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Abstract
Apicomplexans, including species of Eimeria, pose a real threat to the health and wellbeing of animals and humans. Eimeria parasites do not infect humans but cause an important economic impact on livestock, in particular on the poultry industry. Despite its high prevalence and financial costs, little is known about the cell biology of these 'cosmopolitan' parasites found all over the world. In this review, we discuss different aspects of the life cycle and stages of Eimeria species, focusing on cellular structures and organelles typical of the coccidian family as well as genus-specific features, complementing some 'unknowns' with what is described in the closely related coccidian Toxoplasma gondii.
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2
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Gras S, Jimenez-Ruiz E, Klinger CM, Schneider K, Klingl A, Lemgruber L, Meissner M. An endocytic-secretory cycle participates in Toxoplasma gondii in motility. PLoS Biol 2019; 17:e3000060. [PMID: 31233488 PMCID: PMC6611640 DOI: 10.1371/journal.pbio.3000060] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 07/05/2019] [Accepted: 06/14/2019] [Indexed: 12/31/2022] Open
Abstract
Apicomplexan parasites invade host cells in an active process involving their ability to move by gliding motility. While the acto-myosin system of the parasite plays a crucial role in the formation and release of attachment sites during this process, there are still open questions regarding the involvement of other mechanisms in parasite motility. In many eukaryotes, a secretory-endocytic cycle leads to the recycling of receptors (integrins), necessary to form attachment sites, regulation of surface area during motility, and generation of retrograde membrane flow. Here, we demonstrate that endocytosis operates during gliding motility in Toxoplasma gondii and appears to be crucial for the establishment of retrograde membrane flow, because inhibition of endocytosis blocks retrograde flow and motility. We demonstrate that extracellular parasites can efficiently incorporate exogenous material, such as labelled phospholipids, nanogold particles (NGPs), antibodies, and Concanavalin A (ConA). Using labelled phospholipids, we observed that the endocytic and secretory pathways of the parasite converge, and endocytosed lipids are subsequently secreted, demonstrating the operation of an endocytic-secretory cycle. Together our data consolidate previous findings, and we propose an additional model, working in parallel to the acto-myosin motor, that reconciles parasite motility with observations in other eukaryotes: an apicomplexan fountain-flow-model for parasite motility.
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Affiliation(s)
- Simon Gras
- Lehrstuhl für experimentelle Parasitologie, Ludwig-Maximilians-Universität, LMU, Tierärztliche Fakultät, München, Germany
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Elena Jimenez-Ruiz
- Lehrstuhl für experimentelle Parasitologie, Ludwig-Maximilians-Universität, LMU, Tierärztliche Fakultät, München, Germany
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Christen M. Klinger
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Katja Schneider
- Pflanzliche Entwicklungsbiologie, Biozentrum der Ludwig-Maximilians-Universität, Planegg-Martinsried, Germany
| | - Andreas Klingl
- Pflanzliche Entwicklungsbiologie, Biozentrum der Ludwig-Maximilians-Universität, Planegg-Martinsried, Germany
| | - Leandro Lemgruber
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Markus Meissner
- Lehrstuhl für experimentelle Parasitologie, Ludwig-Maximilians-Universität, LMU, Tierärztliche Fakultät, München, Germany
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom
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3
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Bussière FI, Brossier F, Le Vern Y, Niepceron A, Silvestre A, de Sablet T, Lacroix-Lamandé S, Laurent F. Reduced parasite motility and micronemal protein secretion by a p38 MAPK inhibitor leads to a severe impairment of cell invasion by the apicomplexan parasite Eimeria tenella. PLoS One 2015; 10:e0116509. [PMID: 25689363 PMCID: PMC4331428 DOI: 10.1371/journal.pone.0116509] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 12/10/2014] [Indexed: 01/28/2023] Open
Abstract
E. tenella infection is associated with a severe intestinal disease leading to high economic losses in poultry industry. Mitogen activated protein kinases (MAPKs) are implicated in early response to infection and are divided in three pathways: p38, extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK). Our objective was to determine the importance of these kinases on cell invasion by E. tenella. We evaluated the effect of specific inhibitors (ERK: PD98059, JNKII: SP600125, p38 MAPK: SB203580) on the invasion of epithelial cells. Incubation of SP600125 and SB203580 with epithelial cells and parasites significantly inhibited cell invasion with the highest degree of inhibition (90%) for SB203580. Silencing of the host p38α MAPK expression by siRNA led to only 20% decrease in cell invasion. In addition, when mammalian epithelial cells were pre-treated with SB203580, and washed prior infection, a 30% decrease in cell invasion was observed. This decrease was overcome when a p38 MAPK activator, anisomycin was added during infection. This suggests an active but limited role of the host p38 MAPK in this process. We next determined whether SB203580 has a direct effect on the parasite. Indeed, parasite motility and secretion of micronemal proteins (EtMIC1, 2, 3 and 5) that are involved in cell invasion were both decreased in the presence of the inhibitor. After chasing the inhibitor, parasite motility and secretion of micronemal proteins were restored and subsequently cell invasion. SB203580 inhibits cell invasion by acting partly on the host cell and mainly on the parasite.
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Affiliation(s)
- Françoise I. Bussière
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
- * E-mail:
| | - Fabien Brossier
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
| | - Yves Le Vern
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
- Plate-forme d’Analyse Intégrative des Biomolécules, Laboratoire de Cytométrie et Fluorimétrie, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
| | - Alisson Niepceron
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
| | - Anne Silvestre
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
| | - Thibaut de Sablet
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
| | - Sonia Lacroix-Lamandé
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
| | - Fabrice Laurent
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380 Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000 Tours, France
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4
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O'Hara SP, Chen XM. The cell biology of cryptosporidium infection. Microbes Infect 2011; 13:721-30. [PMID: 21458585 DOI: 10.1016/j.micinf.2011.03.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 03/23/2011] [Indexed: 01/13/2023]
Abstract
Cryptosporidiosis remains a significant cause of enteric disease worldwide. Basic investigations of host: pathogen interactions have revealed the intricate processes mediating infection. The following summarizes the interactions that mediate infection and the host responses that both permit and ultimately clear the infection.
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Affiliation(s)
- Steven P O'Hara
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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5
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Abstract
In this chapter, we outline the tools and techniques available to study the process of host cell invasion by apicomplexan parasites and we provide specific examples of how these methods have been used to further our understanding of apicomplexan invasive mechanisms. Throughout the chapter we focus our discussion on Toxoplasmagondii, because T. gondii is the most experimentally accessible model organism for studying apicomplexan invasion (discussed further in the section, "Toxoplasma as a Model Apicomplexan") and more is known about invasion in T. gondii than in any other apicomplexan.
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6
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Heintzelman MB. Cellular and Molecular Mechanics of Gliding Locomotion in Eukaryotes. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 251:79-129. [PMID: 16939778 DOI: 10.1016/s0074-7696(06)51003-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gliding is a form of substrate-dependent cell locomotion exploited by a variety of disparate cell types. Cells may glide at rates well in excess of 1 microm/sec and do so without the gross distortion of cellular form typical of amoeboid crawling. In the absence of a discrete locomotory organelle, gliding depends upon an assemblage of molecules that links cytoplasmic motor proteins to the cell membrane and thence to the appropriate substrate. Gliding has been most thoroughly studied in the apicomplexan parasites, including Plasmodium and Toxoplasma, which employ a unique assortment of proteins dubbed the glideosome, at the heart of which is a class XIV myosin motor. Actin and myosin also drive the gliding locomotion of raphid diatoms (Bacillariophyceae) as well as the intriguing form of gliding displayed by the spindle-shaped cells of the primitive colonial protist Labyrinthula. Chlamydomonas and other flagellated protists are also able to abandon their more familiar swimming locomotion for gliding, during which time they recruit a motility apparatus independent of that driving flagellar beating.
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Affiliation(s)
- Matthew B Heintzelman
- Department of Biology, Program in Cell Biology and Biochemistry, Bucknell University, Lewisburg, PA 17837, USA
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7
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Wetzel DM, Schmidt J, Kuhlenschmidt MS, Dubey JP, Sibley LD. Gliding motility leads to active cellular invasion by Cryptosporidium parvum sporozoites. Infect Immun 2005; 73:5379-87. [PMID: 16113253 PMCID: PMC1231075 DOI: 10.1128/iai.73.9.5379-5387.2005] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We examined gliding motility and cell invasion by an early-branching apicomplexan, Cryptosporidium parvum, which causes diarrheal disease in humans and animals. Real-time video microscopy demonstrated that C. parvum sporozoites undergo circular and helical gliding, two of the three stereotypical movements exhibited by Toxoplasma gondii tachyzoites. C. parvum sporozoites moved more rapidly than T. gondii sporozoites, which showed the same rates of motility as tachyzoites. Motility by C. parvum sporozoites was prevented by latrunculin B and cytochalasin D, drugs that depolymerize the parasite actin cytoskeleton, and by the myosin inhibitor 2,3-butanedione monoxime. Imaging of the initial events in cell entry by Cryptosporidium revealed that invasion occurs rapidly; however, the parasite does not enter deep into the cytosol but rather remains at the cell surface in a membrane-bound compartment. Invasion did not stimulate rearrangement of the host cell cytoskeleton and was inhibited by cytochalasin D, even in host cells that were resistant to the drug. Our studies demonstrate that C. parvum relies on a conserved actin-myosin motor for motility and active penetration of its host cell, thus establishing that this is a widely conserved feature of the Apicomplexa.
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Affiliation(s)
- Dawn M Wetzel
- Department of Molecular Microbiology, Campus Box 8230, Washington University School of Medicine, St. Louis, MO 63110, USA
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8
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Gaffar FR, Yatsuda AP, Franssen FFJ, de Vries E. A Babesia bovis merozoite protein with a domain architecture highly similar to the thrombospondin-related anonymous protein (TRAP) present in Plasmodium sporozoites. Mol Biochem Parasitol 2004; 136:25-34. [PMID: 15138064 DOI: 10.1016/j.molbiopara.2004.02.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2003] [Revised: 02/12/2004] [Accepted: 02/25/2004] [Indexed: 10/26/2022]
Abstract
Recognition and invasion of host cells is a key step in the life-cycle of all apicomplexan parasites. The thrombospondin-related anonymous protein (TRAP) of Plasmodium sporozoites is directly involved in both processes and shares conserved adhesive domains with micronemal transmembrane proteins of other apicomplexans. Here, we report the cloning and characterization of a Babesia bovis TRAP homologue (BbTRAP). It was predicted to be a type 1 transmembrane protein containing a von Willebrand Factor A domain (vWFA), a thrombospondin type 1 domain (TSP1), a conserved transmembrane region and a conserved cytoplasmic C-terminus, thus resembling the domain arrangement of Plasmodium TRAP. In contrast to Plasmodium TRAP, BbTRAP was shown to be present during the asexual erythrocytic cycle, being located mainly at the apical side of merozoites. Polyclonal rabbit antisera directed against synthetic peptides derived from the TSP1 domain or the C-terminal end of the ectodomain were shown to inhibit erythrocyte invasion in vitro. Both antisera recognized a 75 kDa protein in merozoite extracts as well as in a protein fraction that was secreted into the extracellular milieu during in vitro invasion of erythrocytes.
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Affiliation(s)
- Fasila R Gaffar
- Department of Infectious Diseases and Immunology, Division of Parasitology and Tropical Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands
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9
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Wiersma HI, Galuska SE, Tomley FM, Sibley LD, Liberator PA, Donald RGK. A role for coccidian cGMP-dependent protein kinase in motility and invasion. Int J Parasitol 2004; 34:369-80. [PMID: 15003497 DOI: 10.1016/j.ijpara.2003.11.019] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Revised: 11/17/2003] [Accepted: 11/24/2003] [Indexed: 11/24/2022]
Abstract
The coccidian parasite cGMP-dependent protein kinase is the primary target of a novel coccidiostat, the trisubstituted pyrrole 4-[2-(4-fluorophenyl)-5-(1-methylpiperidine-4-yl)-1H-pyrrol-3-yl] pyridine (compound 1), which effectively controls the proliferation of Eimeria tenella and Toxoplasma gondii parasites in animal models. The efficacy of compound 1 in parasite-specific metabolic assays of infected host cell monolayers is critically dependent on the timing of compound addition. Simultaneous addition of compound with extracellular E. tenella sporozoites or T. gondii tachyzoites inhibited [3H]-uracil uptake in a dose-dependent manner, while minimal efficacy was observed if compound addition was delayed, suggesting a block in host cell invasion. Immunofluorescence assays confirmed that compound 1 blocks the attachment of Eimeria sporozoites or Toxoplasma tachyzoites to host cells and inhibits parasite invasion and gliding motility. Compound 1 also inhibits the secretion of micronemal adhesins (E. tenella MIC1, MIC2 and T. gondii MIC2), an activity closely linked to invasion and motility in apicomplexan parasites. The inhibition of T. gondii MIC2 adhesin secretion by compound 1 was not reversed by treatment with calcium ionophores or by ethanol (a microneme secretagogue), suggesting a block downstream of calcium-dependent events commonly associated with the discharge of the microneme organelle in tachyzoites. Transgenic Toxoplasma strains expressing cGMP-dependent protein kinase mutant alleles that are refractory to compound 1 (including cGMP-dependent protein kinase knock-out lines complemented by such mutants) were used as tools to validate the potential role of cGMP-dependent protein kinase in invasion and motility. In these strains, parasite adhesin secretion, gliding motility, host cell attachment and invasion displayed a reduced sensitivity to compound 1. These data clearly demonstrate that cGMP-dependent protein kinase performs an important role in the host-parasite interaction.
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Affiliation(s)
- Helen I Wiersma
- Department of Human and Animal Infectious Disease Research, Merck Research Laboratories, Merck and Co Inc, PO Box 2000, Rahway, NJ 07065, USA
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10
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Abstract
The Apicomplexa are a phylum of diverse obligate intracellular parasites including Plasmodium spp., the cause of malaria; Toxoplasma gondii and Cryptosporidium parvum, opportunistic pathogens of immunocompromised individuals; and Eimeria spp. and Theileria spp., parasites of considerable agricultural importance. These protozoan parasites share distinctive morphological features, cytoskeletal organization, and modes of replication, motility, and invasion. This review summarizes our current understanding of the cytoskeletal elements, the properties of cytoskeletal proteins, and the role of the cytoskeleton in polarity, motility, invasion, and replication. We discuss the unusual properties of actin and myosin in the Apicomplexa, the highly stereotyped microtubule populations in apicomplexans, and a network of recently discovered novel intermediate filament-like elements in these parasites.
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Affiliation(s)
- Naomi S Morrissette
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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11
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Abstract
Apicomplexa constitute one of the largest phyla of protozoa. Most Apicomplexa, including those pathogenic to humans, are obligate intracellular parasites. Their extracellular forms, which are highly polarized and elongated cells, share two unique abilities: they glide on solid substrates without changing their shape and reach an intracellular compartment without active participation from the host cell. There is now ample ultrastructural evidence that these processes result from the backward movement of extracellular interactions along the anteroposterior axis of the parasite. Recent work in several Apicomplexa, including genetic studies in the Plasmodium sporozoite, has provided molecular support for this 'capping' model. It appears that the same machinery drives both gliding motility and host cell invasion. The cytoplasmic motor, a transmembrane bridge and surface ligands essential for cell invasion are conserved among the main apicomplexan pathogens.
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Affiliation(s)
- R Ménard
- Laboratoire de Biologie et Génétique du Paludisme, Institut Pasteur, Paris, France.
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12
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Bumstead J, Tomley F. Induction of secretion and surface capping of microneme proteins in Eimeria tenella. Mol Biochem Parasitol 2000; 110:311-21. [PMID: 11071285 DOI: 10.1016/s0166-6851(00)00280-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Micronemes are secretory organelles of the invasive stages of apicomplexan parasites and contain proteins that are important for parasite motility and host cell invasion. We have examined the induction of microneme secretion in the coccidian Eimeria tenella. When sporozoites were added to MDBK cells in culture, microneme proteins were secreted, capped backwards over the parasite surface and deposited onto underlying host cells from the posterior end of gliding parasites. Induction of secretion was also achieved by the addition of foetal calf serum, or purified albumin, to extracellular sporozoites. Microneme secretion per se was not dependent on parasites being able to move or to invade host cells. However, in the presence of cytochalasin D, which disrupts actin polymerisation and prevents parasite movement, microneme proteins were secreted from the apical tip but were not capped backwards over the sporozoite surface. These observations support the hypothesis that microneme proteins function as ligands which, when secreted out onto the parasite surface, form a link, either directly or indirectly, between the sub-pellicular actin myosin cytoskeletal motor of the parasite and the surface of target host cells.
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Affiliation(s)
- J Bumstead
- Division of Molecular Biology, Institute for Animal Health, Compton, Berkshire, UK
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Ménard R. The journey of the malaria sporozoite through its hosts: two parasite proteins lead the way. Microbes Infect 2000; 2:633-42. [PMID: 10884614 DOI: 10.1016/s1286-4579(00)00362-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Malaria is transmitted to a mammalian host when the sporozoite stage of the Plasmodium parasite is injected by a mosquito vector. Sporozoites are unique in being able to interact with both hosts. Formed and released in the mosquito midgut, sporozoites bind to the salivary glands and invade their secretory cells. Once injected into the mammalian host, they home to the liver and invade hepatocytes. Recent work has shown that two sporozoite surface proteins, CS and TRAP, act in both hosts, perform multiple functions, and are each essential for the parasite at more than one step of its life cycle.
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Affiliation(s)
- R Ménard
- Department of Medical and Molecular Parasitology, NYU School of Medicine, NY, New York, USA
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14
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Nesterenko MV, Woods K, Upton SJ. Receptor/ligand interactions between Cryptosporidium parvum and the surface of the host cell. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1454:165-73. [PMID: 10381561 DOI: 10.1016/s0925-4439(99)00034-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The ability of membrane antigens on sporozoites of the intestinal pathogen, Cryptosporidium parvum, to bind host cell surface antigens was investigated. A novel membrane-associated protein of approximately 47 kDa, designated CP47, was found to possess significant binding affinity for the surface of both human and animal ileal cells. This protein was purified by a combination of anion-exchange chromatography on FPLC and immunoaffinity chromatography. Purified CP47 demonstrated competitive binding with parasite-associated membrane antigens to membranes of HCT-8 and ileal cells in a dose-dependent manner. Furthermore, the binding activity of CP47 was found to be Mn2+-sensitive, and was completely inhibited in the presence of 10 mM MnCl2. These results were consistent with earlier findings demonstrating the inhibitory effect of Mn2+ ions on Cryptosporidium infection both in vitro and in vivo (Nesterenko et al., Biol. Trace Elem. Res. 56 (1997) 243-253). Immunoelectron microscopy using gold-conjugated antibodies revealed CP47 to be localized at the apical end of the sporozoites. A single protein with an electrophoretic mobility of 57 kDa was purified from host cell membranes using CP47-Affigel. Similarly, affinity purification of this protein was abrogated in the presence of Mn2+. These data suggest that a novel parasite protein, CP47, may play an important role in sporozoite/host cell attachment.
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Affiliation(s)
- M V Nesterenko
- Division of Biology, Ackert Hall, Kansas State University, Manhattan, KS 66506, USA.
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15
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Tomley F. Techniques for isolation and characterization of apical organelles from Eimeria tenella sporozoites. Methods 1997; 13:171-6. [PMID: 9405200 DOI: 10.1006/meth.1997.0509] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Apical organelles contain molecules that are of critical importance for the interaction of all apicomplexan parasites with their target host cells. Thus, there is considerable interest in characterizing and understanding the function of molecules that reside in these organelles. Large numbers of surface-sterilized oocysts of Eimeria tenella, an apicomplexan coccidian of the chicken, can be routinely obtained from the animal host, and invasive sporozoites, which contain abundant apical organelles, can be rapidly prepared from these oocysts in the laboratory. Thus, E. tenella is proving to be an amenable parasite for subcellular fractionation techniques that allow the direct isolation and characterization of apical organelles. In this paper, a series of protocols is described for the large-scale culture of E. tenella parasites, the preparation of invasive sporozoites, the isolation of apical organelles, and the use of in vitro culture for localization and functional studies.
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Affiliation(s)
- F Tomley
- Institute for Animal Health, Compton, Newbury, Berkshire, RG20 7NN, United Kingdom
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16
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Sultan AA, Thathy V, Frevert U, Robson KJ, Crisanti A, Nussenzweig V, Nussenzweig RS, Ménard R. TRAP is necessary for gliding motility and infectivity of plasmodium sporozoites. Cell 1997; 90:511-22. [PMID: 9267031 DOI: 10.1016/s0092-8674(00)80511-5] [Citation(s) in RCA: 458] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Many protozoans of the phylum Apicomplexa are invasive parasites that exhibit a substrate-dependent gliding motility. Plasmodium (malaria) sporozoites, the stage of the parasite that invades the salivary glands of the mosquito vector and the liver of the vertebrate host, express a surface protein called thrombospondin-related anonymous protein (TRAP) that has homologs in other Apicomplexa. By gene targeting in a rodent Plasmodium, we demonstrate that TRAP is critical for sporozoite infection of the mosquito salivary glands and the rat liver, and is essential for sporozoite gliding motility in vitro. This suggests that in Plasmodium sporozoites, and likely in other Apicomplexa, gliding locomotion and cell invasion have a common molecular basis.
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Affiliation(s)
- A A Sultan
- Department of Pathology, Kaplan Cancer Center, New York University Medical Center, New York 10016, USA
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17
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Abstract
Toxoplasma gondii tachyzoites execute a complex and little understood combination of rapid movements to reach and penetrate human or other animals cells. In the present study, computer-assisted simulation was used to quantitatively analyze the motility of these parasites in three-dimensional space with spatial and temporal resolutions in the micrometer and subsecond ranges. A digital model based on electron-micrographs of a serially sectioned tachyzoite was animated according to a videomicrographed sequence of a characteristic repetitive movement. Keyframe animation defined over 150 frames by a total of 36 kinematic parameters for specific motions, of both the whole model and particular domains, resulted in a real-time life-like simulation of the videorecorded tachyzoite movement. The kinematic values indicate that a full revolution of the model is composed of three half-turns accomplished in nearly 5 s with two phases: a relatively slow 180 degrees tilting with regard to the substratum plane, followed by fast (over 200 degrees/s) spinning almost simultaneous with pivoting around the posterior end, each clockwise and for about 180 degrees. Maximal flexing of the body, as well as bowing and retraction of its anterior end, occur at midway during the tilting phase. An estimated 70 degrees. clockwise torsion of the body seems to precede the spinning-pivoting phase. The results suggest the operation of two basic forces in the motility of T. gondii tachyzoites: (1) a clockwise torque that causes torsion, spinning, and pivoting; and (2) a longitudinal pull that contracts, bends and tilts the parasite. We discuss the possibility that both of these forces might result from the action of an actin-myosin system enveloping the twisted framework of microtubules characteristic of these organisms.
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Affiliation(s)
- E Frixione
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, Mexico
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Tilley M, Upton SJ. Both CP15 and CP25 are left as trails behind gliding sporozoites of Cryptosporidium parvum (Apicomplexa). FEMS Microbiol Lett 1994; 120:275-8. [PMID: 8076803 DOI: 10.1111/j.1574-6968.1994.tb07045.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Sporozoites of Cryptosporidium parvum were examined after gliding upon glass microscope slides using monoclonal antibodies to the 15 and 25 kDa surface molecules and immunogold-silver enhancement. Both antibodies bound to surface antigen deposited as trials behind parasites, suggesting that both surface molecules are involved in substrate attachment.
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Affiliation(s)
- M Tilley
- Division of Biology, Kansas State University, Manhattan 66506
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Abstract
With the emergence of Cryptosporidium parvum as a major pathogen encountered in human and veterinary clinical practice, a need for increased knowledge of the cellular- and immuno-biology of this Apicomplexan parasite has developed. Initial work has used paradigms taken from other Apicomplexans, especially Plasmodium, Toxoplasma and Eimeria, as a starting point. In this article, Carolyn Petersen discusses the observation that in these organisms, molecular targets of antibodies (which have protective value, in vivo, against disease) have frequently been located in the apical complex or on the surface of the invasive stages of the parasite and appear to mediate biologically crucial processes including motility, attachment to the host cell, modification of the host membrane, and entry into the host cell. Molecular-biology approaches to the study of enzymes and of structural proteins which mediate motility are also considered. Invasion mechanisms, biochemical pathways and motility may involve molecules that will prove susceptible to immunotherapeutic or chemotherapeutic interruption of cryptosporidiosis.
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Affiliation(s)
- C Petersen
- Parasitology Laboratory and the Department of Medicine, San Francisco General Hospital, University of California at San Francisco, San Francisco, CA 94110, USA
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Zgrzebski G, Raether W, Hofmann J, Entzeroth R. Secretion of an Eimeria tenella sporozoite antigen during host-cell invasion: visualization of the parasitophorous vacuole membrane and parasitophorous duct-like structures. Parasitol Res 1993; 79:77-9. [PMID: 8469674 DOI: 10.1007/bf00931223] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- G Zgrzebski
- Zoologisches Institut, Universität Bonn, Germany
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21
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Stewart MJ, Vanderberg JP. Electron microscopic analysis of circumsporozoite protein trail formation by gliding malaria sporozoites. THE JOURNAL OF PROTOZOOLOGY 1992; 39:663-71. [PMID: 1453354 DOI: 10.1111/j.1550-7408.1992.tb04446.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Immunoelectron microscopic techniques were utilized to characterize the morphology of circumsporozoite protein-containing trails deposited on various substrates by gliding Plasmodium berghei and Plasmodium falciparum sporozoites. The basic components of the trails are beadlike particles, 25 to 90 nm in diameter, which are devoid of unit membrane and have an electron-lucent center. Trails were captured on formvar-covered grids coated with anticircumsporozoite protein monoclonal antibodies and compared with trails produced on uncoated formvar; the results suggest that material containing circumsporozoite protein forms the matrix within which the particles are embedded. The trails exhibit morphological features similar to those displayed by circumsporozoite precipitation reactions; of note is the demonstration of sheaths of circumsporozoite protein-containing material that emanate from sporozoites prior to their gliding. The sheaths narrow into accumulations of electron-dense material, which eventually taper to form typical trails. The structural manifestation of sheaths and other morphological details of the formed trails enables us to correlate sporozoite behavior during trail formation with the motile actions of gliding sporozoites observed by light microscopy.
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Affiliation(s)
- M J Stewart
- Department of Medical and Molecular Parasitology, New York University School of Medicine, New York 10016
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Kim K, Goozé L, Petersen C, Gut J, Nelson RG. Isolation, sequence and molecular karyotype analysis of the actin gene of Cryptosporidium parvum. Mol Biochem Parasitol 1992; 50:105-13. [PMID: 1542305 DOI: 10.1016/0166-6851(92)90248-i] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Actin is an ubiquitous and highly conserved microfilament protein which is hypothesized to play a mechanical, force-generating role in the unusual gliding motility of sporozoan zoites and in their active penetration of host cells. We have identified and isolated an actin gene from a Cryptosporidium parvum genomic DNA library using a chicken beta-actin cDNA as an hybridization probe. The nucleotide sequences of two overlapping recombinant clones were identical and the amino acid sequence deduced from the single open reading frame was 85 % identical to the P. falciparum actin I and human gamma-actin proteins. The predicted 42 106-Da Cryptosporidium actin contains 376 amino acids and is encoded by a single-copy gene which contains no introns. The nucleic acid coding sequence is 72% biased to the use of A or T in the third position of codons. Chromosome-sized DNA released from intact C. parvum oocysts was resolved by OFAGE into 5 discrete ethidium bromide-staining DNAs ranging in size from 900 to 1400 kb; the cloned C. parvum actin gene hybridized to a single chromosomal DNA of approximately 1200 kb.
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Affiliation(s)
- K Kim
- Parasitology Laboratory, San Francisco General Hospital, CA
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Stewart MJ, Vanderberg JP. Malaria sporozoites release circumsporozoite protein from their apical end and translocate it along their surface. THE JOURNAL OF PROTOZOOLOGY 1991; 38:411-21. [PMID: 1787427 DOI: 10.1111/j.1550-7408.1991.tb01379.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Plasmodium sporozoites, the causative agents of malaria, release circumsporozoite (CS) protein into medium when under conditions simulating those that the parasites encounter in the bloodstream of the vertebrate host. CS protein of the rodent parasite, Plasmodium berghei, is released as the lower molecular weight form, Pb44. This release is substratum- and antibody-independent. Previous studies show that CS protein is released at the trailing, posterior end of motile sporozoites. Video and electron microscopic studies now demonstrate that CS protein is released at the apical end of cytochalasin b-immobilized sporozoites. We propose that CS protein released from the apical end, the leading end of gliding sporozoites, adheres to the sporozoite surface and is translocated posteriorly by a cytochalasin-sensitive and apparently actin-mediated surface motor, which drives gliding motility. This model explains the mechanism of both the circumsporozoite precipitation (CSP) reaction and formation of the CS protein trail by gliding sporozoites.
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Affiliation(s)
- M J Stewart
- Department of Medical and Molecular Parasitology, New York University School of Medicine, NY 10016
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Bauer C, Dubremetz JF, Entzeroth R. Characterization of surface antigens of Eimeria nieschulzi (Sporozoa, Eimeriidae) merozoites. Parasitol Res 1995; 81:230-4. [PMID: 7770429 DOI: 10.1007/bf00937114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Two surface antigens of Eimeria nieschulzi merozoites were characterized by monoclonal antibodies (Mcab) as follows: an antigen of 31 (reducing conditions), 25 and 31 kDa (nonreducing conditions), by Mcab A1F6; and an antigen of 52 and 30 kDa (reducing conditions) or 42 kDa (nonreducing conditions), by Mcab H7. The localization of the antigens in fluorescence and electron micrographs is presented. Despite being accessible to antibodies on live (nonpermeabilized) parasites, neither antigens were significantly labelled using lactoperoxidase radioiodination.
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Affiliation(s)
- C Bauer
- Institute of Zoology, University of Bonn, Germany
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