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Valenciano AL, Gomez-Lorenzo MG, Vega-Rodríguez J, Adams JH, Roth A. In vitro models for human malaria: targeting the liver stage. Trends Parasitol 2022; 38:758-774. [PMID: 35780012 PMCID: PMC9378454 DOI: 10.1016/j.pt.2022.05.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 11/16/2022]
Abstract
The Plasmodium liver stage represents a vulnerable therapeutic target to prevent disease progression as the parasite resides in the liver before clinical representation caused by intraerythrocytic development. However, most antimalarial drugs target the blood stage of the parasite's life cycle, and the few drugs that target the liver stage are lethal to patients with a glucose-6-phosphate dehydrogenase deficiency. Furthermore, implementation of in vitro liver models to study and develop novel therapeutics against the liver stage of human Plasmodium species remains challenging. In this review, we focus on the progression of in vitro liver models developed for human Plasmodium spp. parasites, provide a brief review on important assay requirements, and lastly present recommendations to improve models to enhance the discovery process of novel preclinical therapeutics.
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Affiliation(s)
- Ana Lisa Valenciano
- Center for Global Health and Infectious Diseases, College of Public Health, University of South Florida, Tampa, FL 33612, USA; Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Maria G Gomez-Lorenzo
- Global Health Medicines R&D, GlaxoSmithKline, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Joel Vega-Rodríguez
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - John H Adams
- Center for Global Health and Infectious Diseases, College of Public Health, University of South Florida, Tampa, FL 33612, USA
| | - Alison Roth
- Department of Drug Discovery, Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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2
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Ruberto AA, Bourke C, Vantaux A, Maher SP, Jex A, Witkowski B, Snounou G, Mueller I. Single-cell RNA sequencing of Plasmodium vivax sporozoites reveals stage- and species-specific transcriptomic signatures. PLoS Negl Trop Dis 2022; 16:e0010633. [PMID: 35926062 PMCID: PMC9380936 DOI: 10.1371/journal.pntd.0010633] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 08/16/2022] [Accepted: 07/04/2022] [Indexed: 11/24/2022] Open
Abstract
Background Plasmodium vivax sporozoites reside in the salivary glands of a mosquito before infecting a human host and causing malaria. Previous transcriptome-wide studies in populations of these parasite forms were limited in their ability to elucidate cell-to-cell variation, thereby masking cellular states potentially important in understanding malaria transmission outcomes. Methodology/Principal findings In this study, we performed transcription profiling on 9,947 P. vivax sporozoites to assess the extent to which they differ at single-cell resolution. We show that sporozoites residing in the mosquito’s salivary glands exist in distinct developmental states, as defined by their transcriptomic signatures. Additionally, relative to P. falciparum, P. vivax displays overlapping and unique gene usage patterns, highlighting conserved and species-specific gene programs. Notably, distinguishing P. vivax from P. falciparum were a subset of P. vivax sporozoites expressing genes associated with translational regulation and repression. Finally, our comparison of single-cell transcriptomic data from P. vivax sporozoite and erythrocytic forms reveals gene usage patterns unique to sporozoites. Conclusions/Significance In defining the transcriptomic signatures of individual P. vivax sporozoites, our work provides new insights into the factors driving their developmental trajectory and lays the groundwork for a more comprehensive P. vivax cell atlas. Plasmodium vivax is the second most common cause of malaria worldwide. It is particularly challenging for malaria elimination as it forms both active blood-stage infections, as well as asymptomatic liver-stage infections that can persist for extended periods of time. The activation of persister forms in the liver (hypnozoites) are responsible for relapsing infections occurring weeks or months following primary infection via a mosquito bite. How P. vivax persists in the liver remains a major gap in understanding of this organism. It has been hypothesized that there is pre-programming of the infectious sporozoite while it is in the salivary-glands that determines if the cell’s fate once in the liver is to progress towards immediate liver stage development or persist for long-periods as a hypnozoite. The aim of this study was to see if such differences were distinguishable at the transcript level in salivary-gland sporozoites. While we found significant variation amongst sporozoites, we did not find clear evidence that they are transcriptionally pre-programmed as has been suggested. Nevertheless, we highlight several intriguing patterns that appear to be P. vivax specific relative to non-relapsing species that cause malaria prompting further investigation.
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Affiliation(s)
- Anthony A. Ruberto
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Caitlin Bourke
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Amélie Vantaux
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Kingdom of Cambodia
| | - Steven P. Maher
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Aaron Jex
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Kingdom of Cambodia
| | - Georges Snounou
- Commissariat à l’Énergie Atomique et aux Énergies Alternatives-Université Paris Sud 11-INSERM U1184, Immunology of Viral Infections and Autoimmune Diseases (IMVA-HB), Infectious Disease Models and Innovative Therapies (IDMIT) Department, Institut de Biologie François Jacob (IBFJ), Direction de la Recherche Fondamentale (DRF), Fontenay-aux-Roses, France
| | - Ivo Mueller
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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3
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Beyer K, Kracht S, Kehrer J, Singer M, Klug D, Frischknecht F. Limited Plasmodium sporozoite gliding motility in the absence of TRAP family adhesins. Malar J 2021; 20:430. [PMID: 34717635 PMCID: PMC8557484 DOI: 10.1186/s12936-021-03960-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 10/19/2021] [Indexed: 12/01/2022] Open
Abstract
Background Plasmodium sporozoites are the highly motile forms of malaria-causing parasites that are transmitted by the mosquito to the vertebrate host. Sporozoites need to enter and cross several cellular and tissue barriers for which they employ a set of surface proteins. Three of these proteins are members of the thrombospondin related anonymous protein (TRAP) family. Here, potential additive, synergistic or antagonistic roles of these adhesion proteins were investigated. Methods Four transgenic Plasmodium berghei parasite lines that lacked two or all three of the TRAP family adhesins TRAP, TLP and TREP were generated using positive–negative selection. The parasite lines were investigated for their capacity to attach to and move on glass, their ability to egress from oocysts and their capacity to enter mosquito salivary glands. One strain was in addition interrogated for its capacity to infect mice. Results The major phenotype of the TRAP single gene deletion dominates additional gene deletion phenotypes. All parasite lines including the one lacking all three proteins were able to conduct some form of active, if unproductive movement. Conclusions The individual TRAP-family adhesins appear to play functionally distinct roles during motility and infection. Other proteins must contribute to substrate adhesion and gliding motility. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03960-3.
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Affiliation(s)
- Konrad Beyer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany
| | - Simon Kracht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany
| | - Jessica Kehrer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany.,German Center for Infection Research, Partner Site Heidelberg, 69120, Heidelberg, Germany
| | - Mirko Singer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany.,Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Lena-Christ-Straße 48, Planegg, 82152, Munich, Germany
| | - Dennis Klug
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany.,Université de Strasbourg, CNRS UPR9022, INSERM U963, Institut de Biologie Moléculaire et Cellulaire, 67000, Strasbourg, France
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 344, 69120, Heidelberg, Germany. .,German Center for Infection Research, Partner Site Heidelberg, 69120, Heidelberg, Germany.
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4
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The Riveting Cellular Structures of Apicomplexan Parasites. Trends Parasitol 2020; 36:979-991. [PMID: 33011071 DOI: 10.1016/j.pt.2020.09.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022]
Abstract
Parasitic protozoa of the phylum Apicomplexa cause a range of human and animal diseases. Their complex life cycles - often heteroxenous with sexual and asexual phases in different hosts - rely on elaborate cytoskeletal structures to enable morphogenesis and motility, organize cell division, and withstand diverse environmental forces. This review primarily focuses on studies using Toxoplasma gondii and Plasmodium spp. as the best studied apicomplexans; however, many cytoskeletal adaptations are broadly conserved and predate the emergence of the parasitic phylum. After decades cataloguing the constituents of such structures, a dynamic picture is emerging of the assembly and maintenance of apicomplexan cytoskeletons, illuminating how they template and orient critical processes during infection. These observations impact our view of eukaryotic diversity and offer future challenges for cell biology.
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5
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A probabilistic model of pre-erythrocytic malaria vaccine combination in mice. PLoS One 2019; 14:e0209028. [PMID: 30625136 PMCID: PMC6326473 DOI: 10.1371/journal.pone.0209028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 11/27/2018] [Indexed: 11/19/2022] Open
Abstract
Malaria remains one the world’s most deadly infectious diseases, with almost half a million deaths and over 150 million clinical cases each year. An effective vaccine would contribute enormously to malaria control and will almost certainly be required for eventual eradication of the disease. However, the leading malaria vaccine candidate, RTS,S, shows only 30–50% efficacy under field conditions, making it less cost-effective than long-lasting insecticide treated bed nets. Other subunit malaria vaccine candidates, including TRAP-based vaccines, show no better protective efficacy. This has led to increased interest in combining subunit malaria vaccines as a means of enhancing protective efficacy. Mathematical models of the effect of combining such vaccines on protective efficacy can help inform optimal vaccine strategies and decision-making at all stages of the clinical process. So far, however, no such model has been developed for pre-clinical murine studies, the stage at which all candidate antigens and combinations begin evaluation. To address this gap, this paper develops a mathematical model of vaccine combination adapted to murine malaria studies. The model is based on simple probabilistic assumptions which put the model on a firmer theoretical footing than previous clinical models, which rather than deriving a relationship between immune responses and protective efficacy posit the relationship to be either exponential or Hill curves. Data from pre-clinical murine malaria studies are used to derive values for unknowns in the model which in turn allows simulations of vaccine combination efficacy and suggests optimal strategies to pursue. Finally, the ability of the model to shed light on fundamental biological variables of murine malaria such as the blood stage growth rate and sporozoite infectivity is explored.
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6
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Roth A, Adapa SR, Zhang M, Liao X, Saxena V, Goffe R, Li S, Ubalee R, Saggu GS, Pala ZR, Garg S, Davidson S, Jiang RHY, Adams JH. Unraveling the Plasmodium vivax sporozoite transcriptional journey from mosquito vector to human host. Sci Rep 2018; 8:12183. [PMID: 30111801 PMCID: PMC6093925 DOI: 10.1038/s41598-018-30713-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 08/03/2018] [Indexed: 02/07/2023] Open
Abstract
Malaria parasites transmitted by mosquito bite are remarkably efficient in establishing human infections. The infection process requires roughly 30 minutes and is highly complex as quiescent sporozoites injected with mosquito saliva must be rapidly activated in the skin, migrate through the body, and infect the liver. This process is poorly understood for Plasmodium vivax due to low infectivity in the in vitro models. To study this skin-to-liver-stage of malaria, we used quantitative bioassays coupled with transcriptomics to evaluate parasite changes linked with mammalian microenvironmental factors. Our in vitro phenotyping and RNA-seq analyses revealed key microenvironmental relationships with distinct biological functions. Most notable, preservation of sporozoite quiescence by exposure to insect-like factors coupled with strategic activation limits untimely activation of invasion-associated genes to dramatically increase hepatocyte invasion rates. We also report the first transcriptomic analysis of the P. vivax sporozoite interaction in salivary glands identifying 118 infection-related differentially-regulated Anopheles dirus genes. These results provide important new insights in malaria parasite biology and identify priority targets for antimalarial therapeutic interventions to block P. vivax infection.
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Affiliation(s)
- Alison Roth
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Swamy R Adapa
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Min Zhang
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Xiangyun Liao
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Vishal Saxena
- Molecular Parasitology and System Biology Lab, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Raaven Goffe
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Suzanne Li
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Ratawan Ubalee
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Gagandeep S Saggu
- Laboratory of Malaria and Vector Research, National Institute of Allergic and Infectious Diseases, National Institute of Health, Rockville, Maryland, USA
| | - Zarna R Pala
- Molecular Parasitology and System Biology Lab, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Shilpi Garg
- Molecular Parasitology and System Biology Lab, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Silas Davidson
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Rays H Y Jiang
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA.
| | - John H Adams
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA.
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7
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Frischknecht F, Matuschewski K. Plasmodium Sporozoite Biology. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025478. [PMID: 28108531 DOI: 10.1101/cshperspect.a025478] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Plasmodium sporozoite transmission is a critical population bottleneck in parasite life-cycle progression and, hence, a target for prophylactic drugs and vaccines. The recent progress of a candidate antisporozoite subunit vaccine formulation to licensure highlights the importance of sporozoite transmission intervention in the malaria control portfolio. Sporozoites colonize mosquito salivary glands, migrate through the skin, penetrate blood vessels, breach the liver sinusoid, and invade hepatocytes. Understanding the molecular and cellular mechanisms that mediate the remarkable sporozoite journey in the invertebrate vector and the vertebrate host can inform evidence-based next-generation drug development programs and immune intervention strategies.
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Affiliation(s)
- Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, University of Heidelberg Medical School, 69120 Heidelberg, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University Berlin, 10115 Berlin, Germany
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8
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Yilmaz B, Portugal S, Tran TM, Gozzelino R, Ramos S, Gomes J, Regalado A, Cowan PJ, d'Apice AJF, Chong AS, Doumbo OK, Traore B, Crompton PD, Silveira H, Soares MP. Gut microbiota elicits a protective immune response against malaria transmission. Cell 2015; 159:1277-89. [PMID: 25480293 PMCID: PMC4261137 DOI: 10.1016/j.cell.2014.10.053] [Citation(s) in RCA: 236] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 11/29/2022]
Abstract
Glycosylation processes are under high natural selection pressure, presumably because these can modulate resistance to infection. Here, we asked whether inactivation of the UDP-galactose:β-galactoside-α1-3-galactosyltransferase (α1,3GT) gene, which ablated the expression of the Galα1-3Galβ1-4GlcNAc-R (α-gal) glycan and allowed for the production of anti-α-gal antibodies (Abs) in humans, confers protection against Plasmodium spp. infection, the causative agent of malaria and a major driving force in human evolution. We demonstrate that both Plasmodium spp. and the human gut pathobiont E. coli O86:B7 express α-gal and that anti-α-gal Abs are associated with protection against malaria transmission in humans as well as in α1,3GT-deficient mice, which produce protective anti-α-gal Abs when colonized by E. coli O86:B7. Anti-α-gal Abs target Plasmodium sporozoites for complement-mediated cytotoxicity in the skin, immediately after inoculation by Anopheles mosquitoes. Vaccination against α-gal confers sterile protection against malaria in mice, suggesting that a similar approach may reduce malaria transmission in humans.
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Affiliation(s)
- Bahtiyar Yilmaz
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Silvia Portugal
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Twinbrook II, Room 125, 12441 Parklawn Drive, Rockville, MD 20852-8180, USA
| | - Tuan M Tran
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Twinbrook II, Room 125, 12441 Parklawn Drive, Rockville, MD 20852-8180, USA
| | - Raffaella Gozzelino
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Susana Ramos
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Joana Gomes
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal; Centro de Malaria e Outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira, 100, 1349-008 Lisboa, Portugal
| | - Ana Regalado
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Peter J Cowan
- Immunology Research Centre, St. Vincent's Hospital, Fitzroy, Melbourne, VIC 3065, Australia; Department of Medicine, University of Melbourne, Parkville, VIC 2900, Australia
| | - Anthony J F d'Apice
- Immunology Research Centre, St. Vincent's Hospital, Fitzroy, Melbourne, VIC 3065, Australia; Department of Medicine, University of Melbourne, Parkville, VIC 2900, Australia
| | - Anita S Chong
- Section of Transplantation, Department of Surgery, University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA
| | - Ogobara K Doumbo
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, 1805 Bamako, Mali
| | - Boubacar Traore
- Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, 1805 Bamako, Mali
| | - Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Twinbrook II, Room 125, 12441 Parklawn Drive, Rockville, MD 20852-8180, USA
| | - Henrique Silveira
- Centro de Malaria e Outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira, 100, 1349-008 Lisboa, Portugal
| | - Miguel P Soares
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal.
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9
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In vivo imaging in NHP models of malaria: challenges, progress and outlooks. Parasitol Int 2013; 63:206-15. [PMID: 24042056 PMCID: PMC7108422 DOI: 10.1016/j.parint.2013.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 08/30/2013] [Accepted: 09/06/2013] [Indexed: 12/22/2022]
Abstract
Animal models of malaria, mainly mice, have made a large contribution to our knowledge of host-pathogen interactions and immune responses, and to drug and vaccine design. Non-human primate (NHP) models for malaria are admittedly under-used, although they are probably closer models than mice for human malaria; in particular, NHP models allow the use of human pathogens (Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae and Plasmodium knowlesi). NHPs, whether natural hosts or experimentally challenged with a simian Plasmodium, can also serve as robust pre-clinical models. Some simian parasites are closely related to a human counterpart, with which they may share a common ancestor, and display similar major features with the human infection and pathology. NHP models allow longitudinal studies, from the early events following sporozoite inoculation to the later events, including analysis of organs and tissues, particularly liver, spleen, brain and bone marrow. NHP models have one other significant advantage over mouse models: NHPs are our closest relatives and thus their biology is very similar to ours. Recently developed in vivo imaging tools have provided insight into malaria parasite infection and disease in mouse models. One advantage of these tools is that they limit the need for invasive procedures, such as tissue biopsies. Many such technologies are now available for NHP studies and provide new opportunities for elucidating host/parasite interactions. The aim of this review is to bring the malaria community up to date on what is currently possible and what soon will be, in terms of in vivo imaging in NHP models of malaria, to consider the pros and the cons of the various techniques, and to identify challenges.
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10
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Lindner SE, Swearingen KE, Harupa A, Vaughan AM, Sinnis P, Moritz RL, Kappe SHI. Total and putative surface proteomics of malaria parasite salivary gland sporozoites. Mol Cell Proteomics 2013; 12:1127-43. [PMID: 23325771 DOI: 10.1074/mcp.m112.024505] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Malaria infections of mammals are initiated by the transmission of Plasmodium salivary gland sporozoites during an Anopheles mosquito vector bite. Sporozoites make their way through the skin and eventually to the liver, where they infect hepatocytes. Blocking this initial stage of infection is a promising malaria vaccine strategy. Therefore, comprehensively elucidating the protein composition of sporozoites will be invaluable in identifying novel targets for blocking infection. Previous efforts to identify the proteins expressed in Plasmodium mosquito stages were hampered by the technical difficulty of separating the parasite from its vector; without effective purifications, the large majority of proteins identified were of vector origin. Here we describe the proteomic profiling of highly purified salivary gland sporozoites from two Plasmodium species: human-infective Plasmodium falciparum and rodent-infective Plasmodium yoelii. The combination of improved sample purification and high mass accuracy mass spectrometry has facilitated the most complete proteome coverage to date for a pre-erythrocytic stage of the parasite. A total of 1991 P. falciparum sporozoite proteins and 1876 P. yoelii sporozoite proteins were identified, with >86% identified with high sequence coverage. The proteomic data were used to confirm the presence of components of three features critical for sporozoite infection of the mammalian host: the sporozoite motility and invasion apparatus (glideosome), sporozoite signaling pathways, and the contents of the apical secretory organelles. Furthermore, chemical labeling and identification of proteins on live sporozoites revealed previously uncharacterized complexity of the putative sporozoite surface-exposed proteome. Taken together, the data constitute the most comprehensive analysis to date of the protein expression of salivary gland sporozoites and reveal novel potential surface-exposed proteins that might be valuable targets for antibody blockage of infection.
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Affiliation(s)
- Scott E Lindner
- Malaria Program, Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109, USA
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11
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Lindner SE, Miller JL, Kappe SHI. Malaria parasite pre-erythrocytic infection: preparation meets opportunity. Cell Microbiol 2012; 14:316-24. [PMID: 22151703 DOI: 10.1111/j.1462-5822.2011.01734.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
For those stricken with malaria, the classic clinical symptoms are caused by the parasite's cyclic infection of red blood cells. However, this erythrocytic phase of the parasite's life cycle initiates from an asymptomatic pre-erythrocytic phase: the injection of sporozoites via the bite of a parasite-carrying Anopheline mosquito, and the ensuing infection of the liver. With the increased capabilities of studying liver stages in mice, much progress has been made elucidating the cellular and molecular basis of the parasite's progression through this bottleneck of its life cycle. Here we review relevant findings on how sporozoites prepare for infection of the liver and factors crucial to liver stage development as well as key host/parasite interactions.
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Affiliation(s)
- Scott E Lindner
- Seattle Biomedical Research Institute, Seattle, WA 98109, USA
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12
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Gomes-Santos CSS, Braks J, Prudêncio M, Carret C, Gomes AR, Pain A, Feltwell T, Khan S, Waters A, Janse C, Mair GR, Mota MM. Transition of Plasmodium sporozoites into liver stage-like forms is regulated by the RNA binding protein Pumilio. PLoS Pathog 2011; 7:e1002046. [PMID: 21625527 PMCID: PMC3098293 DOI: 10.1371/journal.ppat.1002046] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Accepted: 03/22/2011] [Indexed: 12/13/2022] Open
Abstract
Many eukaryotic developmental and cell fate decisions that are effected post-transcriptionally involve RNA binding proteins as regulators of translation of key mRNAs. In malaria parasites (Plasmodium spp.), the development of round, non-motile and replicating exo-erythrocytic liver stage forms from slender, motile and cell-cycle arrested sporozoites is believed to depend on environmental changes experienced during the transmission of the parasite from the mosquito vector to the vertebrate host. Here we identify a Plasmodium member of the RNA binding protein family PUF as a key regulator of this transformation. In the absence of Pumilio-2 (Puf2) sporozoites initiate EEF development inside mosquito salivary glands independently of the normal transmission-associated environmental cues. Puf2- sporozoites exhibit genome-wide transcriptional changes that result in loss of gliding motility, cell traversal ability and reduction in infectivity, and, moreover, trigger metamorphosis typical of early Plasmodium intra-hepatic development. These data demonstrate that Puf2 is a key player in regulating sporozoite developmental control, and imply that transformation of salivary gland-resident sporozoites into liver stage-like parasites is regulated by a post-transcriptional mechanism.
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Affiliation(s)
- Carina S. S. Gomes-Santos
- Malaria Unit, Instituto de Medicina Molecular, Lisboa,
Portugal
- PhD Programme in Experimental Biology and Biomedicine, Center for
Neuroscience and Cell Biology, University of Coimbra, Coimbra,
Portugal
| | - Joanna Braks
- Leiden Malaria Research Group, Parasitology, Leiden University Medical
Centre, Leiden, The Netherlands
| | | | - Céline Carret
- Molecular Parasitology Unit, Instituto de Medicina Molecular, Lisbon,
Portugal
| | - Ana Rita Gomes
- Molecular Parasitology Unit, Instituto de Medicina Molecular, Lisbon,
Portugal
| | - Arnab Pain
- Pathogen Genetics Group, Wellcome Trust Sanger Institute, Cambridge,
United Kingdom
- Computational Bioscience Research Center (CBRC), Chemical Life Sciences
and Engineering Division, King Abdullah University of Science and Technology
(KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Theresa Feltwell
- Pathogen Genetics Group, Wellcome Trust Sanger Institute, Cambridge,
United Kingdom
| | - Shahid Khan
- Leiden Malaria Research Group, Parasitology, Leiden University Medical
Centre, Leiden, The Netherlands
| | - Andrew Waters
- Leiden Malaria Research Group, Parasitology, Leiden University Medical
Centre, Leiden, The Netherlands
- Division of Infection and Immunity, Institute of Biomedical Life Sciences
and Wellcome Centre for Molecular Parasitology, Glasgow Biomedical Research
Centre, University of Glasgow, Glasgow, Scotland
- * E-mail: (GRM); (AW); (MM)
| | - Chris Janse
- Leiden Malaria Research Group, Parasitology, Leiden University Medical
Centre, Leiden, The Netherlands
| | - Gunnar R. Mair
- Molecular Parasitology Unit, Instituto de Medicina Molecular, Lisbon,
Portugal
- * E-mail: (GRM); (AW); (MM)
| | - Maria M. Mota
- Malaria Unit, Instituto de Medicina Molecular, Lisboa,
Portugal
- * E-mail: (GRM); (AW); (MM)
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13
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Müller K, Matuschewski K, Silvie O. The Puf-family RNA-binding protein Puf2 controls sporozoite conversion to liver stages in the malaria parasite. PLoS One 2011; 6:e19860. [PMID: 21673790 PMCID: PMC3097211 DOI: 10.1371/journal.pone.0019860] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 04/06/2011] [Indexed: 12/11/2022] Open
Abstract
Malaria is a vector-borne infectious disease caused by unicellular, obligate intracellular parasites of the genus Plasmodium. During host switch the malaria parasite employs specialized latent stages that colonize the new host environment. Previous work has established that gametocytes, sexually differentiated stages that are taken up by the mosquito vector, control expression of genes required for mosquito colonization by translational repression. Sexual parasite development is controlled by a DEAD-box RNA helicase of the DDX6 family, termed DOZI. Latency of sporozoites, the transmission stage injected during an infectious blood meal, is controlled by the eIF2alpha kinase IK2, a general inhibitor of protein synthesis. Whether RNA-binding proteins participate in translational regulation in sporozoites remains to be studied. Here, we investigated the roles of two RNA-binding proteins of the Puf-family, Plasmodium Puf1 and Puf2, during sporozoite stage conversion. Our data reveal that, in the rodent malaria parasite P. berghei, Puf2 participates in the regulation of IK2 and inhibits premature sporozoite transformation. Inside mosquito salivary glands puf2⁻ sporozoites transform over time to round forms resembling early intra-hepatic stages. As a result, mutant parasites display strong defects in initiating a malaria infection. In contrast, Puf1 is dispensable in vivo throughout the entire Plasmodium life cycle. Our findings support the notion of a central role for Puf2 in parasite latency during switch between the insect and mammalian hosts.
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Affiliation(s)
- Katja Müller
- Max Planck Institute for Infection Biology, Parasitology Unit, Berlin, Germany
| | - Kai Matuschewski
- Max Planck Institute for Infection Biology, Parasitology Unit, Berlin, Germany
| | - Olivier Silvie
- Max Planck Institute for Infection Biology, Parasitology Unit, Berlin, Germany
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