat B, Torii M. Two types of Plasmodium ovale defined by SSU rRNA have distinct sequences for ookinete surface proteins. Mol Biochem Parasitol 2002; 122:223-6. [PMID: 12106877 DOI: 10.1016/s0166-6851(02)00101-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Mayumi Tachibana
- Department of Molecular Parasitology, Ehime University School of Medicine, Shigenobu-cho, Japan
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15
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Tomas AM, Margos G, Dimopoulos G, van Lin LH, de Koning-Ward TF, Sinha R, Lupetti P, Beetsma AL, Rodriguez MC, Karras M, Hager A, Mendoza J, Butcher GA, Kafatos F, Janse CJ, Waters AP, Sinden RE. P25 and P28 proteins of the malaria ookinete surface have multiple and partially redundant functions. EMBO J 2001; 20:3975-83. [PMID: 11483501 PMCID: PMC149139 DOI: 10.1093/emboj/20.15.3975] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ookinete surface proteins (P25 and P28) are proven antimalarial transmission-blocking vaccine targets, yet their biological functions are unknown. By using single (Sko) and double gene knock-out (Dko) Plasmodium berghei parasites, we show that P25 and P28 share multiple functions during ookinete/oocyst development. In the midgut of mosquitoes, the formation of ookinetes lacking both proteins (Dko parasites) is significantly inhibited due to decreased protection against lethal factors, including protease attack. In addition, Dko ookinetes have a much reduced capacity to traverse the midgut epithelium and to transform into the oocyst stage. P25 and P28 are partially redundant in these functions, since the efficiency of ookinete/oocyst development is only mildly compromised in parasites lacking either P25 or P28 (Sko parasites) compared with that of Dko parasites. The fact that Sko parasites are efficiently transmitted by the mosquito is a compelling reason for including both target antigens in transmission-blocking vaccines.
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Affiliation(s)
| | - Gabriele Margos
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - George Dimopoulos
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | | | | | - Ria Sinha
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Pietro Lupetti
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Annette L. Beetsma
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Maria C. Rodriguez
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Marianna Karras
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Ariadne Hager
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Jacqui Mendoza
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Geoffrey A. Butcher
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | - Fotis Kafatos
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
| | | | | | - Robert E. Sinden
- Leiden University Medical Centre, Laboratory of Parasitology, PO Box 9605, 2300 RC Leiden, The Netherlands,
Imperial College of Science, Technology and Medicine, Biology Department, Sir Alexander Fleming Building, Imperial College Road, London SW7 2AZ, UK, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany and Unit of Electron Microscopy and Cryotechniques, Dipartimento Biologia Evolutiva, Università di Siena, Via P.A. Mattioli 4, 53100 Siena, Italy Corresponding author e-mail:
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16
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Tachibana M, Tsuboi T, Templeton TJ, Kaneko O, Torii M. Presence of three distinct ookinete surface protein genes, Pos25, Pos28-1, and Pos28-2, in Plasmodium ovale. Mol Biochem Parasitol 2001; 113:341-4. [PMID: 11295191 DOI: 10.1016/s0166-6851(01)00231-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- M Tachibana
- Department of Molecular Parasitology, Ehime University School of Medicine, Shigenobu-cho, 791-0295, Ehime, Japan
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17
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Hisaeda H, Stowers AW, Tsuboi T, Collins WE, Sattabongkot JS, Suwanabun N, Torii M, Kaslow DC. Antibodies to malaria vaccine candidates Pvs25 and Pvs28 completely block the ability of Plasmodium vivax to infect mosquitoes. Infect Immun 2000; 68:6618-23. [PMID: 11083773 PMCID: PMC97758 DOI: 10.1128/iai.68.12.6618-6623.2000] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2000] [Accepted: 09/16/2000] [Indexed: 11/20/2022] Open
Abstract
Transmission-blocking vaccines are one strategy for controlling malaria, whereby sexual-stage parasites are inhibited from infecting mosquitoes by human antibodies. To evaluate whether the recently cloned Plasmodium vivax proteins Pvs25 and Pvs28 are candidates for a transmission-blocking vaccine, the molecules were expressed in yeast as secreted recombinant proteins. Mice vaccinated with these proteins adsorbed to aluminum hydroxide developed strong antibody responses against the immunogens, although for Pvs28, this response was genetically restricted. Antisera against both recombinant Pvs25 and Pvs28 recognized the corresponding molecules expressed by cultured sexual-stage parasites isolated from patients with P. vivax malaria. The development of malaria parasites in mosquitoes was completely inhibited when these antisera were ingested with the infected blood meal. Pvs25 and Pvs28, expressed in Saccharomyces cerevisiae, are as yet the only fully characterized transmission-blocking vaccine candidates against P. vivax that induce such a potent antiparasite response.
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Affiliation(s)
- H Hisaeda
- Malaria Vaccine Development Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
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18
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Taylor D, Cloonan N, Mann V, Cheng Q, Saul A. Sequence diversity in rodent malaria of the Pfs28 ookinete surface antigen homologs. Mol Biochem Parasitol 2000; 110:429-34. [PMID: 11071297 DOI: 10.1016/s0166-6851(00)00285-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- D Taylor
- Malaria and Arbovirus Unit, The Queensland Institute of Medical Research and the University of Queensland, Royal Brisbane Hospital, Australia
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19
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Zieler H, Nawrocki JP, Shahabuddin M. Plasmodium gallinaceum ookinetes adhere specifically to the midgut epithelium of Aedes aegypti by interaction with a carbohydrate ligand. J Exp Biol 1999; 202:485-95. [PMID: 9929452 DOI: 10.1242/jeb.202.5.485] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During the course of its development in the mosquito and transmission to a new vertebrate host, the malaria parasite must interact with the mosquito midgut and invade the gut epithelium. To investigate how the parasite recognizes the midgut before invasion, we have developed an in vitro adhesion assay based on combining fluorescently labelled ookinetes with isolated midgut epithelia from blood-fed mosquitoes. Using this assay, we found that Plasmodium gallinaceum ookinetes readily adhered to midguts of Aedes aegypti, mimicking the natural recognition of the epithelium by the parasite. This interaction is specific: the ookinetes preferentially adhered to the lumen (microvillar) side of the gut epithelium and did not bind to other mosquito tissues. Conversely, the binding was not due to a non-specific adhesive property of the midguts, because a variety of other cell types, including untransformed P. gallinaceum zygotes or macrogametes, did not show similar binding to the midguts. High concentrations of glycosylated (fetuin, orosomucoid, ovalbumin) or non-glycosylated (bovine serum albumin) proteins, added as non-specific competitors, failed to compete with the ookinetes in binding assays. We also found that the adhesion of ookinetes to the midgut surface is necessary for sporogonic development of the parasite in the mosquito. Antibodies and other reagents that blocked adhesion in vitro also reduced oocyst formation when these reagents were combined with mature ookinetes and fed to mosquitoes. Chemical modification of the midguts with sodium periodate at pH 5.5 destroyed adhesion, indicating that the ookinete binds to a carbohydrate ligand on the surface of the midgut. The ligand is sensitive to periodate concentrations of less than 1 mmol l-1, suggesting that it may contain sialic-acid-like sugars. Furthermore, free N-acetylneuraminic acid competed with the ookinetes in binding aasays, while other monosaccharides had no effect. However, in agreement with the current belief that adult insects do not contain sialic acids, we were unable to detect any sialic acids in mosquito midguts using the most sensitive HPLC-based fluorometric assay currently available. We postulate that a specific carbohydrate group is used by the ookinete to recognize the midgut epithelium and to attach to its surface. This is the first receptor-ligand interaction demonstrated for the ookinete stage of a malaria parasite. Further characterization of the midgut ligand and its parasite counterpart may lead to novel strategies of blocking oocyst development in the mosquito.
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Affiliation(s)
- H Zieler
- Medical Entomology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA
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20
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Dechering KJ, Kaan AM, Mbacham W, Wirth DF, Eling W, Konings RN, Stunnenberg HG. Isolation and functional characterization of two distinct sexual-stage-specific promoters of the human malaria parasite Plasmodium falciparum. Mol Cell Biol 1999; 19:967-78. [PMID: 9891033 PMCID: PMC116028 DOI: 10.1128/mcb.19.2.967] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transmission of malaria depends on the successful development of the sexual stages of the parasite within the midgut of the mosquito vector. The differentiation process leading to the production of the sexual stages is delineated by several developmental switches. Arresting the progression through this sexual differentiation pathway would effectively block the spread of the disease. The successful development of such transmission-blocking agents is hampered by the lack of a detailed understanding of the program of gene expression that governs sexual differentiation of the parasite. Here we describe the isolation and functional characterization of the Plasmodium falciparum pfs16 and pfs25 promoters, whose activation marks the developmental switches executed during the sexual differentiation process. We have studied the differential activation of the pfs16 and pfs25 promoters during intraerythrocytic development by transfection of P. falciparum and during gametogenesis and early sporogonic development by transfection of the related malarial parasite P. gallinaceum. Our data indicate that the promoter of the pfs16 gene is activated at the onset of gametocytogenesis, while the activity of the pfs25 promoter is induced following the transition to the mosquito vector. Both promoters have unusual DNA compositions and are extremely A/T rich. We have identified the regions in the pfs16 and pfs25 promoters that are essential for high transcriptional activity. Furthermore, we have identified a DNA-binding protein, termed PAF-1, which activates pfs25 transcription in the mosquito midgut. The data presented here shed the first light on the details of processes of gene regulation in the important human pathogen P. falciparum.
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Affiliation(s)
- K J Dechering
- Department of Molecular Biology, University of Nijmegen, 6525 ED Nijmegen, The Netherlands
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21
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Tsuboi T, Kaslow DC, Gozar MMG, Tachibana M, Cao YM, Torii M. Sequence Polymorphism in Two Novel Plasmodium vivax Ookinete Surface Proteins, Pvs25 and Pvs28, That Are Malaria Transmission-blocking Vaccine Candidates. Mol Med 1998. [DOI: 10.1007/bf03401770] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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22
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Shahabuddin M. Plasmodium ookinete development in the mosquito midgut: a case of reciprocal manipulation. Parasitology 1998; 116 Suppl:S83-93. [PMID: 9695113 DOI: 10.1017/s0031182000084973] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The ookinete is one of the most important stages of Plasmodium development in the mosquito. It is morphologically and biochemically distinct from the earlier sexual stages--gametocytes and zygote, and from the later stages--oocyst and sporozoites. Development to ookinete allows the parasite to escape from the tightly packed blood bolus, to cross the sturdy peritrophic matrix (PM), to be protected from the digestive environment of the midgut lumen, and to invade the gut epithelium. The success of each of these activities may depend on the degree of the biochemical and physical barriers in the mosquito (such as density of blood bolus, thickness of peritrophic matrix, proteolytic activities in the gut lumen etc.) and the ability of the ookinete to overcome these barriers. Ookinete motility, secretion of chitinase, resistance to the digestive enzymes, and recognition/invasion of the midgut epithelium all may play crucial roles in the transformation to oocyst. The overall sporogonic development of Plasmodium, therefore, depends on the results of the two-way manipulations between the parasite and the vector mosquito. Study of ookinete development and of the cellular and biochemical complexities of the mosquito gut may therefore lead to the design of novel strategies to block the transmission of malaria. This article reviews the intricate interactions between the parasite and the mosquito midgut in the context of development and transmission of Plasmodium parasites.
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Affiliation(s)
- M Shahabuddin
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0425, USA
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23
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Ramasamy R, Wanniarachchi IC, Srikrishnaraj KA, Ramasamy MS. Mosquito midgut glycoproteins and recognition sites for malaria parasites. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1361:114-22. [PMID: 9247095 DOI: 10.1016/s0925-4439(97)00020-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Midgut glycoproteins of the malaria vector Anopheles tessellatus were partially characterised by gel electrophoresis and lectin binding. Specific binding to wheat germ agglutinin (WGA) and Concanavalin A (Con A) indicated the presence of N-linked core oligosaccharides in many proteins. Rabbit antibodies were produced against wheat germ agglutinin binding proteins (WGABP). These antibodies also recognised distinct proteins in the peritrophic membrane which is secreted into the midgut to enclose a bloodmeal. Rabbit anti-WGABP antibodies ingested in a bloodmeal containing infective gametocytes of the human malaria parasites Plasmodium falciparum and P. vivax tended to reduce infectivity of the parasites to vector mosquitoes. Chitotriose added to a bloodmeal also inhibited parasite development in the mosquito. The results are consistent with a hypothesis that N-acetyl glucosamine residues in mosquito midgut glycoproteins and/or midgut chitin and proteoglycan function as recognition sites for malaria parasites.
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Affiliation(s)
- R Ramasamy
- Molecular Biology and Entomology Laboratories, Division of Life Sciences, Institute of Fundamental Studies, Kandy, Sri Lanka.
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24
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Tsuboi T, Kaslow DC, Cao YM, Shiwaku K, Torii M. Comparison of Plasmodium yoelii ookinete surface antigens with human and avian malaria parasite homologues reveals two highly conserved regions. Mol Biochem Parasitol 1997; 87:107-11. [PMID: 9233679 DOI: 10.1016/s0166-6851(97)00049-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- T Tsuboi
- Department of Parasitology, Ehime University School of Medicine, Shigenobu-cho, Japan
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25
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Tsuboi T, Cao YM, Hitsumoto Y, Yanagi T, Kanbara H, Torii M. Two antigens on zygotes and ookinetes of Plasmodium yoelii and Plasmodium berghei that are distinct targets of transmission-blocking immunity. Infect Immun 1997; 65:2260-4. [PMID: 9169761 PMCID: PMC175313 DOI: 10.1128/iai.65.6.2260-2264.1997] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have developed transmission-blocking monoclonal antibodies (MAbs) against Plasmodium yoelii 21-kDa (Pys21) and 28-kDa (Pys25) ookinete surface proteins. These MAbs block infectivity of P. yoelii to Anopheles stephensi. One MAb, 14, cross-reacted by Western blotting with a 28-kDa surface protein (Pbs25) of P. berghei ookinetes and blocked oocyst development, as assayed by direct mosquito feeds on passively immunized P. berghei-infected mice. In total, we have identified two ookinete surface proteins in P. yoelii, one of which is also present in P. berghei. The transmission-blocking activity of the anti-Pys25 MAb 4 was complete and more potent than that of the anti-Pys21 MAb 2. Moreover, Fab fragments of MAb 4 had transmission-blocking activity in mice. In comparison, Fab fragments of MAb 2 did not have detectable transmission-blocking effect, although F(ab')2 did. Furthermore, MAb 2 and MAb 4 appeared to block the in vitro formation and development of zygotes as well.
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Affiliation(s)
- T Tsuboi
- Department of Parasitology, Ehime University School of Medicine, Shigenobu-cho, Japan
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26
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Duffy PE, Kaslow DC. A novel malaria protein, Pfs28, and Pfs25 are genetically linked and synergistic as falciparum malaria transmission-blocking vaccines. Infect Immun 1997; 65:1109-13. [PMID: 9038325 PMCID: PMC175097 DOI: 10.1128/iai.65.3.1109-1113.1997] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Antibodies to Pfs28 block Plasmodium falciparum transmission and when combined with antibodies to Pfs25 provide synergy in blocking transmission. Pfs28 and Pfs25 are immunogenic, have limited antigenic diversity, and are structurally similar and genetically linked on chromosome 10. Pfs28 may prove a useful addition to Pfs25 in an effective transmission-blocking vaccine.
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Affiliation(s)
- P E Duffy
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892-0425, USA
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27
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Tsuboi T, Cao YM, Kaslow DC, Shiwaku K, Torii M. Primary structure of a novel ookinete surface protein from Plasmodium berghei. Mol Biochem Parasitol 1997; 85:131-4. [PMID: 9108555 DOI: 10.1016/s0166-6851(96)02821-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- T Tsuboi
- Department of Parasitology, Ehime University School of Medicine, Japan
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28
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Sinden RE, Butcher GA, Billker O, Fleck SL. Regulation of infectivity of Plasmodium to the mosquito vector. ADVANCES IN PARASITOLOGY 1996; 38:53-117. [PMID: 8701799 DOI: 10.1016/s0065-308x(08)60033-0] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- R E Sinden
- Department of Biology, Imperial College of Science, Technology and Medicine, South Kensington, London, UK
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29
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Margos G, Kurtenbach K, Posnett E, Barker GC, Matsuoka H, Paton MG, Sinden RE. Expression of the Plasmodium berghei ookinete protein Pbs21 in a baculovirus-insect cell system produces an efficient transmission blocking immunogen. Parasite Immunol 1995; 17:167-76. [PMID: 7624157 DOI: 10.1111/j.1365-3024.1995.tb00886.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A surface protein of Plasmodium berghei ookinetes, Pbs21, was expressed in a baculovirus-insect cell system in cell culture and in Heliothis virescens larvae. Groups of BALB/c mice received two intraperitoneal inoculations of either i) Tris-buffer or homogenized H. virescens larvae infected with wild-type baculovirus; ii) enriched, homogenized ookinetes, or iii) homogenized H. virescens larvae expressing recombinant Pbs21 (rPbs21). All animals immunized with ookinetes or with rPbs21 had high titres of antibodies (IgG isotype) that bound to native Pbs21. The large majority of antibodies in immune sera of both groups recognized the antigen under non-reducing but not under reducing conditions. The predominant IgG-subclasses in mice immunized with ookinetes was IgG1 and in mice immunized with rPbs21, the subclasses were IgG1 and IgG2a. Immunization with rPbs21 reduced the infectivity of P.berghei to mosquitoes by 91% compared to a 99% reduction following immunization with ookinetes. This preliminary data indicate that rPbs21 expressed in this eukaryotic system induces a transmission-blocking immunity, which is more effective than that achieved using rPbs21 expressed in Escherichia coli (Matsuoka et al. 1994).
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Affiliation(s)
- G Margos
- Department of Biology, Imperial College of Science, Technology and Medicine, London, UK
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30
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Ray P, Sahoo N, Singh B, Kironde FA. Serum antibody immunoglobulin G of mice convalescent from Plasmodium yoelii infection inhibits growth of Plasmodium falciparum in vitro: blood stage antigens of P. falciparum involved in interspecies cross-reactive inhibition of parasite growth. Infect Immun 1994; 62:2354-61. [PMID: 8188358 PMCID: PMC186518 DOI: 10.1128/iai.62.6.2354-2361.1994] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We demonstrated that antibodies in the serum of BALB/c mice convalescent from Plasmodium yoelii infection inhibit the in vitro growth of Plasmodium falciparum. Blood stage P. falciparum antigens that cross-react with the convalescent-phase mouse serum antibodies were identified and partially characterized. Convalescent-phase mouse serum immunoglobulin G (IgG) reacted with P. falciparum lysates at up to a 1:15,000 dilution of the immune sera and bound to P. falciparum-parasitized erythrocytes at up to a 1:5,000 dilution of the sera. The cross-reactive moieties of antigens in parasite lysates were resistant to oxidation by periodate but sensitive to trypsinization. About 15 polypeptides (M(r)s of 15,000 to 110,000) of P. falciparum blood stages were recognized by the convalescent-phase mouse anti-P. yoelii sera; many of these antigens were metabolically 35S labeled and specifically immunoprecipitated. Also, virtually all of the cross-reactive antigens were recognized by human malaria-immune sera. The anti-P. yoelii serum antibodies bound, with high affinity, to at least five of the cross-reactive antigens (M(r)s of 107,000, 84,000, 53,000, 36,000, and 30,000). By phase separation in Triton X-114, eight interspecies cross-reactive antigens (M(r)s of 84,000, 76,000, 51,000, 31,000, 29,000, 28,000, 23,000, and 22,000) were found to be integral membrane proteins. Convalescent-phase mouse serum IgG strongly inhibited the differentiation of P. falciparum from schizonts to rings; 75 micrograms of IgG per ml caused 80% inhibition of release of merozoites and their invasion into erythrocytes. On the other hand, the anti-P. yoelii serum antibodies also inhibited intracellular development of P. falciparum from rings to schizonts; 25 micrograms of IgG per ml caused 50% inhibition. Inhibition of P. falciparum growth by anti-P. yoelii serum IgG suggests that some of the interspecies cross-reactive antigens contain important conserved epitopes and induce protective antibodies against P. falciparum.
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Affiliation(s)
- P Ray
- Malaria Group, International Center for Genetic Engineering and Biotechnology, New Delhi, India
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31
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Creasey A, Mendis K, Carlton J, Williamson D, Wilson I, Carter R. Maternal inheritance of extrachromosomal DNA in malaria parasites. Mol Biochem Parasitol 1994; 65:95-8. [PMID: 7935632 DOI: 10.1016/0166-6851(94)90118-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Plasmodium falciparum has two extrachromosomal genomes, the mitochondrial 6-kb DNA element and the 35-kb circular DNA. The mitochondrial gene cytochrome b on the 6-kb element has been shown to be inherited uniparentally. In order to ascertain whether the route is maternal or paternal we have examined preparations of male and female gametes of the closely related Plasmodium gallinaceum for the presence of extrachromosomal DNA. DNA from purified preparations of gametes was hybridised to probes for both the 6-kb and 35-kb extrachromosomal genomes. Both probes hybridised to the preparation of Plasmodium gallinaceum female gametes but not to that of the males. We conclude that the extrachromosomal DNAs of malaria parasites are transmitted maternally.
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Affiliation(s)
- A Creasey
- Division of Biological Sciences, I.C.A.P.B., University of Edinburgh, UK
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32
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Matsuoka H, Paton MG, Barker GC, Alejo Blanco AR, Sinden RE. Studies on the immunogenicity of a recombinant ookinete surface antigen Pbs21 from Plasmodium berghei expressed in Escherichia coli. Parasite Immunol 1994; 16:27-34. [PMID: 8152832 DOI: 10.1111/j.1365-3024.1994.tb00301.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Plasmodium berghei ookinete surface antigen (Pbs21), was produced as a fusion product with maltose binding protein (MBP) in Escherichia coli and used to induce transmission-blocking immunity in mice. Specificity of induced antibody was confirmed by Western blotting with native ookinete Pbs21, and by the indirect immunofluorescent antibody test on ookinete bloodfilms. Immunized mice were infected with P. berghei and transmission to Anopheles stephensi mosquitoes determined by both the intensity and prevalence of oocyst infections. Compared with a control group immunized with MBP alone the maximum blockade of oocyst intensity was 66% in the mice immunized with recombinant MBP-Pbs21. Over nine experiments blockade averaged only 33%. By comparison with native Pbs21 protein, which usually induces > or = 90% blockade, our data suggests the recombinant protein produced in this bacterial system is a less effective immunogen despite expressing epitopes recognized by known transmission-blocking monoclonal antibodies.
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Affiliation(s)
- H Matsuoka
- Department of Pure and Applied Biology, Imperial College of Science, Technology and Medicine, London, UK
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Ranawaka G, Alejo-Blanco R, Sinden RE. The effect of transmission-blocking antibody ingested in primary and secondary bloodfeeds, upon the development of Plasmodium berghei in the mosquito vector. Parasitology 1993; 107 ( Pt 3):225-31. [PMID: 8233585 DOI: 10.1017/s0031182000079191] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of purified monoclonal immunoglobulins from control, or transmission-blocking anti-Pbs21 antibodies, upon the infection of Anopheles stephensi by ookinetes of Plasmodium berghei are compared. Anti-Pbs21 antibody reduced mean intensity and prevalence of infection by 94.7 and 58.7% respectively if added to the infectious bloodfeed at a concentration of 100 micrograms/ml. Fab fragments were of similar efficacy. No transmission enhancement was detected with declining antibody concentrations. Addition to subsequent (second) feeds reduced mean oocyst intensity but not prevalence. The reduction in blockade declined from 41% at day 2, to 4% at day 8. Second bloodfeeds, containing control globulin taken 4 or 6 days (but not 2 days) after infection, increased sporozoite burden in the salivary glands. At all times anti-Pbs21 reduced sporozoite number in the thorax compared to time-matched controls, but again highest gland intensities were obtained when the second bloodfeed was given on day 4. We conclude that second bloodfeeds containing transmission-blocking antibody simultaneously serve two opposing roles, (1) inhibition of parasite development and (2) the supply of nutrients which permit more sporozoites to be produced by each oocyst.
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Affiliation(s)
- G Ranawaka
- Department of Biology, Imperial College, London
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Simonetti AB, Billingsley PF, Winger LA, Sinden RE. Kinetics of expression of two major Plasmodium berghei antigens in the mosquito vector, Anopheles stephensi. J Eukaryot Microbiol 1993; 40:569-76. [PMID: 8401470 DOI: 10.1111/j.1550-7408.1993.tb06109.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Expression of a 21 kDa determinant (Pbs21), first detected on the surface of ookinetes, and of the circumsporozoite protein (CSP) was studied by immunofluorescence and Western blots during the developmental cycle of Plasmodium berghei in the mosquito Anopheles stephensi. The expression of Pbs21 was predominantly localised on the ookinete surface one day after the infectious blood meal, and thereafter reactivity declined to a minimum on days 2 and 3, the time of onset of oocyst development. A gradual increase in fluorescence was observed on the oocysts from day 6 that was retained until day 17 post-infection. In contrast, sporozoites released from oocysts or salivary glands showed little or no antibody labelling with anti-Pbs21. Circumsporozoite protein was not detectable in any midgut preparations until 5-6 days after feeding, when reactivity was observed against immature oocysts. Expression then continued and increased throughout oocyst and sporozoite development. Western blots confirmed that Pbs21 was expressed minimally during the oocyst development but was not detectable in sporozoites. Co-localisation of anti-Pbs21 and anti-CSP monoclonal antibodies to the 50 kDa and 60 kDa bands in Western blots of sporozoite suggests immunological cross-reactivity between the CSP and the anti-21 kDa antibodies.
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Affiliation(s)
- A B Simonetti
- Department of Biology, Imperial College of Science, Technology and Medicine, London, United Kingdom
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35
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Abstract
Antibodies to sexual stage malaria parasites block transmission of Plasmodium by female mosquitoes. With the recent isolation of genes encoding several of the target antigens of transmission-blocking antibodies, the development of a subunit transmission-blocking vaccine against malaria is now a realistic goal.
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Affiliation(s)
- D C Kaslow
- Laboratory of Malaria Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
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Paton MG, Barker GC, Matsuoka H, Ramesar J, Janse CJ, Waters AP, Sinden RE. Structure and expression of a post-transcriptionally regulated malaria gene encoding a surface protein from the sexual stages of Plasmodium berghei. Mol Biochem Parasitol 1993; 59:263-75. [PMID: 8341324 DOI: 10.1016/0166-6851(93)90224-l] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The sexual stage-specific protein Pbs21 of the rodent malaria parasite Plasmodium berghei, expressed on the surface of zygotes and ookinetes, has been shown to induce an effective and long-lasting transmission blocking immunity. The gene encoding Pbs21 was cloned by screening a cDNA library prepared from enriched zygotes and ookinetes using the monoclonal antibody 13.1.15, which is capable of blocking subsequent parasite sexual development in the mosquito vector. The Pbs21 gene encoded a protein of 213 amino acids which contained a putative amino-terminal signal sequence and a putative carboxy-terminal hydrophobic membrane anchor. The amino-acid sequence was characterised by a large number of cysteine residues which were organized into 4 epidermal growth factor-like domains. The spacing of the cysteine residues was highly conserved when compared to the 25-kDa ookinete proteins of Plasmodium falciparum (Pfs25), Plasmodium reichenowi (Prs25) and Plasmodium gallinaceum (Pgs25) which were approximately 45%, 45% and 40% homologous to Pbs21 respectively. The gene is located on chromosome 5 and cross-hybridizes to a similarly defined gene unit in the other rodent malaria species Plasmodium chabaudi, Plasmodium vinckei and Plasmodium yoelii. The gene is internally disposed and not in the subtelomeric region of chromosome 5. The gene is transcribed in a stage-specific manner giving rise to an abundant 1.5-kb transcript. This mRNA is synthesised in the precursor cells to female gametes (gametocytes) however the protein is observed only after activation of the gametes, suggesting that translation of the mRNA is controlled by a post-transcriptional process. The Pbs21 gene and the P. berghei parasite system provide an excellent vehicle for the study of stage-specific transcriptional and post-transcriptional control in malaria.
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Affiliation(s)
- M G Paton
- Department of Biology, Imperial College of Science, Technology and Medicine, London, UK
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37
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Duffy PE, Pimenta P, Kaslow DC. Pgs28 belongs to a family of epidermal growth factor-like antigens that are targets of malaria transmission-blocking antibodies. J Exp Med 1993; 177:505-10. [PMID: 8426118 PMCID: PMC2190907 DOI: 10.1084/jem.177.2.505] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Although Pgs28, a 28-kD surface protein of Plasmodium gallinaceum oökinetes, was previously thought not to be a target of transmission-blocking antibodies, we found that polyclonal antisera to Pgs28 completely blocked parasite infectivity to Aedes aegypti mosquitoes. Antisera raised against reduced Pgs28 were less effective in blocking transmission than were antisera to nonreduced Pgs28; thus, the target epitope(s) of transmission-blocking antibodies appears to be conformation dependent. In stage-specific assays, polyclonal antisera impaired the in vitro transformation of zygotes to mature oökinetes, as well as the in vivo development of mature oökinetes to oöcysts. Using microsequence of immunoaffinity-purified Pgs28, we cloned the 666-bp open reading frame of the Pgs28 gene. The deduced amino acid sequence of Pgs28 is strikingly similar to that of a P. gallinaceum zygote surface protein, Pgs25, and its P. falciparum analogue, Pfs25. Pgs28, like Pgs25 and Pfs25, has a presumptive secretory signal sequence, followed by four epidermal growth factor-like domains, and a terminal hydrophobic region.
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Affiliation(s)
- P E Duffy
- Molecular Vaccine Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
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38
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Moelans II, Lal AA, Konings RN, Schoenmakers JG. Sequence of a 16-kilodalton sexual stage and sporozoite surface antigen of Plasmodium reichenowi and comparison with Pfs16 of Plasmodium falciparum. Mol Biochem Parasitol 1992; 50:349-50. [PMID: 1741021 DOI: 10.1016/0166-6851(92)90232-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- I I Moelans
- Department of Molecular Biology, Faculty of Science, University of Nijmegen, The Netherlands
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40
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Shi YP, Alpers MP, Povoa MM, Lal AA. Single amino acid variation in the ookinete vaccine antigen from field isolates of Plasmodium falciparum. Mol Biochem Parasitol 1992; 50:179-80. [PMID: 1542311 DOI: 10.1016/0166-6851(92)90254-h] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Y P Shi
- Malaria Branch, National Center for Infectious Diseases, Center for Disease Control, Atlanta, GA 30333
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41
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Mattei D, Scherf A. Cross-reacting epitopes shared between Plasmodium falciparum and its host: the origin of autoreactive antibodies? RESEARCH IN IMMUNOLOGY 1991; 142:698-703. [PMID: 1726272 DOI: 10.1016/0923-2494(91)90152-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- D Mattei
- Unité de Parasitologie Expérimentale, CNRS URA 361, Institut Pasteur, Paris
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42
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Sieber KP, Huber M, Kaslow D, Banks SM, Torii M, Aikawa M, Miller LH. The peritrophic membrane as a barrier: its penetration by Plasmodium gallinaceum and the effect of a monoclonal antibody to ookinetes. Exp Parasitol 1991; 72:145-56. [PMID: 2009919 DOI: 10.1016/0014-4894(91)90132-g] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We studied the point at which a monoclonal antibody (mAb C5) to a surface protein (Pgs25) on Plasmodium gallinaceum ookinetes blocked the infection of Aedes aegypti mosquitoes. The antibody did not block the development of zygotes to ookinetes in vitro. Development of ookinetes to oocysts in the mosquito was blocked to the same extent whether zygotes grew to ookinetes in the presence of mAb C5 or the antibody was added after the ookinetes had reached full development. When ookinetes developed in vitro in the presence of mAb C5, antibody remained on the surface of the parasite for the next 50 hr and did not block attachment to the peritrophic membrane. When ookinetes were fed to mosquitoes, two subpopulations of mosquitoes were observed (high numbers of oocysts per midgut and low numbers of oocysts per midgut). mAb C5 reduced the number of oocysts per midgut in the subpopulation that had low numbers of oocysts. The subpopulation that had high numbers of oocysts was unaffected by antibody, indicating that the antibody did not block invasion of the midgut epithelium. When mAb C5 was fed with gametocytes, the parasites invaded the epithelium at the same time (between 30 and 35 hr after the blood meal) as in controls, although at a markedly reduced rate. The ultrastructural observations were consistent with a block of parasites within the peritrophic membrane and not with a block at the epithelium, as parasites were not seen to accumulate within the space between the peritrophic membrane and the epithelium. The mechanism by which mAb C5 to Pgs25 of P. gallinaceum blocks the penetration of the peritrophic membrane remains undefined. We present evidence that the parasite modifies the peritrophic membrane during penetration, an observation first made for Babesia microti during penetration of the peritrophic membrane in Ixodes ticks. Ookinetes in the absence of antibodies appeared to disrupt the layers of the peritrophic membrane, suggesting an enzymatic mechanism for penetration.
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Affiliation(s)
- K P Sieber
- Laboratory of Parasitic Diseases, NIAID, NIH, Bethesda, Maryland 20892
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43
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Lal AA, Goldman IF, Campbell GH. Primary structure of the 25-kilodalton ookinete antigen from Plasmodium reichenowi. Mol Biochem Parasitol 1990; 43:143-5. [PMID: 2290442 DOI: 10.1016/0166-6851(90)90139-d] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- A A Lal
- Malaria Branch, Centers for Disease Control, Public Health Service, Atlanta, GA 30333
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44
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Meis JF, Pool G, van Gemert GJ, Lensen AH, Ponnudurai T, Meuwissen JH. Plasmodium falciparum ookinetes migrate intercellularly through Anopheles stephensi midgut epithelium. Parasitol Res 1989; 76:13-9. [PMID: 2695921 DOI: 10.1007/bf00931065] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The migration of Plasmodium falciparum and P. berghei ookinetes through the midgut epithelium in Anopheles stephensi was studied by transmission electron microscopy. With ruthenium red (RR) staining, the results of previous studies were confirmed: P. falciparum ookinetes take an intercellular route through the midgut epithelium. In the same mosquito species, the rodent parasite P. berghei appeared to take an intracellular position, as previously suggested by other authors. The intra- or intercellular ookinete migration of P. berghei or P. falciparum, respectively, can perhaps be related to the higher mortality of P. berghei-infected mosquitoes within the first 2 days of infection. Evidence is presented that oocyst capsule formation begins as early as during the migration of the ookinete. After localization between the epithelial cells and the midgut basal lamina, the rapidly expanding oocyst stretches the overlying layer of the latter at the haemocoelic surface while a new basal lamina is generated between the oocyst and epithelial cell.
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Affiliation(s)
- J F Meis
- Department of Parasitology, University of Nijmegen, The Netherlands
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