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Sassmannshausen J, Bennink S, Distler U, Küchenhoff J, Minns AM, Lindner SE, Burda PC, Tenzer S, Gilberger TW, Pradel G. Comparative proteomics of vesicles essential for the egress of Plasmodium falciparum gametocytes from red blood cells. Mol Microbiol 2024; 121:431-452. [PMID: 37492994 DOI: 10.1111/mmi.15125] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/27/2023]
Abstract
Transmission of malaria parasites to the mosquito is mediated by sexual precursor cells, the gametocytes. Upon entering the mosquito midgut, the gametocytes egress from the enveloping erythrocyte while passing through gametogenesis. Egress follows an inside-out mode during which the membrane of the parasitophorous vacuole (PV) ruptures prior to the erythrocyte membrane. Membrane rupture requires exocytosis of specialized egress vesicles of the parasites; that is, osmiophilic bodies (OBs) involved in rupturing the PV membrane, and vesicles that harbor the perforin-like protein PPLP2 (here termed P-EVs) required for erythrocyte lysis. While some OB proteins have been identified, like G377 and MDV1/Peg3, the majority of egress vesicle-resident proteins is yet unknown. Here, we used high-resolution imaging and BioID methods to study the two egress vesicle types in Plasmodium falciparum gametocytes. We show that OB exocytosis precedes discharge of the P-EVs and that exocytosis of the P-EVs, but not of the OBs, is calcium sensitive. Both vesicle types exhibit distinct proteomes with the majority of proteins located in the OBs. In addition to known egress-related proteins, we identified novel components of OBs and P-EVs, including vesicle-trafficking proteins. Our data provide insight into the immense molecular machinery required for the inside-out egress of P. falciparum gametocytes.
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Affiliation(s)
- Juliane Sassmannshausen
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Ute Distler
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Juliane Küchenhoff
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Allen M Minns
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Scott E Lindner
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Stefan Tenzer
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
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Kundu P, Naskar D, McKie SJ, Dass S, Kanjee U, Introini V, Ferreira MU, Cicuta P, Duraisingh M, Deane JE, Rayner JC. The structure of a Plasmodium vivax Tryptophan Rich Antigen domain suggests a lipid binding function for a pan-Plasmodium multi-gene family. Nat Commun 2023; 14:5703. [PMID: 37709739 PMCID: PMC10502043 DOI: 10.1038/s41467-023-40885-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 08/10/2023] [Indexed: 09/16/2023] Open
Abstract
Tryptophan Rich Antigens (TRAgs) are encoded by a multi-gene family found in all Plasmodium species, but are significantly expanded in P. vivax and closely related parasites. We show that multiple P. vivax TRAgs are expressed on the merozoite surface and that one, PVP01_0000100 binds red blood cells with a strong preference for reticulocytes. Using X-ray crystallography, we solved the structure of the PVP01_0000100 C-terminal tryptophan rich domain, which defines the TRAg family, revealing a three-helical bundle that is conserved across Plasmodium and has structural homology with lipid-binding BAR domains involved in membrane remodelling. Biochemical assays confirm that the PVP01_0000100 C-terminal domain has lipid binding activity with preference for sulfatide, a glycosphingolipid present in the outer leaflet of plasma membranes. Deletion of the putative orthologue in P. knowlesi, PKNH_1300500, impacts invasion in reticulocytes, suggesting a role during this essential process. Together, this work defines an emerging molecular function for the Plasmodium TRAg family.
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Affiliation(s)
- Prasun Kundu
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Deboki Naskar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Shannon J McKie
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Sheena Dass
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Viola Introini
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- Global Health and Tropical Medicine, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Lisbon, Portugal
| | - Pietro Cicuta
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK
| | - Manoj Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Janet E Deane
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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3
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Fan L, Xia J, Shen J, Fang Q, Xia H, Zheng M, Han JH, Han ET, Wang B, Xu Y. An Erythrocyte Membrane-Associated Antigen, PvTRAg-26 of Plasmodium vivax: A Study of Its Antigenicity and Immunogenicity. Front Public Health 2020; 8:148. [PMID: 32411650 PMCID: PMC7198802 DOI: 10.3389/fpubh.2020.00148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/09/2020] [Indexed: 11/17/2022] Open
Abstract
Background:Plasmodium tryptophan-rich (TR) proteins have been proposed as potential vaccine candidate antigens. Among them, P. vivax tryptophan-rich antigens (PvTR-Ags), which have positionally conserved tryptophan residues in a TR domain, are highly antigenic in humans. Several of these antigens, including PvTRAg-26, have exhibited erythrocyte-binding activities. Methods: Subclasses of IgG antibodies against PvTRAg-26 were detected by enzyme-linked immunosorbent assay in 35 P. vivax infected patients and mice immunized with the recombinant antigen to characterize its antigenicity and immunogenicity. Moreover, the antigen-specific immune responses and Th1/Th2-type cytokine patterns of splenocytes from the immunized animals were determined in vitro. The subcellular localization of PvTRAg-26 in ring-stage parasites was also detected by indirect immunofluorescence assay. Results: The IgG1 and IgG3 levels in P. vivax-infected patients were significantly higher than those in uninfected individuals. In the PvTRAg-26-immunized mice, elevated levels of antigen-specific IgG antibodies were observed, dominated by the IgG1 subclass, and Th1-type cytokines were remarkably increased compared with Th2-type cytokines. Additionally, the subcellular location of the PvTRAg-26 protein was closely associated with the caveola-vesicle complex on the infected-erythrocyte membrane in the early ring stage of P. vivax. Conclusions: PvTRAg-26, a P. vivax TR antigen, with high antigenicity and immunogenicity, induces Th1-cytokine response and increases production of IgG1 antibodies. This immune profiling study provided a substantial evidence that PvTRAg-26 may be a potential candidate for P. vivax vaccine development.
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Affiliation(s)
- Liping Fan
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Anhui, China
| | - Jinxing Xia
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Anhui, China
| | - Jilong Shen
- The Key Laboratories of Parasitology and Zoonoses Anhui and Department of Parasitology, Anhui Medical University, Anhui, China
| | - Qiang Fang
- Department of Microbiology and Parasitology, Bengbu Medical College, Anhui, China.,Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, China
| | - Hui Xia
- Department of Microbiology and Parasitology, Bengbu Medical College, Anhui, China.,Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, China
| | - Meijuan Zheng
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Anhui, China
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Bo Wang
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Anhui, China
| | - Yuanhong Xu
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Anhui, China
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4
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Tarr SJ, Díaz-Ingelmo O, Stewart LB, Hocking SE, Murray L, Duffy CW, Otto TD, Chappell L, Rayner JC, Awandare GA, Conway DJ. Schizont transcriptome variation among clinical isolates and laboratory-adapted clones of the malaria parasite Plasmodium falciparum. BMC Genomics 2018; 19:894. [PMID: 30526479 PMCID: PMC6288915 DOI: 10.1186/s12864-018-5257-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/16/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria parasites are genetically polymorphic and phenotypically plastic. In studying transcriptome variation among parasites from different infections, it is challenging to overcome potentially confounding technical and biological variation between samples. We investigate variation in the major human parasite Plasmodium falciparum, generating RNA-seq data on multiple independent replicate sample preparations of merozoite-containing intra-erythrocytic schizonts from a panel of clinical isolates and from long-term laboratory-adapted clones, with a goal of robustly identifying differentially expressed genes. RESULTS Analysis of biological sample replicates shows that increased numbers improve the true discovery rate of differentially expressed genes, and that six independent replicates of each parasite line allowed identification of most differences that could be detected with larger numbers. For highly expressed genes, focusing on the top quartile at schizont stages, there was more power to detect differences. Comparing cultured clinical isolates and laboratory-adapted clones, genes more highly expressed in the laboratory-adapted clones include those encoding an AP2 transcription factor (PF3D7_0420300), a ubiquitin-binding protein and two putative methyl transferases. In contrast, higher expression in clinical isolates was seen for the merozoite surface protein gene dblmsp2, proposed to be a marker of schizonts forming merozoites committed to sexual differentiation. Variable expression was extremely strongly, but not exclusively, associated with genes known to be targeted by Heterochromatin Protein 1. Clinical isolates show variable expression of several known merozoite invasion ligands, as well as other genes for which new RT-qPCR assays validate the quantitation and allow characterisation in samples with more limited material. Expression levels of these genes vary among schizont preparations of different clinical isolates in the first ex vivo cycle in patient erythrocytes, but mean levels are similar to those in continuously cultured clinical isolates. CONCLUSIONS Analysis of multiple biological sample replicates greatly improves identification of genes variably expressed between different cultured parasite lines. Clinical isolates recently established in culture show differences from long-term adapted clones in transcript levels of particular genes, and are suitable for analyses requiring biological replicates to understand parasite phenotypes and variable expression likely to be relevant in nature.
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Affiliation(s)
- Sarah J Tarr
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK.
| | - Ofelia Díaz-Ingelmo
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Lindsay B Stewart
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Suzanne E Hocking
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Lee Murray
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Craig W Duffy
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Thomas D Otto
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Scotland, UK.,Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - Lia Chappell
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | | | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Ghana
| | - David J Conway
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, UK.
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5
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Alam MS, Zeeshan M, Mittra P, Choudhary V, Sharma YD. Receptor specific binding regions of Plasmodium vivax tryptophan rich antigens and parasite growth inhibition activity of PvTRAg35.2. Microbes Infect 2016; 18:550-8. [PMID: 27235199 DOI: 10.1016/j.micinf.2016.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/18/2016] [Accepted: 04/28/2016] [Indexed: 01/21/2023]
Abstract
Plasmodium tryptophan rich proteins play important role in host-parasite interaction. Earlier, we have described that one of the merozoite expressed Plasmodium vivax tryptophan-rich antigen PvTRAg35.2 binds to the host erythrocytes, have conserved sequences in parasite population, and generates humoral as well as cellular immune responses in humans during this parasitic infection. Here, we show that PvTRAg35.2 interferes with the parasite growth in a heterologous Plasmodium falciparum culture system. This probably suggests the recognition of the common erythrocyte receptor(s) by certain merozoite ligands of these two parasite species. We have mapped the erythrocyte binding activity of PvTRAg35.2 to its two different regions positioned at amino acid residues 155-190 and 263-283. Binding of these peptide domains to the erythrocytes was inhibited by anti-PvTRAg35.2 antibodies either raised in rabbit or produced by the P. vivax patients. The cross-competition between peptides of PvTRAg35.2 and PvTRAg33.5 or PvTRAg38 during erythrocyte binding assay suggested sharing of host cell receptors by these PvTRAgs. Further studies on these receptor-ligand interactions may lead to the development of therapeutic agents for P. vivax malaria.
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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
| | - Pooja Mittra
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Vandana Choudhary
- 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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6
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Tyagi K, Hossain ME, Thakur V, Aggarwal P, Malhotra P, Mohmmed A, Sharma YD. Plasmodium vivax Tryptophan Rich Antigen PvTRAg36.6 Interacts with PvETRAMP and PvTRAg56.6 Interacts with PvMSP7 during Erythrocytic Stages of the Parasite. PLoS One 2016; 11:e0151065. [PMID: 26954579 PMCID: PMC4783080 DOI: 10.1371/journal.pone.0151065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/09/2016] [Indexed: 01/09/2023] Open
Abstract
Plasmodium vivax is most wide spread and a neglected malaria parasite. There is a lack of information on parasite biology of this species. Genome of this parasite encodes for the largest number of tryptophan-rich proteins belonging to ‘Pv-fam-a’ family and some of them are potential drug/vaccine targets but their functional role(s) largely remains unexplored. Using bacterial and yeast two hybrid systems, we have identified the interacting partners for two of the P. vivax tryptophan-rich antigens called PvTRAg36.6 and PvTRAg56.2. The PvTRAg36.6 interacts with early transcribed membrane protein (ETRAMP) of P.vivax. It is apically localized in merozoites but in early stages it is seen in parasite periphery suggesting its likely involvement in parasitophorous vacuole membrane (PVM) development or maintenance. On the other hand, PvTRAg56.2 interacts with P.vivax merozoite surface protein7 (PvMSP7) and is localized on merozoite surface. Co-localization of PvTRAg56.2 with PvMSP1 and its molecular interaction with PvMSP7 probably suggest that, PvTRAg56.2 is part of MSP-complex, and might assist or stabilize the protein complex at the merozoite surface. In conclusion, the PvTRAg proteins have different sub cellular localizations and specific associated functions during intra-erythrocytic developmental cycle.
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Affiliation(s)
- Kriti Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Mohammad Enayet Hossain
- Malaria group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Vandana Thakur
- Malaria group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Praveen Aggarwal
- Department of Emergency Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Pawan Malhotra
- Malaria group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Asif Mohmmed
- Malaria group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- * E-mail: (YDS); (AM)
| | - Yagya Dutta Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
- * E-mail: (YDS); (AM)
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7
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Alam MS, Rathore S, Tyagi RK, Sharma YD. Host-parasite interaction: multiple sites in the Plasmodium vivax tryptophan-rich antigen PvTRAg38 interact with the erythrocyte receptor band 3. FEBS Lett 2016; 590:232-41. [PMID: 26823170 PMCID: PMC7163959 DOI: 10.1002/1873-3468.12053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/03/2015] [Accepted: 01/01/2016] [Indexed: 12/25/2022]
Abstract
Tryptophan‐rich antigens of malarial parasites interact with host molecules and play an important role in parasite survival. Merozoite expressed Plasmodium vivax tryptophan‐rich antigen PvTRAg38 binds to human erythrocytes and facilitates parasite growth in a heterlologous Plasmodium falciparum culture system. Recently, we identified band 3 in human erythrocytes as one of its receptors, although the receptor‐ligand binding mechanisms remain unknown. In the present study, using synthetic mutated peptides of PvTRAg38, we show that multiple amino acid residues of its 12 amino acid domain (KWVQWKNDKIRS) at position 197–208 interact with three different ectodomains of band 3 receptor on human erythrocytes. Our findings may help in the design of new therapeutic approaches for malaria.
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Affiliation(s)
- Mohd S Alam
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Sumit Rathore
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Rupesh K Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Yagya D Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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8
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Tyagi K, Gupta D, Saini E, Choudhary S, Jamwal A, Alam MS, Zeeshan M, Tyagi RK, Sharma YD. Recognition of Human Erythrocyte Receptors by the Tryptophan-Rich Antigens of Monkey Malaria Parasite Plasmodium knowlesi. PLoS One 2015; 10:e0138691. [PMID: 26393350 PMCID: PMC4579084 DOI: 10.1371/journal.pone.0138691] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 09/02/2015] [Indexed: 11/18/2022] Open
Abstract
Background The monkey malaria parasite Plasmodium knowlesi also infect humans. There is a lack of information on the molecular mechanisms that take place between this simian parasite and its heterologous human host erythrocytes leading to this zoonotic disease. Therefore, we investigated here the binding ability of P. knowlesi tryptophan-rich antigens (PkTRAgs) to the human erythrocytes and sharing of the erythrocyte receptors between them as well as with other commonly occurring human malaria parasites. Methods Six PkTRAgs were cloned and expressed in E.coli as well as in mammalian CHO-K1 cell to determine their human erythrocyte binding activity by cell-ELISA, and in-vitro rosetting assay, respectively. Results Three of six PkTRAgs (PkTRAg38.3, PkTRAg40.1, and PkTRAg67.1) showed binding to human erythrocytes. Two of them (PkTRAg40.1 and PkTRAg38.3) showed cross-competition with each other as well as with the previously described P.vivax tryptophan-rich antigens (PvTRAgs) for human erythrocyte receptors. However, the third protein (PkTRAg67.1) utilized the additional but different human erythrocyte receptor(s) as it did not cross-compete for erythrocyte binding with either of these two PkTRAgs as well as with any of the PvTRAgs. These three PkTRAgs also inhibited the P.falciparum parasite growth in in-vitro culture, further indicating the sharing of human erythrocyte receptors by these parasite species and the biological significance of this receptor-ligand interaction between heterologous host and simian parasite. Conclusions Recognition and sharing of human erythrocyte receptor(s) by PkTRAgs with human parasite ligands could be part of the strategy adopted by the monkey malaria parasite to establish inside the heterologous human host.
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Affiliation(s)
- Kriti Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Deepali Gupta
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Ekta Saini
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Shilpa Choudhary
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Abhishek Jamwal
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Mohd. Shoeb Alam
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Mohammad Zeeshan
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Rupesh K. Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Yagya D. Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
- * E-mail:
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9
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Alam MS, Choudhary V, Zeeshan M, Tyagi RK, Rathore S, Sharma YD. Interaction of Plasmodium vivax Tryptophan-rich Antigen PvTRAg38 with Band 3 on Human Erythrocyte Surface Facilitates Parasite Growth. J Biol Chem 2015; 290:20257-72. [PMID: 26149684 DOI: 10.1074/jbc.m115.644906] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Indexed: 12/12/2022] Open
Abstract
Plasmodium tryptophan-rich proteins are involved in host-parasite interaction and thus potential drug/vaccine targets. Recently, we have described several P. vivax tryptophan-rich antigens (PvTRAgs), including merozoite expressed PvTRAg38, from this noncultivable human malaria parasite. PvTRAg38 is highly immunogenic in humans and binds to host erythrocytes, and this binding is inhibited by the patient sera. This binding is also affected if host erythrocytes were pretreated with chymotrypsin. Here, Band 3 has been identified as the chymotrypsin-sensitive erythrocyte receptor for this parasite protein. Interaction of PvTRAg38 with Band 3 has been mapped to its three different ectodomains (loops 1, 3, and 6) exposed at the surface of the erythrocyte. The binding region of PvTRAg38 to Band3 has been mapped to its sequence, KWVQWKNDKIRSWLSSEW, present at amino acid positions 197-214. The recombinant PvTRAg38 was able to inhibit the parasite growth in in vitro Plasmodium falciparum culture probably by competing with the ligand(s) of this heterologous parasite for the erythrocyte Band 3 receptor. In conclusion, the host-parasite interaction at the molecular level is much more complicated than known so far and should be considered during the development of anti-malarial therapeutics.
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Affiliation(s)
- Mohd Shoeb Alam
- From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Vandana Choudhary
- From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Mohammad Zeeshan
- From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Rupesh K Tyagi
- From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Sumit Rathore
- From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Yagya D Sharma
- From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India
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10
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Immunoprofiling of the tryptophan-rich antigen family in Plasmodium vivax. Infect Immun 2015; 83:3083-95. [PMID: 25987709 DOI: 10.1128/iai.03067-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 05/12/2015] [Indexed: 11/20/2022] Open
Abstract
Tryptophan-rich antigens (TRAgs) are an antigen family that has been identified in human and rodent malaria parasites. TRAgs have been proposed as candidate antigens for potential vaccines. The Plasmodium vivax TRAg (PvTRAg) family includes 36 members. Each PvTRAg contains a tryptophan-rich (TR) domain in the C-terminal region. In this study, we recombinantly expressed all 36 PvTRAgs using a cell-free expression system, and, for the first time, profiled the IgG antibody responses against all PvTRAgs in the sera from 96 vivax malaria patients and 40 healthy individuals using protein microarray technology. The mean seropositive rate for all PvTRAgs was 60.3%. Among them, nine PvTRAgs were newly identified in this study and showed a seropositive rate of >50%. Five of them, PvTRAg_13, PvTRAg_15, PvTRAg_16, PvTRAg_26, and PvTRAg_29, produced higher levels of IgG antibody, even in low-endemicity countries. In addition, the results of an immunofluorescence analysis suggest that PvTRAgs are, at least in part, associated with caveola-vesicle complexes, a unique structure of P. vivax-infected erythrocytes. The mechanism of formation and the function of these abundant membrane structures are not known. Further investigation aimed at determining the functions of these proteins would lead to a better understanding of the blood-stage biology of P. vivax.
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11
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Schulze J, Kwiatkowski M, Borner J, Schlüter H, Bruchhaus I, Burmester T, Spielmann T, Pick C. The Plasmodium falciparum exportome contains non-canonical PEXEL/HT proteins. Mol Microbiol 2015; 97:301-14. [PMID: 25850860 DOI: 10.1111/mmi.13024] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2015] [Indexed: 11/29/2022]
Abstract
The pathogenicity of Plasmodium falciparum is partly due to parasite-induced host cell modifications. These modifications are facilitated by exported P. falciparum proteins, collectively referred to as the exportome. Export of several hundred proteins is mediated by the PEXEL/HT, a protease cleavage site. The PEXEL/HT is usually comprised of five amino acids, of which R at position 1, L at position 3 and E, D or Q at position 5 are conserved and important for export. Non-canonical PEXEL/HTs with K or H at position 1 and/or I at position 3 are presently considered non-functional. Here, we show that non-canonical PEXEL/HT proteins are overrepresented in P. falciparum and other Plasmodium species. Furthermore, we show that non-canonical PEXEL/HTs can be cleaved and can promote export in both a REX3 and a GBP reporter, but not in a KAHRP reporter, indicating that non-canonical PEXEL/HTs are functional in concert with a supportive sequence environment. We then selected P. falciparum proteins with a non-canonical PEXEL/HT and show that some of these proteins are exported and that their export depends on non-canonical PEXEL/HTs. We conclude that PEXEL/HT plasticity is higher than appreciated and that non-canonical PEXEL/HT proteins cannot categorically be excluded from Plasmodium exportome predictions.
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Affiliation(s)
- Jana Schulze
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
| | - Marcel Kwiatkowski
- Department of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, D-20246, Hamburg, Germany
| | - Janus Borner
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
| | - Hartmut Schlüter
- Department of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, D-20246, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359, Hamburg, Germany
| | - Thorsten Burmester
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359, Hamburg, Germany
| | - Christian Pick
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
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12
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CD4+ T cell response correlates with naturally acquired antibodies against Plasmodium vivax tryptophan-rich antigens. Infect Immun 2015; 83:2018-29. [PMID: 25733522 DOI: 10.1128/iai.03095-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/22/2015] [Indexed: 01/19/2023] Open
Abstract
Tryptophan-rich proteins play important biological functions for the Plasmodium parasite. Plasmodium vivax contains remarkably large numbers of such proteins belonging to the "Pv-fam-a" family that need to be characterized. Earlier, we reported the presence of memory T cells and naturally acquired antibodies against 15 of these proteins in P. vivax malaria-exposed individuals (M. Zeeshan, H. Bora, and Y. D. Sharma, J Infect Dis 207:175-185, 2013, http://dx.doi.org/10.1093/infdis/jis650). Here, we sought to characterize and ascertain the cross talk between effector responses of T and B cells in malarial patients against all Pv-fam-a family proteins. Therefore, we expressed the remaining 21 of these proteins in Escherichia coli and studied the humoral and cellular immune responses based on the same parameters used in our previous study. Naturally acquired IgG antibodies were detected against all 21 antigens in P. vivax patient sera (37.7 to 94.4% seropositivity). These antigens were able to activate the lymphocytes of P. vivax-exposed individuals, and the activated CD4(+) T lymphocytes produced higher levels of Th1 (interleukin-2 [IL-2] and gamma interferon [IFN-γ]) and Th2 (IL-4 and IL-10) cytokines than the healthy controls, but the response was Th2 biased. The combined results of present and previous studies seem to suggest a striking link between induction of the CD4(+) T cell response and naturally acquired antibodies against all 36 proteins of the Pv-fam-a family, the majority of them having conserved sequences in the parasite population. Further work is required to utilize this information to develop immunotherapeutic treatments for this disease.
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Zeeshan M, Tyagi RK, Tyagi K, Alam MS, Sharma YD. Host-parasite interaction: selective Pv-fam-a family proteins of Plasmodium vivax bind to a restricted number of human erythrocyte receptors. J Infect Dis 2014; 211:1111-20. [PMID: 25312039 DOI: 10.1093/infdis/jiu558] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Plasmodium vivax synthesizes the largest number of 36 tryptophan-rich proteins belonging to the Pv-fam-a family. These parasite proteins need to be characterized for their biological function because tryptophan-rich proteins from other Plasmodium species have been proposed as vaccine candidates. METHODS Recombinant P. vivax tryptophan-rich antigens (PvTRAgs) were used to determine their erythrocyte-binding activity by a cell-based enzyme-linked immunosorbent assay, flow cytometry, and a rosetting assay. RESULTS Only 4 (PvTRAg26.3, PvTRAg34, PvTRAg36, and PvTRAg36.6) of 21 PvTRAgs bind to host erythrocytes. The cross-competition data indicated that PvTRAg36 and PvTRAg34 share their erythrocyte receptors with previously described proteins PvTRAg38 and PvTRAg33.5, respectively. On the other hand, PvTRAg26.3 and PvTRAg36.6 cross-compete with each other and not with any other PvTRAg, indicating that these 2 proteins bind to the same but yet another set of erythrocyte receptor(s). Together, 10 of 36 PvTRAgs possess erythrocyte-binding activity in which each protein recognizes >1 erythrocyte receptor. Further, each erythrocyte receptor is shared by >1 PvTRAg. CONCLUSIONS This redundancy may be useful for the parasite to invade red blood cells and cause disease pathogenesis, and it can be exploited to develop therapeutics against P. vivax malaria.
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Affiliation(s)
- Mohammad Zeeshan
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi
| | - Rupesh Kumar Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi
| | - Kriti Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi
| | - Mohd Shoeb Alam
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi
| | - Yagya Dutta Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi
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Zenonos ZA, Rayner JC, Wright GJ. Towards a comprehensive Plasmodium falciparum merozoite cell surface and secreted recombinant protein library. Malar J 2014; 13:93. [PMID: 24620899 PMCID: PMC3995786 DOI: 10.1186/1475-2875-13-93] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 03/07/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium falciparum is the aetiological agent for malaria, a deadly infectious disease for which no vaccine has yet been licensed. The proteins displayed on the merozoite cell surface have long been considered attractive vaccine targets because of their direct exposure to host antibodies; however, progress in understanding the functional role of these targets has been hindered by technical challenges associated with expressing these proteins in a functionally active recombinant form. To address this, a method that enables the systematic expression of functional extracellular Plasmodium proteins was previously developed, and used to create a library of 42 merozoite proteins. METHODS To compile a more comprehensive library of recombinant proteins representing the repertoire of P. falciparum merozoite extracellular proteins for systematic vaccine and functional studies, genome-wide expression profiling was used to identify additional candidates. Candidate proteins were recombinantly produced and their integrity and expression levels were tested by Western blotting and ELISA. RESULTS Twenty-five additional genes that were upregulated during late schizogony, and predicted to encode secreted and cell surface proteins, were identified and expressed as soluble recombinant proteins. A band consistent with the entire ectodomain was observed by immunoblotting for the majority of the proteins and their expression levels were quantified. By using sera from malaria-exposed immune adults, the immunoreactivity of 20 recombinant proteins was assessed, and most of the merozoite ligands were found to carry heat-labile epitopes. To facilitate systematic comparative studies across the entire library, multiple Plasmodium proteins were simultaneously purified using a custom-made platform. CONCLUSIONS A library of recombinant P. falciparum secreted and cell surface proteins was expanded by 20 additional proteins, which were shown to express at usable levels and contain conformational epitopes. This resource of extracellular P. falciparum merozoite proteins, which now contains 62 full-length ectodomains, will be a valuable tool in elucidating the function of these proteins during the blood stages of infection, and facilitate the comparative assessment of blood stage vaccine candidates.
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Affiliation(s)
| | | | - Gavin J Wright
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK.
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15
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Bora H, Tyagi RK, Sharma YD. Defining the erythrocyte binding domains of Plasmodium vivax tryptophan rich antigen 33.5. PLoS One 2013; 8:e62829. [PMID: 23638151 PMCID: PMC3636203 DOI: 10.1371/journal.pone.0062829] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/26/2013] [Indexed: 11/18/2022] Open
Abstract
Tryptophan-rich antigens play important role in host-parasite interaction. One of the Plasmodium vivax tryptophan-rich antigens called PvTRAg33.5 had earlier been shown to be predominantly of alpha helical in nature with multidomain structure, induced immune responses in humans, binds to host erythrocytes, and its sequence is highly conserved in the parasite population. In the present study, we divided this protein into three different parts i.e. N-terminal (amino acid position 24–106), middle (amino acid position 107–192), and C-terminal region (amino acid position 185–275) and determined the erythrocyte binding activity of these fragments. This binding activity was retained by the middle and C-terminal fragments covering 107 to 275 amino acid region of the PvTRAg33.5 protein. Eight non-overlapping peptides covering this 107 to 275 amino acid region were then synthesized and tested for their erythrocyte binding activity to further define the binding domains. Only two peptides, peptide P4 (at 171–191 amino acid position) and peptide P8 (at 255–275 amino acid position), were found to contain the erythrocyte binding activity. Competition assay revealed that each peptide recognizes its own erythrocyte receptor. These two peptides were found to be located on two parallel helices at one end of the protein in the modelled structure and could be exposed on its surface to form a suitable site for protein-protein interaction. Natural antibodies present in the sera of the P. vivax exposed individuals or the polyclonal rabbit antibodies against this protein were able to inhibit the erythrocyte binding activity of PvTRAg33.5, its fragments, and these two synthetic peptides P4 and P8. Further studies on receptor-ligand interaction might lead to the development of the therapeutic reagent.
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Affiliation(s)
- Hema Bora
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Rupesh Kumar Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Yagya Dutta Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
- * E-mail:
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16
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Tyagi RK, Sharma YD. Erythrocyte Binding Activity Displayed by a Selective Group of Plasmodium vivax Tryptophan Rich Antigens Is Inhibited by Patients' Antibodies. PLoS One 2012; 7:e50754. [PMID: 23236392 PMCID: PMC3516511 DOI: 10.1371/journal.pone.0050754] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 10/24/2012] [Indexed: 01/03/2023] Open
Abstract
Plasmodium vivax is a very common but non-cultivable malaria parasite affecting large human population in tropical world. To develop therapeutic reagents for this malaria, the parasite molecules involved in host-parasite interaction need to be investigated as they form effective vaccine or drug targets. We have investigated here the erythrocyte binding activity of a group of 15 different Plasmodium vivax tryptophan rich antigens (PvTRAgs). Only six of them, named PvTRAg, PvTRAg38, PvTRAg33.5, PvTRAg35.2 PvTRAg69.4 and PvATRAg74, showed binding to host erythrocytes. That the PvTRAgs binding to host erythrocytes was specific was evident from the competitive inhibition and saturation kinetics results. The erythrocyte receptors for these six PvTRAgs were resistant to trypsin and neuraminidase. These receptors were also chymotrypsin resistant except the receptors for PvTRAg38 and PvATRAg74 which were partially sensitive to this enzyme. The cross-competition studies showed that the chymotrypsin resistant RBC receptor for each of these two proteins was different. Altogether, there seems to be three RBC receptors for these six PvTRAgs and each PvTRAg has two RBC receptors. Both RBC receptors for PvTRAg, PvTRAg69.4, PvTRAg33.5, and PvTRAg35.2 were common to all these four proteins. These four PvTRAgs also shared one of their RBC receptors with PvTRAg38 as well as with PvATRAg74. The erythrocyte binding activity of these six PvTRAgs was inhibited by the respective rabbit polyclonal antibodies as well as by the natural antibodies produced by the P. vivax exposed individuals. It is concluded that only selective few PvTRAgs show erythrocyte binding activity involving different receptor molecules which can be blocked by the natural antibodies. Further studies on these receptor and ligands may lead to the development of therapeutic reagents for P. vivax malaria.
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Affiliation(s)
- Rupesh Kumar Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Yagya Dutta Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
- * E-mail:
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17
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Zeeshan M, Bora H, Sharma YD. Presence of memory T cells and naturally acquired antibodies in Plasmodium vivax malaria-exposed individuals against a group of tryptophan-rich antigens with conserved sequences. J Infect Dis 2012; 207:175-85. [PMID: 23087432 DOI: 10.1093/infdis/jis650] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Tryptophan-rich antigens of malarial parasites have been proposed to be the potential vaccine candidate antigens. Plasmodium vivax contains the largest number of such antigens, which need to be evaluated for their immune responses. METHODS Recombinant proteins of 15 P. vivax tryptophan-rich antigens (PvTRAgs) were expressed, purified, and used for the human humoral and cellular immune responses. Genetic polymorphism of these 15 genes was also determined among clinical P. vivax isolates. RESULTS The T lymphocytes of P. vivax exposed individuals expressed higher level of CD69 against all 15 PvTRAgs. These antigens also activated the large population of CD4(+) T cells and produced higher level of intracellular IL-2, INF-γ and IL-4. Although there was a mixed Th1 and Th2 response against these antigens, this response was biased toward Th2. The majority of P. vivax patients (75.7%-100%, n = 33) produced IgG antibodies against these antigens. Most of these antigens showed conserved T- and B-cell epitopes in the parasite population. CONCLUSIONS These results suggest the presence of memory T cells in humans against these antigens to generate faster and more specific immune responses to minimize the P. vivax infection. Further characterization of these PvTRAgs may lead to the identification of a potential therapeutic target.
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Affiliation(s)
- Mohammad Zeeshan
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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18
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Bora H, Garg S, Sen P, Kumar D, Kaur P, Khan RH, Sharma YD. Plasmodium vivax tryptophan-rich antigen PvTRAg33.5 contains alpha helical structure and multidomain architecture. PLoS One 2011; 6:e16294. [PMID: 21283717 PMCID: PMC3024423 DOI: 10.1371/journal.pone.0016294] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 12/19/2010] [Indexed: 11/19/2022] Open
Abstract
Tryptophan-rich proteins from several malarial parasites have been identified where they play an important role in host-parasite interaction. Structural characterization of these proteins is needed to develop them as therapeutic targets. Here, we describe a novel Plasmodium vivax tryptophan-rich protein named PvTRAg33.5. It is expressed by blood stage(s) of the parasite and its gene contains two exons. The exon 1 encodes for a 23 amino acids long putative signal peptide which is likely to be cleaved off whereas the exon 2 encodes for the mature protein of 252 amino acids. The mature protein contains B-cell epitopes which were recognized by the human immune system during P.vivax infection. The PvTRAg33.5 contains 24 (9.5%) tryptophan residues and six motifs whose patterns were similar among tryptophan-rich proteins. The modeled structure of the PvTRAg33.5 consists of a multidomain architecture which is stabilized by the presence of large number of tryptophan residues. The recombinant PvTRAg33.5 showed predominantly α helical structure and alpha helix to beta sheet transition at pH below 4.5. Protein acquires an irreversible non-native state at temperature more than 50°C at neutral pH. Its secondary and tertiary structures remain stable in the presence of 35% alcohol but these structures are destabilized at higher alcohol concentrations due to the disturbance of hydrophobic interactions between tryptophanyl residues. These structural changes in the protein might occur during its translocation to interact with other proteins at its final destination for biological function such as erythrocyte invasion.
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Affiliation(s)
- Hema Bora
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Sheena Garg
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Priyankar Sen
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Deepak Kumar
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
- * E-mail: (YDS); (RHK)
| | - Yagya D. Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
- * E-mail: (YDS); (RHK)
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19
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Mittra P, Singh N, Sharma YD. Plasmodium vivax: immunological properties of tryptophan-rich antigens PvTRAg 35.2 and PvTRAg 80.6. Microbes Infect 2010; 12:1019-26. [DOI: 10.1016/j.micinf.2010.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 06/04/2010] [Accepted: 07/05/2010] [Indexed: 11/29/2022]
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20
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Alam MT, Bora H, Singh N, Sharma YD. High immunogenecity and erythrocyte-binding activity in the tryptophan-rich domain (TRD) of the 74-kDa Plasmodium vivax alanine-tryptophan-rich antigen (PvATRAg74). Vaccine 2008; 26:3787-94. [DOI: 10.1016/j.vaccine.2008.05.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 05/12/2008] [Indexed: 11/25/2022]
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21
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ALAM MT, BORA H, MITTRA P, SINGH N, SHARMA YD. Cellular immune responses to recombinant Plasmodium vivax tryptophan-rich antigen (PvTRAg) among individuals exposed to vivax malaria. Parasite Immunol 2008; 30:379-83. [DOI: 10.1111/j.1365-3024.2008.01033.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Siddiqui AA, Singh N, Sharma YD. Expression and purification of a Plasmodium vivax antigen - PvTARAg55 tryptophan- and alanine-rich antigen and its immunological responses in human subjects. Vaccine 2007; 26:96-107. [PMID: 18054126 DOI: 10.1016/j.vaccine.2007.10.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 10/11/2007] [Accepted: 10/18/2007] [Indexed: 01/16/2023]
Abstract
Despite the immense global efforts, the malaria vaccine is not yet available and requires the identification of newer target molecules. Since tryptophan-rich proteins of P. yoelii have been proposed as vaccine candidates, we describe here the expression, purification and immunological characterization of a 55kDa Plasmodium vivax tryptophan- and alanine-rich antigen (PvTARAg55). This protein consists of 480 aa residues with a calculated molecular mass of 55.0kDa. It shows 42% aa sequence identity (64% homology) with PyPAg1 of P. yoelii and shares positional conservation of tryptophan residues. Sequence analysis of PvTARAg55 from different P. vivax isolates revealed that typtophan-rich domain which contains most of the B-cell epitopes was highly conserved in the parasite population while the alanine-rich domain showed polymorphism. Exon-2 covering major part (420 aa) of the protein including both the domains was PCR amplified, cloned, expressed in Escherichia coli, and the recombinant protein purified to its homogeneity. Majority of P. vivax-infected individuals (82.5%, n=40) produced antibodies against this antigen. Proliferative responses to the recombinant PvTARAg55 were observed in 60% (n=20) of individuals who had recently been exposed to the P. vivax infection. Measurement of Th1- (IFN-gamma, TNF-alpha, and IL-12) and Th2-type (IL-4 and IL-10) cytokine production in response to this recombinant antigen revealed a mixed type T-cell response with a Th2 response being more pronounced. These results demonstrate that PvTARAg55 elicits high humoral and cellular immune responses thus establishes its immunogenecity in humans.
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Affiliation(s)
- Asim A Siddiqui
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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23
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Oakley MSM, Kumar S, Anantharaman V, Zheng H, Mahajan B, Haynes JD, Moch JK, Fairhurst R, McCutchan TF, Aravind L. Molecular factors and biochemical pathways induced by febrile temperature in intraerythrocytic Plasmodium falciparum parasites. Infect Immun 2007; 75:2012-25. [PMID: 17283083 PMCID: PMC1865691 DOI: 10.1128/iai.01236-06] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Intermittent episodes of febrile illness are the most benign and recognized symptom of infection with malaria parasites, although the effects on parasite survival and virulence remain unclear. In this study, we identified the molecular factors altered in response to febrile temperature by measuring differential expression levels of individual genes using high-density oligonucleotide microarray technology and by performing biological assays in asexual-stage Plasmodium falciparum parasite cultures incubated at 37 degrees C and 41 degrees C (an elevated temperature that is equivalent to malaria-induced febrile illness in the host). Elevated temperature had a profound influence on expression of individual genes; 336 of approximately 5,300 genes (6.3% of the genome) had altered expression profiles. Of these, 163 genes (49%) were upregulated by twofold or greater, and 173 genes (51%) were downregulated by twofold or greater. In-depth sensitive sequence profile analysis revealed that febrile temperature-induced responses caused significant alterations in the major parasite biologic networks and pathways and that these changes are well coordinated and intricately linked. One of the most notable transcriptional changes occurs in genes encoding proteins containing the predicted Pexel motifs that are exported into the host cytoplasm or inserted into the host cell membrane and are likely to be associated with erythrocyte remodeling and parasite sequestration functions. Using our sensitive computational analysis, we were also able to assign biochemical or biologic functional predictions for at least 100 distinct genes previously annotated as "hypothetical." We find that cultivation of P. falciparum parasites at 41 degrees C leads to parasite death in a time-dependent manner. The presence of the "crisis forms" and the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling-positive parasites following heat treatment strongly support the notion that an apoptosis-like cell death mechanism might be induced in response to febrile temperatures. These studies enhance the possibility of designing vaccines and drugs on the basis of disruption in molecules and pathways of parasite survival and virulence activated in response to febrile temperatures.
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Affiliation(s)
- Miranda S M Oakley
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases/NIH, Rockville, MD 20892, USA
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24
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Curtidor H, Ocampo M, Rodríguez LE, López R, García JE, Valbuena J, Vera R, Puentes A, Leiton J, Cortes LJ, López Y, Patarroyo MA, Patarroyo ME. Plasmodium falciparum TryThrA antigen synthetic peptides block in vitro merozoite invasion to erythrocytes. Biochem Biophys Res Commun 2005; 339:888-96. [PMID: 16329993 DOI: 10.1016/j.bbrc.2005.11.089] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 11/14/2005] [Indexed: 11/27/2022]
Abstract
Tryptophan-threonine-rich antigen (TryThrA) is a Plasmodium falciparum homologue of Plasmodium yoelii-infected erythrocyte membrane pypAg-1 antigen. pypAg-1 binds to the surface of uninfected mouse erythrocytes and has been used successfully in vaccine studies. The two antigens are characterized by an unusual tryptophan-rich domain, suggesting similar biological properties. Using synthetic peptides spanning the TryThrA sequence and human erythrocyte we have done binding assays to identify possible TryThrA functional regions. We describe four peptides outside the tryptophan-rich domain having high activity binding to normal human erythrocytes. The peptides termed HABPs (high activity binding peptides) are 30884 ((61)LKEKKKKVLEFFENLVLNKKY(80)) located at the N-terminal and 30901 ((401)RKSLEQQFGDNMDKMNKLKKY(420)), 30902 ((421)KKILKFFPLFNYKSDLESIM(440)) and 30913 ((641)DLESTAEQKAEKKGGKAKAKY(660)) located at the C-terminal. Studies with polyclonal goat antiserum against synthetic peptides chosen to represent the whole length of the protein showed that TryThrA has fluorescence pattern similar to PypAg-1 of P. yoelii. All HABPs inhibited merozoite in vitro invasion, suggesting that TryThrA protein may be participating in merozoite-erythrocyte interaction during invasion.
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Affiliation(s)
- Hernando Curtidor
- Fundación Instituto de Inmunología de Colombia (FIDIC), Universidad Nacional de Colombia, Colombia.
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25
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Ntumngia FB, Bahamontes-Rosa N, Kun JFJ. Genes coding for tryptophan-rich proteins are transcribed throughout the asexual cycle of Plasmodium falciparum. Parasitol Res 2005; 96:347-53. [PMID: 15924221 DOI: 10.1007/s00436-005-1398-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Accepted: 04/07/2005] [Indexed: 10/25/2022]
Abstract
Multigene families are a common feature in Plasmodia spp. and constitute a substantial content of the parasite genome. Here, we analyse the structural organisation and sequence diversity of two further members of the Trp-rich multigene family of P. falciparum. The complete DNA sequence of both genes was determined from a series of laboratory adapted and field isolates. Based on the amino acid sequences, we have termed them tryptophan-rich antigen-3 (TrpA-3) and lysine-tryptophan-rich antigen (LysTrpA). Analysis of the genes using reverse transcriptase-polymerase chain reaction (RT-PCR), showed that both genes are transcribed and that introns are spliced out at predicted positions. Gene expression profiles obtained from microarray analysis indicate that both genes are expressed in the mid-stages of the asexual cycle. In-frame stop codons were detected which interrupted the reading frame of LysTrpA. Whereas the number of the Trp-rich proteins is rather low in P. falciparum, P. chabaudi, P. berghei and P. yoelii, this family seems to have 15 or more members in P. knowlesi and P. vivax.
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Affiliation(s)
- Francis B Ntumngia
- Department of Parasitology, Institute of Tropical Medicine, Wilhelmstr. 27, 72074 Tübingen, Germany
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Jalah R, Sarin R, Sud N, Alam MT, Parikh N, Das TK, Sharma YD. Identification, expression, localization and serological characterization of a tryptophan-rich antigen from the human malaria parasite Plasmodium vivax. Mol Biochem Parasitol 2005; 142:158-69. [PMID: 15869815 DOI: 10.1016/j.molbiopara.2005.01.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2004] [Revised: 01/11/2005] [Accepted: 01/26/2005] [Indexed: 11/26/2022]
Abstract
Plasmodium vivax is most common but non-cultivable human malaria parasite which is poorly characterized at the molecular level. Here, we describe the identification and characterization of a P. vivax Tryptophan-Rich Antigen (PvTRAg) which contains unusually high (8.28%) tryptophan residues and is expressed by all blood stages of the parasite. The pvtrag gene comprises a 978bp open reading frame interrupted by two introns. The first intron is located in the 5'-untranslated region while the second one is positioned 174bp downstream to the ATG codon. The encoded approximately 40kDa protein contains a transmembrane domain near the N-terminus followed by a tryptophan-rich domain with significantly high surface probability and antigenic index. It is localized in the parasite cytoplasm as well as in the cytoplasm of the parasitized erythrocyte. The purified E. coli expressed recombinant PvTRAg protein showed a very high seropositivity rate for the presence of antibodies amongst the P. vivax patients, indicating that the antigen generates significant humoral immune response during the natural course of P. vivax infection. Analysis of various field isolates revealed that the tryptophan-rich domain is highly conserved except for three-point mutations. The PvTRAg could be a potential vaccine candidate since similar tryptophan-rich antigens of P. yoelii have shown protection against malaria in murine model.
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Affiliation(s)
- Rashmi Jalah
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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