1
|
Paul KMM, Simpson SV, Nundu SS, Arima H, Yamamoto T. Genetic diversity of glutamate-rich protein (GLURP) in Plasmodium falciparum isolates from school-age children in Kinshasa, DRC. Parasitol Int 2024; 100:102866. [PMID: 38350548 DOI: 10.1016/j.parint.2024.102866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/15/2024]
Abstract
Malaria infections in school-age children further make it difficult to control the disease's spread. Moreover, the genetic diversity of glutamate-rich protein, potentially a candidate for vaccine development, has not yet been investigated in the Democratic Republic of Congo. Therefore, we aimed to assess the genetic diversity of the immunodominant C-terminal repetitive region (R2) of Plasmodium falciparum glutamate-rich protein gene (pfglurp) among school-age children living in Kinshasa, DRC. We conducted nested PCR targeting R2 of pfglurp and the amplicon were directly sequenced. We summarized the prevalence of mutations of bases and amino acids and indicated the amino acid repeat sequence in the R2 region by the unit code. We then statistically analyzed whether there was a relationship between the number of mutations in the pfglurp gene and attributes. In 221 samples, haplotype 1 was the most common (n = 137, 61.99%), with the same sequence as the 3D7 strain. Regarding the number of base mutations, it was higher in urban areas than rural areas (p = 0.0363). When genetic neutrality was tested using data from 171 samples of the single strain, Tajima's D was -1.857 (p = 0.0059). In addition, FST as the genetic distance between all attributes was very small and no significant difference was observed. This study clarified the genetic mutation status and relevant patient attributes among School-age children in the DRC. We found that urban areas are more likely to harbour pfglurp mutations. Future research needs to clarify the reason and mechanism involved.
Collapse
Affiliation(s)
- Kambale Mathe Mowa Paul
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan; Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Nagasaki University, Nagasaki, Japan
| | - Shirley V Simpson
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan; Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Nagasaki University, Nagasaki, Japan
| | - Sabin S Nundu
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Hiroaki Arima
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
| | - Taro Yamamoto
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan; Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Nagasaki University, Nagasaki, Japan
| |
Collapse
|
2
|
Ogwang R, Murugu L, Nkumama IN, Nyamako L, Kai O, Mwai K, Murungi L, Idro R, Bejon P, Tuju J, Kinyanjui SM, Osier FHA. Bi-isotype immunoglobulins enhance antibody-mediated neutrophil activity against Plasmodium falciparum parasites. Front Immunol 2024; 15:1360220. [PMID: 38650925 PMCID: PMC11033408 DOI: 10.3389/fimmu.2024.1360220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Background Malaria remains a major global health priority, and monoclonal antibodies (mAbs) are emerging as potential new tools to support efforts to control the disease. Recent data suggest that Fc-dependent mechanisms of immunity are important mediators of protection against the blood stages of the infection, but few studies have investigated this in the context of mAbs. We aimed to isolate mAbs agnostic to cognate antigens that target whole merozoites and simultaneously induce potent neutrophil activity measured by the level of reactive oxygen species (ROS) production using an antibody-dependent respiratory burst (ADRB) assay. Methods We used samples from semi-immune adults living in coastal Kenya to isolate mAbs that induce merozoite-specific ADRB activity. We then tested whether modifying the expressed IgG1 isotype to an IgG-IgA Fc region chimera would enhance the level of ADRB activity. Results We isolated a panel of nine mAbs with specificity to whole merozoites. mAb J31 induced ADRB activity in a dose-dependent fashion. Compared to IgG1, our modified antibody IgG-IgA bi-isotype induced higher ADRB activity across all concentrations tested. Further, we observed a negative hook effect at high IgG1 mAb concentrations (i.e., >200 µg/mL), but this was reversed by Fc modification. We identified MSP3.5 as the potential cognate target of mAb J31. Conclusions We demonstrate an approach to engineer mAbs with enhanced ADRB potency against blood-stage parasites.
Collapse
Affiliation(s)
- Rodney Ogwang
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Lewis Murugu
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
| | - Irene N. Nkumama
- Centre of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Lydia Nyamako
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Oscar Kai
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kennedy Mwai
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Linda Murungi
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Richard Idro
- College of Health Sciences, Makerere University, Kampala, Uganda
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Philip Bejon
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - James Tuju
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
| | - Sam Muchina Kinyanjui
- Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Faith H. A. Osier
- Department of Life Sciences, Imperial College London, London, United Kingdom
| |
Collapse
|
3
|
Sheokand PK, Yamaryo-Botté Y, Narwal M, Arnold CS, Thakur V, Islam MM, Banday MM, Asad M, Botté CY, Mohmmed A. A Plasmodium falciparum lysophospholipase regulates host fatty acid flux via parasite lipid storage to enable controlled asexual schizogony. Cell Rep 2023; 42:112251. [PMID: 37015228 DOI: 10.1016/j.celrep.2023.112251] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 11/04/2022] [Accepted: 02/24/2023] [Indexed: 04/05/2023] Open
Abstract
Phospholipid metabolism is crucial for membrane biogenesis and homeostasis of Plasmodium falciparum. To generate such phospholipids, the parasite extensively scavenges, recycles, and reassembles host lipids. P. falciparum possesses an unusually large number of lysophospholipases, whose roles and importance remain to be elucidated. Here, we functionally characterize one P. falciparum lysophospholipase, PfLPL3, to reveal its key role in parasite propagation during asexual blood stages. PfLPL3 displays a dynamic localization throughout asexual stages, mainly localizing in the host-parasite interface. Inducible knockdown of PfLPL3 disrupts parasite development from trophozoites to schizont, inducing a drastic reduction in merozoite progenies. Detailed lipidomic analyses show that PfLPL3 generates fatty acids from scavenged host lipids to generate neutral lipids. These are then timely mobilized to allow schizogony and merozoite formation. We then identify inhibitors of PfLPL3 from Medicine for Malaria Venture (MMV) with potent antimalarial activity, which could also serve as pertinent chemical tools to study parasite lipid synthesis.
Collapse
Affiliation(s)
- Pradeep Kumar Sheokand
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India
| | - Yoshiki Yamaryo-Botté
- ApicoLipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Monika Narwal
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India
| | - Christophe-Sébastien Arnold
- ApicoLipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Vandana Thakur
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India
| | - Md Muzahidul Islam
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India
| | - Mudassir M Banday
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India
| | - Mohd Asad
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India
| | - Cyrille Y Botté
- ApicoLipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France.
| | - Asif Mohmmed
- International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India.
| |
Collapse
|
4
|
Recent advances on the piezoelectric, electrochemical, and optical biosensors for the detection of protozoan pathogens. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
5
|
Gupta P, Pandey R, Thakur V, Parveen S, Kaur I, Panda A, Bishi R, Mehrotra S, Akhtar A, Gupta D, Mohmmed A, Malhotra P. Heme Detoxification Protein ( PfHDP) is essential for the hemoglobin uptake and metabolism in Plasmodium falciparum. FASEB Bioadv 2022; 4:662-674. [PMID: 36238365 PMCID: PMC9536087 DOI: 10.1096/fba.2022-00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 06/15/2022] [Accepted: 06/22/2022] [Indexed: 11/11/2022] Open
Abstract
Hemoglobin degradation is crucial for the growth and survival of Plasmodium falciparum in human erythrocytes. Although the process of Hb degradation has been studied in detail, the mechanisms of Hb uptake remain ambiguous to date. Here, we characterized Heme Detoxification Protein (PfHDP); a protein localized in the parasitophorus vacuole, parasite food vacuole, and infected erythrocyte cytosol for its role in Hb uptake. Immunoprecipitation of PfHDP-GFP fusion protein from a transgenic line using GFP trap beads showed the association of PfHDP with Hb as well as with the members of PTEX translocon complex. Association of PfHDP with Hb or Pfexp-2, a component of translocon complex was confirmed by protein-protein interaction and immunolocalization tools. Based on these associations, we studied the role of PfHDP in Hb uptake using the PfHDP-HA-GlmS transgenic parasites line. PfHDP knockdown significantly reduced the Hb uptake in these transgenic parasites in comparison to the wild-type parasites. Morphological analysis of PfHDP-HA-GlmS transgenic parasites in the presence of GlcN showed food vacuole abnormalities and parasite stress, thereby causing a growth defect in the development of these parasites. Transient knockdown of a member of translocon complex, PfHSP101 in HSP101-DDDHA parasites also showed a decreased uptake of Hb inside the parasite. Together, these results advocate an interaction between PfHDP and the translocon complex at the parasitophorus vacuole membrane and also suggest a role for PfHDP in the uptake of Hb and parasite development. The study thus reveals new insights into the function of PfHDP, making it an extremely important target for developing new antimalarials.
Collapse
Affiliation(s)
- Priya Gupta
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Rajan Pandey
- Translational Bioinformatics GroupInternational Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Vandana Thakur
- Parasite Cell Biology GroupInternational Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Sadaf Parveen
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Inderjeet Kaur
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Ashutosh Panda
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Rashmita Bishi
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Sonali Mehrotra
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Asif Akhtar
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Dinesh Gupta
- Translational Bioinformatics GroupInternational Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Asif Mohmmed
- Parasite Cell Biology GroupInternational Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| | - Pawan Malhotra
- Malaria Biology Group, International Centre for Genetic Engineering and BiotechnologyNew DelhiIndia
| |
Collapse
|
6
|
ABO blood group and risk of malaria during pregnancy: a systematic review and meta-analysis. Epidemiol Infect 2022; 150:e25. [PMID: 35193716 PMCID: PMC8888275 DOI: 10.1017/s095026882200005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The association between the ABO blood group and the risk of malaria during pregnancy has not been clearly established. The present study summarised relevant knowledge and reassessed the association through meta-analysis. Articles in MEDICINE and PubMed published before 30 November 2021 were searched. Five studies satisfied the inclusion criteria and were enrolled in the meta-analysis. It was shown that primiparae with different ABO blood group, multiparae with blood group A and non-A, AB and non-AB had a comparable risk of malaria. However, multiparae with blood group B had a significantly higher risk than non-B group [odds ratio (OR) = 1.23, 95% confidence interval (CI) was 1.01 to 1.50, P = 0.04], while multiparae with blood group O had a significantly lower risk than non-O group (OR = 0.78, 95% CI was 0.63 to 0.97, P = 0.03). Therefore, the ABO blood group may not result in a different risk of malaria in primiparae. Blood group B is potentially a risk factor while blood group O is a protective factor for multiparae.
Collapse
|
7
|
Asad M, Yamaryo-Botté Y, Hossain ME, Thakur V, Jain S, Datta G, Botté CY, Mohmmed A. An essential vesicular-trafficking phospholipase mediates neutral lipid synthesis and contributes to hemozoin formation in Plasmodium falciparum. BMC Biol 2021; 19:159. [PMID: 34380472 PMCID: PMC8359613 DOI: 10.1186/s12915-021-01042-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/30/2021] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium falciparum is the pathogen responsible for the most devastating form of human malaria. As it replicates asexually in the erythrocytes of its human host, the parasite feeds on haemoglobin uptaken from these cells. Heme, a toxic by-product of haemoglobin utilization by the parasite, is neutralized into inert hemozoin in the food vacuole of the parasite. Lipid homeostasis and phospholipid metabolism are crucial for this process, as well as for the parasite’s survival and propagation within the host. P. falciparum harbours a uniquely large family of phospholipases, which are suggested to play key roles in lipid metabolism and utilization. Results Here, we show that one of the parasite phospholipase (P. falciparum lysophospholipase, PfLPL1) plays an essential role in lipid homeostasis linked with the haemoglobin degradation and heme conversion pathway. Fluorescence tagging showed that the PfLPL1 in infected blood cells localizes to dynamic vesicular structures that traffic from the host-parasite interface at the parasite periphery, through the cytosol, to get incorporated into a large vesicular lipid rich body next to the food-vacuole. PfLPL1 is shown to harbour enzymatic activity to catabolize phospholipids, and its transient downregulation in the parasite caused a significant reduction of neutral lipids in the food vacuole-associated lipid bodies. This hindered the conversion of heme, originating from host haemoglobin, into the hemozoin, and disrupted the parasite development cycle and parasite growth. Detailed lipidomic analyses of inducible knock-down parasites deciphered the functional role of PfLPL1 in generation of neutral lipid through recycling of phospholipids. Further, exogenous fatty-acids were able to complement downregulation of PfLPL1 to rescue the parasite growth as well as restore hemozoin levels. Conclusions We found that the transient downregulation of PfLPL1 in the parasite disrupted lipid homeostasis and caused a reduction in neutral lipids essentially required for heme to hemozoin conversion. Our study suggests a crucial link between phospholipid catabolism and generation of neutral lipids (TAGs) with the host haemoglobin degradation pathway. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01042-z.
Collapse
Affiliation(s)
- Mohd Asad
- International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India
| | - Yoshiki Yamaryo-Botté
- ApicoLipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Mohammad E Hossain
- International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India
| | - Vandana Thakur
- International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India
| | - Shaifali Jain
- International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India
| | - Gaurav Datta
- International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India
| | - Cyrille Y Botté
- ApicoLipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Asif Mohmmed
- International Centre for Genetic Engineering and Biotechnology, New Delhi, 110 067, India.
| |
Collapse
|
8
|
Plasmodium falciparum Clag9-Associated PfRhopH Complex Is Involved in Merozoite Binding to Human Erythrocytes. Infect Immun 2020; 88:IAI.00504-19. [PMID: 31712270 DOI: 10.1128/iai.00504-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/01/2019] [Indexed: 02/05/2023] Open
Abstract
Cytoadherence-linked asexual gene 9 (Clag9), a conserved Plasmodium protein expressed during the asexual blood stages, is involved in the cytoadherence of infected red blood cells (RBCs) to the endothelial lining of blood vessels. Here, we show that Plasmodium falciparum Clag9 (PfClag9) is a component of the PfClag9-RhopH complex that is involved in merozoite binding to human erythrocytes. To characterize PfClag9, we expressed four fragments of PfClag9, encompassing the entire protein. Immunostaining analysis using anti-PfClag9 antibodies showed expression and localization of PfClag9 at the apical end of the merozoites. Mass spectrometric analysis of merozoite extracts after immunoprecipitation using anti-PfClag9 antibody identified P. falciparum rhoptry-associated protein 1 (PfRAP1), PfRAP2, PfRAP3, PfRhopH2, and PfRhopH3 as associated proteins. The identified rhoptry proteins were expressed, and their association with PfClag9 domains was assessed by using protein-protein interaction tools. We further showed that PfClag9 binds human RBCs by interacting with the glycophorin A-band 3 receptor-coreceptor complex. In agreement with its cellular localization, PfClag9 was strongly recognized by antibodies generated during natural infection. Mice immunized with the C-terminal domain of PfClag9 were partially protected against a subsequent challenge infection with Plasmodium berghei, further supporting a biological role of PfClag9 during natural infection. Taken together, these results provide direct evidence for the existence of a PfRhopH-Clag9 complex on the Plasmodium merozoite surface that binds to human RBCs.
Collapse
|
9
|
Plasmodium falciparum MSP3 Exists in a Complex on the Merozoite Surface and Generates Antibody Response during Natural Infection. Infect Immun 2018; 86:IAI.00067-18. [PMID: 29760216 DOI: 10.1128/iai.00067-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022] Open
Abstract
Plasmodium falciparum merozoite surface protein 3 (MSP3) is an abundantly expressed secreted merozoite surface protein and a leading malaria vaccine candidate antigen. However, it is unclear how MSP3 is retained on the surface of merozoites without a glycosylphosphatidylinositol (GPI) anchor or a transmembrane domain. In the present study, we identified an MSP3-associated network on the Plasmodium merozoite surface by immunoprecipitation of Plasmodium merozoite lysate using antibody to the N terminus of MSP3 (anti-MSP3N) followed by mass spectrometry analysis. The results suggested the association of MSP3 with other merozoite surface proteins: MSP1, MSP6, MSP7, RAP2, and SERA5. Protein-protein interaction studies by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) analysis showed that MSP3 complex consists of MSP1, MSP6, and MSP7 proteins. Immunological characterization of MSP3 revealed that MSP3N is strongly recognized by hyperimmune serum from African and Asian populations. Furthermore, we demonstrate that human antibodies, affinity purified against recombinant MSP3N (rMSP3N), promote opsonic phagocytosis of merozoites in cooperation with monocytes. At nonphysiological concentrations, anti-MSP3N antibodies inhibited the growth of P. falciparum in vitro Together, the data suggest that MSP3 and especially its N-terminal region containing known B/T cell epitopes are targets of naturally acquired immunity against malaria and also comprise an important candidate for a multisubunit malaria vaccine.
Collapse
|
10
|
Protein-protein interaction studies reveal the Plasmodium falciparum merozoite surface protein-1 region involved in a complex formation that binds to human erythrocytes. Biochem J 2018; 475:1197-1209. [PMID: 29511044 DOI: 10.1042/bcj20180017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/23/2018] [Accepted: 03/05/2018] [Indexed: 11/17/2022]
Abstract
Plasmodium falciparum merozoite surface protein (PfMSP) 1 has been studied extensively as a vaccine candidate antigen. PfMSP-1 undergoes proteolytic processing into four major products, such as p83, p30, p38, and p42, that are associated in the form of non-covalent complex(s) with other MSPs. To delineate MSP1 regions involved in the interaction with other MSPs, here we expressed recombinant proteins (PfMSP-165) encompassing part of p38 and p42 regions and PfMSP-119 PfMSP-165 interacted strongly with PfMSP-3, PfMSP-6, PfMSP-7, and PfMSP-9, whereas PfMSP-119 did not interact with any of these proteins. Since MSP-1 complex binds human erythrocytes, we examined the ability of these proteins to bind human erythrocyte. Among the proteins of MSP-1 complex, PfMSP-6 and PfMSP-9 bound to human erythrocytes. Serological studies showed that PfMSP-165 was frequently recognized by sera from malaria endemic regions, whereas this was not the case for PfMSP-119 In contrast, antibodies against PfMSP-119 showed much higher inhibition of merozoite invasion compared with antibodies against the larger PfMSP-165 fragment. Importantly, anti-PfMSP-119 antibodies recognized both recombinant proteins, PfMSP-119 and PfMSP-165; however, anti-PfMSP-165 antibody failed to recognize the PfMSP-119 protein. Taken together, these results demonstrate that PfMSP-1 sequences upstream of the 19 kDa C-terminal region are involved in molecular interactions with other MSPs, and these sequences may probably serve as a smoke screen to evade antibody response to the membrane-bound C-terminal 19 kDa region.
Collapse
|
11
|
Pattaradilokrat S, Trakoolsoontorn C, Simpalipan P, Warrit N, Kaewthamasorn M, Harnyuttanakorn P. Size and sequence polymorphisms in the glutamate-rich protein gene of the human malaria parasite Plasmodium falciparum in Thailand. Parasit Vectors 2018; 11:49. [PMID: 29357909 PMCID: PMC5778735 DOI: 10.1186/s13071-018-2630-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/08/2018] [Indexed: 11/10/2022] Open
Abstract
Background The glutamate-rich protein (GLURP) of the malaria parasite Plasmodium falciparum is a key surface antigen that serves as a component of a clinical vaccine. Moreover, the GLURP gene is also employed routinely as a genetic marker for malarial genotyping in epidemiological studies. While extensive size polymorphisms in GLURP are well recorded, the extent of the sequence diversity of this gene is rarely investigated. The present study aimed to explore the genetic diversity of GLURP in natural populations of P. falciparum. Results The polymorphic C-terminal repetitive R2 region of GLURP sequences from 65 P. falciparum isolates in Thailand were generated and combined with the data from 103 worldwide isolates to generate a GLURP database. The collection was comprised of 168 alleles, encoding 105 unique GLURP subtypes, characterized by 18 types of amino acid repeat units (AAU). Of these, 28 GLURP subtypes, formed by 10 AAU types, were detected in P. falciparum in Thailand. Among them, 19 GLURP subtypes and 2 AAU types are described for the first time in the Thai parasite population. The AAU sequences were highly conserved, which is likely due to negative selection. Standard Fst analysis revealed the shared distributions of GLURP types among the P. falciparum populations, providing evidence of gene flow among the different demographic populations. Conclusions Sequence diversity causing size variations in GLURP in Thai P. falciparum populations were detected, and caused by non-synonymous substitutions in repeat units and some insertion/deletion of aspartic acid or glutamic acid codons between repeat units. The P. falciparum population structure based on GLURP showed promising implications for the development of GLURP-based vaccines and for monitoring vaccine efficacy. Electronic supplementary material The online version of this article (doi: 10.1186/s13071-018-2630-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sittiporn Pattaradilokrat
- Department of Biology, Faculty of Science, Chualongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand. .,Veterinary Parasitology Research Group, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
| | - Chawinya Trakoolsoontorn
- Department of Biology, Faculty of Science, Chualongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand
| | - Phumin Simpalipan
- Department of Biology, Faculty of Science, Chualongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand
| | - Natapot Warrit
- Department of Biology, Faculty of Science, Chualongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand
| | - Morakot Kaewthamasorn
- Veterinary Parasitology Research Group, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Pongchai Harnyuttanakorn
- Department of Biology, Faculty of Science, Chualongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand
| |
Collapse
|
12
|
Theisen M, Adu B, Mordmüller B, Singh S. The GMZ2 malaria vaccine: from concept to efficacy in humans. Expert Rev Vaccines 2017; 16:907-917. [PMID: 28699823 DOI: 10.1080/14760584.2017.1355246] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION GMZ2 is a recombinant protein consisting of conserved domains of GLURP and MSP3, two asexual blood-stage antigens of Plasmodium falciparum, and is designed with the aim of mimicking naturally acquired anti-malarial immunity. The rationale for combining these two antigens is based on a series of immune epidemiological studies from geographically diverse malaria endemic regions; functional in vitro studies; and pre-clinical studies in rodents and New World monkeys. GMZ2 adjuvanted with alhydrogel® (alum) was well tolerated and immunogenic in three phase 1 studies. The recently concluded phase 2 trial of GMZ2/alum, involving 1849 participants 12 to 60 month of age in four countries in West, Central and Eastern Africa, showed that GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects for clinical development of GMZ2 sub-unit vaccine. We will focus on discovery, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production, pre-clinical and clinical studies. Expert commentary: GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. More immunogenic formulations should be developed.
Collapse
Affiliation(s)
- Michael Theisen
- a Department for Congenital Disorders , Statens Serum Institut , Copenhagen , Denmark.,b Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology , University of Copenhagen , Copenhagen , Denmark.,c Department of Infectious Diseases , Copenhagen University Hospital , Rigshospitalet , Denmark
| | - Bright Adu
- d Noguchi Memorial Institute for Medical Research , University of Ghana , Legon , Ghana
| | - Benjamin Mordmüller
- e Institute of Tropical Medicine and Center for Infection Research, partner site Tübingen , University of Tübingen , Tübingen , Germany
| | - Subhash Singh
- f Indian Institute of Integrative Medicine , Jammu , India
| |
Collapse
|