151
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Jaskiewicz E, Peyrard T, Kaczmarek R, Zerka A, Jodlowska M, Czerwinski M. The Gerbich blood group system: old knowledge, new importance. Transfus Med Rev 2018. [PMID: 29540278 DOI: 10.1016/j.tmrv.2018.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Antigens of the Gerbich blood group system are expressed on glycophorin C (GPC) and glycophorin D (GPD), minor sialoglycoproteins of human erythrocytes. GPC and GPD help maintain erythrocyte shape of and contributes to the stability of its membrane. There are six high-prevalence Gerbich antigens: Ge2, Ge3, Ge4, GEPL (GE10), GEAT (GE11), GETI (GE12) and five low-prevalence Gerbich antigens: Wb (GE5), Lsa (GE6), Ana (GE7), Dha (GE8), GEIS (GE9). Some Gerbich antigens (Ge4, Wb, Dha, GEAT) are expressed only on GPC, two (Ge2, Ana) are expressed only on GPD, while others (Ge3, Lsa, GEIS, GEPL, GETI) are expressed on both GPC and GPD. Antibodies recognizing GPC/GPD may arise naturally (so-called "naturally-occurring RBC antibodies") or as the result of alloimmunization, and some of them may be clinically relevant. Gerbich antibodies usually do not cause serious hemolytic transfusion reactions (HTR); autoantibodies of anti-Ge2- or anti-Ge3 specificity can cause autoimmune hemolytic anemia (AIHA).
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Affiliation(s)
- Ewa Jaskiewicz
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland; Faculty of Biological Sciences, University of Zielona Góra, Zielona Góra, Poland.
| | - Thierry Peyrard
- Institut National de la Transfusion Sanguine (INTS), Département Centre National de Référence pour les Groupes Sanguins (CNRGS), Paris, France; UMR_S1134 Inserm Université Paris Diderot, Paris, France; Laboratoire d'Excellence GR-Ex, Institut Imagine, Paris, France
| | - Radoslaw Kaczmarek
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Agata Zerka
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Marlena Jodlowska
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Marcin Czerwinski
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland; Faculty of Physiotherapy and Physical Education, Opole University of Technology, Opole, Poland
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152
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Calcium-Dependent Protein Kinase 5 Is Required for Release of Egress-Specific Organelles in Plasmodium falciparum. mBio 2018; 9:mBio.00130-18. [PMID: 29487234 PMCID: PMC5829822 DOI: 10.1128/mbio.00130-18] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human malaria parasite Plasmodium falciparum requires efficient egress out of an infected red blood cell for pathogenesis. This egress event is highly coordinated and is mediated by several signaling proteins, including the plant-like Pfalciparum calcium-dependent protein kinase 5 (PfCDPK5). Knockdown of PfCDPK5 results in an egress block where parasites are trapped inside their host cells. The mechanism of this PfCDPK5-dependent block, however, remains unknown. Here, we show that PfCDPK5 colocalizes with a specialized set of parasite organelles known as micronemes and is required for their discharge, implicating failure of this step as the cause of the egress defect in PfCDPK5-deficient parasites. Furthermore, we show that PfCDPK5 cooperates with the Pfalciparum cGMP-dependent kinase (PfPKG) to fully activate the protease cascade critical for parasite egress. The PfCDPK5-dependent arrest can be overcome by hyperactivation of PfPKG or by physical disruption of the arrested parasite, and we show that both treatments facilitate the release of the micronemes required for egress. Our results define the molecular mechanism of PfCDPK5 function and elucidate the complex signaling pathway of parasite egress.IMPORTANCE The signs and symptoms of clinical malaria result from the replication of parasites in human blood. Efficient egress of the malaria parasite Plasmodium falciparum out of an infected red blood cell is critical for pathogenesis. The Pfalciparum calcium-dependent protein kinase 5 (PfCDPK5) is essential for parasite egress. Following PfCDPK5 knockdown, parasites remain trapped inside their host cell and do not egress, but the mechanism for this block remains unknown. We show that PfCDPK5 colocalizes with parasite organelles known as micronemes. We demonstrate that PfCDPK5 is critical for the discharge of these micronemes and that failure of this step is the molecular mechanism of the parasite egress arrest. We also show that hyperactivation of the cGMP-dependent kinase PKG can overcome this arrest. Our data suggest that small molecules that inhibit the egress signaling pathway could be effective antimalarial therapeutics.
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153
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Garzón-Ospina D, Buitrago SP, Ramos AE, Patarroyo MA. Identifying Potential Plasmodium vivax Sporozoite Stage Vaccine Candidates: An Analysis of Genetic Diversity and Natural Selection. Front Genet 2018; 9:10. [PMID: 29422913 PMCID: PMC5788960 DOI: 10.3389/fgene.2018.00010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/09/2018] [Indexed: 11/30/2022] Open
Abstract
Parasite antigen genetic diversity represents a great obstacle when designing a vaccine against malaria caused by Plasmodium vivax. Selecting vaccine candidate antigens has been focused on those fulfilling a role in invasion and which are conserved, thus avoiding specific-allele immune responses. Most antigens described to date belong to the blood stage, thereby blocking parasite development within red blood cells, whilst studying antigens from other stages has been quite restricted. Antigens from different parasite stages are required for developing a completely effective vaccine; thus, pre-erythrocyte stage antigens able to block the first line of infection becoming established should also be taken into account. However, few antigens from this stage have been studied to date. Several P. falciparum sporozoite antigens are involved in invasion. Since 77% of genes are orthologous amongst Plasmodium parasites, P. vivax sporozoite antigen orthologs to those of P. falciparum might be present in its genome. Although these genes might have high genetic diversity, conserved functionally-relevant regions (ideal for vaccine development) could be predicted by comparing genetic diversity patterns and evolutionary rates. This study was thus aimed at searching for putative P. vivax sporozoite genes so as to analyse their genetic diversity for determining their potential as vaccine candidates. Several DNA sequence polymorphism estimators were computed at each locus. The evolutionary force (drift, selection and recombination) drawing the genetic diversity pattern observed was also determined by using tests based on polymorphism frequency spectrum as well as the type of intra- and inter-species substitutions. Likewise, recombination was assessed both indirectly and directly. The results showed that sporozoite genes were more conserved than merozoite genes evaluated to date. Putative domains implied in cell traversal, gliding motility and hepatocyte interaction had a negative selection signal, being conserved amongst different species in the genus. PvP52, PvP36, PvSPATR, PvPLP1, PvMCP1, PvTLP, PvCelTOS, and PvMB2 antigens or functionally restricted regions within them would thus seem promising vaccine candidates and could be used when designing a pre-erythrocyte and/or multi-stage vaccine against P. vivax to avoid allele-specific immune responses that could reduce vaccine efficacy.
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Affiliation(s)
- Diego Garzón-Ospina
- Molecular Biology and Immunology Laboratory, Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,PhD Programme in Biomedical and Biological Sciences, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Sindy P Buitrago
- Molecular Biology and Immunology Laboratory, Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia
| | - Andrea E Ramos
- Molecular Biology and Immunology Laboratory, Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia
| | - Manuel A Patarroyo
- Molecular Biology and Immunology Laboratory, Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
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154
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Disrupting CD147-RAP2 interaction abrogates erythrocyte invasion by Plasmodium falciparum. Blood 2018; 131:1111-1121. [PMID: 29352039 DOI: 10.1182/blood-2017-08-802918] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/08/2018] [Indexed: 11/20/2022] Open
Abstract
Effective vaccines against malaria caused by Plasmodium falciparum are still lacking, and the molecular mechanism of the host-parasite interaction is not fully understood. Here we demonstrate that the interaction of RAP2, a parasite-secreted rhoptry protein that functions in the parasitophorous vacuole formation stage of the invasion, and CD147 on the host erythrocyte is essential for erythrocyte invasion by P falciparum and is independent from all previously identified interactions involved. Importantly, the blockade of the CD147-RAP2 interaction by HP6H8, a humanized CD147 antibody, completely abolished the parasite invasion with both cure and preventative functions in a humanized mouse model. Together with its long half-life on human red blood cells and its safety profile in cynomolgus monkeys, HP6H8 is the first antibody that offers an advantageous approach by targeting a more conserved late-stage parasite ligand for preventing as well as treating severe malaria.
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155
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Gruszczyk J, Kanjee U, Chan LJ, Menant S, Malleret B, Lim NT, Schmidt CQ, Mok YF, Lin KM, Pearson RD, Rangel G, Smith BJ, Call MJ, Weekes MP, Griffin MDW, Murphy JM, Abraham J, Sriprawat K, Menezes MJ, Ferreira MU, Russell B, Renia L, Duraisingh MT, Tham WH. Transferrin receptor 1 is a reticulocyte-specific receptor for Plasmodium vivax. Science 2018; 359:48-55. [PMID: 29302006 PMCID: PMC5788258 DOI: 10.1126/science.aan1078] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 09/29/2017] [Accepted: 11/16/2017] [Indexed: 12/15/2022]
Abstract
Plasmodium vivax shows a strict host tropism for reticulocytes. We identified transferrin receptor 1 (TfR1) as the receptor for P. vivax reticulocyte-binding protein 2b (PvRBP2b). We determined the structure of the N-terminal domain of PvRBP2b involved in red blood cell binding, elucidating the molecular basis for TfR1 recognition. We validated TfR1 as the biological target of PvRBP2b engagement by means of TfR1 expression knockdown analysis. TfR1 mutant cells deficient in PvRBP2b binding were refractory to invasion of P. vivax but not to invasion of P. falciparum Using Brazilian and Thai clinical isolates, we show that PvRBP2b monoclonal antibodies that inhibit reticulocyte binding also block P. vivax entry into reticulocytes. These data show that TfR1-PvRBP2b invasion pathway is critical for the recognition of reticulocytes during P. vivax invasion.
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Affiliation(s)
- Jakub Gruszczyk
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, 02115, USA
| | - Li-Jin Chan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Sébastien Menant
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Benoit Malleret
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore
- Singapore Immunology Network, A*STAR, 138648 Singapore
| | - Nicholas T.Y. Lim
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Christoph Q. Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Germany
| | - Yee-Foong Mok
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kai-Min Lin
- Cambridge Institute for Medical Research, Cambridge, CB2 OXY, United Kingdom
| | - Richard D. Pearson
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
| | - Gabriel Rangel
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, 02115, USA
| | - Brian J. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne Victoria 3086, Australia
| | - Melissa J. Call
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Michael P. Weekes
- Cambridge Institute for Medical Research, Cambridge, CB2 OXY, United Kingdom
| | - Michael D. W. Griffin
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - James M. Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jonathan Abraham
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Maria J. Menezes
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Laurent Renia
- Singapore Immunology Network, A*STAR, 138648 Singapore
| | - Manoj T. Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, 02115, USA
| | - Wai-Hong Tham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
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156
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Ademolue TW, Awandare GA. Evaluating antidisease immunity to malaria and implications for vaccine design. Immunology 2017; 153:423-434. [PMID: 29211303 PMCID: PMC5838420 DOI: 10.1111/imm.12877] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 12/29/2022] Open
Abstract
Immunity to malaria could be categorized broadly as antiparasite or antidisease immunity. While most vaccine research efforts have focused on antiparasite immunity, the evidence from endemic populations suggest that antidisease immunity is an important component of natural immunity to malaria. The processes that mediate antidisease immunity have, however, attracted little to no attention, and most interests have been directed towards the antibody responses. This review evaluates the evidence for antidisease immunity in endemic areas and discusses the possible mechanisms responsible for it. Given the key role that inflammation plays in the pathogenesis of malaria, regulation of the inflammatory response appears to be a major mechanism for antidisease immunity in naturally exposed individuals.
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Affiliation(s)
- Temitope W Ademolue
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Gordon A Awandare
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
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157
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Goheen MM, Bah A, Wegmüller R, Verhoef H, Darboe B, Danso E, Prentice AM, Cerami C. Host iron status and erythropoietic response to iron supplementation determines susceptibility to the RBC stage of falciparum malaria during pregnancy. Sci Rep 2017; 7:17674. [PMID: 29247172 PMCID: PMC5732269 DOI: 10.1038/s41598-017-16896-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/14/2017] [Indexed: 01/14/2023] Open
Abstract
Anaemia and malaria are both common in pregnant women in Sub-Saharan Africa. Previous evidence has shown that iron supplementation may increase malaria risk. In this observational cohort study, we evaluated P. falciparum pathogenesis in vitro in RBCs from pregnant women during their 2nd and 3rd trimesters. RBCs were collected and assayed before (n = 327), 14 days (n = 82), 49 days (n = 112) and 84 days (n = 115) after iron supplementation (60 mg iron as ferrous fumarate daily). P. falciparum erythrocytic stage growth in vitro is reduced in anaemic pregnant women at baseline, but increased during supplementation. The elevated growth rates parallel increases in circulating CD71-positive reticulocytes and other markers of young RBCs. We conclude that Plasmodium growth in vitro is associated with elevated erythropoiesis, an obligate step towards erythroid recovery in response to supplementation. Our findings support current World Health Organization recommendations that iron supplementation be given in combination with malaria prevention and treatment services in malaria endemic areas.
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Affiliation(s)
- Morgan M Goheen
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Amat Bah
- Nutrition Theme, MRC Unit The Gambia, MRC International Nutrition Group, Keneba, The Gambia
| | - Rita Wegmüller
- Nutrition Theme, MRC Unit The Gambia, MRC International Nutrition Group, Keneba, The Gambia
| | - Hans Verhoef
- London School of Hygiene & Tropical Medicine, London, UK.,Division of Human Nutrition and Cell Biology and Immunology Group, Wageningen University, Wageningen, The Netherlands
| | - Bakary Darboe
- Nutrition Theme, MRC Unit The Gambia, MRC International Nutrition Group, Keneba, The Gambia
| | - Ebrima Danso
- Nutrition Theme, MRC Unit The Gambia, MRC International Nutrition Group, Keneba, The Gambia
| | - Andrew M Prentice
- Nutrition Theme, MRC Unit The Gambia, MRC International Nutrition Group, Keneba, The Gambia.,London School of Hygiene & Tropical Medicine, London, UK
| | - Carla Cerami
- Nutrition Theme, MRC Unit The Gambia, MRC International Nutrition Group, Keneba, The Gambia.
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158
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Leitgeb AM, Charunwatthana P, Rueangveerayut R, Uthaisin C, Silamut K, Chotivanich K, Sila P, Moll K, Lee SJ, Lindgren M, Holmer E, Färnert A, Kiwuwa MS, Kristensen J, Herder C, Tarning J, Wahlgren M, Dondorp AM. Inhibition of merozoite invasion and transient de-sequestration by sevuparin in humans with Plasmodium falciparum malaria. PLoS One 2017; 12:e0188754. [PMID: 29244851 PMCID: PMC5731734 DOI: 10.1371/journal.pone.0188754] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 11/03/2017] [Indexed: 11/19/2022] Open
Abstract
SEVERE MALARIA Even with the best available treatment, the mortality from severe Plasmodium falciparum malaria remains high. Typical features at death are high parasite loads and obstructed micro- vasculature. Infected erythrocytes (IE) containing mature parasites bind to the host receptor heparan sulfate, which is also an important receptor for merozoite invasion. To block merozoite invasion has not previously been proposed as an adjunctive therapeutic approach but it may preclude the early expansion of an infection that else leads to exacerbated sequestration and death. SEVUPARIN IN PHASE I STUDY The drug sevuparin was developed from heparin because heparan sulfate and heparin are nearly identical, so the rationale was that sevuparin would act as a decoy receptor during malaria infection. A phase I study was performed in healthy male volunteers and sevuparin was found safe and well tolerated. SEVUPARIN IN PHASE I/II CLINICAL STUDY A phase I/II clinical study was performed in which sevuparin was administered via short intravenous infusions to malaria patients with uncomplicated malaria who were also receiving atovaquone/proguanil treatment. This was a Phase I/II, randomized, open label, active control, parallel assignment study. Sevuparin was safe and well tolerated in the malaria patients. The mean relative numbers of ring-stage IEs decreased after a single sevuparin infusion and mature parasite IEs appeared transiently in the circulation. The effects observed on numbers of merozoites and throphozoites in the circulation, were detected already one hour after the first sevuparin injection. Here we report the development of a candidate drug named sevuparin that both blocks merozoite invasion and transiently de-sequesters IE in humans with P. falciparum malaria. TRIAL REGISTRATION ClinicalTrials.gov NCT01442168.
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Affiliation(s)
| | | | | | | | - Kamolrat Silamut
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | | | - Kirsten Moll
- Department of Microbiology, Tumor- and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sue J. Lee
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | | | - Anna Färnert
- Department of Infectious Diseases, Karolinska University Hospital and Department Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Mpungu S. Kiwuwa
- Department of Pediatrics, School of Medicine, Makerere University College of Health Sciences, and Department of Biochemistry, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | | | | | - Joel Tarning
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mats Wahlgren
- Department of Microbiology, Tumor- and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Arjen M. Dondorp
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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159
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Lavazec C. Molecular mechanisms of deformability of Plasmodium -infected erythrocytes. Curr Opin Microbiol 2017; 40:138-144. [DOI: 10.1016/j.mib.2017.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 12/11/2022]
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160
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Human Cyclophilin B forms part of a multi-protein complex during erythrocyte invasion by Plasmodium falciparum. Nat Commun 2017; 8:1548. [PMID: 29146974 PMCID: PMC5691159 DOI: 10.1038/s41467-017-01638-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 10/04/2017] [Indexed: 12/13/2022] Open
Abstract
Invasion of human erythrocytes by Plasmodium falciparum merozoites involves multiple interactions between host receptors and their merozoite ligands. Here we report human Cyclophilin B as a receptor for PfRhopH3 during merozoite invasion. Localization and binding studies show that Cyclophilin B is present on the erythrocytes and binds strongly to merozoites. We demonstrate that PfRhopH3 binds to the RBCs and their treatment with Cyclosporin A prevents merozoite invasion. We also show a multi-protein complex involving Cyclophilin B and Basigin, as well as PfRhopH3 and PfRh5 that aids the invasion. Furthermore, we report identification of a de novo peptide CDP3 that binds Cyclophilin B and blocks invasion by up to 80%. Collectively, our data provide evidence of compounded interactions between host receptors and merozoite surface proteins and paves the way for developing peptide and small-molecules that inhibit the protein−protein interactions, individually or in toto, leading to abrogation of the invasion process. Invasion of red blood cells by Plasmodium falciparum is a complex process and relies on several receptor-ligand interactions. Here, the authors show that human cyclophilin B binds Plasmodium surface protein PfRhopH3 and that interruption of this interaction reduces invasion by 80%.
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161
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Scully EJ, Kanjee U, Duraisingh MT. Molecular interactions governing host-specificity of blood stage malaria parasites. Curr Opin Microbiol 2017; 40:21-31. [PMID: 29096194 DOI: 10.1016/j.mib.2017.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/04/2017] [Accepted: 10/08/2017] [Indexed: 11/18/2022]
Abstract
Non-human primates harbor diverse species of malaria parasites, including the progenitors of Plasmodium falciparum and Plasmodium vivax. Cross-species transmission of some malaria parasites-most notably the macaque parasite, Plasmodium knowlesi-continues to this day, compelling the scientific community to ask whether these zoonoses could impede malaria control efforts by acting as a source of recurrent human infection. Host-restriction varies considerably among parasite species and is governed by both ecological and molecular variables. In particular, the efficiency of red blood cell invasion constitutes a prominent barrier to zoonotic emergence. Although proteins expressed upon the erythrocyte surface exhibit considerable diversity both within and among hosts, malaria parasites have adapted to this heterogeneity via the expansion of protein families associated with invasion, offering redundant mechanisms of host cell entry. This molecular toolkit may enable some parasites to circumvent host barriers, potentially yielding host shifts upon subsequent adaptation. Recent studies have begun to elucidate the molecular determinants of host-specificity, as well as the mechanisms that malaria parasites use to overcome these restrictions. We review recent studies concerning host tropism in the context of erythrocyte invasion by focusing on three malaria parasites that span the zoonotic spectrum: P. falciparum, P. knowlesi, and P. vivax.
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Affiliation(s)
- Erik J Scully
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Ave, Cambridge, MA 02138, USA; Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Ave, Boston, MA 02115, USA
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Ave, Boston, MA 02115, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Ave, Boston, MA 02115, USA.
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162
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Identification of Heparin Modifications and Polysaccharide Inhibitors of Plasmodium falciparum Merozoite Invasion That Have Potential for Novel Drug Development. Antimicrob Agents Chemother 2017; 61:AAC.00709-17. [PMID: 28893781 DOI: 10.1128/aac.00709-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/03/2017] [Indexed: 11/20/2022] Open
Abstract
Despite recent successful control efforts, malaria remains a leading global health burden. Alarmingly, resistance to current antimalarials is increasing and the development of new drug families is needed to maintain malaria control. Current antimalarials target the intraerythrocytic developmental stage of the Plasmodium falciparum life cycle. However, the invasive extracellular parasite form, the merozoite, is also an attractive target for drug development. We have previously demonstrated that heparin-like molecules, including those with low molecular weights and low anticoagulant activities, are potent and specific inhibitors of merozoite invasion and blood-stage replication. Here we tested a large panel of heparin-like molecules and sulfated polysaccharides together with various modified chemical forms for their inhibitory activity against P. falciparum merozoite invasion. We identified chemical modifications that improve inhibitory activity and identified several additional sulfated polysaccharides with strong inhibitory activity. These studies have important implications for the further development of heparin-like molecules as antimalarial drugs and for understanding merozoite invasion.
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163
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Synergistic malaria vaccine combinations identified by systematic antigen screening. Proc Natl Acad Sci U S A 2017; 114:12045-12050. [PMID: 29078270 PMCID: PMC5692528 DOI: 10.1073/pnas.1702944114] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Malaria still kills hundreds of thousands of children each year. Malaria vaccine development is complicated by high levels of parasite genetic diversity, which makes single target vaccines vulnerable to the development of variant-specific immunity. To overcome this hurdle, we systematically screened a panel of 29 blood-stage antigens from the most deadly human malaria parasite, Plasmodium falciparum. We identified several targets that were able to inhibit erythrocyte invasion in two genetically diverse strains. Testing these targets in combination identified several pairs that blocked invasion more effectively in combination than in isolation. Video microscopy and studies of natural immune responses to malaria in patients suggest that targeting multiple steps in invasion is more likely to produce a synergistic vaccine response. A highly effective vaccine would be a valuable weapon in the drive toward malaria elimination. No such vaccine currently exists, and only a handful of the hundreds of potential candidates in the parasite genome have been evaluated. In this study, we systematically evaluated 29 antigens likely to be involved in erythrocyte invasion, an essential developmental stage during which the malaria parasite is vulnerable to antibody-mediated inhibition. Testing antigens alone and in combination identified several strain-transcending targets that had synergistic combinatorial effects in vitro, while studies in an endemic population revealed that combinations of the same antigens were associated with protection from febrile malaria. Video microscopy established that the most effective combinations targeted multiple discrete stages of invasion, suggesting a mechanistic explanation for synergy. Overall, this study both identifies specific antigen combinations for high-priority clinical testing and establishes a generalizable approach that is more likely to produce effective vaccines.
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164
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CRISPR/Cas9 knockouts reveal genetic interaction between strain-transcendent erythrocyte determinants of Plasmodium falciparum invasion. Proc Natl Acad Sci U S A 2017; 114:E9356-E9365. [PMID: 29078358 DOI: 10.1073/pnas.1711310114] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
During malaria blood-stage infections, Plasmodium parasites interact with the RBC surface to enable invasion followed by intracellular proliferation. Critical factors involved in invasion have been identified using biochemical and genetic approaches including specific knockdowns of genes of interest from primary CD34+ hematopoietic stem cells (cRBCs). Here we report the development of a robust in vitro culture system to produce RBCs that allow the generation of gene knockouts via CRISPR/Cas9 using the immortal JK-1 erythroleukemia line. JK-1 cells spontaneously differentiate, generating cells at different stages of erythropoiesis, including terminally differentiated nucleated RBCs that we term "jkRBCs." A screen of small-molecule epigenetic regulators identified several bromodomain-specific inhibitors that promote differentiation and enable production of synchronous populations of jkRBCs. Global surface proteomic profiling revealed that jkRBCs express all known Pfalciparum host receptors in a similar fashion to cRBCs and that multiple Pfalciparum strains invade jkRBCs at comparable levels to cRBCs and RBCs. Using CRISPR/Cas9, we deleted two host factors, basigin (BSG) and CD44, for which no natural nulls exist. BSG interacts with the parasite ligand Rh5, a prominent vaccine candidate. A BSG knockout was completely refractory to parasite invasion in a strain-transcendent manner, confirming the essential role for BSG during invasion. CD44 was recently identified in an RNAi screen of blood group genes as a host factor for invasion, and we show that CD44 knockout results in strain-transcendent reduction in invasion. Furthermore, we demonstrate a functional interaction between these two determinants in mediating Pfalciparum erythrocyte invasion.
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165
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Glushakova S, Busse BL, Garten M, Beck JR, Fairhurst RM, Goldberg DE, Zimmerberg J. Exploitation of a newly-identified entry pathway into the malaria parasite-infected erythrocyte to inhibit parasite egress. Sci Rep 2017; 7:12250. [PMID: 28947749 PMCID: PMC5612957 DOI: 10.1038/s41598-017-12258-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 09/05/2017] [Indexed: 12/20/2022] Open
Abstract
While many parasites develop within host cells to avoid antibody responses and to utilize host cytoplasmic resources, elaborate egress processes have evolved to minimize the time between escaping and invading the next cell. In human erythrocytes, malaria parasites perforate their enclosing erythrocyte membrane shortly before egress. Here, we show that these pores clearly function as an entry pathway into infected erythrocytes for compounds that inhibit parasite egress. The natural glycosaminoglycan heparin surprisingly inhibited malaria parasite egress, trapping merozoites within infected erythrocytes. Labeled heparin neither bound to nor translocated through the intact erythrocyte membrane during parasite development, but fluxed into erythrocytes at the last minute of the parasite lifecycle. This short encounter was sufficient to significantly inhibit parasite egress and dispersion. Heparin blocks egress by interacting with both the surface of intra-erythrocytic merozoites and the inner aspect of erythrocyte membranes, preventing the rupture of infected erythrocytes but not parasitophorous vacuoles, and independently interfering with merozoite disaggregation. Since this action of heparin recapitulates that of neutralizing antibodies, membrane perforation presents a brief opportunity for a new strategy to inhibit parasite egress and replication.
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Affiliation(s)
- Svetlana Glushakova
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Brad L Busse
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Matthias Garten
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Josh R Beck
- Division of Infectious Diseases, Department of Medicine, Washington University, St. Louis, MO, 63110, USA
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases; National Institutes of Health, Bethesda, MD, 20892, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine, Washington University, St. Louis, MO, 63110, USA
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
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166
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167
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Arévalo-Pinzón G, Bermúdez M, Hernández D, Curtidor H, Patarroyo MA. Plasmodium vivax ligand-receptor interaction: PvAMA-1 domain I contains the minimal regions for specific interaction with CD71+ reticulocytes. Sci Rep 2017; 7:9616. [PMID: 28855657 PMCID: PMC5577344 DOI: 10.1038/s41598-017-10025-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/02/2017] [Indexed: 12/18/2022] Open
Abstract
The malarial parasite’s invasion is complex, active and coordinated, involving many low and high affinity interactions with receptors on target cell membrane. Proteomics analysis has described around 40 proteins in P. vivax which could be involved in reticulocyte invasion; few have been studied with the aim of elucidating how many of them establish specific interactions with their respective host cells. Given the importance of knowing which of the parasite’s protein regions are functionally important for invasion, minimum regions mediating specific interaction between Plasmodium vivax apical membrane antigen 1 (PvAMA-1) and its host cell were here elucidated. The region covering PvAMA-1 domains I and II (PvAMA-DI-II) specifically bound to the CD71+ red blood cell subpopulation. A 20 residue-long region (81EVENAKYRIPAGRCPVFGKG100) located in domain I was capable of inhibiting PvAMA-DI-II recombinant protein binding to young reticulocytes (CD71+CD45−) and rosette formation. This conserved peptide specifically interacted with high affinity with reticulocytes (CD71+) through a neuraminidase- and chymotrypsin-treatment sensitive receptor. Such results showed that, despite AMA-1 having universal functions during late Plasmodium invasion stages, PvAMA-1 had reticulocyte-preferring binding regions, suggesting that P. vivax target cell selection is not just restricted to initial interactions but maintained throughout the erythrocyte invasion cycle, having important implications for designing a specific anti-P. vivax vaccine.
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Affiliation(s)
- Gabriela Arévalo-Pinzón
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia.,PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Carrera 24 #, 63C-69, Bogotá, Colombia
| | - Maritza Bermúdez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia.,MSc Program in Biological Sciences, Pontificia Universidad Javeriana, Carrera 7 # 40-62, Bogotá, Colombia
| | - Diana Hernández
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, 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
| | - 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.
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168
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Abstract
It is only in the last decade that sub-cellular resolution of red cell invasion by the malaria parasite Plasmodium falciparum has been possible. Here we look back on the development of methodologies that led to this possibility and the subsequent advancements made in understanding this key event in malaria disease.
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Affiliation(s)
- Jake Baum
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
| | - Dave Richard
- Department of Microbiology, Infectious Diseases, and Immunology, Laval University, Quebec City, QC G1V 0A6, Canada
| | - David T Riglar
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
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169
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Das S, Lemgruber L, Tay CL, Baum J, Meissner M. Multiple essential functions of Plasmodium falciparum actin-1 during malaria blood-stage development. BMC Biol 2017; 15:70. [PMID: 28810863 PMCID: PMC5557482 DOI: 10.1186/s12915-017-0406-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 07/14/2017] [Indexed: 01/04/2023] Open
Abstract
Background The phylum Apicomplexa includes intracellular parasites causing immense global disease burden, the deadliest of them being the human malaria parasite Plasmodium falciparum, which invades and replicates within erythrocytes. The cytoskeletal protein actin is well conserved within apicomplexans but divergent from mammalian actins, and was primarily reported to function during host cell invasion. However, novel invasion mechanisms have been described for several apicomplexans, and specific functions of the acto-myosin system are being reinvestigated. Of the two actin genes in P. falciparum, actin-1 (pfact1) is ubiquitously expressed in all life-cycle stages and is thought to be required for erythrocyte invasion, although its functions during parasite development are unknown, and definitive in vivo characterisation during invasion is lacking. Results Here we have used a conditional Cre-lox system to investigate the functions of PfACT1 during P. falciparum blood-stage development and host cell invasion. We demonstrate that PfACT1 is crucially required for segregation of the plastid-like organelle, the apicoplast, and for efficient daughter cell separation during the final stages of cytokinesis. Surprisingly, we observe that egress from the host cell is not an actin-dependent process. Finally, we show that parasites lacking PfACT1 are capable of microneme secretion, attachment and formation of a junction with the erythrocyte, but are incapable of host cell invasion. Conclusions This study provides important mechanistic insights into the definitive essential functions of PfACT1 in P. falciparum, which are not only of biological interest, but owing to functional divergence from mammalian actins, could also form the basis for the development of novel therapeutics against apicomplexans. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0406-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sujaan Das
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK.
| | - Leandro Lemgruber
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK
| | - Chwen L Tay
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Jake Baum
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Markus Meissner
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK. .,Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany.
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170
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Abstract
Malaria is caused in humans by five species of single-celled eukaryotic Plasmodium parasites (mainly Plasmodium falciparum and Plasmodium vivax) that are transmitted by the bite of Anopheles spp. mosquitoes. Malaria remains one of the most serious infectious diseases; it threatens nearly half of the world's population and led to hundreds of thousands of deaths in 2015, predominantly among children in Africa. Malaria is managed through a combination of vector control approaches (such as insecticide spraying and the use of insecticide-treated bed nets) and drugs for both treatment and prevention. The widespread use of artemisinin-based combination therapies has contributed to substantial declines in the number of malaria-related deaths; however, the emergence of drug resistance threatens to reverse this progress. Advances in our understanding of the underlying molecular basis of pathogenesis have fuelled the development of new diagnostics, drugs and insecticides. Several new combination therapies are in clinical development that have efficacy against drug-resistant parasites and the potential to be used in single-dose regimens to improve compliance. This ambitious programme to eliminate malaria also includes new approaches that could yield malaria vaccines or novel vector control strategies. However, despite these achievements, a well-coordinated global effort on multiple fronts is needed if malaria elimination is to be achieved.
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Affiliation(s)
- Margaret A Phillips
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA
| | | | | | | | - Wesley C Van Voorhis
- University of Washington, Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Re-emerging Infectious Diseases, Seattle, Washington, USA
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171
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Deu E. Proteases as antimalarial targets: strategies for genetic, chemical, and therapeutic validation. FEBS J 2017; 284:2604-2628. [PMID: 28599096 PMCID: PMC5575534 DOI: 10.1111/febs.14130] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 04/29/2017] [Accepted: 06/06/2017] [Indexed: 01/17/2023]
Abstract
Malaria is a devastating parasitic disease affecting half of the world's population. The rapid emergence of resistance against new antimalarial drugs, including artemisinin-based therapies, has made the development of drugs with novel mechanisms of action extremely urgent. Proteases are enzymes proven to be well suited for target-based drug development due to our knowledge of their enzymatic mechanisms and active site structures. More importantly, Plasmodium proteases have been shown to be involved in a variety of pathways that are essential for parasite survival. However, pharmacological rather than target-based approaches have dominated the field of antimalarial drug development, in part due to the challenge of robustly validating Plasmodium targets at the genetic level. Fortunately, over the last few years there has been significant progress in the development of efficient genetic methods to modify the parasite, including several conditional approaches. This progress is finally allowing us not only to validate essential genes genetically, but also to study their molecular functions. In this review, I present our current understanding of the biological role proteases play in the malaria parasite life cycle. I also discuss how the recent advances in Plasmodium genetics, the improvement of protease-oriented chemical biology approaches, and the development of malaria-focused pharmacological assays, can be combined to achieve a robust biological, chemical and therapeutic validation of Plasmodium proteases as viable drug targets.
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Affiliation(s)
- Edgar Deu
- Chemical Biology Approaches to Malaria LaboratoryThe Francis Crick InstituteLondonUK
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172
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Abstract
Organisms with identical genome sequences can show substantial differences in their phenotypes owing to epigenetic changes that result in different use of their genes. Epigenetic regulation of gene expression plays a key role in the control of several fundamental processes in the biology of malaria parasites, including antigenic variation and sexual differentiation. Some of the histone modifications and chromatin-modifying enzymes that control the epigenetic states of malaria genes have been characterized, and their functions are beginning to be unraveled. The fundamental principles of epigenetic regulation of gene expression appear to be conserved between malaria parasites and model eukaryotes, but important peculiarities exist. Here, we review the current knowledge of malaria epigenetics and discuss how it can be exploited for the development of new molecular markers and new types of drugs that may contribute to malaria eradication efforts.
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Affiliation(s)
- Alfred Cortés
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia 08036, Spain.,ICREA, Barcelona, Catalonia 08010, Spain
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065
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173
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Ntege EH, Takashima E, Morita M, Nagaoka H, Ishino T, Tsuboi T. Blood-stage malaria vaccines: post-genome strategies for the identification of novel vaccine candidates. Expert Rev Vaccines 2017; 16:769-779. [PMID: 28604122 DOI: 10.1080/14760584.2017.1341317] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION An efficacious malaria vaccine is necessary to advance the current control measures towards malaria elimination. To-date, only RTS,S/AS01, a leading pre-erythrocytic stage vaccine completed phase 3 trials, but with an efficacy of 28-36% in children, and 18-26% in infants, that waned over time. Blood-stage malaria vaccines protect against disease, and are considered effective targets for the logical design of next generation vaccines to improve the RTS,S field efficacy. Therefore, novel blood-stage vaccine candidate discovery efforts are critical, albeit with several challenges including, high polymorphisms in vaccine antigens, poor understanding of targets of naturally protective immunity, and difficulties in the expression of high AT-rich plasmodial proteins. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects of malaria vaccine research and development. We focused on post-genome vaccine candidate discovery, malaria vaccine development, sequence diversity, pre-clinical and clinical trials. Expert commentary: Post-genome high-throughput technologies using wheat germ cell-free protein synthesis technology and immuno-profiling with sera from malaria patients with clearly defined outcomes are highlighted to overcome current challenges of malaria vaccine candidate discovery.
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Affiliation(s)
- Edward H Ntege
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Eizo Takashima
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Masayuki Morita
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Hikaru Nagaoka
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Tomoko Ishino
- b Division of Molecular Parasitology , Proteo-Science Center, Ehime University , Toon , Ehime , Japan
| | - Takafumi Tsuboi
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
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174
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Santos JM, Josling G, Ross P, Joshi P, Orchard L, Campbell T, Schieler A, Cristea IM, Llinás M. Red Blood Cell Invasion by the Malaria Parasite Is Coordinated by the PfAP2-I Transcription Factor. Cell Host Microbe 2017; 21:731-741.e10. [PMID: 28618269 PMCID: PMC5855115 DOI: 10.1016/j.chom.2017.05.006] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 02/16/2017] [Accepted: 05/23/2017] [Indexed: 10/19/2022]
Abstract
Obligate intracellular parasites must efficiently invade host cells in order to mature and be transmitted. For the malaria parasite Plasmodium falciparum, invasion of host red blood cells (RBCs) is essential. Here we describe a parasite-specific transcription factor PfAP2-I, belonging to the Apicomplexan AP2 (ApiAP2) family, that is responsible for regulating the expression of genes involved in RBC invasion. Our genome-wide analysis by ChIP-seq shows that PfAP2-I interacts with a specific DNA motif in the promoters of target genes. Although PfAP2-I contains three AP2 DNA-binding domains, only one is required for binding of the target genes during blood stage development. Furthermore, we find that PfAP2-I associates with several chromatin-associated proteins, including the Plasmodium bromodomain protein PfBDP1 and that complex formation is associated with transcriptional regulation. As a key regulator of red blood cell invasion, PfAP2-I represents a potential new antimalarial therapeutic target.
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Affiliation(s)
- Joana Mendonca Santos
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Gabrielle Josling
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA
| | - Philipp Ross
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA
| | - Preeti Joshi
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Lindsey Orchard
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA
| | - Tracey Campbell
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Ariel Schieler
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research, Pennsylvania State University, State College, PA 16802, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry and Huck Center for Infectious Disease Dynamics, Pennsylvania State University, State College, PA 16802, USA.
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175
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Tardieux I, Baum J. Reassessing the mechanics of parasite motility and host-cell invasion. J Cell Biol 2017; 214:507-15. [PMID: 27573462 PMCID: PMC5004448 DOI: 10.1083/jcb.201605100] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/09/2016] [Indexed: 12/20/2022] Open
Abstract
The capacity to migrate is fundamental to multicellular and single-celled life. Apicomplexan parasites, an ancient protozoan clade that includes malaria parasites (Plasmodium) and Toxoplasma, achieve remarkable speeds of directional cell movement. This rapidity is achieved via a divergent actomyosin motor system, housed within a narrow compartment that lies underneath the length of the parasite plasma membrane. How this motor functions at a mechanistic level during motility and host cell invasion is a matter of debate. Here, we integrate old and new insights toward refining the current model for the function of this motor with the aim of revitalizing interest in the mechanics of how these deadly pathogens move.
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Affiliation(s)
- Isabelle Tardieux
- Institute of Advanced BioSciences, Institut National de la Santé et de la Recherche Médicale U1209, Centre National de la Recherche Scientifique UMR 5309, Université Grenoble Alpes, 38000, Grenoble, France
| | - Jake Baum
- Department of Life Sciences, Imperial College London, London SW7 2AZ, England, UK
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176
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Aniweh Y, Gao X, Hao P, Meng W, Lai SK, Gunalan K, Chu TT, Sinha A, Lescar J, Chandramohanadas R, Li HY, Sze SK, Preiser PR. P. falciparum RH5-Basigin interaction induces changes in the cytoskeleton of the host RBC. Cell Microbiol 2017; 19. [PMID: 28409866 DOI: 10.1111/cmi.12747] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 04/06/2017] [Accepted: 04/07/2017] [Indexed: 11/26/2022]
Abstract
The successful invasion of Plasmodium is an essential step in their life cycle. The parasite reticulocyte-binding protein homologues (RHs) and erythrocyte-binding like proteins are two families involved in the invasion leading to merozoite-red blood cell (RBC) junction formation. Ca2+ signaling has been shown to play a critical role in the invasion. RHs have been linked to Ca2+ signaling, which triggers the erythrocyte-binding like proteins release ahead of junction formation, consistent with RHs performing an initial sensing function in identifying suitable RBCs. RH5, the only essential RHs, is a highly promising vaccine candidate. RH5-basigin interaction is essential for merozoite invasion and also important in determining host tropism. Here, we show that RH5 has a distinct function from the other RHs. We show that RH5-Basigin interaction on its own triggers a Ca2+ signal in the RBC resulting in changes in RBC cytoskeletal proteins phosphorylation and overall alterations in RBC cytoskeleton architecture. Antibodies targeting RH5 that block the signal prevent invasion before junction formation consistent with the Ca2+ signal in the RBC leading to rearrangement of the cytoskeleton required for invasion. This work provides the first time a functional context for the essential role of RH5 and will now open up new avenues to target merozoite invasion.
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Affiliation(s)
- Yaw Aniweh
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Xiaohong Gao
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Piliang Hao
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Wei Meng
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Soak Kuan Lai
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Karthigayan Gunalan
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Trang T Chu
- Pillar of Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore
| | - Ameya Sinha
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore.,Pillar of Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore
| | - Julien Lescar
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Rajesh Chandramohanadas
- Pillar of Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore
| | - Hoi Yeung Li
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Siu Kwan Sze
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Peter R Preiser
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
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177
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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: 2.4] [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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178
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John Von Freyend S, Kwok-Schuelein T, Netter HJ, Haqshenas G, Semblat JP, Doerig C. Subverting Host Cell P21-Activated Kinase: A Case of Convergent Evolution across Pathogens. Pathogens 2017; 6:pathogens6020017. [PMID: 28430160 PMCID: PMC5488651 DOI: 10.3390/pathogens6020017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/29/2017] [Accepted: 04/09/2017] [Indexed: 12/14/2022] Open
Abstract
Intracellular pathogens have evolved a wide range of strategies to not only escape from the immune systems of their hosts, but also to directly exploit a variety of host factors to facilitate the infection process. One such strategy is to subvert host cell signalling pathways to the advantage of the pathogen. Recent research has highlighted that the human serine/threonine kinase PAK, or p21-activated kinase, is a central component of host-pathogen interactions in many infection systems involving viruses, bacteria, and eukaryotic pathogens. PAK paralogues are found in most mammalian tissues, where they play vital roles in a wide range of functions. The role of PAKs in cell proliferation and survival, and their involvement in a number of cancers, is of great interest in the context of drug discovery. In this review we discuss the latest insights into the surprisingly central role human PAK1 plays for the infection by such different infectious disease agents as viruses, bacteria, and parasitic protists. It is our intention to open serious discussion on the applicability of PAK inhibitors for the treatment, not only of neoplastic diseases, which is currently the primary objective of drug discovery research targeting these enzymes, but also of a wide range of infectious diseases.
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Affiliation(s)
- Simona John Von Freyend
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
| | - Terry Kwok-Schuelein
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
- Cancer Program, Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia.
| | - Hans J Netter
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
- Victorian Infectious Diseases Reference Laboratory, Melbourne Health, The Peter Doherty Institute, Melbourne, Victoria 3000, Australia.
| | - Gholamreza Haqshenas
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
| | | | - Christian Doerig
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia.
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179
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Plasmodium falciparum erythrocyte-binding antigen 175 triggers a biophysical change in the red blood cell that facilitates invasion. Proc Natl Acad Sci U S A 2017; 114:4225-4230. [PMID: 28373555 DOI: 10.1073/pnas.1620843114] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Invasion of the red blood cell (RBC) by the Plasmodium parasite defines the start of malaria disease pathogenesis. To date, experimental investigations into invasion have focused predominantly on the role of parasite adhesins or signaling pathways and the identity of binding receptors on the red cell surface. A potential role for signaling pathways within the erythrocyte, which might alter red cell biophysical properties to facilitate invasion, has largely been ignored. The parasite erythrocyte-binding antigen 175 (EBA175), a protein required for entry in most parasite strains, plays a key role by binding to glycophorin A (GPA) on the red cell surface, although the function of this binding interaction is unknown. Here, using real-time deformability cytometry and flicker spectroscopy to define biophysical properties of the erythrocyte, we show that EBA175 binding to GPA leads to an increase in the cytoskeletal tension of the red cell and a reduction in the bending modulus of the cell's membrane. We isolate the changes in the cytoskeleton and membrane and show that reduction in the bending modulus is directly correlated with parasite invasion efficiency. These data strongly imply that the malaria parasite primes the erythrocyte surface through its binding antigens, altering the biophysical nature of the target cell and thus reducing a critical energy barrier to invasion. This finding would constitute a major change in our concept of malaria parasite invasion, suggesting it is, in fact, a balance between parasite and host cell physical forces working together to facilitate entry.
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180
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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: 47] [Impact Index Per Article: 5.9] [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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181
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Chen L, Xu Y, Wong W, Thompson JK, Healer J, Goddard-Borger ED, Lawrence MC, Cowman AF. Structural basis for inhibition of erythrocyte invasion by antibodies to Plasmodium falciparum protein CyRPA. eLife 2017; 6. [PMID: 28195530 PMCID: PMC5349848 DOI: 10.7554/elife.21347] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/31/2017] [Indexed: 02/01/2023] Open
Abstract
Plasmodium falciparum causes malaria in humans with over 450,000 deaths annually. The asexual blood stage involves invasion of erythrocytes by merozoites, in which they grow and divide to release daughter merozoites, which in turn invade new erythrocytes perpetuating the cycle responsible for malaria. A key step in merozoite invasion is the essential binding of PfRh5/CyRPA/PfRipr complex to basigin, a step linked to the formation of a pore between merozoites and erythrocytes. We show CyRPA interacts directly with PfRh5. An invasion inhibitory monoclonal antibody to CyRPA blocks binding of CyRPA to PfRh5 and complex formation thus illuminating the molecular mechanism for inhibition of parasite growth. We determined the crystal structures of CyRPA alone and in complex with an antibody Fab fragment. CyRPA has a six-bladed β-propeller fold, and we identify the region that interacts with PfRh5. This functionally conserved epitope is a potential target for vaccines against P. falciparum.
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Affiliation(s)
- Lin Chen
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Yibin Xu
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Wilson Wong
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Jennifer K Thompson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Julie Healer
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Ethan D Goddard-Borger
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Michael C Lawrence
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
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182
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P113 is a merozoite surface protein that binds the N terminus of Plasmodium falciparum RH5. Nat Commun 2017; 8:14333. [PMID: 28186186 PMCID: PMC5309799 DOI: 10.1038/ncomms14333] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 12/16/2016] [Indexed: 01/12/2023] Open
Abstract
Invasion of erythrocytes by Plasmodium falciparum merozoites is necessary for malaria pathogenesis and is therefore a primary target for vaccine development. RH5 is a leading subunit vaccine candidate because anti-RH5 antibodies inhibit parasite growth and the interaction with its erythrocyte receptor basigin is essential for invasion. RH5 is secreted, complexes with other parasite proteins including CyRPA and RIPR, and contains a conserved N-terminal region (RH5Nt) of unknown function that is cleaved from the native protein. Here, we identify P113 as a merozoite surface protein that directly interacts with RH5Nt. Using recombinant proteins and a sensitive protein interaction assay, we establish the binding interdependencies of all the other known RH5 complex components and conclude that the RH5Nt-P113 interaction provides a releasable mechanism for anchoring RH5 to the merozoite surface. We exploit these findings to design a chemically synthesized peptide corresponding to RH5Nt, which could contribute to a cost-effective malaria vaccine. The secreted Plasmodium falciparum protein RH5 is essential for invasion of erythrocytes and is a promising vaccine candidate. Here, Galaway et al. show that the N-terminal region of RH5 binds the GPI-anchored merozoite surface protein P113 and can elicit invasion-blocking antibodies.
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183
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Patarroyo ME, Alba MP, Rojas-Luna R, Bermudez A, Aza-Conde J. Functionally relevant proteins in Plasmodium falciparum host cell invasion. Immunotherapy 2017; 9:131-155. [DOI: 10.2217/imt-2016-0091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A totally effective, antimalarial vaccine must involve sporozoite and merozoite proteins (or their fragments) to ensure complete parasite blocking during critical invasion stages. This Special Report examines proteins involved in critical biological functions for parasite survival and highlights the conserved amino acid sequences of the most important proteins involved in sporozoite invasion of hepatocytes and merozoite invasion of red blood cells. Conserved high activity binding peptides are located in such proteins’ functionally strategic sites, whose functions are related to receptor binding, nutrient and protein transport, enzyme activity and molecule–molecule interactions. They are thus excellent targets for vaccine development as they block proteins binding function involved in invasion and also their biological function.
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Affiliation(s)
- Manuel E Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
- Universidad Nacional de Colombia, Bogotá DC, Colombia
| | - Martha P Alba
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
- Universidad de Ciencias Aplicadas y Ambientales (UDCA), Bogotá, Colombia
| | - Rocío Rojas-Luna
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
| | - Adriana Bermudez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
- Universidad del Rosario, Bogotá DC, Colombia
| | - Jorge Aza-Conde
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
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184
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The Rheopathobiology of Plasmodium vivax and Other Important Primate Malaria Parasites. Trends Parasitol 2016; 33:321-334. [PMID: 28040374 DOI: 10.1016/j.pt.2016.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/17/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
Our current understanding of how malaria parasites remodel their host red blood cells (RBCs) and ultimately cause disease is largely based on studies of Plasmodium falciparum. In this review, we expand our knowledge to include what is currently known about pathophysiological changes to RBCs that are infected by non-falciparum malaria parasites. We highlight the potential folly of making generalizations about the rheology of malaria infection, and emphasize the need for more systematic studies into the erythrocytic biology of non-falciparum malaria parasites. We propose that a better understanding of the mechanisms that underlie the changes to RBCs induced by malaria parasites other than P. falciparum may be highly informative for the development of therapeutics that specifically disrupt the altered rheological profile of RBCs infected with either sexual- or asexual-stage parasites, resulting in drugs that block transmission, reduce disease severity, and help delay the onset of resistance to current and future anti-malaria drugs.
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185
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Malaria: Biology and Disease. Cell 2016; 167:610-624. [PMID: 27768886 DOI: 10.1016/j.cell.2016.07.055] [Citation(s) in RCA: 503] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/17/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.
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186
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Buitrago SP, Garzón-Ospina D, Patarroyo MA. Size polymorphism and low sequence diversity in the locus encoding the Plasmodium vivax rhoptry neck protein 4 (PvRON4) in Colombian isolates. Malar J 2016; 15:501. [PMID: 27756311 PMCID: PMC5069803 DOI: 10.1186/s12936-016-1563-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/07/2016] [Indexed: 11/12/2022] Open
Abstract
Background Designing a vaccine against Plasmodium vivax has focused on selecting antigens involved in invasion mechanisms that must have domains with low polymorphism for avoiding allele-specific immune responses. The rhoptry neck protein 4 (RON4) forms part of the tight junction, which is essential in the invasion of hepatocytes and/or erythrocytes; however, little is known about this locus’ genetic diversity. Methods DNA sequences from 73 Colombian clinical isolates from pvron4 gene were analysed for characterizing their genetic diversity; pvron4 haplotype number and distribution, as well as the evolutionary forces determining diversity pattern, were assessed by population genetics and molecular evolutionary approaches. Results ron4 has low genetic diversity in P. vivax at sequence level; however, a variable amount of tandem repeats at the N-terminal region leads to extensive size polymorphism. This region seems to be exposed to the immune system. The central region has a putative esterase/lipase domain which, like the protein’s C-terminal fragment, is highly conserved at intra- and inter-species level. Both regions are under purifying selection. Conclusions pvron4 is the locus having the lowest genetic diversity described to date for P. vivax. The repeat regions in the N-terminal region could be associated with immune evasion mechanisms while the central region and the C-terminal region seem to be under functional or structural constraint. Bearing such results in mind, the PvRON4 central and/or C-terminal portions represent promising candidates when designing a subunit-based vaccine as they are aimed at avoiding an allele-specific immune response, which might limit vaccine efficacy. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1563-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sindy P Buitrago
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá D.C., Colombia.,Microbiology Postgraduate Program, Universidad Nacional de Colombia, Bogotá D.C., Colombia
| | - Diego Garzón-Ospina
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá D.C., Colombia.,School of Medicine and Health Sciences, Universidad del Rosario, Bogotá D.C., Colombia
| | - Manuel A Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá D.C., Colombia. .,School of Medicine and Health Sciences, Universidad del Rosario, Bogotá D.C., Colombia.
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187
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Hierarchical phosphorylation of apical membrane antigen 1 is required for efficient red blood cell invasion by malaria parasites. Sci Rep 2016; 6:34479. [PMID: 27698395 PMCID: PMC5048298 DOI: 10.1038/srep34479] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/08/2016] [Indexed: 12/03/2022] Open
Abstract
Central to the pathogenesis of malaria is the proliferation of Plasmodium falciparum parasites within human erythrocytes. Parasites invade erythrocytes via a coordinated sequence of receptor-ligand interactions between the parasite and host cell. One key ligand, Apical Membrane Antigen 1 (AMA1), is a leading blood-stage vaccine and previous work indicates that phosphorylation of its cytoplasmic domain (CPD) is important to its function during invasion. Here we investigate the significance of each of the six available phospho-sites in the CPD. We confirm that the cyclic AMP/protein kinase A (PKA) signalling pathway elicits a phospho-priming step upon serine 610 (S610), which enables subsequent phosphorylation in vitro of a conserved, downstream threonine residue (T613) by glycogen synthase kinase 3 (GSK3). Both phosphorylation steps are required for AMA1 to function efficiently during invasion. This provides the first evidence that the functions of key invasion ligands of the malaria parasite are regulated by sequential phosphorylation steps.
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188
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Plasmodium vivax Reticulocyte Binding Proteins Are Key Targets of Naturally Acquired Immunity in Young Papua New Guinean Children. PLoS Negl Trop Dis 2016; 10:e0005014. [PMID: 27677183 PMCID: PMC5038947 DOI: 10.1371/journal.pntd.0005014] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/30/2016] [Indexed: 11/19/2022] Open
Abstract
Background Major gaps in our understanding of Plasmodium vivax biology and the acquisition of immunity to this parasite hinder vaccine development. P. vivax merozoites exclusively invade reticulocytes, making parasite proteins that mediate reticulocyte binding and/or invasion potential key vaccine or drug targets. While protein interactions that mediate invasion are still poorly understood, the P. vivax Reticulocyte-Binding Protein family (PvRBP) is thought to be involved in P. vivax restricted host-cell selectivity. Methodology/Principal findings We assessed the binding specificity of five members of the PvRBP family (PvRBP1a, PvRBP1b, PvRBP2a, PvRBP2b, PvRBP2-P2 and a non-binding fragment of PvRBP2c) to normocytes or reticulocytes. PvRBP2b was identified as the only reticulocyte-specific binder (P<0.001), whereas the others preferentially bound to normocytes (PvRBP1a/b P≤0.034), or showed comparable binding to both (PvRBP2a/2-P2, P = 0.38). Furthermore, we measured levels of total and IgG subclasses 1, 2, 3 and 4 to the six PvRBPs in a cohort of young Papua New Guinean children, and assessed their relationship with prospective risk of P. vivax malaria. Children had substantial, highly correlated (rho = 0.49–0.82, P<0.001) antibody levels to all six PvRBPs, with dominant IgG1 and IgG3 subclasses. Both total IgG (Incidence Rate Ratio [IRR] 0.63–0.73, P = 0.008–0.041) and IgG1 (IRR 0.56–0.69, P = 0.001–0.035) to PvRBP2b and PvRBP1a were strongly associated with reduced risk of vivax-malaria, independently of age and exposure. Conclusion/Significance These results demonstrate a diversity of erythrocyte-binding phenotypes of PvRBPs, indicating binding to both reticulocyte-specific and normocyte-specific ligands. Our findings provide further insights into the naturally acquired immunity to P. vivax and highlight the importance of PvRBP proteins as targets of naturally acquired humoral immunity. In-depth studies of the role of PvRBPs in P. vivax invasion and functional validation of the role of anti-PvRBP antibodies in clinical immunity against P. vivax are now required to confirm the potential of the reticulocyte-binding PvRBP2b and PvRBP1a as vaccine candidate antigens. In parallel with the tremendous reduction in malaria burden, Plasmodium vivax (Pv) is now the predominant malaria species in the Asia-Pacific and Americas. Pv can only invade young erythrocytes (reticulocytes) and this restriction is thought to involve the Reticulocyte-Binding Protein family (PvRBP). Given their predicted role, PvRBPs are potentially interesting vaccine targets. However, the acquisition of immunity to Pv in general (PvRBPs in particular) is poorly understood, hindering vaccine development. Here, we show that out of five PvRBPs, only one (PvRBP2b) binds exclusively to reticulocytes. Furthermore, we measured antibody levels to all six PvRBPs in a cohort of young Papua New Guinean children, assessing the relationship between antibodies to PvRBPs and risk of malaria disease. Both total and specific antibody subclass levels (IgG1 and IgG3) to the reticulocyte-specific binder PvRBP2b, and the non-specific binder PvRBP1a were strongly associated with lower risk of clinical disease. Our findings indicate a diversity of roles of PvRBPs in erythrocyte invasion and highlight their importance as targets of the naturally acquired immunity to Pv. Functional studies of the role of PvRBPs in reticulocyte invasion will be required to fully understand the potential of PvRBP1a and PvRBP2b as vaccine candidates.
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189
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Kobayashi K, Kato K. Evaluating the use of heparin for synchronization of in vitro culture of Plasmodium falciparum. Parasitol Int 2016; 65:549-551. [PMID: 27600143 DOI: 10.1016/j.parint.2016.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/01/2016] [Accepted: 09/02/2016] [Indexed: 11/25/2022]
Abstract
The malaria parasite Plasmodium falciparum infects human erythrocytes and reproduces asexually through an intraerythrocytic developmental cycle. In vitro culture of P. falciparum allows investigation of the parasite's blood-stage development, which spans approximately 48h from the time of invasion to the lysis of mature schizonts to release merozoites. To focus on a specific step in the developmental cycle, synchronization techniques are utilized. d-Sorbitol treatment and the Percoll-sorbitol method have been used; however, these techniques have limitations in terms of the degree of synchronization achieved, the amount of synchronized parasite acquired, convenience, reproducibility, and cost. Here, we evaluated an existing synchronization method involving heparin. Heparin reversibly inhibits erythrocyte invasion by P. falciparum merozoites. We confirm that parasite cultures can be inexpensively, reproducibly, and tightly synchronized by combining a sorbitol step to limit cultures to the ring stages and by adding and removing heparin to manipulate the window during which merozoites can invade erythrocytes.
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Affiliation(s)
- Kyousuke Kobayashi
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; Division of Host-Parasite Interaction, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Kentaro Kato
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Hokkaido 080-8555, Japan.
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190
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Teo A, Feng G, Brown GV, Beeson JG, Rogerson SJ. Functional Antibodies and Protection against Blood-stage Malaria. Trends Parasitol 2016; 32:887-898. [PMID: 27546781 DOI: 10.1016/j.pt.2016.07.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/09/2016] [Accepted: 07/14/2016] [Indexed: 01/06/2023]
Abstract
Numerous efforts to understand the functional roles of antibodies demonstrated that they can protect against malaria. However, it is unclear which antibody responses are the best correlates of immunity, and which antibody functions are most important in protection from disease. Understanding the role of antibodies in protection against malaria is crucial for antimalarial vaccine design. In this review, the specific functional properties of naturally acquired and vaccine-induced antibodies that correlate to protection from the blood stages of Plasmodium falciparum malaria are re-examined and the gaps in knowledge related to antibody function in malarial immunity are highlighted.
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Affiliation(s)
- Andrew Teo
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Australia
| | - Graham V Brown
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia; Victorian Infectious Diseases Service, Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - James G Beeson
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Stephen J Rogerson
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia; Victorian Infectious Diseases Service, Doherty Institute for Infection and Immunity, Melbourne, Australia.
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191
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Alam MS, Zeeshan M, Rathore S, Sharma YD. Multiple Plasmodium vivax proteins of Pv-fam-a family interact with human erythrocyte receptor Band 3 and have a role in red cell invasion. Biochem Biophys Res Commun 2016; 478:1211-6. [PMID: 27545606 DOI: 10.1016/j.bbrc.2016.08.096] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 08/17/2016] [Indexed: 01/16/2023]
Abstract
Elucidation of molecular mechanisms of receptor-ligand biology during host-parasite interaction helps in developing therapeutic targets. Several Pv-fam-a family proteins of Plasmodium vivax bind to host erythrocytes but their erythrocyte receptors remains to be explored. Here, we show that three merozoite proteins (PvTRAg36, PvATRAg74, and PvTRAg38) of this family interact with Band 3 on human erythrocytes through its three exofacial loops (loop 1, loop 3, and loop 6). These parasite proteins also interfered with the parasite growth in in-vitro, and the inhibition rate seems to be associated with their binding affinity to Band 3. This redundancy in receptor-ligand interaction could be one of the probable mechanism parasite utilizes to invade the host erythrocyte more efficiently.
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Affiliation(s)
- Mohd Shoeb Alam
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Mohammad Zeeshan
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Sumit Rathore
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Yagya D Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India.
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192
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Aniweh Y, Gao X, Gunalan K, Preiser PR. PfRH2b specific monoclonal antibodies inhibit merozoite invasion. Mol Microbiol 2016; 102:386-404. [DOI: 10.1111/mmi.13468] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Yaw Aniweh
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
| | - Xiaohong Gao
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
| | - Karthigayan Gunalan
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
| | - Peter R. Preiser
- Division of Molecular Genetics and Cell biology, School of Biological Sciences; Nanyang Technological University; 637551 Singapore
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193
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Baculovirus-expressed Plasmodium reichenowi EBA-140 merozoite ligand is host specific. Parasitol Int 2016; 65:708-714. [PMID: 27443851 DOI: 10.1016/j.parint.2016.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 07/14/2016] [Accepted: 07/15/2016] [Indexed: 12/23/2022]
Abstract
Plasmodium reichenowi, an ape malaria parasite is morphologically identical and genetically similar to Plasmodium falciparum, infects chimpanzees but not humans. Genomic studies revealed that all primate malaria parasites belong to Laverania subgenus. Laverania parasites exhibit strict host specificity, but the molecular mechanisms underlying these host restrictions remain unexplained. Plasmodium merozoites express multiple binding ligands that recognize specific receptors on erythrocytes, including micronemal proteins belonging to P. falciparum EBL family. It was shown that erythrocyte binding antigen-175 (EBA-175), erythrocyte binding ligand-1 (EBL-1), erythrocyte binding antigen-140 (EBA-140) recognize erythrocyte surface sialoglycoproteins - glycophorins A, B, C, respectively. EBA-140 merozoite ligand hijacks glycophorin C (GPC), a minor erythrocyte sialoglycoprotein, to invade the erythrocyte through an alternative invasion pathway. A homolog of P. falciparum EBA-140 protein was identified in P. reichenowi. The amino acid sequences of both EBA-140 ligands are very similar, especially in the conservative erythrocyte binding region (Region II). It has been suggested that evolutionary changes in the sequence of EBL proteins may be associated with Plasmodium host restriction. In this study we obtained, for the first time, the recombinant P. reichenowi EBA-140 ligand Region II using baculovirus expression vector system. We show that the ape EBA-140 Region II is host specific and binds to chimpanzee erythrocytes in the dose and sialic acid dependent manner. Further identification of the erythrocyte receptor for this ape ligand is of great interests, since it may reveal the molecular basis of host restriction of both P. reichenowi and its deadliest human counterpart, P. falciparum.
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194
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Essential Role of the PfRh5/PfRipr/CyRPA Complex during Plasmodium falciparum Invasion of Erythrocytes. Cell Host Microbe 2016; 20:60-71. [DOI: 10.1016/j.chom.2016.06.004] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 04/05/2016] [Accepted: 05/18/2016] [Indexed: 01/30/2023]
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195
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Absalon S, Robbins JA, Dvorin JD. An essential malaria protein defines the architecture of blood-stage and transmission-stage parasites. Nat Commun 2016; 7:11449. [PMID: 27121004 PMCID: PMC4853479 DOI: 10.1038/ncomms11449] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 03/29/2016] [Indexed: 11/30/2022] Open
Abstract
Blood-stage replication of the human malaria parasite Plasmodium falciparum occurs via schizogony, wherein daughter parasites are formed by a specialized cytokinesis known as segmentation. Here we identify a parasite protein, which we name P. falciparum Merozoite Organizing Protein (PfMOP), as essential for cytokinesis of blood-stage parasites. We show that, following PfMOP knockdown, parasites undergo incomplete segmentation resulting in a residual agglomerate of partially divided cells. While organelles develop normally, the structural scaffold of daughter parasites, the inner membrane complex (IMC), fails to form in this agglomerate causing flawed segmentation. In PfMOP-deficient gametocytes, the IMC formation defect causes maturation arrest with aberrant morphology and death. Our results provide insight into the mechanisms of replication and maturation of malaria parasites. Blood-stage malaria parasites replicate through a specialised type of cell division known as schizogony. Here, Absalon et al. identify a parasite protein that is essential during schizogony for cytokinesis and formation of the inner membrane complex, the structural scaffold of daughter parasites.
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Affiliation(s)
- Sabrina Absalon
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jonathan A Robbins
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Infectious Diseases, Massachusetts General Hospital/Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA
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196
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Li JP, Kusche-Gullberg M. Heparan Sulfate: Biosynthesis, Structure, and Function. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:215-73. [PMID: 27241222 DOI: 10.1016/bs.ircmb.2016.02.009] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Heparan sulfate (HS) proteoglycans (PGs) are ubiquitously expressed on cell surfaces and in the extracellular matrix of most animal tissues, having essential functions in development and homeostasis, as well as playing various roles in disease processes. The functions of HSPGs are mainly dependent on interactions between the HS-side chains with a variety of proteins including cytokines, growth factors, and their receptors. In a given HS polysaccharide, negatively charged sulfate and carboxylate groups are arranged in various types of domains, generated through strictly regulated biosynthetic reactions and with enormous potential for structural variability. The mode of HS-protein interactions is assessed through binding experiments using saccharides of defined composition in vitro, signaling assays in cell models where HS structures are manipulated, and targeted disruption of genes for biosynthetic enzymes in animals (mouse, zebrafish, Drosophila, and Caenorhabditis elegans) followed by phenotype analysis. Whereas some protein ligands appear to require strictly defined HS structure, others bind to variable saccharide domains without apparent dependence on distinct saccharide sequence. These findings raise intriguing questions concerning the functional significance of regulation in HS biosynthesis and the potential for development of therapeutics targeting HS-protein interactions.
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Affiliation(s)
- J-P Li
- Department of Medical Biochemistry and Microbiology, University of Uppsala, Uppsala, Sweden; SciLifeLab, University of Uppsala, Uppsala, Sweden.
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197
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Ahouidi AD, Amambua-Ngwa A, Awandare GA, Bei AK, Conway DJ, Diakite M, Duraisingh MT, Rayner JC, Zenonos ZA. Malaria Vaccine Development: Focusing Field Erythrocyte Invasion Studies on Phenotypic Diversity: The West African Merozoite Invasion Network (WAMIN). Trends Parasitol 2016; 32:274-283. [PMID: 26725306 PMCID: PMC7021314 DOI: 10.1016/j.pt.2015.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 12/14/2022]
Abstract
Erythrocyte invasion by Plasmodium falciparum merozoites is an essential step for parasite survival and proliferation. Invasion is mediated by multiple ligands, which could be promising vaccine targets. The usage and sequence of these ligands differs between parasites, yet most studies of them have been carried out in only a few laboratory-adapted lines. To understand the true extent of natural variation in invasion phenotypes and prioritize vaccine candidates on a relevant evidence base, we need to develop and apply standardized assays to large numbers of field isolates. The West African Merozoite Invasion Network (WAMIN) has been formed to meet these goals, expand training in Plasmodium phenotyping, and perform large-scale field phenotyping studies in order to prioritize blood stage vaccine candidates.
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Affiliation(s)
- Ambroise D Ahouidi
- Laboratory of Bacteriology and Virology, Le Dantec Hospital, Faculty of Medicine and Pharmacy, Cheikh Anta Diop University, Dakar, Senegal
| | | | - Gordon A Awandare
- West African Center for Cell Biology of Infectious Pathogens and Department of Biochemistry, Cell, and Molecular Biology, University of Ghana, Legon, Accra, Ghana
| | - Amy K Bei
- Laboratory of Bacteriology and Virology, Le Dantec Hospital, Faculty of Medicine and Pharmacy, Cheikh Anta Diop University, Dakar, Senegal; Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - David J Conway
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - Mahamadou Diakite
- Faculty of Medicine, Pharmacy, and Odontostomatology, University of Bamako, Bamako, Mali
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Julian C Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge CB10 1SA, UK.
| | - Zenon A Zenonos
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge CB10 1SA, UK
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198
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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: 5.8] [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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199
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Brochet M, Billker O. Calcium signalling in malaria parasites. Mol Microbiol 2016; 100:397-408. [PMID: 26748879 DOI: 10.1111/mmi.13324] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2016] [Indexed: 12/24/2022]
Abstract
Ca(2+) is a ubiquitous intracellular messenger in malaria parasites with important functions in asexual blood stages responsible for malaria symptoms, the preceding liver-stage infection and transmission through the mosquito. Intracellular messengers amplify signals by binding to effector molecules that trigger physiological changes. The characterisation of some Ca(2+) effector proteins has begun to provide insights into the vast range of biological processes controlled by Ca(2+) signalling in malaria parasites, including host cell egress and invasion, protein secretion, motility and cell cycle regulation. Despite the importance of Ca(2+) signalling during the life cycle of malaria parasites, little is known about Ca(2+) homeostasis. Recent findings highlighted that upstream of stage-specific Ca(2+) effectors is a conserved interplay between second messengers to control critical intracellular Ca(2+) signals throughout the life cycle. The identification of the molecular mechanisms integrating stage-transcending mechanisms of Ca(2+) homeostasis in a network of stage-specific regulator and effector pathways now represents a major challenge for a meaningful understanding of Ca(2+) signalling in malaria parasites.
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Affiliation(s)
- Mathieu Brochet
- Faculty of Medicine, Department of Microbiology and Molecular Medicine, University of Geneva, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland.,UMR5235 CNRS-Université Montpellier 2, 34095, Montpellier, France
| | - Oliver Billker
- Wellcome Trust Sanger Institute, Malaria Programme, CB10 1SA, Hinxton, UK
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200
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Satchwell TJ. Erythrocyte invasion receptors for Plasmodium falciparum: new and old. Transfus Med 2016; 26:77-88. [PMID: 26862042 DOI: 10.1111/tme.12280] [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: 10/28/2015] [Revised: 12/18/2015] [Accepted: 01/11/2016] [Indexed: 12/20/2022]
Abstract
Understanding the complex process by which the invasive form of the Plasmodium falciparum parasite, the merozoite, attaches to and invades erythrocytes as part of its blood stage life cycle represents a key area of research in the battle to combat malaria. Central to this are efforts to determine the identity of receptors on the host cell surface, their corresponding merozoite-binding proteins and the functional relevance of these binding events as part of the invasion process. This review will provide an updated summary of studies identifying receptor interactions essential for or implicated in P. falciparum merozoite invasion of human erythrocytes, highlighting the recent identification of new receptors using groundbreaking high throughput approaches and with particular focus on the properties and putative involvement of the erythrocyte proteins targeted by these invasion pathways.
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Affiliation(s)
- T J Satchwell
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, UK
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