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Anderson DC, Peterson MS, Lapp SA, Galinski MR. Proteomes of plasmodium knowlesi early and late ring-stage parasites and infected host erythrocytes. J Proteomics 2024; 302:105197. [PMID: 38759952 DOI: 10.1016/j.jprot.2024.105197] [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: 10/08/2022] [Revised: 05/05/2024] [Accepted: 05/14/2024] [Indexed: 05/19/2024]
Abstract
The emerging malaria parasite Plasmodium knowlesi threatens the goal of worldwide malaria elimination due to its zoonotic spread in Southeast Asia. After brief ex-vivo culture we used 2D LC/MS/MS to examine the early and late ring stages of infected Macaca mulatta red blood cells harboring P. knowlesi. The M. mulatta clathrin heavy chain and T-cell and macrophage inhibitor ERMAP were overexpressed in the early ring stage; glutaredoxin 3 was overexpressed in the late ring stage; GO term differential enrichments included response to oxidative stress and the cortical cytoskeleton in the early ring stage. P. knowlesi clathrin heavy chain and 60S acidic ribosomal protein P2 were overexpressed in the late ring stage; GO term differential enrichments included vacuoles in the early ring stage, ribosomes and translation in the late ring stage, and Golgi- and COPI-coated vesicles, proteasomes, nucleosomes, vacuoles, ion-, peptide-, protein-, nucleocytoplasmic- and RNA-transport, antioxidant activity and glycolysis in both stages. SIGNIFICANCE: Due to its zoonotic spread, cases of the emerging human pathogen Plasmodium knowlesi in southeast Asia, and particularly in Malaysia, threaten regional and worldwide goals for malaria elimination. Infection by this parasite can be fatal to humans, and can be associated with significant morbidity. Due to zoonotic transmission from large macaque reservoirs that are untreatable by drugs, and outdoor biting mosquito vectors that negate use of preventive measures such as bed nets, its containment remains a challenge. Its biology remains incompletely understood. Thus we examine the expressed proteome of the early and late ex-vivo cultured ring stages, the first intraerythrocyte developmental stages after infection of host rhesus macaque erythrocytes. We used GO term enrichment strategies and differential protein expression to compare early and late ring stages. The early ring stage is characterized by the enrichment of P. knowlesi vacuoles, and overexpression of the M. mulatta clathrin heavy chain, important for clathrin-coated pits and vesicles, and clathrin-mediated endocytosis. The M. mulatta protein ERMAP was also overexpressed in the early ring stage, suggesting a potential role in early ring stage inhibition of T-cells and macrophages responding to P. knowlesi infection of reticulocytes. This could allow expansion of the host P. knowlesi cellular niche, allowing parasite adaptation to invasion of a wider age range of RBCs than the preferred young RBCs or reticulocytes, resulting in proliferation and increased pathogenesis in infected humans. Other GO terms differentially enriched in the early ring stage include the M. mulatta cortical cytoskeleton and response to oxidative stress. The late ring stage is characterized by overexpression of the P. knowlesi clathrin heavy chain. Combined with late ring stage GO term enrichment of Golgi-associated and coated vesicles, and enrichment of COPI-coated vesicles in both stages, this suggests the importance to P. knowlesi biology of clathrin-mediated endocytosis. P. knowlesi ribosomes and translation were also differentially enriched in the late ring stage. With expression of a variety of heat shock proteins, these results suggest production of folded parasite proteins is increasing by the late ring stage. M. mulatta endocytosis was differentially enriched in the late ring stage, as were clathrin-coated vesicles and endocytic vesicles. This suggests that M. mulatta clathrin-based endocytosis, perhaps in infected reticulocytes rather than mature RBC, may be an important process in the late ring stage. Additional ring stage biology from enriched GO terms includes M. mulatta proteasomes, protein folding and the chaperonin-containing T complex, actin and cortical actin cytoskeletons. P knowlesi biology also includes proteasomes, as well as nucleosomes, antioxidant activity, a variety of transport processes, glycolysis, vacuoles and protein folding. Mature RBCs have lost internal organelles, suggesting infection here may involve immature reticulocytes still retaining organelles. P. knowlesi parasite proteasomes and translational machinery may be ring stage drug targets for known selective inhibitors of these processes in other Plasmodium species. To our knowledge this is the first examination of more than one timepoint within the ring stage. Our results expand knowledge of both host and parasite proteins, pathways and organelles underlying P. knowlesi ring stage biology.
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Affiliation(s)
- D C Anderson
- Biosciences Division, SRI International, Harrisonburg, VA 22802, USA.
| | - Mariko S Peterson
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA
| | - Stacey A Lapp
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA
| | - Mary R Galinski
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
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2
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Chen Y, Zeng Z, Chen Z, Yuan N, Ye X, Zhang C, Xia N, Luo W. A new mechanism of antibody diversity: formation of the natural antibodies containing LAIR1 and LILRB1 extracellular domains. Antib Ther 2024; 7:157-163. [PMID: 38933531 PMCID: PMC11200687 DOI: 10.1093/abt/tbae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/18/2024] [Indexed: 06/28/2024] Open
Abstract
The recent discovery of public antibodies targeting Plasmodium falciparum-encoded repetitive interspersed families of polypeptides (RIFINs), which contain extracellular immunoglobulin-like domains from LAIR1 or LILRB1, constitutes a significant step forward in comprehending the reactivity of the Plasmodium parasite. These antibodies arise from unique B cell clones and demonstrate extensive cross-reactivity through their interaction with P. falciparum RIFINs. LAIR1 and LILRBs are specialized type I transmembrane glycoproteins, classified as immune inhibitory receptors, restricted to primates and mainly found on hematopoietic cells. They are instrumental in modulating interactions within the tumor microenvironment and across the immune system, and are increasingly recognized as important in anti-cancer immunotherapy and pathogen defense. The presence of LAIR1/LILRB1-containing antibodies offers new insights into malaria parasite evasion strategies and the immune system's response. Additionally, the innovative method of integrating extra exons into the antibody switch region is a noteworthy advancement, enriching the strategies for the generation of a varied array of bispecific and multispecific antibodies.
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Affiliation(s)
- Yuanzhi Chen
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
| | - Zhiren Zeng
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
| | - Ziyou Chen
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
| | - Na Yuan
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
| | - Xinya Ye
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
| | - Chengcheng Zhang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Ningshao Xia
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
- Research Unit of Frontier Technology of Structural Vaccinology, Chinese Academy of Medical Sciences, Xiamen 361102, China
| | - Wenxin Luo
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, School of Public Health and School of Life Sciences, Xiamen University, Xiamen 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen 361102, China
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3
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Vydyam P, Roy N, Bhattacharyya MK. Uncovering the role of Rad51 in homologous recombination-mediated antigenic diversification in the human malaria parasite Plasmodium falciparum. Front Mol Biosci 2023; 10:1223682. [PMID: 37593128 PMCID: PMC10427863 DOI: 10.3389/fmolb.2023.1223682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/13/2023] [Indexed: 08/19/2023] Open
Abstract
The human malaria parasite Plasmodium falciparum maintains the chronicity of infections through antigenic variation, a well-coordinated immune evasion mechanism. The most prominent molecular determinant of antigenic variation in this parasite includes the members of the var multigene family. Homologous recombination (HR)-mediated genomic rearrangements have been implicated to play a major role in var gene diversification. However, the key molecular factors involved in the generation of diversity at var loci are less known. Here, we tested the hypothesis that PfRad51 could carry out recombination between var genes that are not homologous but homeologous in nature. We employed the whole-genome sequencing (WGS) approach to investigate recombination events among var sequences over 100 generations and compared the rate of sequence rearrangement at the var loci in both PfRad51-proficient and -deficient parasite lines. This brief report provides evidence that the loss of the key recombinase function renders the parasite with inefficient HR and results in fewer recombination events among the var sequences, thereby impacting the diversification of the var gene repertoire.
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Wu Y, Leyk S, Torabi H, Höhn K, Honecker B, Tauler MDPM, Cadar D, Jacobs T, Bruchhaus I, Metwally NG. Plasmodium falciparum infection reshapes the human microRNA profiles of red blood cells and their extracellular vesicles. iScience 2023; 26:107119. [PMID: 37534175 PMCID: PMC10391920 DOI: 10.1016/j.isci.2023.107119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 03/08/2023] [Accepted: 06/09/2023] [Indexed: 08/04/2023] Open
Abstract
Plasmodium falciparum, a human malaria parasite, develops in red blood cells (RBCs), which represent approximately 70% of all human blood cells. Additionally, RBC-derived extracellular vesicles (RBC-EVs) represent 7.3% of the total EV population. The roles of microRNAs (miRNAs) in the consequences of P. falciparum infection are unclear. Here, we analyzed the miRNA profiles of non-infected human RBCs (niRBCs), ring-infected RBCs (riRBCs), and trophozoite-infected RBCs (trRBCs), as well as those of EVs secreted from these cells. Hsa-miR-451a was the most abundant miRNA in all RBC and RBC-EV populations, but its expression level was not affected by P. falciparum infection. Overall, the miRNA profiles of RBCs and their EVs were altered significantly after infection. Most of the differentially expressed miRNAs were shared between RBCs and their EVs. A target prediction analysis of the miRNAs revealed the possible identity of the genes targeted by these miRNAs (CXCL10, OAS1, IL7, and CCL5) involved in immunomodulation.
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Affiliation(s)
- Yifan Wu
- Research Group Host Parasite Interaction, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stephanie Leyk
- Research Group Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Hanifeh Torabi
- Research Group Host Parasite Interaction, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Katharina Höhn
- Cellular Parasitology Department, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Barbara Honecker
- Research Group Host Parasite Interaction, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Dániel Cadar
- Arbovirology Department, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Thomas Jacobs
- Research Group Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Iris Bruchhaus
- Research Group Host Parasite Interaction, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department University of Hamburg, Hamburg, Germany
| | - Nahla Galal Metwally
- Research Group Host Parasite Interaction, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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5
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Pohl K, Cockburn IA. Innate immunity to malaria: The good, the bad and the unknown. Front Immunol 2022; 13:914598. [PMID: 36059493 PMCID: PMC9437427 DOI: 10.3389/fimmu.2022.914598] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/21/2022] [Indexed: 12/04/2022] Open
Abstract
Malaria is the cause of 600.000 deaths annually. However, these deaths represent only a tiny fraction of total malaria cases. Repeated natural infections with the causative agent, Plasmodium sp. parasites, induce protection from severe disease but not sterile immunity. Thus, immunity to Plasmodium is incomplete. Conversely, immunization with attenuated sporozoite stage parasites can induce sterile immunity albeit after multiple vaccinations. These different outcomes are likely to be influenced strongly by the innate immune response to different stages of the parasite lifecycle. Even small numbers of sporozoites can induce a robust proinflammatory type I interferon response, which is believed to be driven by the sensing of parasite RNA. Moreover, induction of innate like gamma-delta cells contributes to the development of adaptive immune responses. Conversely, while blood stage parasites can induce a strong proinflammatory response, regulatory mechanisms are also triggered. In agreement with this, intact parasites are relatively weakly sensed by innate immune cells, but isolated parasite molecules, notably DNA and RNA can induce strong responses. Thus, the innate response to Plasmodium parasite likely represents a trade-off between strong pro-inflammatory responses that may potentiate immunity and regulatory processes that protect the host from cytokine storms that can induce life threatening illness.
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Affiliation(s)
- Kai Pohl
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität Berlin, Berlin, Germany
- Division of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University Canberra, Canberra, ACT, Australia
| | - Ian A. Cockburn
- Division of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University Canberra, Canberra, ACT, Australia
- *Correspondence: Ian A. Cockburn,
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6
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Giorgalli M, Cunningham DA, Broncel M, Sait A, Harrison TE, Hosking C, Vandomme A, Amis SI, Antonello A, Sullivan L, Uwadiae F, Torella L, Higgins MK, Langhorne J. Differential Trafficking and Expression of PIR Proteins in Acute and Chronic Plasmodium Infections. Front Cell Infect Microbiol 2022; 12:877253. [PMID: 35782145 PMCID: PMC9245118 DOI: 10.3389/fcimb.2022.877253] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/12/2022] [Indexed: 12/02/2022] Open
Abstract
Plasmodium multigene families are thought to play important roles in the pathogenesis of malaria. Plasmodium interspersed repeat (pir) genes comprise the largest multigene family in many Plasmodium species. However, their expression pattern and localisation remain to be elucidated. Understanding protein subcellular localisation is fundamental to reveal the functional importance and cell-cell interactions of the PIR proteins. Here, we use the rodent malaria parasite, Plasmodium chabaudi chabaudi, as a model to investigate the localisation pattern of this gene family. We found that most PIR proteins are co-expressed in clusters during acute and chronic infection; members of the S7 clade are predominantly expressed during the acute-phase, whereas members of the L1 clade dominate the chronic-phase of infection. Using peptide antisera specific for S7 or L1 PIRS, we show that these PIRs have different localisations within the infected red blood cells. S7 PIRs are exported into the infected red blood cell cytoplasm where they are co-localised with parasite-induced host cell modifications termed Maurer’s clefts, whereas L1 PIRs are localised on or close to the parasitophorous vacuolar membrane. This localisation pattern changes following mosquito transmission and during progression from acute- to chronic-phase of infection. The presence of PIRs in Maurer’s clefts, as seen for Plasmodium falciparum RIFIN and STEVOR proteins, might suggest trafficking of the PIRs on the surface of the infected erythrocytes. However, neither S7 nor L1 PIR proteins detected by the peptide antisera are localised on the surface of infected red blood cells, suggesting that they are unlikely to be targets of surface variant-specific antibodies or to be directly involved in adhesion of infected red blood cells to host cells, as described for Plasmodium falciparum VAR proteins. The differences in subcellular localisation of the two major clades of Plasmodium chabaudi PIRs across the blood cycle, and the apparent lack of expression on the red cell surface strongly suggest that the function(s) of this gene family may differ from those of other multigene families of Plasmodium, such as the var genes of Plasmodium falciparum.
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Affiliation(s)
- Maria Giorgalli
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | | | - Malgorzata Broncel
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Aaron Sait
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Thomas E. Harrison
- Laboratory of Molecular Parasitology, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Caroline Hosking
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Audrey Vandomme
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Sarah I. Amis
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ana Antonello
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lauren Sullivan
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Faith Uwadiae
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Laura Torella
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Matthew K. Higgins
- Laboratory of Molecular Parasitology, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Jean Langhorne
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
- *Correspondence: Jean Langhorne,
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7
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Rabah H, Chukkalore D, El-Charabaty E, Mobarakai N. Babesiosis and the human immune system. IDCases 2022; 27:e01368. [PMID: 34993053 PMCID: PMC8713127 DOI: 10.1016/j.idcr.2021.e01368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 11/21/2022] Open
Abstract
Immunological phenomena have been described in infections such as infective endocarditis. However, none has been reported in the context of Babesiosis. Babesiosis is a tick-borne illness caused by the protozoa of the genus Babesia and causes infections that range from asymptomatic to severe and sometimes are fatal. This report presents the first case of ANCA/ANA positive severe babesiosis in an asplenic patient treated with repeated red blood cell exchange transfusion.
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Affiliation(s)
- Hussein Rabah
- Staten Island University Hospital, Department of Medicine, New York, USA
| | - Divya Chukkalore
- Staten Island University Hospital, Department of Medicine, New York, USA
| | - Elie El-Charabaty
- Staten Island University Hospital, Department of Medicine, New York, USA
| | - Neville Mobarakai
- Staten Island University Hospital, Department of Medicine, New York, USA
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8
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Chadha A, Chadee K. The NF-κB Pathway: Modulation by Entamoeba histolytica and Other Protozoan Parasites. Front Cell Infect Microbiol 2021; 11:748404. [PMID: 34595137 PMCID: PMC8476871 DOI: 10.3389/fcimb.2021.748404] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/27/2021] [Indexed: 12/15/2022] Open
Abstract
Protozoan parasites have led to worldwide devastation because of their ability to cause infectious diseases. They have evolved as successful pathogens in part because of their remarkable and sophisticated ways to evade innate host defenses. This holds true for both intracellular and extracellular parasites that deploy multiple strategies to circumvent innate host defenses for their survival. The different strategies protozoan parasites use include hijacking the host cellular signaling pathways and transcription factors. In particular, the nuclear factor-κB (NF-κB) pathway seems to be an attractive target for different pathogens owing to their central role in regulating prompt innate immune responses in host defense. NF-κB is a ubiquitous transcription factor that plays an indispensable role not only in regulating immediate immune responses against invading pathogens but is also a critical regulator of cell proliferation and survival. The major immunomodulatory components include parasite surface and secreted proteins/enzymes and stimulation of host cells intracellular pathways and inflammatory caspases that directly or indirectly interfere with the NF-κB pathway to thwart immune responses that are directed for containment and/or elimination of the pathogen. To showcase how protozoan parasites exploits the NF-κB signaling pathway, this review highlights recent advances from Entamoeba histolytica and other protozoan parasites in contact with host cells that induce outside-in and inside-out signaling to modulate NF-κB in disease pathogenesis and survival in the host.
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Affiliation(s)
- Attinder Chadha
- Departments of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Kris Chadee
- Departments of Microbiology, Immunology, and Infectious Diseases, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
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9
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Xie Y, Li X, Chai Y, Song H, Qi J, Gao GF. Structural basis of malarial parasite RIFIN-mediated immune escape against LAIR1. Cell Rep 2021; 36:109600. [PMID: 34433057 DOI: 10.1016/j.celrep.2021.109600] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/17/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
Malaria infection by Plasmodium falciparum continues to pose a global threat to the human population. P. falciparum expresses variable erythrocyte surface antigens such as RIFINs. Public antibodies with LAIR1 insertion have been identified from malarial patients against a subset of RIFINs. In this study, we solve a LAIR1-binding RIFIN structure: the complex structures of two RIFINs bound to mutated or wild-type LAIR1 in two distinct patterns. Notably, the two RIFINs engage similar binding sites on LAIR1 with different angles, and the RIFIN-binding sites overlap with the collagen-binding site. Surprisingly, RIFINs use completely different binding sites to bind to LAIR1 or LILRB1, indicating the kaleidoscopic change of RIFINs. We then verify that RIFIN could induce LAIR1-mediated cell signaling, and LAIR1-containing antibodies could block the pathway. The findings of this study provide structural insights into the mechanism of the immune escape of P. falciparum and the endless arms race between parasite and host.
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Affiliation(s)
- Yijia Xie
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Li
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Chai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hao Song
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jianxun Qi
- University of Chinese Academy of Sciences, Beijing 100049, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - George F Gao
- Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Influenza Research and Early Warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China.
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10
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Memvanga PB, Nkanga CI. Liposomes for malaria management: the evolution from 1980 to 2020. Malar J 2021; 20:327. [PMID: 34315484 PMCID: PMC8313885 DOI: 10.1186/s12936-021-03858-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 07/16/2021] [Indexed: 12/31/2022] Open
Abstract
Malaria is one of the most prevalent parasitic diseases and the foremost cause of morbidity in the tropical regions of the world. Strategies for the efficient management of this parasitic infection include adequate treatment with anti-malarial therapeutics and vaccination. However, the emergence and spread of resistant strains of malaria parasites to the majority of presently used anti-malarial medications, on the other hand, complicates malaria treatment. Other shortcomings of anti-malarial drugs include poor aqueous solubility, low permeability, poor bioavailability, and non-specific targeting of intracellular parasites, resulting in high dose requirements and toxic side effects. To address these limitations, liposome-based nanotechnology has been extensively explored as a new solution in malaria management. Liposome technology improves anti-malarial drug encapsulation, bioavailability, target delivery, and controlled release, resulting in increased effectiveness, reduced resistance progression, and fewer adverse effects. Furthermore, liposomes are exploited as immunological adjuvants and antigen carriers to boost the preventive effectiveness of malaria vaccine candidates. The present review discusses the findings from studies conducted over the last 40 years (1980-2020) using in vitro and in vivo settings to assess the prophylactic and curative anti-malarial potential of liposomes containing anti-malarial agents or antigens. This paper and the discussion herein provide a useful resource for further complementary investigations and may pave the way for the research and development of several available and affordable anti-malarial-based liposomes and liposomal malaria vaccines by allowing a thorough evaluation of liposomes developed to date for the management of malaria.
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Affiliation(s)
- Patrick B Memvanga
- Faculty of Pharmaceutical Sciences, Laboratory of Pharmaceutics and Phytopharmaceutical Drug Development, University of Kinshasa, B.P. 212, Kinshasa XI, Democratic Republic of the Congo.
| | - Christian I Nkanga
- Faculty of Pharmaceutical Sciences, Laboratory of Pharmaceutics and Phytopharmaceutical Drug Development, University of Kinshasa, B.P. 212, Kinshasa XI, Democratic Republic of the Congo
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11
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Whitlock AOB, Juliano JJ, Mideo N. Immune selection suppresses the emergence of drug resistance in malaria parasites but facilitates its spread. PLoS Comput Biol 2021; 17:e1008577. [PMID: 34280179 PMCID: PMC8321109 DOI: 10.1371/journal.pcbi.1008577] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 07/29/2021] [Accepted: 06/04/2021] [Indexed: 12/23/2022] Open
Abstract
Although drug resistance in Plasmodium falciparum typically evolves in regions of low transmission, resistance spreads readily following introduction to regions with a heavier disease burden. This suggests that the origin and the spread of resistance are governed by different processes, and that high transmission intensity specifically impedes the origin. Factors associated with high transmission, such as highly immune hosts and competition within genetically diverse infections, are associated with suppression of resistant lineages within hosts. However, interactions between these factors have rarely been investigated and the specific relationship between adaptive immunity and selection for resistance has not been explored. Here, we developed a multiscale, agent-based model of Plasmodium parasites, hosts, and vectors to examine how host and parasite dynamics shape the evolution of resistance in populations with different transmission intensities. We found that selection for antigenic novelty (“immune selection”) suppressed the evolution of resistance in high transmission settings. We show that high levels of population immunity increased the strength of immune selection relative to selection for resistance. As a result, immune selection delayed the evolution of resistance in high transmission populations by allowing novel, sensitive lineages to remain in circulation at the expense of the spread of a resistant lineage. In contrast, in low transmission settings, we observed that resistant strains were able to sweep to high population prevalence without interference. Additionally, we found that the relationship between immune selection and resistance changed when resistance was widespread. Once resistance was common enough to be found on many antigenic backgrounds, immune selection stably maintained resistant parasites in the population by allowing them to proliferate, even in untreated hosts, when resistance was linked to a novel epitope. Our results suggest that immune selection plays a role in the global pattern of resistance evolution. Drug resistance in the malaria parasite, Plasmodium falciparum, presents an ongoing public health challenge, but aspects of its evolution are poorly understood. Although antimalarial resistance is common worldwide, it can typically be traced to just a handful of evolutionary origins. Counterintuitively, although Sub Saharan Africa bears 90% of the global malaria burden, resistance typically originates in regions where transmission intensity is low. In high transmission regions, infections are genetically diverse, and hosts have significant standing adaptive immunity, both of which are known to suppress the frequency of resistance within infections. However, interactions between immune-driven selection, transmission intensity, and resistance have not been investigated. Using a multiscale, agent-based model, we found that high transmission intensity slowed the evolution of resistance via its effect on host population immunity. High host immunity strengthened selection for antigenic novelty, interfering with selection for resistance and allowing sensitive lineages to suppress resistant lineages in untreated hosts. However, once resistance was common in the circulating parasite population, immune selection maintained it in the population at a high prevalence. Our findings provide a novel explanation for observations about the origin of resistance and suggest that adaptive immunity is a critical component of selection.
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Affiliation(s)
| | - Jonathan J. Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Nicole Mideo
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada
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12
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Xu K, Wang Y, Shen CH, Chen Y, Zhang B, Liu K, Tsybovsky Y, Wang S, Farney SK, Gorman J, Stephens T, Verardi R, Yang Y, Zhou T, Chuang GY, Lanzavecchia A, Piccoli L, Kwong PD. Structural basis of LAIR1 targeting by polymorphic Plasmodium RIFINs. Nat Commun 2021; 12:4226. [PMID: 34244481 PMCID: PMC8270905 DOI: 10.1038/s41467-021-24291-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/11/2021] [Indexed: 11/18/2022] Open
Abstract
RIFIN, a large family of Plasmodium variant surface antigens, plays a crucial role in malaria pathogenesis by mediating immune suppression through activation of inhibitory receptors such as LAIR1, and antibodies with LAIR1 inserts have been identified that bind infected erythrocytes through RIFIN. However, details of RIFIN-mediated LAIR1 recognition and receptor activation have been unclear. Here, we use negative-stain EM to define the architecture of LAIR1-inserted antibodies and determine crystal structures of RIFIN-variable 2 (V2) domain in complex with a LAIR1 domain. These structures reveal the LAIR1-binding region of RIFIN to be hydrophobic and membrane-distal, to exhibit extensive structural diversity, and to interact with RIFIN-V2 in a one-to-one fashion. Through structural and sequence analysis of various LAIR1 constructs, we identify essential elements of RIFIN-binding on LAIR1. Furthermore, a structure-derived LAIR1-binding sequence signature ascertained >20 LAIR1-binding RIFINs, including some from P. falciparum field strains and Plasmodium species infecting gorillas and chimpanzees.
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MESH Headings
- Antibodies, Protozoan/genetics
- Antibodies, Protozoan/metabolism
- Antigenic Variation/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/metabolism
- Antigens, Protozoan/ultrastructure
- Crystallography, X-Ray
- Humans
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Membrane Proteins/immunology
- Membrane Proteins/metabolism
- Membrane Proteins/ultrastructure
- Mutation
- Plasmodium falciparum/immunology
- Plasmodium falciparum/metabolism
- Protein Domains/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/metabolism
- Protozoan Proteins/ultrastructure
- Receptors, Immunologic/immunology
- Receptors, Immunologic/metabolism
- Receptors, Immunologic/ultrastructure
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Affiliation(s)
- Kai Xu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
| | - Yiran Wang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Chen-Hsiang Shen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Yiwei Chen
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
- Institute of Microbiology, ETH Zurich, Wolfgang-Pauli-Strasse 10, Zurich, Switzerland
| | - Baoshan Zhang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kevin Liu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Yaroslav Tsybovsky
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Shuishu Wang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - S Katie Farney
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tyler Stephens
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Yongping Yang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
- National Institute of Molecular Genetics (INGM), Milano, Italy
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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13
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Vijayan K, Wei L, Glennon EKK, Mattocks C, Bourgeois N, Staker B, Kaushansky A. Host-targeted Interventions as an Exciting Opportunity to Combat Malaria. Chem Rev 2021; 121:10452-10468. [PMID: 34197083 DOI: 10.1021/acs.chemrev.1c00062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Terminal and benign diseases alike in adults, children, pregnant women, and others are successfully treated by pharmacological inhibitors that target human enzymes. Despite extensive global efforts to fight malaria, the disease continues to be a massive worldwide health burden, and new interventional strategies are needed. Current drugs and vector control strategies have contributed to the reduction in malaria deaths over the past 10 years, but progress toward eradication has waned in recent years. Resistance to antimalarial drugs is a substantial and growing problem. Moreover, targeting dormant forms of the malaria parasite Plasmodium vivax is only possible with two approved drugs, which are both contraindicated for individuals with glucose-6-phosphate dehydrogenase deficiency and in pregnant women. Plasmodium parasites are obligate intracellular parasites and thus have specific and absolute requirements of their hosts. Growing evidence has described these host necessities, paving the way for opportunities to pharmacologically target host factors to eliminate Plasmodium infection. Here, we describe progress in malaria research and adjacent fields and discuss key challenges that remain in implementing host-directed therapy against malaria.
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Affiliation(s)
| | - Ling Wei
- Seattle Children's Research Institute, Seattle, Washington 98109, United States
| | | | - Christa Mattocks
- Department of Global Health, University of Washington, Seattle, Washington 98195, United States
| | - Natasha Bourgeois
- Seattle Children's Research Institute, Seattle, Washington 98109, United States.,Department of Global Health, University of Washington, Seattle, Washington 98195, United States
| | - Bart Staker
- Seattle Children's Research Institute, Seattle, Washington 98109, United States
| | - Alexis Kaushansky
- Seattle Children's Research Institute, Seattle, Washington 98109, United States.,Department of Global Health, University of Washington, Seattle, Washington 98195, United States.,Department of Pediatrics, University of Washington, Seattle, Washington 98105, United States.,Brotman Baty Institute for Precision Medicine, Seattle, Washington 98195, United States
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14
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Doritchamou JYA, Suurbaar J, Tuikue Ndam N. Progress and new horizons toward a VAR2CSA-based placental malaria vaccine. Expert Rev Vaccines 2021; 20:215-226. [PMID: 33472449 DOI: 10.1080/14760584.2021.1878029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Several malaria vaccines are under various phases of development with some promising results. In placental malaria (PM) a deliberately anti-disease approach is considered as many studies have underlined the key role of VAR2CSA protein, which therefore represents the leading vaccine candidate. However, evidence indicates that VAR2CSA antigenic polymorphism remains an obstacle to overcome.Areas covered: This review analyzes the progress made thus far in developing a VAR2CSA-based vaccine, and addresses the current issues and challenges that must be overcome to develop an effective PM vaccine.Expert opinion: Phase I trials of PAMVAC and PRIMVAC VAR2CSA vaccines have shown more or less satisfactory results with regards to safety and immunogenicity. The second generation of VAR2CSA-based vaccines could benefit from optimization approaches to broaden the activity spectrum against various placenta-binding isolates through continued advances in the structural understanding of the interaction with CSA.
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Affiliation(s)
- Justin Yai Alamou Doritchamou
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer Suurbaar
- Université de Paris, MERIT, IRD, F-75006 Paris, France.,Noguchi Memorial Institute for Medical Research, Department of Immunology, University of Ghana, Accra, Ghana
| | - Nicaise Tuikue Ndam
- Université de Paris, MERIT, IRD, F-75006 Paris, France.,Noguchi Memorial Institute for Medical Research, Department of Immunology, University of Ghana, Accra, Ghana
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15
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Wu Y, Bouws P, Lorenzen S, Bruchhaus I, Metwally NG. Analysis of the Interaction Between Plasmodium falciparum-Infected Erythrocytes and Human Endothelial Cells Using a Laminar Flow System, Bioinformatic Tracking and Transcriptome Analysis. Methods Mol Biol 2021; 2369:187-197. [PMID: 34313990 DOI: 10.1007/978-1-0716-1681-9_11] [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] [Indexed: 06/13/2023]
Abstract
During malaria infection, the endothelial lining of the small blood vessels of the brain and other vital organs is strongly stimulated. This leads to fatal complications and poor prognosis of the infection. It is believed that two main reasons are responsible for this pathology, namely the cytoadhesion of Plasmodium falciparum-infected erythrocytes (IEs) on the one hand and the proinflammatory products released by the IEs which activate the endothelial cells (ECs) on the other hand. Until recently, most of the studies that characterized the activation of ECs were performed under static conditions, which do not reflect the real sequelae in vivo. In this chapter, we present a system, which allows authentic simulation of the IEs-ECs interactions during P. falciparum infection.The main idea of the system is to provide an adequate shear stress over the ECs during the cytoadhesion and stimulation with IEs, which provides a better basis for the investigation of the cytoadhesion pathology through analyzing the ECs' transcriptome after stimulation. On the other hand, analyzing the transcriptome of the IEs might also give deeper analysis of their response to shear stress. Deep understanding of these events might help in the development of novel treatment strategies that interfere with this cell-cell interaction.
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Affiliation(s)
- Yifan Wu
- Bernhard Nocht Institut for Tropical Medicine, Hamburg, Germany
| | - Philip Bouws
- Bernhard Nocht Institut for Tropical Medicine, Hamburg, Germany
| | | | - Iris Bruchhaus
- Bernhard Nocht Institut for Tropical Medicine, Hamburg, Germany.
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16
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Childs LM, Larremore DB. Network Models for Malaria: Antigens, Dynamics, and Evolution Over Space and Time. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11512-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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17
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Kiyuka PK, Meri S, Khattab A. Complement in malaria: immune evasion strategies and role in protective immunity. FEBS Lett 2020; 594:2502-2517. [PMID: 32181490 PMCID: PMC8653895 DOI: 10.1002/1873-3468.13772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 12/12/2022]
Abstract
The malaria parasite has for long been thought to escape host complement attack as a survival strategy. However, it was only recently that complement evasion mechanisms of the parasite were described. Simultaneously, the role of complement in antibody-mediated naturally acquired and vaccine-induced protection against malaria has also been reported. Such findings should be considered in future vaccine design, given the current need to develop more efficacious vaccines against malaria. Parasite antigens derived from molecules mediating functions crucial for parasite survival, such as complement evasion, or parasite antigens against which antibody responses lead to an efficient complement attack could present new candidates for vaccines. In this review, we discuss recent findings on complement evasion by the malaria parasites and the emerging role of complement in antibody-mediated protection against malaria. We emphasize that immune responses to vaccines based on complement inhibitors should not only induce complement-activating antibodies but also neutralize the escape mechanisms of the parasite.
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Affiliation(s)
- Patience Kerubo Kiyuka
- Department of Bacteriology and Immunology, Translational Immunology Research Program, Haartman Institute, University of Helsinki, Finland
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Seppo Meri
- Department of Bacteriology and Immunology, Translational Immunology Research Program, Haartman Institute, University of Helsinki, Finland
- Helsinki University Central Hospital, Finland
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - Ayman Khattab
- Department of Bacteriology and Immunology, Translational Immunology Research Program, Haartman Institute, University of Helsinki, Finland
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
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18
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Brown DD, Solomon S, Lerner D, Del Rio M. Malaria and acute kidney injury. Pediatr Nephrol 2020; 35:603-608. [PMID: 30706124 DOI: 10.1007/s00467-018-4191-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 12/19/2018] [Accepted: 12/28/2018] [Indexed: 10/27/2022]
Abstract
Malaria is a parasitic infection transmitted by mosquitos, resulting in significant morbidity and mortality. It affects 212 million worldwide, causing death in up to 303,000 children annually. In the USA, up to 1700 people are affected yearly. Although the prevalence in developed countries is less than in developing countries, travelers from low transmission areas, and those from endemic areas who later return, are very susceptible to malaria and its complications. Severe malaria can cause significant multiorgan dysfunction including acute kidney injury (AKI). The pathogenesis is not clearly understood but proposed mechanisms include acute tubular necrosis (ATN) due to impediments in renal microcirculation, infection-triggered proinflammatory reactions within the kidney, and metabolic disturbances. Providers must consider malarial infection in cases of AKI in someone with a travel history, as early recognition and treatment are crucial to improving outcomes. This article will review malaria-induced AKI in order to provide a better understanding of this infection's effect on the kidneys.
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Affiliation(s)
- Denver D Brown
- Department of Pediatric Nephrology at The Children's Hospital at Montefiore, 3326 Bainbridge Ave, Bronx, NY, 10029, USA.
| | - Sonia Solomon
- Department of Pediatric Nephrology at The Children's Hospital at Montefiore, 3326 Bainbridge Ave, Bronx, NY, 10029, USA
| | - Daniele Lerner
- Department of Pediatric Nephrology at The Children's Hospital at Montefiore, 3326 Bainbridge Ave, Bronx, NY, 10029, USA
| | - Marcela Del Rio
- Department of Pediatric Nephrology at The Children's Hospital at Montefiore, 3326 Bainbridge Ave, Bronx, NY, 10029, USA
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19
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Lubiana P, Bouws P, Roth LK, Dörpinghaus M, Rehn T, Brehmer J, Wichers JS, Bachmann A, Höhn K, Roeder T, Thye T, Gutsmann T, Burmester T, Bruchhaus I, Metwally NG. Adhesion between P. falciparum infected erythrocytes and human endothelial receptors follows alternative binding dynamics under flow and febrile conditions. Sci Rep 2020; 10:4548. [PMID: 32161335 PMCID: PMC7066226 DOI: 10.1038/s41598-020-61388-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/25/2020] [Indexed: 11/10/2022] Open
Abstract
Characterizing the adhesive dynamics of Plasmodium falciparum infected erythrocytes (IEs) to different endothelial cell receptors (ECRs) in flow is a big challenge considering available methods. This study investigated the adhesive dynamics of IEs to five ECRs (CD36, ICAM-1, P-selectin, CD9, CSA) using simulations of in vivo-like flow and febrile conditions. To characterize the interactions between ECRs and knobby and knobless IEs of two laboratory-adapted P. falciplarum isolates, cytoadhesion analysis over time was performed using a new tracking bioinformatics method. The results revealed that IEs performed rolling adhesion exclusively over CD36, but exhibited stationary binding to the other four ECRs. The absence of knobs affected rolling adhesion both with respect to the distance travelled by IEs and their velocity. Knobs played a critical role at febrile temperatures by stabilizing the binding interaction. Our results clearly underline the complexity of the IE-receptor interaction and the importance of knobs for the survival of the parasite at fever temperatures, and lead us to propose a new hypothesis that could open up new strategies for the treatment of malaria.
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Affiliation(s)
- Pedro Lubiana
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Philip Bouws
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | | | - Torben Rehn
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jana Brehmer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Katharina Höhn
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Thomas Roeder
- Molecular Physiology Department, Zoological Institute, Christian-Albrechts University Kiel, Kiel, Germany
| | - Thorsten Thye
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Thomas Gutsmann
- Division of Biophysics, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
| | - Thorsten Burmester
- Zoological Institute, Department of Molecular Physiology, Hamburg University, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. .,Department of Biology, University of Hamburg, Hamburg, Germany.
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20
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Old and Recent Advances in Life Cycle, Pathogenesis, Diagnosis, Prevention, and Treatment of Malaria Including Perspectives in Ethiopia. ScientificWorldJournal 2020. [DOI: 10.1155/2020/1295381] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Malaria, caused by apicomplexan parasite, is an old disease and continues to be a major public health threat in many countries. This article aims to present different aspects of malaria including causes, pathogenesis, prevention, and treatment in an articulate and comprehensive manner. Six Plasmodium species are recognized as the etiology of human malaria, of which Plasmodium falciparum is popular in East and Southern Africa. Malaria is transmitted mainly through Anopheles gambiae and Anopheles funestus, the two most effective malaria vectors in the world. Half of the world’s population is at risk for malaria infection. Globally, the morbidity and mortality rates of malaria have become decreased even though few reports in Ethiopia showed high prevalence of malaria. The malaria parasite has a complex life cycle that takes place both inside the mosquito and human beings. Generally, diagnosis of malaria is classified into clinical and parasitological diagnoses. Lack of clear understanding on the overall biology of Plasmodium has created a challenge in an effort to develop new drugs, vaccines, and preventive methods against malaria. However, three types of vaccines and a lot of novel compounds are under perclinical and clinical studies that are triggered by the occurrence of resistance among commonly used drugs and insecticides. Antiadhesion adjunctive therapies are also under investigation in the laboratory. In addition to previously known targets for diagnostic tool, vaccine and drug discovery scientists from all corner of the world are in search of new targets and chemical entities.
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21
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Oludele OJ, Adisa BA, Olufunso OO. Regulated rutin co-administration reverses mitochondrial-mediated apoptosis in Plasmodium berghei-infected mice. Biochem Biophys Res Commun 2019; 522:328-334. [PMID: 31767147 DOI: 10.1016/j.bbrc.2019.11.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 11/11/2019] [Indexed: 12/19/2022]
Abstract
Malarial infection causes apoptosis in hepatocytes. However, it is not known if co-administration of antimalarial drug with rutin will reverse the apoptotic effects of malarial infection. Plasmodium berghei-infected mice were assigned into groups as follows: groups I to III were treated with the vehicle (Parasitised Untreated, PU), 10 mg/kg body weight of Artesunate-Mefloquine (AM) and Dihydroartemisinin-Piperaquine (DP) respectively. Groups IV to VII were treated with AM, DP but co-administered with 100, 200 mg rutin/kg body weight while groups VIII and IX received rutin (100 and 200 mg/kg body weight). Liver mitochondrial Permeability Transition (mPT) and ATPase (mATPase) were determined spectrophotometrically. Caspases 3 and 9 were assayed using ELISA while the levels of bax, cytochrome c release (CCR), p53 and bcl-2 expressions were assayed immunohistochemically. The mPT pore opening fold of 5 (PU), 16 (AM), 14 (AM + 100 mg rutin/kg body weight), 9 (AM + 200 mg rutin/kg body weight), 4(DP), were observed relative to calcium (24) while DP, rutin and their combinations did not open the pore. AM and DP significantly increased caspases 3 and 9 activities, enhanced mATPase activity but co-treatment with rutin (100 mg/kg) decreased these effects significantly. AM + rutin (100 mg/kg body weight) significantly decreased bax, p53, CCR and increased bcl-2 expression. The results showed that supplementing malarial treatment with rutin decreased apoptosis suggesting that rutin supplementation can minimise apoptosis in malarial infection.
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Affiliation(s)
- Olanlokun John Oludele
- Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Nigeria.
| | - Balogun Abayomi Adisa
- Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Nigeria
| | - Olorunsogo Olabode Olufunso
- Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Nigeria
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22
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Host Cytoskeleton Remodeling throughout the Blood Stages of Plasmodium falciparum. Microbiol Mol Biol Rev 2019; 83:83/4/e00013-19. [PMID: 31484690 DOI: 10.1128/mmbr.00013-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The asexual intraerythrocytic development of Plasmodium falciparum, causing the most severe form of human malaria, is marked by extensive host cell remodeling. Throughout the processes of invasion, intracellular development, and egress, the erythrocyte membrane skeleton is remodeled by the parasite as required for each specific developmental stage. The remodeling is facilitated by a plethora of exported parasite proteins, and the erythrocyte membrane skeleton is the interface of most of the observed interactions between the parasite and host cell proteins. Host cell remodeling has been extensively described and there is a vast body of information on protein export or the description of parasite-induced structures such as Maurer's clefts or knobs on the host cell surface. Here we specifically review the molecular level of each host cell-remodeling step at each stage of the intraerythrocytic development of P. falciparum We describe key events, such as invasion, knob formation, and egress, and identify the interactions between exported parasite proteins and the host cell cytoskeleton. We discuss each remodeling step with respect to time and specific requirement of the developing parasite to explain host cell remodeling in a stage-specific manner. Thus, we highlight the interaction with the host membrane skeleton as a key event in parasite survival.
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23
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Izak D, Klim J, Kaczanowski S. Host-parasite interactions and ecology of the malaria parasite-a bioinformatics approach. Brief Funct Genomics 2019; 17:451-457. [PMID: 29697785 DOI: 10.1093/bfgp/ely013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Malaria remains one of the highest mortality infectious diseases. Malaria is caused by parasites from the genus Plasmodium. Most deaths are caused by infections involving Plasmodium falciparum, which has a complex life cycle. Malaria parasites are extremely well adapted for interactions with their host and their host's immune system and are able to suppress the human immune system, erase immunological memory and rapidly alter exposed antigens. Owing to this rapid evolution, parasites develop drug resistance and express novel forms of antigenic proteins that are not recognized by the host immune system. There is an emerging need for novel interventions, including novel drugs and vaccines. Designing novel therapies requires knowledge about host-parasite interactions, which is still limited. However, significant progress has recently been achieved in this field through the application of bioinformatics analysis of parasite genome sequences. In this review, we describe the main achievements in 'malarial' bioinformatics and provide examples of successful applications of protein sequence analysis. These examples include the prediction of protein functions based on homology and the prediction of protein surface localization via domain and motif analysis. Additionally, we describe PlasmoDB, a database that stores accumulated experimental data. This tool allows data mining of the stored information and will play an important role in the development of malaria science. Finally, we illustrate the application of bioinformatics in the development of population genetics research on malaria parasites, an approach referred to as reverse ecology.
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Affiliation(s)
- Dariusz Izak
- Department of Bioinformatics at the Institute of Biochemistry and Biophysics of the Polish Academy of Sciences
| | - Joanna Klim
- Department of Microbial Chemistry at the Institute of Biochemistry and Biophysics of the Polish Academy of Sciences
| | - Szymon Kaczanowski
- Department of Bioinformatics at the Institute of Biochemistry and Biophysics of the Polish Academy of Sciences
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24
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Bruske E, Otto TD, Frank M. Whole genome sequencing and microsatellite analysis of the Plasmodium falciparum E5 NF54 strain show that the var, rifin and stevor gene families follow Mendelian inheritance. Malar J 2018; 17:376. [PMID: 30348135 PMCID: PMC6198375 DOI: 10.1186/s12936-018-2503-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022] Open
Abstract
Background Plasmodium falciparum exhibits a high degree of inter-isolate genetic diversity in its variant surface antigen (VSA) families: P. falciparum erythrocyte membrane protein 1, repetitive interspersed family (RIFIN) and subtelomeric variable open reading frame (STEVOR). The role of recombination for the generation of this diversity is a subject of ongoing research. Here the genome of E5, a sibling of the 3D7 genome strain is presented. Short and long read whole genome sequencing (WGS) techniques (Ilumina, Pacific Bioscience) and a set of 84 microsatellites (MS) were employed to characterize the 3D7 and non-3D7 parts of the E5 genome. This is the first time that VSA genes in sibling parasites were analysed with long read sequencing technology. Results Of the 5733 E5 genes only 278 genes, mostly var and rifin/stevor genes, had no orthologues in the 3D7 genome. WGS and MS analysis revealed that chromosomal crossovers occurred at a rate of 0–3 per chromosome. var, stevor and rifin genes were inherited within the respective non-3D7 or 3D7 chromosomal context. 54 of the 84 MS PCR fragments correctly identified the respective MS as 3D7- or non-3D7 and this correlated with var and rifin/stevor gene inheritance in the adjacent chromosomal regions. E5 had 61 var and 189 rifin/stevor genes. One large non-chromosomal recombination event resulted in a new var gene on chromosome 14. The remainder of the E5 3D7-type subtelomeric and central regions were identical to 3D7. Conclusions The data show that the rifin/stevor and var gene families represent the most diverse compartments of the P. falciparum genome but that the majority of var genes are inherited without alterations within their respective parental chromosomal context. Furthermore, MS genotyping with 54 MS can successfully distinguish between two sibling progeny of a natural P. falciparum cross and thus can be used to investigate identity by descent in field isolates. Electronic supplementary material The online version of this article (10.1186/s12936-018-2503-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ellen Bruske
- Institute of Tropical Medicine, University of Tuebingen, Wilhelmstr. 27, 72074, Tuebingen, Germany
| | - Thomas D Otto
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK. .,Centre of Immunobiology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Matthias Frank
- Institute of Tropical Medicine, University of Tuebingen, Wilhelmstr. 27, 72074, Tuebingen, Germany.
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25
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Yam XY, Preiser PR. Host immune evasion strategies of malaria blood stage parasite. MOLECULAR BIOSYSTEMS 2018; 13:2498-2508. [PMID: 29091093 DOI: 10.1039/c7mb00502d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Host immune evasion is a key strategy for the continual survival of many microbial pathogens including Apicomplexan protozoan: Plasmodium spp., the causative agent of Malaria. The malaria parasite has evolved a variety of mechanisms to evade the host immune responses within its two hosts: the female Anopheles mosquito vector and vertebrate host. In this review, we will focus on the molecular mechanisms of the immune evasion strategies used by the Plasmodium parasite at the blood stage which is responsible for the clinical manifestations of human malaria. We also aim to provide some insights on the potential targets for malaria interventions through the recent advancement in understanding the molecular biology of the parasite.
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Affiliation(s)
- Xue Yan Yam
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
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26
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Hemmink JD, Sitt T, Pelle R, de Klerk-Lorist LM, Shiels B, Toye PG, Morrison WI, Weir W. Ancient diversity and geographical sub-structuring in African buffalo Theileria parva populations revealed through metagenetic analysis of antigen-encoding loci. Int J Parasitol 2018; 48:287-296. [PMID: 29408266 PMCID: PMC5854372 DOI: 10.1016/j.ijpara.2017.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/17/2017] [Accepted: 10/21/2017] [Indexed: 10/27/2022]
Abstract
An infection and treatment protocol involving infection with a mixture of three parasite isolates and simultaneous treatment with oxytetracycline is currently used to vaccinate cattle against Theileria parva. While vaccination results in high levels of protection in some regions, little or no protection is observed in areas where animals are challenged predominantly by parasites of buffalo origin. A previous study involving sequencing of two antigen-encoding genes from a series of parasite isolates indicated that this is associated with greater antigenic diversity in buffalo-derived T. parva. The current study set out to extend these analyses by applying high-throughput sequencing to ex vivo samples from naturally infected buffalo to determine the extent of diversity in a set of antigen-encoding genes. Samples from two populations of buffalo, one in Kenya and the other in South Africa, were examined to investigate the effect of geographical distance on the nature of sequence diversity. The results revealed a number of significant findings. First, there was a variable degree of nucleotide sequence diversity in all gene segments examined, with the percentage of polymorphic nucleotides ranging from 10% to 69%. Second, large numbers of allelic variants of each gene were found in individual animals, indicating multiple infection events. Third, despite the observed diversity in nucleotide sequences, several of the gene products had highly conserved amino acid sequences, and thus represent potential candidates for vaccine development. Fourth, although compelling evidence for population differentiation between the Kenyan and South African T. parva parasites was identified, analysis of molecular variance for each gene revealed that the majority of the underlying nucleotide sequence polymorphism was common to both areas, indicating that much of this aspect of genetic variation in the parasite population arose prior to geographic separation.
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Affiliation(s)
- Johanneke D Hemmink
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK; The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Tatjana Sitt
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Roger Pelle
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Lin-Mari de Klerk-Lorist
- Department of Agriculture, Forestry and Fisheries (DAFF), National Department of Agriculture, PO Box 12, Skukuza, Kruger National Park, 1350, South Africa
| | - Brian Shiels
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Henry Wellcome Building, Garscube Campus, Bearsden Road, Glasgow G61 1QH, UK
| | - Philip G Toye
- The International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - W Ivan Morrison
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK.
| | - William Weir
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Henry Wellcome Building, Garscube Campus, Bearsden Road, Glasgow G61 1QH, UK; School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK
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27
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Role of Chromatin assembly factor 1 in DNA replication of Plasmodium falciparum. Biochem Biophys Res Commun 2018; 495:1285-1291. [DOI: 10.1016/j.bbrc.2017.11.131] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 11/19/2017] [Indexed: 01/11/2023]
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28
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Saito F, Hirayasu K, Satoh T, Wang CW, Lusingu J, Arimori T, Shida K, Palacpac NMQ, Itagaki S, Iwanaga S, Takashima E, Tsuboi T, Kohyama M, Suenaga T, Colonna M, Takagi J, Lavstsen T, Horii T, Arase H. Immune evasion of Plasmodium falciparum by RIFIN via inhibitory receptors. Nature 2017; 552:101-105. [PMID: 29186116 PMCID: PMC5748893 DOI: 10.1038/nature24994] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 11/02/2017] [Indexed: 11/25/2022]
Abstract
Malaria is among the most serious infectious diseases affecting humans, accounting for approximately half a million deaths annually1. Plasmodium falciparum is the causative agent of most life-threatening malaria cases. Acquired immunity to malaria is inefficient, even after repeated exposures to P. falciparum2; immune regulatory mechanisms employed by P. falciparum remain largely unclear. Here, we show that P. falciparum uses immune inhibitory receptors for immune evasion. RIFINs, products of a polymorphic multigene family comprising approximately 150–200 genes per parasite genome3, are expressed on the surface of infected erythrocytes. We found that a subset of RIFINs binds to either leucocyte immunoglobulin-like receptor B1 (LILRB1) or leucocyte-associated immunoglobulin-like receptor 1 (LAIR1). LILRB1-binding RIFINs inhibited activation of LILRB1-expressing B cells and NK cells. Furthermore, interactions between LILRB1 and P. falciparum-infected erythrocytes isolated from malaria patients were associated with severe malaria, although an extended study with larger sample sizes is required to confirm the findings. These results suggest that P. falciparum has acquired multiple RIFINs to evade the host immune system by targeting immune inhibitory receptors.
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Affiliation(s)
- Fumiji Saito
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kouyuki Hirayasu
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takeshi Satoh
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Christian W Wang
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - John Lusingu
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Takao Arimori
- Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kyoko Shida
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Nirianne Marie Q Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Sawako Itagaki
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shiroh Iwanaga
- Department of Medical Zoology, School of Medicine, Mie University, Tsu, Mie 514-8507, Japan.,Department of Environmental Parasitology, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Centre, Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Centre, Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Masako Kohyama
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tadahiro Suenaga
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Junichi Takagi
- Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hisashi Arase
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
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29
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Naturally Acquired Antibody Responses to a Synthetic Malaria Antigen AS202.11. J Trop Med 2017; 2017:6843701. [PMID: 29138641 PMCID: PMC5613363 DOI: 10.1155/2017/6843701] [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: 05/08/2017] [Accepted: 08/07/2017] [Indexed: 11/20/2022] Open
Abstract
Background A major challenge to malaria vaccine development is identification of protective epitopes and respective protective immune responses. Objective To characterize naturally acquired Immunoglobulin G (IgG) responses to the synthetic peptide AS202.11, a malaria vaccine candidate. Methodology This community based cross-sectional study enrolled 320 participants aged 1 year and above. Demographic information was recorded through interviews. Detection of P. falciparum infection was done by microscopy, malaria rapid diagnostic test, and polymerase chain reaction. ELISA was used to detect IgG antibody. Data was analyzed using STATA. Results The overall AS202.11 IgG seropositivity was 78.8% (73.9–82.9). Seropositivity by age categories was ≤12 years [74.3% (67.4–80.2)], 13–40 years [85.3% (76.5–91.1)], and >40 years [82.6% (68.7–91.1)]. Compared to the ≤ 12-year-old group, aORs for the other groups were 2.22 (1.14–4.32), p = 0.019, and 1.87 (0.81–4.35), p = 0.143, for the 13–40-year-old and >40-year-old groups, respectively. The 13–40-year-old group had more seropositive individuals compared to the ≤ 12-year-old group. Conclusion We report a high degree of recognition of AS202.11 by IgG elicited by field P. falciparum strains, suggesting its close similarity to native P. falciparum antigens and possible suitability of the peptide as a future malaria vaccine candidate.
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30
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Abstract
Organisms with identical genome sequences can show substantial differences in their phenotypes owing to epigenetic changes that result in different use of their genes. Epigenetic regulation of gene expression plays a key role in the control of several fundamental processes in the biology of malaria parasites, including antigenic variation and sexual differentiation. Some of the histone modifications and chromatin-modifying enzymes that control the epigenetic states of malaria genes have been characterized, and their functions are beginning to be unraveled. The fundamental principles of epigenetic regulation of gene expression appear to be conserved between malaria parasites and model eukaryotes, but important peculiarities exist. Here, we review the current knowledge of malaria epigenetics and discuss how it can be exploited for the development of new molecular markers and new types of drugs that may contribute to malaria eradication efforts.
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Affiliation(s)
- Alfred Cortés
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia 08036, Spain.,ICREA, Barcelona, Catalonia 08010, Spain
| | - Kirk W Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10065
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31
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Abstract
Heparin is one of the oldest drugs, which nevertheless remains in widespread clinical use as an inhibitor of blood coagulation. The history of its identification a century ago unfolded amid one of the most fascinating scientific controversies turning around the distribution of credit for its discovery. The composition, purification and structure-function relationship of this naturally occurring glycosaminoglycan regarding its classical role as anticoagulant will be dealt with before proceeding to discuss its therapeutic potential in, among other, inflammatory and infectious disease, cancer treatment, cystic fibrosis and Alzheimer's disease. The first bibliographic reference hit using the words 'nanomedicine' and 'heparin' is as recent as 2008. Since then, nanomedical applications of heparin have experienced an exponential growth that will be discussed in detail, with particular emphasis on its antimalarial activity. Some of the most intriguing potential applications of heparin nanomedicines will be exposed, such as those contemplating the delivery of drugs to the mosquito stages of malaria parasites.
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Affiliation(s)
| | - Elena Lantero
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, ES-08028 Barcelona, Spain.,Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Rosselló 149-153, ES-08036 Barcelona, Spain
| | - Xavier Fernàndez-Busquets
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, ES-08028 Barcelona, Spain.,Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Rosselló 149-153, ES-08036 Barcelona, Spain.,Nanoscience & Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, ES-08028 Barcelona, Spain
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32
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Dara A, Drábek EF, Travassos MA, Moser KA, Delcher AL, Su Q, Hostelley T, Coulibaly D, Daou M, Dembele A, Diarra I, Kone AK, Kouriba B, Laurens MB, Niangaly A, Traore K, Tolo Y, Fraser CM, Thera MA, Djimde AA, Doumbo OK, Plowe CV, Silva JC. New var reconstruction algorithm exposes high var sequence diversity in a single geographic location in Mali. Genome Med 2017; 9:30. [PMID: 28351419 PMCID: PMC5368897 DOI: 10.1186/s13073-017-0422-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 03/02/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Encoded by the var gene family, highly variable Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP1) proteins mediate tissue-specific cytoadherence of infected erythrocytes, resulting in immune evasion and severe malaria disease. Sequencing and assembling the 40-60 var gene complement for individual infections has been notoriously difficult, impeding molecular epidemiological studies and the assessment of particular var elements as subunit vaccine candidates. METHODS We developed and validated a novel algorithm, Exon-Targeted Hybrid Assembly (ETHA), to perform targeted assembly of var gene sequences, based on a combination of Pacific Biosciences and Illumina data. RESULTS Using ETHA, we characterized the repertoire of var genes in 12 samples from uncomplicated malaria infections in children from a single Malian village and showed them to be as genetically diverse as vars from isolates from around the globe. The gene var2csa, a member of the var family associated with placental malaria pathogenesis, was present in each genome, as were vars previously associated with severe malaria. CONCLUSION ETHA, a tool to discover novel var sequences from clinical samples, will aid the understanding of malaria pathogenesis and inform the design of malaria vaccines based on PfEMP1. ETHA is available at: https://sourceforge.net/projects/etha/ .
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Affiliation(s)
- Antoine Dara
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD USA
| | - Elliott F. Drábek
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Mark A. Travassos
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD USA
| | - Kara A. Moser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Arthur L. Delcher
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Qi Su
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Timothy Hostelley
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Modibo Daou
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Ahmadou Dembele
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Issa Diarra
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye K. Kone
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Matthew B. Laurens
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD USA
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Karim Traore
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Youssouf Tolo
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Claire M. Fraser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD USA
| | - Mahamadou A. Thera
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye A. Djimde
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Ogobara K. Doumbo
- Malaria Research and Training Center, University of Science, Techniques and Technologies, Bamako, Mali
| | - Christopher V. Plowe
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD USA
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD USA
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33
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Antibody-independent mechanisms regulate the establishment of chronic Plasmodium infection. Nat Microbiol 2017; 2:16276. [PMID: 28165471 DOI: 10.1038/nmicrobiol.2016.276] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 12/22/2016] [Indexed: 01/15/2023]
Abstract
Malaria is caused by parasites of the genus Plasmodium. All human-infecting Plasmodium species can establish long-lasting chronic infections1-5, creating an infectious reservoir to sustain transmission1,6. It is widely accepted that the maintenance of chronic infection involves evasion of adaptive immunity by antigenic variation7. However, genes involved in this process have been identified in only two of five human-infecting species: Plasmodium falciparum and Plasmodium knowlesi. Furthermore, little is understood about the early events in the establishment of chronic infection in these species. Using a rodent model we demonstrate that from the infecting population, only a minority of parasites, expressing one of several clusters of virulence-associated pir genes, establishes a chronic infection. This process occurs in different species of parasites and in different hosts. Establishment of chronicity is independent of adaptive immunity and therefore different from the mechanism proposed for maintenance of chronic P. falciparum infections7-9. Furthermore, we show that the proportions of parasites expressing different types of pir genes regulate the time taken to establish a chronic infection. Because pir genes are common to most, if not all, species of Plasmodium10, this process may be a common way of regulating the establishment of chronic infections.
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Antibody responses to the full-length VAR2CSA and its DBL domains in Cameroonian children and teenagers. Malar J 2016; 15:532. [PMID: 27814765 PMCID: PMC5097422 DOI: 10.1186/s12936-016-1585-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antigenic variation of Plasmodium falciparum erythrocyte membrane protein 1 is a key parasite mechanism for immune evasion and parasite survival. It is assumed that the number of parasites expressing the same var gene must reach high enough numbers before the host can produce detectable levels of antibodies (Ab) to the variant. VAR2CSA is a protein coded for by one of 60 var genes that is expressed on the surface of infected erythrocytes (IE) and mediates IE binding to the placenta. The idea that Ab to VAR2CSA are pregnancy-associated was challenged when VAR2CSA-specific Ab were reported in children and men. However, the frequency and conditions under which Ab to VAR2CSA are produced outside pregnancy is unclear. This study sought to determine frequency, specificity and level of Ab to VAR2CSA produced in children and whether children with hyperparasitaemia and severe malaria are more likely to produce Ab to VAR2CSA compared to healthy children. METHODS Antibody responses to a panel of recombinant proteins consisting of multiple VAR2CSA Duffy-binding-like domains (DBL) and full-length VAR2CSA (FV2) were characterized in 193 1-15 year old children from rural Cameroonian villages and 160 children with severe malaria from the city. RESULTS Low Ab levels to VAR2CSA were detected in children; however, Ab levels to FV2 in teenagers were rare. Children preferentially recognized DBL2 (56-70%) and DBL4 (50-60%), while multigravidae produced high levels of IgG to DBL3, DBL5 and FV2. Sixty-seven percent of teenage girls (n = 16/24) recognized ID1-ID2a region of VAR2CSA. Children with severe forms of malaria had significantly higher IgG to merozoite antigens (all p < 0.05), but not to VAR2CSA (all p > 0.05) when compared to the healthy children. CONCLUSION The study suggests that children, including teenage girls acquire Ab to VAR2CSA domains and FV2, but Ab levels are much lower than those needed to protect women from placental infections and repertoire of Ab responses to DBL domains is different from those in pregnant women. Interestingly, children with severe malaria did not have higher Ab levels to VAR2CSA compared to healthy children.
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35
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Marques J, Valle-Delgado JJ, Urbán P, Baró E, Prohens R, Mayor A, Cisteró P, Delves M, Sinden RE, Grandfils C, de Paz JL, García-Salcedo JA, Fernàndez-Busquets X. Adaptation of targeted nanocarriers to changing requirements in antimalarial drug delivery. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2016; 13:515-525. [PMID: 27720930 PMCID: PMC5332526 DOI: 10.1016/j.nano.2016.09.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 09/05/2016] [Accepted: 09/25/2016] [Indexed: 11/19/2022]
Abstract
The adaptation of existing antimalarial nanocarriers to new Plasmodium stages, drugs, targeting molecules, or encapsulating structures is a strategy that can provide new nanotechnology-based, cost-efficient therapies against malaria. We have explored the modification of different liposome prototypes that had been developed in our group for the targeted delivery of antimalarial drugs to Plasmodium-infected red blood cells (pRBCs). These new models include: (i) immunoliposome-mediated release of new lipid-based antimalarials; (ii) liposomes targeted to pRBCs with covalently linked heparin to reduce anticoagulation risks; (iii) adaptation of heparin to pRBC targeting of chitosan nanoparticles; (iv) use of heparin for the targeting of Plasmodium stages in the mosquito vector; and (v) use of the non-anticoagulant glycosaminoglycan chondroitin 4-sulfate as a heparin surrogate for pRBC targeting. The results presented indicate that the tuning of existing nanovessels to new malaria-related targets is a valid low-cost alternative to the de novo development of targeted nanosystems.
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Affiliation(s)
- Joana Marques
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain
| | - Juan José Valle-Delgado
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain
| | - Patricia Urbán
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain
| | - Elisabet Baró
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain
| | - Rafel Prohens
- Unitat de Polimorfisme i Calorimetria, Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Spain
| | - Alfredo Mayor
- Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| | - Pau Cisteró
- Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| | - Michael Delves
- Department of Life Sciences, Imperial College, South Kensington, London, UK
| | - Robert E Sinden
- Department of Life Sciences, Imperial College, South Kensington, London, UK
| | - Christian Grandfils
- Interfacultary Research Center of Biomaterials (CEIB), University of Liège, Chemistry Institute, Liège (Sart-Tilman), Belgium
| | - José L de Paz
- Instituto de Investigaciones Químicas (IIQ) CSIC-US, Centro de Investigaciones Científicas Isla de La Cartuja, Sevilla, Spain
| | - José A García-Salcedo
- Unidad de Enfermedades Infecciosas y Microbiología, Instituto de Investigación Biosanitaria ibs. Granada, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
| | - Xavier Fernàndez-Busquets
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain.
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Wah ST, Hananantachai H, Kerdpin U, Plabplueng C, Prachayasittikul V, Nuchnoi P. Molecular basis of human cerebral malaria development. Trop Med Health 2016; 44:33. [PMID: 27708543 PMCID: PMC5037602 DOI: 10.1186/s41182-016-0033-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/14/2016] [Indexed: 12/18/2022] Open
Abstract
Cerebral malaria is still a deleterious health problem in tropical countries. The wide spread of malarial drug resistance and the lack of an effective vaccine are obstacles for disease management and prevention. Parasite and human genetic factors play important roles in malaria susceptibility and disease severity. The malaria parasite exerted a potent selective signature on the human genome, which is apparent in the genetic polymorphism landscape of genes related to pathogenesis. Currently, much genomic data and a novel body of knowledge, including the identification of microRNAs, are being increasingly accumulated for the development of laboratory testing cassettes for cerebral malaria prevention. Therefore, understanding of the underlying complex molecular basis of cerebral malaria is important for the design of strategy for cerebral malaria treatment and control.
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Affiliation(s)
- Saw Thu Wah
- Department of Clinical Microscopy, Faculty of Medical Technology, Mahidol University, Bangkok, 10700 Thailand
| | | | - Usanee Kerdpin
- Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok, 65000 Thailand
| | - Chotiros Plabplueng
- Department of Clinical Microscopy, Faculty of Medical Technology, Mahidol University, Bangkok, 10700 Thailand ; Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Virapong Prachayasittikul
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Pornlada Nuchnoi
- Department of Clinical Microscopy, Faculty of Medical Technology, Mahidol University, Bangkok, 10700 Thailand ; Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
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The Association of High Prevalence of Trophozoites in Peripheral Blood with Lower Antibody Response to P. falciparum Infected Erythrocytes among Asymptomatic Children in Sudan. Mediators Inflamm 2016; 2016:7987686. [PMID: 27433028 PMCID: PMC4940569 DOI: 10.1155/2016/7987686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 06/01/2016] [Indexed: 11/18/2022] Open
Abstract
Background. The most prominent variant surface antigens (VSAs) of Plasmodium falciparum are the var gene-encoded Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family, which serves as a parasite-sequestering ligand to endothelial cells. In this study we have examined the antibody reactivity of autologous plasma from symptomatic and asymptomatic malaria infected children against the infected erythrocytes' surface antigens using flow cytometry. Methods. Ethidium-bromide-labelled erythrocytic mature forms of P. falciparum parasites obtained from symptomatic and asymptomatic children were sequentially incubated with autologous plasma and fluorescein isothiocyanate-conjugated (FITC) antihuman IgG. Plasma antibody reactivity was detected by flow cytometry. Results. Asymptomatic children had more prevalence of trophozoites in peripheral blood (66%) compared to symptomatic children (16%), p = 0.002. The mean percentage of infected RBCs reacting with autologous sera was 89.78 among symptomatic children compared to 79.62 among asymptomatic children (p = 0.09). Moreover, the mean fluorescence intensity (MFI) in the asymptomatic was significantly higher compared to symptomatic children (p value = 0.040). Conclusion. Variant surface antigens on Plasmodium falciparum infected RBCs from symptomatic malaria children tend to be better recognized by IgG antibodies. This may suggest a role of some IgG antibodies in severity of malaria.
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Antony HA, Pathak V, Parija SC, Ghosh K, Bhattacherjee A. Transcriptomic Analysis of Chloroquine-Sensitive and Chloroquine-Resistant Strains ofPlasmodium falciparum: Toward Malaria Diagnostics and Therapeutics for Global Health. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:424-32. [DOI: 10.1089/omi.2016.0058] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Hiasindh Ashmi Antony
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
| | - Vrushali Pathak
- Department of Haematogenetics, National Institute of Immunohaematology (NII), Mumbai, India
| | - Subhash Chandra Parija
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
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Molecular dissection of placental malaria protein VAR2CSA interaction with a chemo-enzymatically synthesized chondroitin sulfate library. Glycoconj J 2016; 33:985-994. [DOI: 10.1007/s10719-016-9685-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 12/27/2022]
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Na+ Influx Induced by New Antimalarials Causes Rapid Alterations in the Cholesterol Content and Morphology of Plasmodium falciparum. PLoS Pathog 2016; 12:e1005647. [PMID: 27227970 PMCID: PMC4881962 DOI: 10.1371/journal.ppat.1005647] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/28/2016] [Indexed: 12/27/2022] Open
Abstract
Among the several new antimalarials discovered over the past decade are at least three clinical candidate drugs, each with a distinct chemical structure, that disrupt Na+ homeostasis resulting in a rapid increase in intracellular Na+ concentration ([Na+]i) within the erythrocytic stages of Plasmodium falciparum. At present, events triggered by Na+ influx that result in parasite demise are not well-understood. Here we report effects of two such drugs, a pyrazoleamide and a spiroindolone, on intraerythrocytic P. falciparum. Within minutes following the exposure to these drugs, the trophozoite stage parasite, which normally contains little cholesterol, was made permeant by cholesterol-dependent detergents, suggesting it acquired a substantial amount of the lipid. Consistently, the merozoite surface protein 1 and 2 (MSP1 and MSP2), glycosylphosphotidylinositol (GPI)-anchored proteins normally uniformly distributed in the parasite plasma membrane, coalesced into clusters. These alterations were not observed following drug treatment of P. falciparum parasites adapted to grow in a low [Na+] growth medium. Both cholesterol acquisition and MSP1 coalescence were reversible upon the removal of the drugs, implicating an active process of cholesterol exclusion from trophozoites that we hypothesize is inhibited by high [Na+]i. Electron microscopy of drug-treated trophozoites revealed substantial morphological changes normally seen at the later schizont stage including the appearance of partial inner membrane complexes, dense organelles that resemble "rhoptries" and apparent nuclear division. Together these results suggest that [Na+]i disruptor drugs by altering levels of cholesterol in the parasite, dysregulate trophozoite to schizont development and cause parasite demise.
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41
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Hoo R, Zhu L, Amaladoss A, Mok S, Natalang O, Lapp SA, Hu G, Liew K, Galinski MR, Bozdech Z, Preiser PR. Integrated analysis of the Plasmodium species transcriptome. EBioMedicine 2016; 7:255-66. [PMID: 27322479 PMCID: PMC4909483 DOI: 10.1016/j.ebiom.2016.04.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/09/2016] [Accepted: 04/11/2016] [Indexed: 01/18/2023] Open
Abstract
The genome sequence available for different Plasmodium species is a valuable resource for understanding malaria parasite biology. However, comparative genomics on its own cannot fully explain all the species-specific differences which suggests that other genomic aspects such as regulation of gene expression play an important role in defining species-specific characteristics. Here, we developed a comprehensive approach to measure transcriptional changes of the evolutionary conserved syntenic orthologs during the intraerythrocytic developmental cycle across six Plasmodium species. We show significant transcriptional constraint at the mid-developmental stage of Plasmodium species while the earliest stages of parasite development display the greatest transcriptional variation associated with critical functional processes. Modeling of the evolutionary relationship based on changes in transcriptional profile reveal a phylogeny pattern of the Plasmodium species that strictly follows its mammalian hosts. In addition, the work shows that transcriptional conserved orthologs represent potential future targets for anti-malaria intervention as they would be expected to carry out key essential functions within the parasites. This work provides an integrated analysis of orthologous transcriptome, which aims to provide insights into the Plasmodium evolution thereby establishing a framework to explore complex pathways and drug discovery in Plasmodium species with broad host range. Comparison of variations in mRNA abundance across six different Plasmodium species. Transcriptional conservation and divergence of Plasmodium syntenic orthologs. Pattern of Plasmodium transcriptome evolution are established. Transcriptionally conserved orthologs represent attractive intervention targets.
Malaria remains a major public health concern despite global efforts in the fight against this disease. The intraerythrocytic stage of the malaria parasites is currently in the spotlight for anti-malarial intervention and vaccine targets. The primary goal of this study is to generate a comprehensive and directly comparable transcriptome dataset across multiple Plasmodium species originating from different hosts. We establish that specific pathways and intraerythrocytic stages are more transcriptionally diverged than others, reflecting transcriptional evolutionary diversity. We further propose a panel of transcriptionally conserved genes as potential drug targets.
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Affiliation(s)
- Regina Hoo
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Lei Zhu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Anburaj Amaladoss
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Sachel Mok
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Onguma Natalang
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Stacey A Lapp
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Guangan Hu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kingsley Liew
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Mary R Galinski
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA; Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, GA, USA
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, Singapore.
| | - Peter R Preiser
- School of Biological Sciences, Nanyang Technological University, Singapore.
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Arnot DE, Jensen ATR. Antigenic Variation and the Genetics and Epigenetics of the PfEMP1 Erythrocyte Surface Antigens in Plasmodium falciparum Malaria. ADVANCES IN APPLIED MICROBIOLOGY 2016; 74:77-96. [PMID: 21459194 DOI: 10.1016/b978-0-12-387022-3.00007-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
How immunity to malaria develops remains one of the great unresolved issues in bio-medicine and resolution of its various paradoxes is likely to be the key to developing effective malaria vaccines. The basic epidemiological observations are; under conditions of intense natural transmission, humans do become immune to P. falciparum malaria, but this is a slow process requiring multiple disease episodes which many, particularly young children, do not survive. Adult survivors are immune to the symptoms of malaria, and unless pregnant, can control the growth of most or all new inoculations. Sterile immunity is not achieved and chronic parasitization of apparently healthy adults is the norm. In this article, we analyse the best understood malaria "antigenic variation" system, that based on Plasmodium falciparum's PfEMP1-type cytoadhesion antigens, and critically review recent literature on the function and control of this multi-gene family of parasite variable surface antigens.
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Affiliation(s)
- David E Arnot
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, CSS Oester Farimagsgade 5, Copenhagen K, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), CSS Oester Farimagsgade 5, Copenhagen K, Denmark; Institute of Immunology and Infection Research, School of Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
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43
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Loading antimalarial drugs into noninfected red blood cells: an undesirable roommate for Plasmodium. Future Med Chem 2016; 7:837-40. [PMID: 26061102 DOI: 10.4155/fmc.15.35] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Marine organism sulfated polysaccharides exhibiting significant antimalarial activity and inhibition of red blood cell invasion by Plasmodium. Sci Rep 2016; 6:24368. [PMID: 27071342 PMCID: PMC4829872 DOI: 10.1038/srep24368] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 03/21/2016] [Indexed: 11/10/2022] Open
Abstract
The antimalarial activity of heparin, against which there are no resistances known, has not been therapeutically exploited due to its potent anticoagulating activity. Here, we have explored the antiplasmodial capacity of heparin-like sulfated polysaccharides from the sea cucumbers Ludwigothurea grisea and Isostichopus badionotus, from the red alga Botryocladia occidentalis, and from the marine sponge Desmapsamma anchorata. In vitro experiments demonstrated for most compounds significant inhibition of Plasmodium falciparum growth at low-anticoagulant concentrations. This activity was found to operate through inhibition of erythrocyte invasion by Plasmodium, likely mediated by a coating of the parasite similar to that observed for heparin. In vivo four-day suppressive tests showed that several of the sulfated polysaccharides improved the survival of Plasmodium yoelii-infected mice. In one animal treated with I. badionotus fucan parasitemia was reduced from 10.4% to undetectable levels, and Western blot analysis revealed the presence of antibodies against P. yoelii antigens in its plasma. The retarded invasion mediated by sulfated polysaccharides, and the ensuing prolonged exposure of Plasmodium to the immune system, can be explored for the design of new therapeutic approaches against malaria where heparin-related polysaccharides of low anticoagulating activity could play a dual role as drugs and as potentiators of immune responses.
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Fernàndez-Busquets X. Novel strategies for Plasmodium-targeted drug delivery. Expert Opin Drug Deliv 2016; 13:919-22. [DOI: 10.1517/17425247.2016.1167038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Xavier Fernàndez-Busquets
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
- Barcelona Institute for Global Health (ISGlobal, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain
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Clinical manifestations and molecular mechanisms in the changing paradigm of vivax malaria in India. INFECTION GENETICS AND EVOLUTION 2016; 39:317-324. [PMID: 26876067 DOI: 10.1016/j.meegid.2016.02.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/14/2016] [Accepted: 02/09/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Plasmodium vivax once considered benign is now being increasingly associated with complicated malaria where the spectrum of complications is vast and like Plasmodium falciparum. The clinical data is important with respect to the immunopathological status of the patient. Several genes like the vir genes and pvcrt-o are speculated to be attributing to the severity of P. vivax malaria. METHODS In the present study we carried out the transcription analysis of five vir genes (vir 14-related, vir 12, vir 17-like, putative vir 14 and vir 10-related) and pvcrt-o gene in severe (n=12) and non-severe (n=7) P. vivax clinical infections and studied the correlation of these genes with clinical disease severity. RESULTS This study revealed multiorgan involvement in severe vivax cases with severe thrombocytopenia and anemia, the predominantly occurring symptoms. Four out of five vir genes and pvcrt-o showed a significant increase in expression levels of severe infections compared to the non-severe infections indicating their possible role in the changing pathogenesis of P. vivax. CONCLUSIONS The increased virulence in vivax malaria seems to be the result of multifactorial parameters changing it phenotypically as well as genotypically. However more studies are needed to understand the still nascent severity of P. vivax malaria.
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Global selection of Plasmodium falciparum virulence antigen expression by host antibodies. Sci Rep 2016; 6:19882. [PMID: 26804201 PMCID: PMC4726288 DOI: 10.1038/srep19882] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 12/21/2015] [Indexed: 12/22/2022] Open
Abstract
Parasite proteins called PfEMP1 that are inserted on the surface of infected erythrocytes, play a key role in the severe pathology associated with infection by the Plasmodium falciparum malaria parasite. These proteins mediate binding of infected cells to the endothelial lining of blood vessels as a strategy to avoid clearance by the spleen and are major targets of naturally acquired immunity. PfEMP1 is encoded by a large multi-gene family called var. Mutually-exclusive transcriptional switching between var genes allows parasites to escape host antibodies. This study examined in detail the patterns of expression of var in a well-characterized sample of parasites from Kenyan Children. Instead of observing clear inverse relationships between the expression of broad sub-classes of PfEMP1, we found that expression of different PfEMP1 groups vary relatively independently. Parasite adaptation to host antibodies also appears to involve a general reduction in detectable var gene expression. We suggest that parasites switch both between different PfEMP1 variants and between high and low expression states. Such a strategy could provide a means of avoiding immunological detection and promoting survival under high levels of host immunity.
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48
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Differential Plasmodium falciparum surface antigen expression among children with Malarial Retinopathy. Sci Rep 2015; 5:18034. [PMID: 26657042 PMCID: PMC4677286 DOI: 10.1038/srep18034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/10/2015] [Indexed: 11/08/2022] Open
Abstract
Retinopathy provides a window into the underlying pathology of life-threatening malarial coma ("cerebral malaria"), allowing differentiation between 1) coma caused by sequestration of Plasmodium falciparum-infected erythrocytes in the brain and 2) coma with other underlying causes. Parasite sequestration in the brain is mediated by PfEMP1; a diverse parasite antigen that is inserted into the surface of infected erythrocytes and adheres to various host receptors. PfEMP1 sub-groups called "DC8" and "DC13" have been proposed to cause brain pathology through interactions with endothelial protein C receptor. To test this we profiled PfEMP1 gene expression in parasites from children with clinically defined cerebral malaria, who either had or did not have accompanying retinopathy. We found no evidence for an elevation of DC8 or DC13 PfEMP1 expression in children with retinopathy. However, the proportional expression of a broad subgroup of PfEMP1 called "group A" was elevated in retinopathy patients suggesting that these variants may play a role in the pathology of cerebral malaria. Interventions targeting group A PfEMP1 may be effective at reducing brain pathology.
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Sumbele IUN, Bopda OSM, Kimbi HK, Ning TR, Nkuo-Akenji T. Influence of Plasmodium gametocyte carriage on the prevalence of fever, splenomegaly and cardiovascular parameters in children less than 15 years in the Mount Cameroon area: cross sectional study. BMC Infect Dis 2015; 15:547. [PMID: 26612502 PMCID: PMC4661959 DOI: 10.1186/s12879-015-1290-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 11/24/2015] [Indexed: 01/19/2023] Open
Abstract
Background Cardiovascular parameters can be impaired by repeated infections with P. falciparum. This study aimed at investigating the influence of gametocyte carriage on; the prevalence of fever and splenomegaly, blood pressure, heart rate and haematological indices in children <15 years, in the Mount Cameroon area. Methods A cross-sectional study was carried out, from February to July 2013. A child with axillary body temperature ≥37.5 °C was considered febrile and splenomegaly was investigated by palpation. Systolic and diastolic blood pressures as well as heart rate were assessed by non-invasive methods. Malaria parasites were detected and density assessed from Giemsa-stained thin and thick blood films. An auto haematology analyser was used to obtain complete blood count values such as haemoglobin (Hb), haematocrit (Hct), red blood cell (RBC) and white blood cell (WBC) counts, mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular haemoglobin (MCH). Univariate analyses were used to examine influence of gametocyte carriage on fever and splenomegaly while, multiple linear regression models were used to evaluate influence of independent variables on the dependent variables. Results Of a total of 454 children examined, malaria parasitaemia, fever, splenomegaly and gametocyte carriage were detected in 36.6, 21.6, 14.3 and 7.3 % of them respectively. Children who were asexual parasite and gametocyte positive (ASP + Gam Pos) had significantly highest (P = 0.03, P = 0.002) prevalence of fever and splenomegaly (39.4 %, 33.3 %) respectively than their aparasitaemic (AP) and asexual parasite positive (ASP Pos) equivalents (19.0 %, 10.9 % and 22.8 %, 16.9 % respectively). The presence of asexual malaria parasitaemia significantly influenced the MCV (P = 0.03), MCH (P = 0.03) and heart beats /min (0.03) while gametocytaemia significantly influenced the Hb (P < 0.001), Hct (P < 0.001), RBC (P < 0.001) and systolic blood pressure (P < 0.05). Conclusion Gametocyte carriage significantly influenced the prevalence of fever, splenomegaly and some cardiovascular indices. In effect, children concurrently having asexual parasitaemia and gametocytes had significantly lower, Hct, Hb levels, RBC and platelet counts and systolic blood pressure.
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Affiliation(s)
| | | | - Helen Kuokuo Kimbi
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.
| | - Teh Rene Ning
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.
| | - Theresa Nkuo-Akenji
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.
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50
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Niang M, Bei AK, Madnani KG, Pelly S, Dankwa S, Kanjee U, Gunalan K, Amaladoss A, Yeo KP, Bob NS, Malleret B, Duraisingh MT, Preiser PR. STEVOR is a Plasmodium falciparum erythrocyte binding protein that mediates merozoite invasion and rosetting. Cell Host Microbe 2015; 16:81-93. [PMID: 25011110 DOI: 10.1016/j.chom.2014.06.004] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 05/06/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
Abstract
Variant surface antigens play an important role in Plasmodium falciparum malaria pathogenesis and in immune evasion by the parasite. Although most work to date has focused on P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1), two other multigene families encoding STEVOR and RIFIN are expressed in invasive merozoites and on the infected erythrocyte surface. However, their role during parasite infection remains to be clarified. Here we report that STEVOR functions as an erythrocyte-binding protein that recognizes Glycophorin C (GPC) on the red blood cell (RBC) surface and that its binding correlates with the level of GPC on the RBC surface. STEVOR expression on the RBC leads to PfEMP1-independent binding of infected RBCs to uninfected RBCs (rosette formation), while antibodies targeting STEVOR in the merozoite can effectively inhibit invasion. Our results suggest a PfEMP1-independent role for STEVOR in enabling infected erythrocytes at the schizont stage to form rosettes and in promoting merozoite invasion.
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Affiliation(s)
- Makhtar Niang
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Amy Kristine Bei
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
| | - Kripa Gopal Madnani
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Shaaretha Pelly
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Selasi Dankwa
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
| | - Karthigayan Gunalan
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Anburaj Amaladoss
- Singapore-MIT Alliance for Research and Technology (SMART)-Interdisciplinary Research Group in Infectious Diseases, Singapore 117456, Singapore
| | - Kim Pin Yeo
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Ndeye Sakha Bob
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Benoit Malleret
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore 117545, Singapore; Singapore Immunology Network, A(∗)STAR, Singapore 138648, Singapore
| | - Manoj Theodore Duraisingh
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
| | - Peter Rainer Preiser
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore.
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